Title of Invention	SINGLE CHAMBER COMPACT FUEL PROCESSOR
Abstract	SINGLE CHAMBER COMPACT FUEL PROCESSOR ABSTRACT An apparatus for carrying out a multi-step process of converting hydrocarbon fuel to a substantially pure hydrogen gas feed includes a plurality of reaction zones arranged in a common reaction chamber. The multi-step process includes; providing a fuel to the fuel processor so that as the fiiel reacts and forms the hydrogen rich gas, the intermediate gas products pass through each reaction zone as arranged in the reactor to produce the hydrogen rich gas.

Title of Invention

SINGLE CHAMBER COMPACT FUEL PROCESSOR

Abstract

SINGLE CHAMBER COMPACT FUEL PROCESSOR ABSTRACT An apparatus for carrying out a multi-step process of converting hydrocarbon fuel to a substantially pure hydrogen gas feed includes a plurality of reaction zones arranged in a common reaction chamber. The multi-step process includes; providing a fuel to the fuel processor so that as the fiiel reacts and forms the hydrogen rich gas, the intermediate gas products pass through each reaction zone as arranged in the reactor to produce the hydrogen rich gas.

Full Text	BACKGROUND OF THE INVENTION Priority of U.S. Provisional Patent Application No. 60/286,684, filed April 26, 2001 is claimed under 35 U.S.C. §119. Fuel cells provide electricity from chemical oxidation-reduction reactions and possess significant advantages over other fornis of power generation in terms of cleanliness and efficiency. Typically, fiiel cells employ hydrogen as the fuel and oxygen as the oxidizing agent. The power generation is proportional to the consumption rate of the reactants. A significant disadvantage that inhibits the wider use of fuel cells is the lack of a widespread hydrogen infrastructure. Hydrogen has a relatively low volumetric energy density and is more difficult to store and transport than the hydrocarbon fUels currently used in most power generation systems. One way to overcome this difficulty is the use of reformers to convert the hydrocarbons to a hydrogen rich gas stream which can be used as a feed for fuel cells. Hydrocarbon-based fuels, such as natural ^, LPG> gasoline, and diesel, require conversion processes to be used as fuel sources for most fuel cells. Current art uses multi-step processes combining an initial conversion process with several clean-up processes. The initial process is most often steam reforming (SR), autothermal reforming (ATR), catalytic partial oxidation (CPOX), or non-catalytic partial oxidation (POX). The clean-up processes usually include a combination of desulfiirization, high temperature water-gas shift, low temperature water-gas shift, selective CO oxidation, or selective CO metiianation. Altemative processes include hydrogen selective membrane reactors and filters. E)espite the above work, tiiere remains a need for a simple unit for converting a hydrocarbon fuel to a hydrogen rich gas stream for use in conjunction with a fiiel cell, SUMMARY OF THE INVENTION The present invention is generally directed to an apparatus for converting hydrocarbon fuel into a hydrogen rich gas. In one illustrative embodiment, the present invention includes a lompacl fuel processor for converting a hydrocarbon fuel feed into hydrogen rich gas, in which iie fuel processor assembly includes a cylinder having a feed end and a manifold end, a :emovable manifold, and a plurality of predefined reaction zones within the cylinder, wherein ;ach reaction zone is characterized by a chemical reaction that takes place withm the reaction zone. The ftiel processor also includes at least one cooling coil having an inlet end and an outlet end connected to the manifold end, wherein each of the at least one cooling coils is internally positioned so as to remove heat from a particular reaction zone. Within such an illustrative embodiment, the plurality of catalysts includes autothermal reforming catalyst, desulfiirization catalyst, water gas shift catalyst, preferential oxidation catalyst, and combinations of these and similar catalysts. The hydrocarbon fuel feed utilized in the illustrative fuel processor is preheated, preferably by passing through a heat exchanger prior to being introduced to the cylinder or alternatively by a fiiel pre-heater located in a fimction upstream position from the autothemial reforming reaction zone. It is preferred in one illustrative embodiment that the cylinder is oriented substantially vertically with the manifold end of the cylinder being on top and the flow of reactants being generally upward from the feed end to the manifold end. The present illustrative embodiment includes a first reaction zone containing autothermal reforming catalyst, a second reaction zone containing desuliurization catalyst, a third reaction zone containing water gas shift catalyst, and a fourth reaction zone containing preferential oxid^on catalyst. Preferably, the first reaction zone is positioned at the feed end of the cylinder, the second reaction zone is positioned adjacent to the first reaction zone, the third reaction zone is positioned adj^ent to the second reaction zone, and the fourth reaction zone is positioned at the manifold end of the cylitider. A zone of ceramic beads may also be positioned between the third reaction zone and the fourth reaction zone in order to improve the mixing of the hydrogen rich gas with air, which is injected into the zone of ceramics beads through a fixed nozzle in the manifold. This injection of air may be accomplished by well-known means such as a simple gas injection tube or a porous tube. It should be appreciated by one of skill in the art that each reaction zone of the plurality of reaction zones may contain one or more catalysts. It should be appreciated by one of skill in the art that each reaction zone of the plurality of reaction zones may contan one or more cat^ysts. In one such illustrative embodiment, the catalysts are selected from autothermal reforming catalyst, desulfurization catalyst, water gas shift catalyst, preferential oxidation catalyst as well as mixtures and combinations of these and similar catalysts. Any particular reaction zone containing more than one catalyst may be separated from an adjacent reaction zone by a permeable plate that also serves to support the adjacent reaction zones. In one illustrative embodiment, the plate is selected from perforated metal, metal screen, metal mesh, sintered metal, porous ceramic, or combinations of these materials and similar materials. It is preferred within such an illustrative embodiment that the plate be at least partially composed of inconel, carbon steel, stainless steel, hatelloy, or other material suitable for the temperature, pressure, and composition. In a preferred aspect of the present invention, the compact fijel processor also includes a second cylinder having an anode tail gas oxidation catalyst bed for oxidizing the anode tail gas from a fiiel cell to produce an exhaust gas. The second cylinder may have a pre-heat exchanger for heating the hydrocarbon fuel prior to feeding tiie hydrocarbon friel to the iirst cylinder, and such a pre-heat exchanger may be positioned within the anode tail gas oxidation catalyst bed. It is envisioned that die present illustrative embodiment also includes a fifth reaction zone containing another preferential oxidation catalyst bed. In siu:h an embodiment, a second zorte of ceramic beads, including air injection nozzles as discussed above, may be positioned between the fourth reaction zone and the fifth reaction zone to ensure adequate mixing. BRIEF DESCRIPTION OF THE DRAWINGS The description is presented with reference to the accompanying drawings in which: FIG. 1 depicts a simple process flow diagram for one illusttative embodiment of the present invention. FIG. 2 depicts a first illustrative embodiment of a compact fuel processor apparatus of the present invention; and FIG. 3 depicts a second illustrative embodiment of a compact fuel processor apparatus of the present invention. FIG. 4 depicts a third illustrative embodiment of a compact fiiel processor apparatus of the present invention. DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS The present invention is generally directed to an apparatus for converting hydrocarbon fuel into a hydrogen rich gas. In a preferred aspect, the apparatus and method described herein relate to a compact ftiel processor for producing a hydrogen rich gas stream from a hydrocarbon fuel for use in fuel cells. However, other possible uses are contemplated for the apparatus and method described herein, including any use wherein a hydrogen rich stream is desired. Accordingly, while the invention is described herein as being used in conjunction widi a fijel cell, the scope of the invention is not limited to such use. Each of the illustrative embodiments of the present invention describes a fiiel processor or a process for using such a fuel processor with the hydrocarbon fiiel feed being directed throt^ the fuel processor. TTie hydrocarbon fuel may be liquid or gas at ambient conditions as long as it can be vaporized. As used herein the term "hydrocarbon" includes organic compounds having C-H bonds which are capable of producing hydrogen from a partial oxidation or steam refonning reaction. The presence of atoms other than carbon and hydrogen in the molecular structure of the compound is not excluded. Thus, suitable fuels for use in the method and apparatus disclosed herein include, but are not limited to hydrocarbon fiiels such as natural gas, methane, ethane, propane, butane, naphtha, gasoline, and diesel fuel, and alcohols such as methanol, ethanol, propanol, and the like. The fiiel processor feeds include hydrocarbon fiiel, oxygen, and water. The oxygen can K in the form of air, enriched air, or substantially pure oxygen. The water can be introduced as a iquid or vapor. The composition percentages of the feed components are determined by the lesired operating conditions, as discussed below. The fuel processor effluent stream from the present invention includes hydrogen and arbon dioxide and can also include some water, unconverted hydrocaiiwns, carbon monoxide, npurities (e.g. hydrogen sulfide and ammonia) and inert components (e.g., nitrogen and aigon, specially if air was a component of the feed stream). Figure I depicts a general process flow diagram ittustrating the process steps included in le illustrative embodiments of the present invention. One of skill in the art should appreciate at a certain amount of progressive order is needed in the flow of the reactants through the actors disclosed herein. Process step A is an autothennal reforming process in which two reactions, partial :idation (formula 1, below) and optionally also steam reforming (formula II, below), arc mbined to convert the feed stream F into a synthesis gas containing hydrogen and carbon jnoxide. Fonnulas I and II are exemplary reaction formulas wherein methane is considered as : hydrocarbon: CH4+540: - 2H2+CO a) CH4 + H2O -* 3H2 + CO The partial oxidation reaction occurs very quickly to the complete conversion of oxygen added and produces heat. The steam reforming reaction occurs slower and consumes heat. A higher concentration of oxygen in the feed stream fevors partial oxidation whereas a higher concentration of water vapor favors steam refonning. Therefore, the ratios of oxygen to hydrocarbon and water to hydrocarbon become characterizing parameters. These ratios affect the operating temperature and hydrogen yield. TTie operating temperature of the autothermal reforming step can range from about 5S0°C to about 9(}0'C, depending on the feed conditions and the catalyst. The invention uses a catalyst bed of a partial oxidation catalyst with or without a steam reforming catalyst. The cataJyst may be in any form including pellets, spheres, extrudate, monoliths, and the like. Partial oxidation catalysts should be well known to those with skill in the art and ate often comprised of noble metals such as platinum, palladium, rhodium, and/or ruthenium on an alumina washcoat on a monolith, extrudate, pellet or other support. Non-noble metals sudi as nickel or cobalt have been used. Other washcoats such as titam'a, zirconia, silica, and m^nesia have been cited in the literature. Many additional materials such as lan&anum, cerium, and potassium have been cited in the literature as "proototers" that improve the performance of the partial oxidation catalyst. Steam reforming catalysts should be known to those with skill in the art and can include nickel with amounts of cobalt or a noble metal such as platinum, palladium, rhodium, ruthenium, and/or iridium. The catalyst can be supported, for example, on m^nesia, alumina, silica, zirconia, or magnesium aluminate, singly or in combination. Alternatively, the steam reforming catalyst can include nickel, preferably supported on magnesia, alumina, silica, zirconia, or niE^nesium aluminate, singly or in combinatioti, promoted by an alkali metal such as potassium. Process step B is a cooling step for cooling the synthesis gas stream fi^m process step A to a temperature of from about 200°C to about 600°C, preferably from about 3000 to about 500°C, and more preferably from about STS'C to about 425C, to optimize the temperature of the synthesis gas effluent for the next step. This cooling may be achieved with heat sinks, heat pipes or heat exchangers depending upon the design specifications and the need to recover / recycle the heat content of the gas stream. One illustrative embodiment for step B is the use of a heat exchai^er utilizing feed stream F as the coolant circulated through the heat exchanger. The heat exchanger can be of any suitable construction known to those with skill in the art including shell and tube, plate, spiral, etc. Alternatively, or in addition thereto, cooling step B may be accomplished by injecting additional feed components such as fiiel, air or water. Water is preferred because of its ability to absorb a large amount of heat as it is vaporized to steam. The amounts of added components depend upon the degree of cooling desired and are readily determined by those with skill in the art. Process step C is a purifying step. One of the main impurities of the hydrocarbon stream is typically sulfur, which is converted by the autothermal reforming step A to hydrogen sulfide. The processing core used in process step C preferably includes zinc oxide and/or other material capable of absorbing and converting hydrogen sulfide, and may include a support (e.g., monolith, extrudate, pellet etc.). Desulftirization is accomplished by converting the hydrogen sulfide to water in accordance with the following reaction formula III: HzS + ZnO -* HiO + ZnS (III) Other impurities such as chlorides can also be removed. The reaction is preferably cairied out at a temperature of from about SOCC to ^>out 500°C, and more preferably from about 375°C to about 425'C. Zinc oxide is an effective hydrogen sulfide absorbent over a wide range of temperatures fh)m about 25°C to about 700°C and affords great flexibility for optimizing the sequence of processing steps by appropriate selection of operating temperature. The effluent stream may then be sent to a mixing step D in \^ch water is optionally added to the gas stream. The addition of water lowers the temperature of the reactant stream as it vaporizes and supplies more water for the water gas shift reaction of process step E (discussed below). The water vapor and other effluent stream components are mixed by being passed through a processing core of inert materials such as ceramic beads or other similar materials that effectively mix and/or assist in the valorization of the water. Alternatively, any additional water can be introduced witii feed, and the mixing step can be repositioned to provide better mixing of the oxidant gas in the CO oxidation step G disclosed below. Process step E is a water gas shift reaction that converts carbon monoxide to carbon dioxide in accordance with formula IV; H:0 + CO -► H2 + CO2 (IV) This is an important step because carbon monoxide, in Midition to being highly toxio to humans, is a poison to fuel cells. The concentration of carbon monoxide should preferably be lowered to a level that can be tolerated by fuel cells, typically below 50 ppm. Generally, the water gas shift reaction can take place at temperatures of from ! 50°C to eOCC depending on dw catalyst used. Under such conditions, most of the carbon monoxide in the gas stream is converted in this step. Low temperature shift catalysts operate at a range of from about ISO^C to about SOCC and include for example, copper oxide, or copper supported on other transition metal oxides such as ztrconia, zinc supported on transition metal oxides or refractory supports such as silica, alumina, zirconia, etc., or a noble metal such as platinum, rhenium, palladium, rhodium or gold on a suitable support such as silica, alumina, zirconia, and the like. High temperature shift catalysts are preferably operated at temperatures ranging from about 300" to about 600°C and can include transition metal oxides such as ferric oxide or chromic oxide, and optionally including a promoter such as copper or iron silicide. Also included, as high temperature shift catalysts are supported noble metals such as supported platinum, palladium and/or other platinum group members. The processing core utilized to carry out this step can include a packed bed of high temperature or low temperature shift catalyst such as described above, or a combination of both high temperature and low temperature shift catalysts. The process should be operated at any temperature suitable for the water gas shift reaction, preferably at a temperature of from 150°C to about 400'C depending on the type of catalyst used. Optionally, a cooling element such as a cooling coil may be disposed in the processing core of the shift reactor to lower the reaction temperature within the packed bed of catalyst. Lower temperatures favor the conversion of carbon monoxide to carbon dioxide. Also, a purification processing step C can be performed between high and low shift conversions by providing separate steps for high temperature and low temperature shift with a desulfurization module between the high and low temperature shift steps. Process step F is a cooling step performed in one embodiment by a heat exchanger. The heat exchanger can be of any suitable construction including shell and tube, plate, spiral, etc. Alternatively a heat pipe or other form of heat sink may be utilized. The goal of the heat exchanger is to reduce the temperature of the gas stream to produce an effluent having a temperature preferably in the range of from about 90°C to about ISO'C. Oxygen is added to the process in step F. The oxygen is consumed by the reactions of process step G described below. The oxygen can be in the form of air, enriched air, or substantially pure oxygen. The heat exchanger may by design provide mixing of the air with the hydrogen rich gas. Alternatively, the embodiment of process step D may be used to perform the mixing. Process step G is an oxidation step wherein almost all of the remaining carbon monoxide in the effluent stream is converted to carbon dioxide. The processing is carried out in the presence of a catalyst for the oxidation of carbon monoxide and may be in any suitable fonn, such as pellets, spheres, monolith, etc. Oxidation catalysts for carbon monoxide are known and typically include noble metals (e.g., platinum, palladium) and/or transition metals (e.g., iron, chromium, manganese), and/or compounds of noble or transition metals, particularly oxides. A preferred oxidation catalyst is platinum on an alumina washcoat. The washcoai may be applied to a monolith, extrudate, pellet or other support. Additional materials such as cerium or lanthanum may be added to improve performance. Many othra- formulations have been cited in the literature vdth some practitioners claiming superior performance from rhodium or alumina catalysts. Ruthenium, palladium, gold, and other materials have been cited in the literature as being active for this use. Two reactions occur in process step G: the desired oxidation of carbon monoxide (formula V) and the undesired oxidation of hydrogen (formula VI) as follows: CO + 14O2 ~* CO2 (V) Hz + /1O2 ->■ H2O (VI) The preferential oxidation of carbon monoxide is favored by low temperatures. Since bodi reactions produce heat it may be advantageous to optionally include a cooling element such as a cooling coil disposed within the process. The operating temperature of process is preferably kept in the range of from about 90'C to about ISO^C. Process step G preferably reduces the carbon monoxide level to less than 50 ppm, which is a suitable level for use in fiiel cells, but one of skill in the art should appreciate that the present invention can be adapted to produce a hydrogen rich product with higher and lower levels of carbon monoxide. The effluent exiting the fuel processor is a hydrogen rich gas containing carbon dioxide and other constituents which may be present such as water, inert components (e.g., nitrogen, argon), residual hydrocarbon, etc. Product gas may be used as the feed for a fuel cell or for other applications where a hydrogen rich feed stream is desired. Optionaliy, jn-oduct gas may be sent on to fijrther processing, for example, to remove the carbon dioxide, water or other components. Figwe 2 depicts a cross-sectional view of a fuel processor 20 that is an illustrative embodiment of the present invention. One of ordinary skill in the art should see and appreciate that fuel or alternatively a fuel / oxygen or alternatively a fuel / oxygen / water mixture F, is introduced to the inlet of a heat exchanger 200. The preheated fuel F' leaves the heat exchanger 200 and is routed to the first reaction zone 202. The first reaction zone 202 in the present illustrative embodiment is packed with a autothermal refomiing reaction catalyst. Alternatively, this zone may be packed with a steam reforming catalyst. Such catalyst may be in pellet, sphere, or extmdate form; or supported on a monolith, reticulated foam, or any other catalyst support material. In some instances a distribution plate (not shown) may be needed to achieve an even distribution of fuel to the entire first reaction zone. Also optionally an electric pre-heater (not shown) may be utilized in the start-up of the fuel processor. Af^er the fuel has reacted in the first reaction zone to form a hydrogen rich gas, the natural flow of the gas due to pressure is for the hydrogen rich gas to flow into the second reaction zone 204. In the present illustrative Embodiment, the second reaction zone is packed with a desulfiirizadon catalyst, preferably zinc jxide. Passage of the hydrogen rich gas over a desulfiirization catalyst, such as zinc oxide, iubstantially reduces the concentration of sulfur containing compounds in the hydrogen rich gas ;tream. The desulfurized hydrogen rich gas then passes into lhe third reaction zone 206. The bird reaction zone of the present illustrative embodiment is packed with a water-gas shift reactor ;atalyst or mixture of such catalyst as discussed above. The passage of the hydrogen rich gas >ver this catalyst further enriches the hydrogen content and reduces the carbon monoxide ;oncentration. In some instances air or another suitable oxygen source may now be injected into he fourth reaction zone so that the preferential oxidation reaction is optimized. This may be ccomplished by well-known means such as a simple gas injection tube (not shown) inserted into he partial oxidation catalyst bed. In one preferred embodiment a porous tube is substantially icorporatcd into ihc design of the preferential oxidation reaction zone design and is designed such that an even distribution of injected oxygen is achieved. In the embodiment shown in this figure, the hydrogen rich gas is passed over a zone of ceramic beads 208, which provides adequate mixing of the hydrogen rich gas with the air before entering the fourth reaction zone 210. The hydrogen rich gas is then passed into the fourth reaction zone 210 which contains a preferential oxidation catalyst. Such a catalyst will reduce the cartwn monoxide concentration to preferably less than 50 part per million as discussed above. The final product is a hydrogen rich gas H. It should also be noted that in one preferred and illustrative embodiment, an inert but porous and flexible material such as glass wool, ceramic wool, rock wool, or other similar inert material may be used in the reaction zone transition regions 212. Such a material serves to aid in the packing of the reactor with the various catalysts, assists in preventing inadvertent mixing of catalysts during transport and provides a cushioning or buffer zone between each of the differing reaction zones. Reaction temperature is controlled in the second, third, and fourth reaction zones by using cooling coils (218, 220, 222), \s4iich circulate coolant, such as water, air, hydrocarbon fuel feed, or any refrigerant, through the catalyst bed. In this illustrative embodiment, the inlet and outlet ends of each cooling coil are fixed in a manifold 224 that is contained in the top cover for cylinder 226, which encloses the various reaction zones. One of skill in the art should appreciate that a number of factors affect the heat transfer process including the flow rate of fuel, the number of coils present in any particular reaction zone, the diameter of the tubing used to make the coils, the presence or absence of fins on the coils and so forth. However, such heat transfer considerations can be optimized through routine calculations and experimentation. In this embodiment, air A is also injected into the zone of ceramic beads through a nozzle fixed in manifold 224. Hydrogen rich gas H is also withdrawn through manifold 224. Figure 2 also shows the optional embodiment of adding an additional heat exchanger 214 and preferential oxidation catalyst bed 216. The purpose for heat exchanger 214 is primarily to cool the hydrogen rich gas H. The amount of cooling may or may not result in condensing water W out of the gas, for fiirther oxidation in bed 216, which ensures achieving a carbon monoxide concentration of less that 50 part per million in hydrogen rich gas H' The hydrogen rich gas H or H' is preferably used in a fuel cell or may be stored or used in other processes diat should be apparent to one of skill in the art. Another preferred embodiment of the present invention includes an anode tail gas oxidizer, which oxidizes the anode tail gas T from a fuel cell (not shown). This addition is a useful heat source for preheating hydrocarbon fuel F in heat exchanger 200. One of skill in the art after reviewing the above description of Figure 2 should understand and appreciate that each reaction zone performs a separate operational function. Reaction zone 202 is the autothermal reforming reaction zone corresponding to process step A of Figure I. An electric heater (not shown) may be installed at the bottom inlet of the reactor for start-up heat. Reaction zone 204 is a purifying reaction zone corresponding to process step C of Figure 1. Reaction zone 206 is a water gas shift reaction zone corresponding to process step E of Figure 1. The cooling step corresponding to process step F of Figure 1 is carried out by cooling coil 220. Reaction zone 210 is an oxidation step corresponding to process step G of Figure 1. An air source (not shown) provides a source for oxygen to process gas for the oxidation reaction (Equation V) of reaction zone 210. Reaction zone 210 also contains cooling coil 222 positioned within or surrounding the catalyst bed so as to maintain a desired oxidation reaction temperature. One of skill in the an should appreciate that the process configuration described in this embodiment may vary depending on numerous factors, including but not limited to feedstock quality and required product quality. Figure 3 depicts a cross-sectional view of a fuel processor 30 that is another illustrative embodiment of the present invention. One of ordinary ^11 in the art should see and appreciate that fuel or alternatively a fuel / oxygen or alternatively a fuel / oxygen / water mixture F, is introduced to the inlet of a container 300, which contains an anode tail gas oxidizer catalyst bed, which oxidizes the anode tail gas T from a fuel cell (not shown). Container 300 also contains a heat exchanger wtich provides a useful preheating of hydrocaiton fuel F. The preheated fuel F' leaves container 300 and is routed to the first reaction zone 302. The first reaction zone 302 in the present illustrative embodiment is packed with a autothermal reforming reaction catalyst. Such catalyst may be in pellet, sphere, or extrudate form; or supported on a monolith, reticulated foam, or any other catalyst support matenal. In some instances a distribution plate (not shown) Tiay be needed to achieve an even distribution of fuel to the entire first reaction zone. Also jptionally an electric pre-heater (not shovra) may be utilized in the start-up of the fuel processor. \fter the fuel has reacted in the first reaction zone to form a hydrogen rich gas, the natural flow )f the gas due to pressure is for the hydrogen rich gas to flow into the second reaction zone 304. In the present illustrative embodiment, the second reaction zone is packed with a desulfiirizatioo catalyst, preferably zinc oxide. Passage of the hydrogen rich gas over a desulfurization catalyst, such as zinc oxide, substantially reduces the concentration of siUfttt containing compounds in the hydrogen rich gas stream. The desulftirized hydrogen rich gas is then passes into the third reaction zone 306. The third reaction zone of Uie present illustrative embodiment is packed with a water-gas shift reactor catalyst or mixture of such catalyst as discussed above. The passage of the hydrogen rich gas over this catalyst further enriches the hydrogen content and reduces the carbon monoxide concentration. In some instances air or another suitable oxygen source may now be injected into the fourth reaction zone so that the preferential oxidation reaction is optimized. This may be accomplished by well-known means such as a simple gas injection tube (not shown) inserted into the partial oxidation catalyst bed. In one preferred embodiment a porous tube is substantially incorporated into the design of the preferential oxidation reaction zone design and is designed such that an even distribution of injected oxygen is achieved. In the embodiment shown in this figure, the hydrogen rich gas is passed over a zone of ceramic beads 308, which provides adequate mixing of the hydrogen rich gas with the air before entering the fourth reaction zone 310. The hydrogen rich gas is then passed into the fourth reaction zone 310 which contains a preferential oxidation catalyst. Such a catalyst will reduce the carbon monoxide concentration to preferably less that 50 part per million as discussed above. Optionally, an additional layer of ceramic beads and a fifth reaction zone (not shown) containing a preferential oxidation catalyst can be employed to ensure that the carbon monoxide concentration is reducedto preferably less than 50 parts per million. The final product is a hydrogen rich gas H. It should also be noted that in one preferred and illustrative embodiment, Ml inert but porous and flexible material such as glass wool, ceramic wool, rock wool, or other similar inert material may be used in the reaction zone transition regions 312. Such a material «rves to aid in the packing of the reactor with the various catalysts, assists in preventing nadvertent mixing of catalysts during transport and provides a cushioning or buffer zone •etween each of the differing reaction zones. Reaction temperature is controlled in the second, lird, and fourth reaction zones by using cooling coils (318, 320, 322), which circulate coolant, uch as water, air, hydrocarbon fuel feed, or any refrigerant, through the catalyst bed. In fliis lustrative embodiment, the inlet and outlet ends of each coolino mil nt^ fiv*.H in = ^^^-.r^iA 11.1 that is contained in ihe lop cover for cylinder 326, which encloses the various reaction zones. One of skill in the art should appreciate that a number of factors affect the heat transfer process including the flow rate of fuel, the number of coils present in any particular reaction zone, the diameter of the tubing used to make the coils, the presence or absence of fins on the coils and so forth. However, such heat transfer considerations can be optimized through routine escalations and experimentation. In this embodiment, air A is also injected into the zone of ceramic beads through a nozzle fixed in manifold 324. Hydrogen rich gas H is also withdrawn through manifold 324. One of skill in the art after reviewing the above description of Figure 3 should understand and appreciate that each ceaction zone performs a separate operational function. Reaction zone 302 is the autothermal reforming reaction zone corresponding to process step A of Figure i. An electric heater (not shown) may be installed at the bottom inlet of the reactor for start-up heat. Reaction zone 304 is a purifying reaction zone corresponding to process step C of Figure 1. Reaction zone 306 is a water gas shift reaction zone corresponding to process step E of Figure 1. The cooling step corresponding to process step F of Figure I is carried out by cooling coil 320. Reaction zone 310 is an oxidation step corresponding to process step G of Figure 1. Air source (not shown) provides a source for oxygen to process gas for the oxidation reaction (Equation V) of reaction zone 310. Reaction zone 310 also contains cooling coil 322 positioned within or siUTOunding the catalyst bed so as to maintain a desired oxidation reaction temperature. One of skill in the art should appreciate that the process configuration described in this embodiment may vary depending on numerous factors, including but not limited to feedstock quality and required product quality. Figure 4 depicts a cross-sectional view of a fuel processor 40 that is yet another illustrative embodiment of the present invention. One of ordinary skill In the art should see and appreciate that fuel or alternatively a fuel / oxygen or alternatively a fuel / oxygen / water mixture F, is introduced to the inlet of a heat exchanger 400. The preheated fiiel F' leaves the heat exchanger 400 and is routed to the first reaction zone 402. The first reaction zone 402 in the present illustrative embodiment is packed with a autothermal reforming catalyst or steam reforming catalyst. Such catalyst may be in pellet, sphere, or extrudate form; or supported on a monolith, reticulated foam, or any other catalyst support material. In some instances a distribution plate (not shown) may be needed to achieve an even distribution of ftiel to the entire first reaction zone. Also optionally an electric pre-heater (not shown) may be utilized in the start-up of the fuel processor. After the fiiel has reacted in the first reaction zone to form a hydrogen rich gas, the natural flow of the gas due to pressure is for the hydrogen rich gas to flow into the second reaction zone 404. In the present illustrative embodiment, the second reaction zone is jacked with a desulfurization catalyst, preferably zinc oxide. Passage of the hydrogen rich gas over a desulfurization catalyst, such as zinc oxide, substantially reduces the concentration of sulfur containing compounds in the hydrogen rich gas stream. The desulfurized hydrogen rich gas is then passes into the third reaction zone 406. The third reaction zone of the present illustrative embodiment is packed with a water-gas shift reactor catalyst or mixture of such catalyst as discussed above. The passage of the hydrogen rich gas over this catalyst further enriches the hydrogen content and reduces the carbon monoxide concentration. In some instances air or anotfier suitable oxygen source may now be injected into the fourth reaction zoi\e 50 that the preferential oxidation reaction is optimized. This may be accomplished by well-known means such as a simple gas injection tube (not shown) inserted into the partial oxidation catalyst bed. In one preferred embodiment a porous tube is substantially incorporated into the design of the preferential oxidation reaction zone design and is designed such that an even distribution of injected oxygen is achieved. In the embodiment shown in this figure, the hydrogen rich gas is passed over a zone of ceramic beads 408, which provides adequate mixing of the hydrogen rich gas with the air before entering the fourth reaction zone 410. The hydrogen rich gas is then passed into the fourth reaction zone 410 which contains a preferential oxidation catalyst. Such a catalyst will reduce the carbon monoxide concentration to preferably less than 50 parts per million as discussed above. The final product is a hydrogen rich gas H. It should also be noted that in one preferred and illustrative embodiment, an inert but porous and flexible material such as glass wool, ceramic wool, rock wool, or other similar inert material may be used in the reaction zone transition regions 412. Such a material serves to aid in the packing of the reactor with the various catalysts, assists in preventing inadvertent mixing of catalysts during transport and provides a cushioning or buffer zone between each of the differing reaction zones. Reaction temperature is controlled in the second, third, and fourth reaction 2ones by directly injecting water into the catalyst beds. In this illustrative embodiment, the inlet nozzle for each injection line is fixed in a manifold 424 that is contained in the top cover for cylinder 426, which encloses the various reaction zones. One of skill in the art should appreciate that a number of factors affect the controllability of the reaction temperatures, including the size of the nozzles, the flow rate of fuel, and the number and location of the nozzles in each catalyst bed. However, such heat transfer considerations can be optimized through routine calculations and experimentation. In this embodiment, air A is also injected into the zone of ceramic beads through a nozzle fixed in manifold 424. Hydrogen rich gas H is also withdrawn through manifold 424. Figure 4 also shows the optional embodiment of adding an additional heat exchanger 414 and preferential oxidation catalyst bed 416. The purpose for heat exchanger 414 is primarily to cool the hydrogen rich gas H, thereby condensing water W out of the gas, for further oxidation in bed 416, which ensures achieving a carbon monoxide concentration of less than 50 parts per million in hydrogen rich gas H' The hydrogen rich gas H or H' is preferably used in a fuel cell or may be stored or used in other processes that should be apparent to one of skill in tiw art. Another preferred embodiment of the present invention is anode tail gas oxidizer, which oxidjss the anode tail gas T from a fuel cell (not shown). This addition is a useful heat source for preheating hydrocarbon fuel F in heat exchanger 400. One of skill in the art afler reviewing the above description of Figure 4 should understand and appreciate that each reaction zone performs a separate operational function. Reaction zone 402 is the autothemial reforming reaction zone corresponding to process step A of Figure 1, An electric heater (not shown) may be installed at the bottom inlet of the reactor for start-up heat. Reaction zone 404 is a purifying reaction zone corresponding to process step C of Figure 1. Reaction zone 406 is a water gas shift reaction zone corresponding to process step E of Figure 1. The cooling step corresponding to process step F of Figure 1 is carried out by the direct water injection into reaction zone 406. Reaction zone 410 is an oxidation step corresponding to process step G of Figure 1. Air source (not shown) provides a source for oxygen to process gas for the oxidation reaction (Equation V) of reaction zone 410. Reaction zone 410 also contains direct water injection to maintain a desired oxidation reaction temperature. One of skill in the art should appreciate that the process configuration described in this embodiment may vary depending on numerous factors, including but not limited to feedstock quality and required product quality. In view of the above disclosure, one of ordinary skill in the art should understand and appreciate that the present invention includes many possible illustrative embodiments that depend upon design criteria. One such illustrative embodiment includes a compact iliel processor for converting a hydrocarbon fiiei feed into hydrogen rich gas, in which the fuel processor assembly includes a cylinder having a feed end and a manifold end, a removable manifold, and a plurality of predefined reaction zones within the cylinder, wherein each reaction zone is characterized by a chemical reaction that takes place within the reaction zone. The fuel processor also includes at least one cooling coil having an inlet end and an outlet end connected to the manifold end, wherein each of the at least one cooling coils is internally positioned so as to remove heat from a particular reaction zone or direct injection of water to control the temperature in a particular reaction zone. Within such an illustrative embodiment, the plurality of catalysts includes autotherma! reforming catalyst or steam reforming catalyst, desulfiirization catalyst, water gas shift catalyst, preferential oxidation catalyst, and mixtures and combinations of these and similar catalysts. The hydrocarbon ftiel feed utilized in the illustrative fuel processor is preheated, preferably by passing through a heat exchanger prior to being introduced to the cylinder or alternatively by a fuel pre-heater located in a function upstream position from the autothermal reforming reaction zone. A wide variety of hydrocarbon fuels may be utilized. However, in one illustrative embodiment die hydrocarbon fuel is selected form natural gas, gasoline, diesel, fuel oil, propane, liquefied petroleum, methanol, ethanol or other similar and suitable hydrocarbons and mixtures of these. It is preferred in one illustrative embodiment that the cylinder is oriented substantially vertically with the manifold end of the cylinder being on top md the flow of reactants being generally upward from the feed end to the maijifold end. The aresent illustrative embodiment comprises a first reaction zone containing autothermal reforming ;atalyst, a second reaction zone containmg desulfiirization catalyst, a third reaction zone :ontaining water gas shift catalyst, and a fourth reaction zone containing preferential oxidation ;atalyst. Preferably, the first reaction zone is positioned at the feed end of the cylinder, the lecond reaction zone is positioned adjacent to the first reaction zone, the third reaction zone is )ositioned adjacent to the second reaction zone, and the fourth reaction zone is positioned at the manifold end of tiie cylinder. A zone of ceramic beads may also be positioned between the fliird reaction zone and the fourth reaction zone in order to improve the mixir^ of the hydrogen rich gas with air, which is injected into the zone of ceramics beads through a fixed nozzle in the manifold. This injection of air may be accomplished by well-known means such as a simple gas injection tube or a porous tube. It should be appreciated by one of skill in the art that each reaction zone of &e plurality of reaction zones may contain one or more catalysts. In one such illustrative embodiment, tfie catalysts ^^e selected from autothermal reforming catalyst, desulfurization catalyst, water gas shift catalyst, preferential oxidation catalyst as well as mixtures and combinations of these and similar catalysts. Any particular reaction zone containing more than one catalyst may be separated from an adjacent reaction zone by a permeable plate that also serves to support the adjacent reaction zones. In one illustrative embodiment, the plate is selected from perforated metal, metal screen, metat mesh, sintered metal, porous ceramic, or combinations of these materials and similar materials. It is prefened within such an illustrative einbodimeni that the plate be at least partially composed of inconel, carbon steel, stainless steel, hatelloy, or other material suitable for the temperature, pressure, and composition. In a preferred aspect of the present invention, the compact fuel processor also comprises a second cylinder having an anode tail gas oxidation catalyst bed for oxidizing the anode tail gas from a fuel cell to produce an exhaust gas. The second cylinder may have a pre¬heat exchanger for heating the hydrocarbon fuel prior to feeding the hydrocarbon fiiel to the first cylinder, and such a pre-heat exchanger may be positioned within the anode tail gas oxidation catalyst bed. It is envisioned that the present illustrative embodiment also includes a fifth reaction zone containing another preferential oxidation catalyst bed. In such an embodiment, a second zone of ceiamic beads, including air injection nozzles as discussed above, may be positioned between the fourth reaction zone and the fifth reaction zone to ensure adequate nixing. Another such illustrative embodiment includes a compact fuel processor for converting a lydrocarbon fuel feed into hydrogen rich gas, in which the fuel processor assembly includes a ylinder having a feed end and a manifold end, a removable manifold, and a plurality of iredefined reaction zones within the cylinder, wherein each reaction zone is characterized by a hemical reaction that takes place within the reaction zone. Instead of cooling coils or other heat exchangers, temperature control in each reaction zone is controlled through direct water injection. It is preferred in one illustrative embodiment that the cylinder is oriented substantially vertically with the manifold end of the cylinder being on top and the flow of ceactants being generally upward from the feed end to the manifold end. The present illustrative embodiment comprises a first reaction zone containing autothemial reforming catalyst, a second reaction zone containing desulflirization catalyst, a third reaction zone containing water gas shift catalyst, and a fourth reaction zone containing preferential oxidation catalyst. Preferably, die first reaction zone is positioned at the feed end of the cylinder, the second reaction zone is positioned adjacent to the first reaction zone, the third reaction zone is positioned adjacent to the second reaction zone, and the fourth reaction zone is positioned at the manifold end of the cylinder. A zone of ceramic beads may also be positioned between the third reaction zone and the fourth reaction zone in order to improve the mixing of the hydrogen rich gas with air, which is injected into the zone of ceramics beads through a fixed nozzle in the manifold. This injection of air may be accomplished by well-known means such as a simple gas injection tube or a porous tube. It should be appreciated by one of skill in the art that each reaction zone of the plurality of reaction zones may contain one or more catalysts. In one such illustrative embodiment, the catalysts are selected from autothermal reforming catalyst or steam reforming catalyst, desulfiirization catalyst, water gas shift catalyst, prefo^ntial oxidation catalyst as well as mixtures and combinations of these and similar catalysts. Any particular reaction zone containing more than one catalyst may be separated from an adjacent reaction zone by a penneable plate that also serves to support the adjacent reaction zones. In one illustrative embodiment, the plate is selected fi«m perforated metal, metal screen, metal mesh, sintered metal, porous ceramic, or combinations of these materials and similar materials. It is preferred within such an illustrative embodiment that the plate be at least partially composed of inconel, carbon steel, stainless steel, hastelloy, or other material suitable for temperature, pressure, and composition. While the apparahis, compositions and methods of this invention have been described in terms of preferred or illustrative embodiments, it will be apparent to those of skill in the art that variations may be applied to the process described herein without departing from the concept and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the scope and concept of the invention as it is set out in the following claims. WE CLAIM : 1. A compact fuel processor for converting a hydrocarbon fuel feed to hydrogen rich gas, comprising: a cylinder having a feed end and a manifold end, wherein the cylinder has a removable manifold; a plurality of predefined reaction zones within the cylinder, wherein each reaction zone is characterized by a chemical reaction that takes place within the reaction zone; and at least one cooling coil having an inlet end and an outlet end connected to the manifold end, wherein each of the at least one cooling coils is internally positioned so as to remove heat from a particular reaction zone. 2. The compact fuel processor as claimed in claim I, wherein the cylinder is oriented substantially vertically with the manifold end of the cylinder being on top. 3. The compact fuel processor as claimed in claim 1, wherein a first reaction zone contains autothermal reforming catalyst or steam reforming catalyst, a second reaction zone contains desulfurization catalyst, a third reaction zone contains water gas shift catalyst, and a fourth reaction zone contains preferential oxidation catalyst. 4. The compact fuel processor as claimed in claim 3, wherein the first reaction zone is positioned at the feed end of the cylinder, the second reaction zone is positioned adjacent to the first reaction zone, the third reaction zone is positioned adjacent to the second reaction zone, and the fourth reaction zone is positioned at the manifold end of the cylinder. 5. The compact fuel processor as claimed in claim 4, wherein a zone of ceramic beads is positioned between the third reaction zone and the fourth reaction zone. 6. The compact fuel processor as claimed in claim 5, comprising an air injection means for . injecting air into the zone of ceramic beads, wherein the air injection means is connected to the manifold. 7. The compact fuel processor as claimed in claim 4, wherein a reaction zone containing more than one catalyst is separated from an adjacent reaction zone by a permeable plate. 8. The compact fiiel processor as claimed in claim 7, wherein the permeable plate is perforated metal, metal screen, metal mesh, sintered metal, or porous ceramic. 9. The compact fuel processor as claimed in claim 8, wherein the permeable plate is of a material selected from the group consisting of inconel, carbon steel, stainless steel, hastelloy, and other material suitable for the temperature, pressure, and composition. 10. The compact fuel processor as claimed in claim I, comprising a second cylinder comprising a anode tail gas oxidation catalyst bed for oxidizing the anode tail gas from a fiiel cell to produce an exhaust gas. 11. The compact fuel processor as claimed in claim 10, wherein the second cylinder comprises a preheat exchanger for heating the hydrocarbon fiiel prior to feeding the hydrocarbon fuel to the first cylinder. 12. The compact fuel processor as claimed in claim 11, wherein the pre-heat exchanger is positioned within the anode tail gas oxidation catalyst bed. 13. The compact fuel processor as claimed in claim 3, wherein a fifth reaction zone contains preferential oxidation catalyst, 14. The compact fuel processor as claimed in claim 13, wherein the first reaction zone is positioned at the feed end of the cylinder, the second reaction zone is positioned adjacent to the first reaction zone, the third reaction zone is positioned adjacent to the second reaction zone, the fourth reaction zone is positioned adjacent to the third reaction zone, and the fifth reaction zone is positioned at the manifold end of the cylinder. 15. The compact fuel processor as claimed in claim 14, comprising a first zone of ceramic beads positioned between the third reaction zone and the fourth reaction zone, and a second zone of ceramic beads positioned between the fourth reaction zone and the fifth reaction zone. 16. The compact fuel processor as claimed in claim 15, comprising air injection means for injecting air into each zone of ceramic beads, wherein the air injection means is cotmected to the manifold. 17. A compact fuel processor for converting a hydrocarbon fuel feed to hydrogen rich gas, comprising: a cylinder having a feed end and a manifold end, wherein the cylinder has a removable manifold; a plurality of predefined reaction zones within the cylinder, wherein each reaction zone is characterized by a chemical reaction that takes place within the reaction zone; and at least one injection means for injecting water into a particular reaction zone, wherein each injection means is cormected to the manifold. 18. The compact fuel processor as claimed in claim 17, wherein the cylinder is oriented substantially vertically with the manifold end of the cylinder being on top. 19. The compact fuel processor as claimed in claim 17, wherein a first reaction zone contains autothermal reforming catalyst or steam reforming catalyst, a second reaction zone contains desulflirization catalyst, a third reaction zone contains water gas shift catalyst, and a fourth reaction zone contains preferential oxidation catalyst. -20. The compact fuel processor as claimed in claim 19, wherein the first reaction zone is positioned at the feed end of the cylinder, the second reaction zone is positioned adjacent to the first reaction zone, the third reaction zone is positioned adjacent to the second reaction zone, and the fourth reaction zone is positioned at the manifold end of the cylinder. 21. The compact fuel processor as claimed in claim 20, wherein a zone of ceramic beads is positioned between the third reaction zone and the fourth reaction zone. 22. The compact fuel processor as claimed in claim 21, comprising an air injection means for injecting air into the zone of ceramic beads, wherein the air injection means is connected to the manifold. 23. The compact fuel processor as claimed in claim 19, wherein a reaction zone is separated from an adjacent reaction zone by a permeable plate. 24. The compact fuel processor as claimed in claim 23, wherein the permeable plate is perforated metal, metal screen, metal mesh, sintered metal, or porous ceramic. 25. The compact fuel processor as claimed in claim 24, wherein the permeable plate is of a material selected from the group consisting of inconel, carbon steel, stamless steel, hastelloy, and other material suitable for the temperature, pressure, and composition.

Full Text

BACKGROUND OF THE INVENTION
Priority of U.S. Provisional Patent Application No. 60/286,684, filed April 26, 2001 is claimed under 35 U.S.C. §119.
Fuel cells provide electricity from chemical oxidation-reduction reactions and possess significant advantages over other fornis of power generation in terms of cleanliness and efficiency. Typically, fiiel cells employ hydrogen as the fuel and oxygen as the oxidizing agent. The power generation is proportional to the consumption rate of the reactants.
A significant disadvantage that inhibits the wider use of fuel cells is the lack of a widespread hydrogen infrastructure. Hydrogen has a relatively low volumetric energy density and is more difficult to store and transport than the hydrocarbon fUels currently used in most power generation systems. One way to overcome this difficulty is the use of reformers to convert the hydrocarbons to a hydrogen rich gas stream which can be used as a feed for fuel cells.
Hydrocarbon-based fuels, such as natural ^, LPG> gasoline, and diesel, require conversion processes to be used as fuel sources for most fuel cells. Current art uses multi-step processes combining an initial conversion process with several clean-up processes. The initial process is most often steam reforming (SR), autothermal reforming (ATR), catalytic partial oxidation (CPOX), or non-catalytic partial oxidation (POX). The clean-up processes usually include a combination of desulfiirization, high temperature water-gas shift, low temperature water-gas shift, selective CO oxidation, or selective CO metiianation. Altemative processes include hydrogen selective membrane reactors and filters.
E)espite the above work, tiiere remains a need for a simple unit for converting a hydrocarbon fuel to a hydrogen rich gas stream for use in conjunction with a fiiel cell,
SUMMARY OF THE INVENTION The present invention is generally directed to an apparatus for converting hydrocarbon fuel into a hydrogen rich gas. In one illustrative embodiment, the present invention includes a lompacl fuel processor for converting a hydrocarbon fuel feed into hydrogen rich gas, in which iie fuel processor assembly includes a cylinder having a feed end and a manifold end, a :emovable manifold, and a plurality of predefined reaction zones within the cylinder, wherein ;ach reaction zone is characterized by a chemical reaction that takes place withm the reaction

zone. The ftiel processor also includes at least one cooling coil having an inlet end and an outlet end connected to the manifold end, wherein each of the at least one cooling coils is internally positioned so as to remove heat from a particular reaction zone. Within such an illustrative embodiment, the plurality of catalysts includes autothermal reforming catalyst, desulfiirization catalyst, water gas shift catalyst, preferential oxidation catalyst, and combinations of these and similar catalysts. The hydrocarbon fuel feed utilized in the illustrative fuel processor is preheated, preferably by passing through a heat exchanger prior to being introduced to the cylinder or alternatively by a fiiel pre-heater located in a fimction upstream position from the autothemial reforming reaction zone.
It is preferred in one illustrative embodiment that the cylinder is oriented substantially vertically with the manifold end of the cylinder being on top and the flow of reactants being generally upward from the feed end to the manifold end. The present illustrative embodiment includes a first reaction zone containing autothermal reforming catalyst, a second reaction zone containing desuliurization catalyst, a third reaction zone containing water gas shift catalyst, and a fourth reaction zone containing preferential oxid^on catalyst. Preferably, the first reaction zone is positioned at the feed end of the cylinder, the second reaction zone is positioned adjacent to the first reaction zone, the third reaction zone is positioned adj^ent to the second reaction zone, and the fourth reaction zone is positioned at the manifold end of the cylitider. A zone of ceramic beads may also be positioned between the third reaction zone and the fourth reaction zone in order to improve the mixing of the hydrogen rich gas with air, which is injected into the zone of ceramics beads through a fixed nozzle in the manifold. This injection of air may be accomplished by well-known means such as a simple gas injection tube or a porous tube. It should be appreciated by one of skill in the art that each reaction zone of the plurality of reaction zones may contain one or more catalysts.
It should be appreciated by one of skill in the art that each reaction zone of the plurality of reaction zones may contan one or more cat^ysts. In one such illustrative embodiment, the catalysts are selected from autothermal reforming catalyst, desulfurization catalyst, water gas shift catalyst, preferential oxidation catalyst as well as mixtures and combinations of these and similar catalysts. Any particular reaction zone containing more than one catalyst may be separated from an adjacent reaction zone by a permeable plate that also serves to support the

adjacent reaction zones. In one illustrative embodiment, the plate is selected from perforated metal, metal screen, metal mesh, sintered metal, porous ceramic, or combinations of these materials and similar materials. It is preferred within such an illustrative embodiment that the plate be at least partially composed of inconel, carbon steel, stainless steel, hatelloy, or other material suitable for the temperature, pressure, and composition.
In a preferred aspect of the present invention, the compact fijel processor also includes a second cylinder having an anode tail gas oxidation catalyst bed for oxidizing the anode tail gas from a fiiel cell to produce an exhaust gas. The second cylinder may have a pre-heat exchanger for heating the hydrocarbon fuel prior to feeding tiie hydrocarbon friel to the iirst cylinder, and such a pre-heat exchanger may be positioned within the anode tail gas oxidation catalyst bed. It is envisioned that die present illustrative embodiment also includes a fifth reaction zone containing another preferential oxidation catalyst bed. In siu:h an embodiment, a second zorte of ceramic beads, including air injection nozzles as discussed above, may be positioned between the fourth reaction zone and the fifth reaction zone to ensure adequate mixing.
BRIEF DESCRIPTION OF THE DRAWINGS The description is presented with reference to the accompanying drawings in which: FIG. 1 depicts a simple process flow diagram for one illusttative embodiment of the present invention.
FIG. 2 depicts a first illustrative embodiment of a compact fuel processor apparatus of the present invention; and
FIG. 3 depicts a second illustrative embodiment of a compact fuel processor apparatus of the present invention.
FIG. 4 depicts a third illustrative embodiment of a compact fiiel processor apparatus of the present invention.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS The present invention is generally directed to an apparatus for converting hydrocarbon fuel into a hydrogen rich gas. In a preferred aspect, the apparatus and method described herein relate to a compact ftiel processor for producing a hydrogen rich gas stream from a hydrocarbon fuel for use in fuel cells. However, other possible uses are contemplated for the apparatus and method described herein, including any use wherein a hydrogen rich stream is desired.

Accordingly, while the invention is described herein as being used in conjunction widi a fijel cell, the scope of the invention is not limited to such use.
Each of the illustrative embodiments of the present invention describes a fiiel processor or a process for using such a fuel processor with the hydrocarbon fiiel feed being directed throt^ the fuel processor. TTie hydrocarbon fuel may be liquid or gas at ambient conditions as long as it can be vaporized. As used herein the term "hydrocarbon" includes organic compounds having C-H bonds which are capable of producing hydrogen from a partial oxidation or steam refonning reaction. The presence of atoms other than carbon and hydrogen in the molecular structure of the compound is not excluded. Thus, suitable fuels for use in the method and apparatus disclosed herein include, but are not limited to hydrocarbon fiiels such as natural gas, methane, ethane, propane, butane, naphtha, gasoline, and diesel fuel, and alcohols such as methanol, ethanol, propanol, and the like.
The fiiel processor feeds include hydrocarbon fiiel, oxygen, and water. The oxygen can K in the form of air, enriched air, or substantially pure oxygen. The water can be introduced as a iquid or vapor. The composition percentages of the feed components are determined by the lesired operating conditions, as discussed below.
The fuel processor effluent stream from the present invention includes hydrogen and arbon dioxide and can also include some water, unconverted hydrocaiiwns, carbon monoxide, npurities (e.g. hydrogen sulfide and ammonia) and inert components (e.g., nitrogen and aigon, specially if air was a component of the feed stream).
Figure I depicts a general process flow diagram ittustrating the process steps included in le illustrative embodiments of the present invention. One of skill in the art should appreciate at a certain amount of progressive order is needed in the flow of the reactants through the actors disclosed herein.
Process step A is an autothennal reforming process in which two reactions, partial :idation (formula 1, below) and optionally also steam reforming (formula II, below), arc mbined to convert the feed stream F into a synthesis gas containing hydrogen and carbon jnoxide. Fonnulas I and II are exemplary reaction formulas wherein methane is considered as : hydrocarbon:
CH4+540: - 2H2+CO a)

CH4 + H2O -* 3H2 + CO The partial oxidation reaction occurs very quickly to the complete conversion of oxygen added and produces heat. The steam reforming reaction occurs slower and consumes heat. A higher concentration of oxygen in the feed stream fevors partial oxidation whereas a higher concentration of water vapor favors steam refonning. Therefore, the ratios of oxygen to hydrocarbon and water to hydrocarbon become characterizing parameters. These ratios affect the operating temperature and hydrogen yield.
TTie operating temperature of the autothermal reforming step can range from about 5S0°C to about 9(}0'C, depending on the feed conditions and the catalyst. The invention uses a catalyst bed of a partial oxidation catalyst with or without a steam reforming catalyst. The cataJyst may be in any form including pellets, spheres, extrudate, monoliths, and the like. Partial oxidation catalysts should be well known to those with skill in the art and ate often comprised of noble metals such as platinum, palladium, rhodium, and/or ruthenium on an alumina washcoat on a monolith, extrudate, pellet or other support. Non-noble metals sudi as nickel or cobalt have been used. Other washcoats such as titam'a, zirconia, silica, and m^nesia have been cited in the literature. Many additional materials such as lan&anum, cerium, and potassium have been cited in the literature as "proototers" that improve the performance of the partial oxidation catalyst.
Steam reforming catalysts should be known to those with skill in the art and can include nickel with amounts of cobalt or a noble metal such as platinum, palladium, rhodium, ruthenium, and/or iridium. The catalyst can be supported, for example, on m^nesia, alumina, silica, zirconia, or magnesium aluminate, singly or in combination. Alternatively, the steam reforming catalyst can include nickel, preferably supported on magnesia, alumina, silica, zirconia, or niE^nesium aluminate, singly or in combinatioti, promoted by an alkali metal such as potassium. Process step B is a cooling step for cooling the synthesis gas stream fi^m process step A to a temperature of from about 200°C to about 600°C, preferably from about 300*0 to about 500°C, and more preferably from about STS'C to about 425*C, to optimize the temperature of the synthesis gas effluent for the next step. This cooling may be achieved with heat sinks, heat pipes or heat exchangers depending upon the design specifications and the need to recover / recycle the heat content of the gas stream. One illustrative embodiment for step B is the use of a heat exchai^er utilizing feed stream F as the coolant circulated through the heat exchanger. The

heat exchanger can be of any suitable construction known to those with skill in the art including shell and tube, plate, spiral, etc. Alternatively, or in addition thereto, cooling step B may be accomplished by injecting additional feed components such as fiiel, air or water. Water is preferred because of its ability to absorb a large amount of heat as it is vaporized to steam. The amounts of added components depend upon the degree of cooling desired and are readily determined by those with skill in the art.
Process step C is a purifying step. One of the main impurities of the hydrocarbon stream is typically sulfur, which is converted by the autothermal reforming step A to hydrogen sulfide. The processing core used in process step C preferably includes zinc oxide and/or other material capable of absorbing and converting hydrogen sulfide, and may include a support (e.g., monolith, extrudate, pellet etc.). Desulftirization is accomplished by converting the hydrogen sulfide to water in accordance with the following reaction formula III:
HzS + ZnO -* HiO + ZnS (III)
Other impurities such as chlorides can also be removed. The reaction is preferably cairied out at a temperature of from about SOCC to ^>out 500°C, and more preferably from about 375°C to about 425'C. Zinc oxide is an effective hydrogen sulfide absorbent over a wide range of temperatures fh)m about 25°C to about 700°C and affords great flexibility for optimizing the sequence of processing steps by appropriate selection of operating temperature.
The effluent stream may then be sent to a mixing step D in \^ch water is optionally added to the gas stream. The addition of water lowers the temperature of the reactant stream as it vaporizes and supplies more water for the water gas shift reaction of process step E (discussed below). The water vapor and other effluent stream components are mixed by being passed through a processing core of inert materials such as ceramic beads or other similar materials that effectively mix and/or assist in the valorization of the water. Alternatively, any additional water can be introduced witii feed, and the mixing step can be repositioned to provide better mixing of the oxidant gas in the CO oxidation step G disclosed below.
Process step E is a water gas shift reaction that converts carbon monoxide to carbon dioxide in accordance with formula IV;
H:0 + CO -► H2 + CO2 (IV)

This is an important step because carbon monoxide, in Midition to being highly toxio to humans, is a poison to fuel cells. The concentration of carbon monoxide should preferably be lowered to a level that can be tolerated by fuel cells, typically below 50 ppm. Generally, the water gas shift reaction can take place at temperatures of from ! 50°C to eOCC depending on dw catalyst used. Under such conditions, most of the carbon monoxide in the gas stream is converted in this step.
Low temperature shift catalysts operate at a range of from about ISO^C to about SOCC and include for example, copper oxide, or copper supported on other transition metal oxides such as ztrconia, zinc supported on transition metal oxides or refractory supports such as silica, alumina, zirconia, etc., or a noble metal such as platinum, rhenium, palladium, rhodium or gold on a suitable support such as silica, alumina, zirconia, and the like.
High temperature shift catalysts are preferably operated at temperatures ranging from about 300" to about 600°C and can include transition metal oxides such as ferric oxide or chromic oxide, and optionally including a promoter such as copper or iron silicide. Also included, as high temperature shift catalysts are supported noble metals such as supported platinum, palladium and/or other platinum group members.
The processing core utilized to carry out this step can include a packed bed of high temperature or low temperature shift catalyst such as described above, or a combination of both high temperature and low temperature shift catalysts. The process should be operated at any temperature suitable for the water gas shift reaction, preferably at a temperature of from 150°C to about 400'C depending on the type of catalyst used. Optionally, a cooling element such as a cooling coil may be disposed in the processing core of the shift reactor to lower the reaction temperature within the packed bed of catalyst. Lower temperatures favor the conversion of carbon monoxide to carbon dioxide. Also, a purification processing step C can be performed between high and low shift conversions by providing separate steps for high temperature and low temperature shift with a desulfurization module between the high and low temperature shift steps.
Process step F is a cooling step performed in one embodiment by a heat exchanger. The heat exchanger can be of any suitable construction including shell and tube, plate, spiral, etc. Alternatively a heat pipe or other form of heat sink may be utilized. The goal of the heat

exchanger is to reduce the temperature of the gas stream to produce an effluent having a temperature preferably in the range of from about 90°C to about ISO'C.
Oxygen is added to the process in step F. The oxygen is consumed by the reactions of process step G described below. The oxygen can be in the form of air, enriched air, or substantially pure oxygen. The heat exchanger may by design provide mixing of the air with the hydrogen rich gas. Alternatively, the embodiment of process step D may be used to perform the mixing.
Process step G is an oxidation step wherein almost all of the remaining carbon monoxide in the effluent stream is converted to carbon dioxide. The processing is carried out in the presence of a catalyst for the oxidation of carbon monoxide and may be in any suitable fonn, such as pellets, spheres, monolith, etc. Oxidation catalysts for carbon monoxide are known and typically include noble metals (e.g., platinum, palladium) and/or transition metals (e.g., iron, chromium, manganese), and/or compounds of noble or transition metals, particularly oxides. A preferred oxidation catalyst is platinum on an alumina washcoat. The washcoai may be applied to a monolith, extrudate, pellet or other support. Additional materials such as cerium or lanthanum may be added to improve performance. Many othra- formulations have been cited in the literature vdth some practitioners claiming superior performance from rhodium or alumina catalysts. Ruthenium, palladium, gold, and other materials have been cited in the literature as being active for this use.
Two reactions occur in process step G: the desired oxidation of carbon monoxide (formula V) and the undesired oxidation of hydrogen (formula VI) as follows:
CO + 14O2 ~* CO2 (V)
Hz + /1O2 ->■ H2O (VI)
The preferential oxidation of carbon monoxide is favored by low temperatures. Since bodi reactions produce heat it may be advantageous to optionally include a cooling element such as a cooling coil disposed within the process. The operating temperature of process is preferably kept in the range of from about 90'C to about ISO^C. Process step G preferably reduces the carbon monoxide level to less than 50 ppm, which is a suitable level for use in fiiel cells, but one of skill in the art should appreciate that the present invention can be adapted to produce a hydrogen rich product with higher and lower levels of carbon monoxide.

The effluent exiting the fuel processor is a hydrogen rich gas containing carbon dioxide and other constituents which may be present such as water, inert components (e.g., nitrogen, argon), residual hydrocarbon, etc. Product gas may be used as the feed for a fuel cell or for other applications where a hydrogen rich feed stream is desired. Optionaliy, jn-oduct gas may be sent on to fijrther processing, for example, to remove the carbon dioxide, water or other components.
Figwe 2 depicts a cross-sectional view of a fuel processor 20 that is an illustrative embodiment of the present invention. One of ordinary skill in the art should see and appreciate that fuel or alternatively a fuel / oxygen or alternatively a fuel / oxygen / water mixture F, is introduced to the inlet of a heat exchanger 200. The preheated fuel F' leaves the heat exchanger 200 and is routed to the first reaction zone 202. The first reaction zone 202 in the present illustrative embodiment is packed with a autothermal refomiing reaction catalyst. Alternatively, this zone may be packed with a steam reforming catalyst. Such catalyst may be in pellet, sphere, or extmdate form; or supported on a monolith, reticulated foam, or any other catalyst support material. In some instances a distribution plate (not shown) may be needed to achieve an even distribution of fuel to the entire first reaction zone. Also optionally an electric pre-heater (not shown) may be utilized in the start-up of the fuel processor. Af^er the fuel has reacted in the first reaction zone to form a hydrogen rich gas, the natural flow of the gas due to pressure is for the hydrogen rich gas to flow into the second reaction zone 204. In the present illustrative Embodiment, the second reaction zone is packed with a desulfiirizadon catalyst, preferably zinc jxide. Passage of the hydrogen rich gas over a desulfiirization catalyst, such as zinc oxide, iubstantially reduces the concentration of sulfur containing compounds in the hydrogen rich gas ;tream. The desulfurized hydrogen rich gas then passes into lhe third reaction zone 206. The bird reaction zone of the present illustrative embodiment is packed with a water-gas shift reactor ;atalyst or mixture of such catalyst as discussed above. The passage of the hydrogen rich gas >ver this catalyst further enriches the hydrogen content and reduces the carbon monoxide ;oncentration. In some instances air or another suitable oxygen source may now be injected into he fourth reaction zone so that the preferential oxidation reaction is optimized. This may be ccomplished by well-known means such as a simple gas injection tube (not shown) inserted into he partial oxidation catalyst bed. In one preferred embodiment a porous tube is substantially icorporatcd into ihc design of the preferential oxidation reaction zone design and is designed

such that an even distribution of injected oxygen is achieved. In the embodiment shown in this figure, the hydrogen rich gas is passed over a zone of ceramic beads 208, which provides adequate mixing of the hydrogen rich gas with the air before entering the fourth reaction zone 210. The hydrogen rich gas is then passed into the fourth reaction zone 210 which contains a preferential oxidation catalyst. Such a catalyst will reduce the cartwn monoxide concentration to preferably less than 50 part per million as discussed above. The final product is a hydrogen rich gas H. It should also be noted that in one preferred and illustrative embodiment, an inert but porous and flexible material such as glass wool, ceramic wool, rock wool, or other similar inert material may be used in the reaction zone transition regions 212. Such a material serves to aid in the packing of the reactor with the various catalysts, assists in preventing inadvertent mixing of catalysts during transport and provides a cushioning or buffer zone between each of the differing reaction zones. Reaction temperature is controlled in the second, third, and fourth reaction zones by using cooling coils (218, 220, 222), \s4iich circulate coolant, such as water, air, hydrocarbon fuel feed, or any refrigerant, through the catalyst bed. In this illustrative embodiment, the inlet and outlet ends of each cooling coil are fixed in a manifold 224 that is contained in the top cover for cylinder 226, which encloses the various reaction zones. One of skill in the art should appreciate that a number of factors affect the heat transfer process including the flow rate of fuel, the number of coils present in any particular reaction zone, the diameter of the tubing used to make the coils, the presence or absence of fins on the coils and so forth. However, such heat transfer considerations can be optimized through routine calculations and experimentation. In this embodiment, air A is also injected into the zone of ceramic beads through a nozzle fixed in manifold 224. Hydrogen rich gas H is also withdrawn through manifold 224.
Figure 2 also shows the optional embodiment of adding an additional heat exchanger 214 and preferential oxidation catalyst bed 216. The purpose for heat exchanger 214 is primarily to cool the hydrogen rich gas H. The amount of cooling may or may not result in condensing water W out of the gas, for fiirther oxidation in bed 216, which ensures achieving a carbon monoxide concentration of less that 50 part per million in hydrogen rich gas H' The hydrogen rich gas H or H' is preferably used in a fuel cell or may be stored or used in other processes diat should be apparent to one of skill in the art. Another preferred embodiment of the present invention includes an anode tail gas oxidizer, which oxidizes the anode tail gas T from a fuel cell (not

shown). This addition is a useful heat source for preheating hydrocarbon fuel F in heat exchanger 200.
One of skill in the art after reviewing the above description of Figure 2 should understand and appreciate that each reaction zone performs a separate operational function. Reaction zone 202 is the autothermal reforming reaction zone corresponding to process step A of Figure I. An electric heater (not shown) may be installed at the bottom inlet of the reactor for start-up heat. Reaction zone 204 is a purifying reaction zone corresponding to process step C of Figure 1. Reaction zone 206 is a water gas shift reaction zone corresponding to process step E of Figure 1. The cooling step corresponding to process step F of Figure 1 is carried out by cooling coil 220. Reaction zone 210 is an oxidation step corresponding to process step G of Figure 1. An air source (not shown) provides a source for oxygen to process gas for the oxidation reaction (Equation V) of reaction zone 210. Reaction zone 210 also contains cooling coil 222 positioned within or surrounding the catalyst bed so as to maintain a desired oxidation reaction temperature. One of skill in the an should appreciate that the process configuration described in this embodiment may vary depending on numerous factors, including but not limited to feedstock quality and required product quality.
Figure 3 depicts a cross-sectional view of a fuel processor 30 that is another illustrative embodiment of the present invention. One of ordinary ^11 in the art should see and appreciate that fuel or alternatively a fuel / oxygen or alternatively a fuel / oxygen / water mixture F, is introduced to the inlet of a container 300, which contains an anode tail gas oxidizer catalyst bed, which oxidizes the anode tail gas T from a fuel cell (not shown). Container 300 also contains a heat exchanger wtich provides a useful preheating of hydrocaiton fuel F. The preheated fuel F' leaves container 300 and is routed to the first reaction zone 302. The first reaction zone 302 in the present illustrative embodiment is packed with a autothermal reforming reaction catalyst. Such catalyst may be in pellet, sphere, or extrudate form; or supported on a monolith, reticulated foam, or any other catalyst support matenal. In some instances a distribution plate (not shown) Tiay be needed to achieve an even distribution of fuel to the entire first reaction zone. Also jptionally an electric pre-heater (not shovra) may be utilized in the start-up of the fuel processor. \fter the fuel has reacted in the first reaction zone to form a hydrogen rich gas, the natural flow )f the gas due to pressure is for the hydrogen rich gas to flow into the second reaction zone 304.

In the present illustrative embodiment, the second reaction zone is packed with a desulfiirizatioo catalyst, preferably zinc oxide. Passage of the hydrogen rich gas over a desulfurization catalyst, such as zinc oxide, substantially reduces the concentration of siUfttt containing compounds in the hydrogen rich gas stream. The desulftirized hydrogen rich gas is then passes into the third reaction zone 306. The third reaction zone of Uie present illustrative embodiment is packed with a water-gas shift reactor catalyst or mixture of such catalyst as discussed above. The passage of the hydrogen rich gas over this catalyst further enriches the hydrogen content and reduces the carbon monoxide concentration. In some instances air or another suitable oxygen source may now be injected into the fourth reaction zone so that the preferential oxidation reaction is optimized. This may be accomplished by well-known means such as a simple gas injection tube (not shown) inserted into the partial oxidation catalyst bed. In one preferred embodiment a porous tube is substantially incorporated into the design of the preferential oxidation reaction zone design and is designed such that an even distribution of injected oxygen is achieved. In the embodiment shown in this figure, the hydrogen rich gas is passed over a zone of ceramic beads 308, which provides adequate mixing of the hydrogen rich gas with the air before entering the fourth reaction zone 310. The hydrogen rich gas is then passed into the fourth reaction zone 310 which contains a preferential oxidation catalyst. Such a catalyst will reduce the carbon monoxide concentration to preferably less that 50 part per million as discussed above. Optionally, an additional layer of ceramic beads and a fifth reaction zone (not shown) containing a preferential oxidation catalyst can be employed to ensure that the carbon monoxide concentration is reducedto preferably less than 50 parts per million. The final product is a hydrogen rich gas H. It should also be noted that in one preferred and illustrative embodiment, Ml inert but porous and flexible material such as glass wool, ceramic wool, rock wool, or other similar inert material may be used in the reaction zone transition regions 312. Such a material «rves to aid in the packing of the reactor with the various catalysts, assists in preventing nadvertent mixing of catalysts during transport and provides a cushioning or buffer zone •etween each of the differing reaction zones. Reaction temperature is controlled in the second, lird, and fourth reaction zones by using cooling coils (318, 320, 322), which circulate coolant, uch as water, air, hydrocarbon fuel feed, or any refrigerant, through the catalyst bed. In fliis lustrative embodiment, the inlet and outlet ends of each coolino mil nt^ fiv*.H in = ^^^-.r^iA 11.1

that is contained in ihe lop cover for cylinder 326, which encloses the various reaction zones. One of skill in the art should appreciate that a number of factors affect the heat transfer process including the flow rate of fuel, the number of coils present in any particular reaction zone, the diameter of the tubing used to make the coils, the presence or absence of fins on the coils and so forth. However, such heat transfer considerations can be optimized through routine escalations and experimentation. In this embodiment, air A is also injected into the zone of ceramic beads through a nozzle fixed in manifold 324. Hydrogen rich gas H is also withdrawn through manifold 324.
One of skill in the art after reviewing the above description of Figure 3 should understand and appreciate that each ceaction zone performs a separate operational function. Reaction zone 302 is the autothermal reforming reaction zone corresponding to process step A of Figure i. An electric heater (not shown) may be installed at the bottom inlet of the reactor for start-up heat. Reaction zone 304 is a purifying reaction zone corresponding to process step C of Figure 1. Reaction zone 306 is a water gas shift reaction zone corresponding to process step E of Figure 1. The cooling step corresponding to process step F of Figure I is carried out by cooling coil 320. Reaction zone 310 is an oxidation step corresponding to process step G of Figure 1. Air source (not shown) provides a source for oxygen to process gas for the oxidation reaction (Equation V) of reaction zone 310. Reaction zone 310 also contains cooling coil 322 positioned within or siUTOunding the catalyst bed so as to maintain a desired oxidation reaction temperature. One of skill in the art should appreciate that the process configuration described in this embodiment may vary depending on numerous factors, including but not limited to feedstock quality and required product quality.
Figure 4 depicts a cross-sectional view of a fuel processor 40 that is yet another illustrative embodiment of the present invention. One of ordinary skill In the art should see and appreciate that fuel or alternatively a fuel / oxygen or alternatively a fuel / oxygen / water mixture F, is introduced to the inlet of a heat exchanger 400. The preheated fiiel F' leaves the heat exchanger 400 and is routed to the first reaction zone 402. The first reaction zone 402 in the present illustrative embodiment is packed with a autothermal reforming catalyst or steam reforming catalyst. Such catalyst may be in pellet, sphere, or extrudate form; or supported on a monolith, reticulated foam, or any other catalyst support material. In some instances a

distribution plate (not shown) may be needed to achieve an even distribution of ftiel to the entire first reaction zone. Also optionally an electric pre-heater (not shown) may be utilized in the start-up of the fuel processor. After the fiiel has reacted in the first reaction zone to form a hydrogen rich gas, the natural flow of the gas due to pressure is for the hydrogen rich gas to flow into the second reaction zone 404. In the present illustrative embodiment, the second reaction zone is jacked with a desulfurization catalyst, preferably zinc oxide. Passage of the hydrogen rich gas over a desulfurization catalyst, such as zinc oxide, substantially reduces the concentration of sulfur containing compounds in the hydrogen rich gas stream. The desulfurized hydrogen rich gas is then passes into the third reaction zone 406. The third reaction zone of the present illustrative embodiment is packed with a water-gas shift reactor catalyst or mixture of such catalyst as discussed above. The passage of the hydrogen rich gas over this catalyst further enriches the hydrogen content and reduces the carbon monoxide concentration. In some instances air or anotfier suitable oxygen source may now be injected into the fourth reaction zoi\e 50 that the preferential oxidation reaction is optimized. This may be accomplished by well-known means such as a simple gas injection tube (not shown) inserted into the partial oxidation catalyst bed. In one preferred embodiment a porous tube is substantially incorporated into the design of the preferential oxidation reaction zone design and is designed such that an even distribution of injected oxygen is achieved. In the embodiment shown in this figure, the hydrogen rich gas is passed over a zone of ceramic beads 408, which provides adequate mixing of the hydrogen rich gas with the air before entering the fourth reaction zone 410. The hydrogen rich gas is then passed into the fourth reaction zone 410 which contains a preferential oxidation catalyst. Such a catalyst will reduce the carbon monoxide concentration to preferably less than 50 parts per million as discussed above. The final product is a hydrogen rich gas H. It should also be noted that in one preferred and illustrative embodiment, an inert but porous and flexible material such as glass wool, ceramic wool, rock wool, or other similar inert material may be used in the reaction zone transition regions 412. Such a material serves to aid in the packing of the reactor with the various catalysts, assists in preventing inadvertent mixing of catalysts during transport and provides a cushioning or buffer zone between each of the differing reaction zones. Reaction temperature is controlled in the second, third, and fourth reaction 2ones by directly injecting water into the catalyst beds. In this illustrative embodiment, the inlet nozzle for each

injection line is fixed in a manifold 424 that is contained in the top cover for cylinder 426, which encloses the various reaction zones. One of skill in the art should appreciate that a number of factors affect the controllability of the reaction temperatures, including the size of the nozzles, the flow rate of fuel, and the number and location of the nozzles in each catalyst bed. However, such heat transfer considerations can be optimized through routine calculations and experimentation. In this embodiment, air A is also injected into the zone of ceramic beads through a nozzle fixed in manifold 424. Hydrogen rich gas H is also withdrawn through manifold 424.
Figure 4 also shows the optional embodiment of adding an additional heat exchanger 414 and preferential oxidation catalyst bed 416. The purpose for heat exchanger 414 is primarily to cool the hydrogen rich gas H, thereby condensing water W out of the gas, for further oxidation in bed 416, which ensures achieving a carbon monoxide concentration of less than 50 parts per million in hydrogen rich gas H' The hydrogen rich gas H or H' is preferably used in a fuel cell or may be stored or used in other processes that should be apparent to one of skill in tiw art. Another preferred embodiment of the present invention is anode tail gas oxidizer, which oxidjss the anode tail gas T from a fuel cell (not shown). This addition is a useful heat source for preheating hydrocarbon fuel F in heat exchanger 400.
One of skill in the art afler reviewing the above description of Figure 4 should understand and appreciate that each reaction zone performs a separate operational function. Reaction zone 402 is the autothemial reforming reaction zone corresponding to process step A of Figure 1, An electric heater (not shown) may be installed at the bottom inlet of the reactor for start-up heat. Reaction zone 404 is a purifying reaction zone corresponding to process step C of Figure 1. Reaction zone 406 is a water gas shift reaction zone corresponding to process step E of Figure 1. The cooling step corresponding to process step F of Figure 1 is carried out by the direct water injection into reaction zone 406. Reaction zone 410 is an oxidation step corresponding to process step G of Figure 1. Air source (not shown) provides a source for oxygen to process gas for the oxidation reaction (Equation V) of reaction zone 410. Reaction zone 410 also contains direct water injection to maintain a desired oxidation reaction temperature. One of skill in the art should appreciate that the process configuration described in this embodiment may vary

depending on numerous factors, including but not limited to feedstock quality and required product quality.
In view of the above disclosure, one of ordinary skill in the art should understand and appreciate that the present invention includes many possible illustrative embodiments that depend upon design criteria. One such illustrative embodiment includes a compact iliel processor for converting a hydrocarbon fiiei feed into hydrogen rich gas, in which the fuel processor assembly includes a cylinder having a feed end and a manifold end, a removable manifold, and a plurality of predefined reaction zones within the cylinder, wherein each reaction zone is characterized by a chemical reaction that takes place within the reaction zone. The fuel processor also includes at least one cooling coil having an inlet end and an outlet end connected to the manifold end, wherein each of the at least one cooling coils is internally positioned so as to remove heat from a particular reaction zone or direct injection of water to control the temperature in a particular reaction zone. Within such an illustrative embodiment, the plurality of catalysts includes autotherma! reforming catalyst or steam reforming catalyst, desulfiirization catalyst, water gas shift catalyst, preferential oxidation catalyst, and mixtures and combinations of these and similar catalysts. The hydrocarbon ftiel feed utilized in the illustrative fuel processor is preheated, preferably by passing through a heat exchanger prior to being introduced to the cylinder or alternatively by a fuel pre-heater located in a function upstream position from the autothermal reforming reaction zone. A wide variety of hydrocarbon fuels may be utilized. However, in one illustrative embodiment die hydrocarbon fuel is selected form natural gas, gasoline, diesel, fuel oil, propane, liquefied petroleum, methanol, ethanol or other similar and suitable hydrocarbons and mixtures of these. It is preferred in one illustrative embodiment that the cylinder is oriented substantially vertically with the manifold end of the cylinder being on top md the flow of reactants being generally upward from the feed end to the maijifold end. The aresent illustrative embodiment comprises a first reaction zone containing autothermal reforming ;atalyst, a second reaction zone containmg desulfiirization catalyst, a third reaction zone :ontaining water gas shift catalyst, and a fourth reaction zone containing preferential oxidation ;atalyst. Preferably, the first reaction zone is positioned at the feed end of the cylinder, the lecond reaction zone is positioned adjacent to the first reaction zone, the third reaction zone is )ositioned adjacent to the second reaction zone, and the fourth reaction zone is positioned at the

manifold end of tiie cylinder. A zone of ceramic beads may also be positioned between the fliird reaction zone and the fourth reaction zone in order to improve the mixir^ of the hydrogen rich gas with air, which is injected into the zone of ceramics beads through a fixed nozzle in the manifold. This injection of air may be accomplished by well-known means such as a simple gas injection tube or a porous tube. It should be appreciated by one of skill in the art that each reaction zone of &e plurality of reaction zones may contain one or more catalysts. In one such illustrative embodiment, tfie catalysts ^^e selected from autothermal reforming catalyst, desulfurization catalyst, water gas shift catalyst, preferential oxidation catalyst as well as mixtures and combinations of these and similar catalysts. Any particular reaction zone containing more than one catalyst may be separated from an adjacent reaction zone by a permeable plate that also serves to support the adjacent reaction zones. In one illustrative embodiment, the plate is selected from perforated metal, metal screen, metat mesh, sintered metal, porous ceramic, or combinations of these materials and similar materials. It is prefened within such an illustrative einbodimeni that the plate be at least partially composed of inconel, carbon steel, stainless steel, hatelloy, or other material suitable for the temperature, pressure, and composition. In a preferred aspect of the present invention, the compact fuel processor also comprises a second cylinder having an anode tail gas oxidation catalyst bed for oxidizing the anode tail gas from a fuel cell to produce an exhaust gas. The second cylinder may have a pre¬heat exchanger for heating the hydrocarbon fuel prior to feeding the hydrocarbon fiiel to the first cylinder, and such a pre-heat exchanger may be positioned within the anode tail gas oxidation catalyst bed. It is envisioned that the present illustrative embodiment also includes a fifth reaction zone containing another preferential oxidation catalyst bed. In such an embodiment, a second zone of ceiamic beads, including air injection nozzles as discussed above, may be positioned between the fourth reaction zone and the fifth reaction zone to ensure adequate nixing.
Another such illustrative embodiment includes a compact fuel processor for converting a lydrocarbon fuel feed into hydrogen rich gas, in which the fuel processor assembly includes a ylinder having a feed end and a manifold end, a removable manifold, and a plurality of iredefined reaction zones within the cylinder, wherein each reaction zone is characterized by a hemical reaction that takes place within the reaction zone. Instead of cooling coils or other heat

exchangers, temperature control in each reaction zone is controlled through direct water injection. It is preferred in one illustrative embodiment that the cylinder is oriented substantially vertically with the manifold end of the cylinder being on top and the flow of ceactants being generally upward from the feed end to the manifold end. The present illustrative embodiment comprises a first reaction zone containing autothemial reforming catalyst, a second reaction zone containing desulflirization catalyst, a third reaction zone containing water gas shift catalyst, and a fourth reaction zone containing preferential oxidation catalyst. Preferably, die first reaction zone is positioned at the feed end of the cylinder, the second reaction zone is positioned adjacent to the first reaction zone, the third reaction zone is positioned adjacent to the second reaction zone, and the fourth reaction zone is positioned at the manifold end of the cylinder. A zone of ceramic beads may also be positioned between the third reaction zone and the fourth reaction zone in order to improve the mixing of the hydrogen rich gas with air, which is injected into the zone of ceramics beads through a fixed nozzle in the manifold. This injection of air may be accomplished by well-known means such as a simple gas injection tube or a porous tube. It should be appreciated by one of skill in the art that each reaction zone of the plurality of reaction zones may contain one or more catalysts. In one such illustrative embodiment, the catalysts are selected from autothermal reforming catalyst or steam reforming catalyst, desulfiirization catalyst, water gas shift catalyst, prefo^ntial oxidation catalyst as well as mixtures and combinations of these and similar catalysts. Any particular reaction zone containing more than one catalyst may be separated from an adjacent reaction zone by a penneable plate that also serves to support the adjacent reaction zones. In one illustrative embodiment, the plate is selected fi«m perforated metal, metal screen, metal mesh, sintered metal, porous ceramic, or combinations of these materials and similar materials. It is preferred within such an illustrative embodiment that the plate be at least partially composed of inconel, carbon steel, stainless steel, hastelloy, or other material suitable for temperature, pressure, and composition.
While the apparahis, compositions and methods of this invention have been described in terms of preferred or illustrative embodiments, it will be apparent to those of skill in the art that variations may be applied to the process described herein without departing from the concept and scope of the invention. All such similar substitutes and modifications apparent to those skilled in

the art are deemed to be within the scope and concept of the invention as it is set out in the following claims.

WE CLAIM :
1. A compact fuel processor for converting a hydrocarbon fuel feed to hydrogen rich gas,
comprising:
a cylinder having a feed end and a manifold end, wherein the cylinder has a removable manifold;
a plurality of predefined reaction zones within the cylinder, wherein each reaction zone is characterized by a chemical reaction that takes place within the reaction zone; and
at least one cooling coil having an inlet end and an outlet end connected to the manifold end, wherein each of the at least one cooling coils is internally positioned so as to remove heat from a particular reaction zone.
2. The compact fuel processor as claimed in claim I, wherein the cylinder is oriented substantially vertically with the manifold end of the cylinder being on top.
3. The compact fuel processor as claimed in claim 1, wherein a first reaction zone contains autothermal reforming catalyst or steam reforming catalyst, a second reaction zone contains desulfurization catalyst, a third reaction zone contains water gas shift catalyst, and a fourth reaction zone contains preferential oxidation catalyst.
4. The compact fuel processor as claimed in claim 3, wherein the first reaction zone is positioned at the feed end of the cylinder, the second reaction zone is positioned adjacent to the first reaction zone, the third reaction zone is positioned adjacent to the second reaction zone, and the fourth reaction zone is positioned at the manifold end of the cylinder.
5. The compact fuel processor as claimed in claim 4, wherein a zone of ceramic beads is positioned between the third reaction zone and the fourth reaction zone.
6. The compact fuel processor as claimed in claim 5, comprising an air injection means for

. injecting air into the zone of ceramic beads, wherein the air injection means is connected to the manifold.
7. The compact fuel processor as claimed in claim 4, wherein a reaction zone containing
more than one catalyst is separated from an adjacent reaction zone by a permeable plate.
8. The compact fiiel processor as claimed in claim 7, wherein the permeable plate is
perforated metal, metal screen, metal mesh, sintered metal, or porous ceramic.
9. The compact fuel processor as claimed in claim 8, wherein the permeable plate is of a material selected from the group consisting of inconel, carbon steel, stainless steel, hastelloy, and other material suitable for the temperature, pressure, and composition.
10. The compact fuel processor as claimed in claim I, comprising a second cylinder comprising a anode tail gas oxidation catalyst bed for oxidizing the anode tail gas from a fiiel cell to produce an exhaust gas.
11. The compact fuel processor as claimed in claim 10, wherein the second cylinder comprises a preheat exchanger for heating the hydrocarbon fiiel prior to feeding the hydrocarbon fuel to the first cylinder.
12. The compact fuel processor as claimed in claim 11, wherein the pre-heat exchanger is positioned within the anode tail gas oxidation catalyst bed.
13. The compact fuel processor as claimed in claim 3, wherein a fifth reaction zone contains preferential oxidation catalyst,
14. The compact fuel processor as claimed in claim 13, wherein the first reaction zone is positioned at the feed end of the cylinder, the second reaction zone is positioned adjacent to the

first reaction zone, the third reaction zone is positioned adjacent to the second reaction zone, the fourth reaction zone is positioned adjacent to the third reaction zone, and the fifth reaction zone is positioned at the manifold end of the cylinder.
15. The compact fuel processor as claimed in claim 14, comprising a first zone of ceramic beads positioned between the third reaction zone and the fourth reaction zone, and a second zone of ceramic beads positioned between the fourth reaction zone and the fifth reaction zone.
16. The compact fuel processor as claimed in claim 15, comprising air injection means for injecting air into each zone of ceramic beads, wherein the air injection means is cotmected to the manifold.
17. A compact fuel processor for converting a hydrocarbon fuel feed to hydrogen rich gas, comprising:
a cylinder having a feed end and a manifold end, wherein the cylinder has a removable manifold;
a plurality of predefined reaction zones within the cylinder, wherein each reaction zone is characterized by a chemical reaction that takes place within the reaction zone; and
at least one injection means for injecting water into a particular reaction zone, wherein each injection means is cormected to the manifold.
18. The compact fuel processor as claimed in claim 17, wherein the cylinder is oriented substantially vertically with the manifold end of the cylinder being on top.
19. The compact fuel processor as claimed in claim 17, wherein a first reaction zone contains autothermal reforming catalyst or steam reforming catalyst, a second reaction zone contains desulflirization catalyst, a third reaction zone contains water gas shift catalyst, and a fourth reaction zone contains preferential oxidation catalyst.

-20. The compact fuel processor as claimed in claim 19, wherein the first reaction zone is positioned at the feed end of the cylinder, the second reaction zone is positioned adjacent to the first reaction zone, the third reaction zone is positioned adjacent to the second reaction zone, and the fourth reaction zone is positioned at the manifold end of the cylinder.
21. The compact fuel processor as claimed in claim 20, wherein a zone of ceramic beads is
positioned between the third reaction zone and the fourth reaction zone.
22. The compact fuel processor as claimed in claim 21, comprising an air injection means
for injecting air into the zone of ceramic beads, wherein the air injection means is connected to
the manifold.
23. The compact fuel processor as claimed in claim 19, wherein a reaction zone is separated
from an adjacent reaction zone by a permeable plate.
24. The compact fuel processor as claimed in claim 23, wherein the permeable plate is perforated metal, metal screen, metal mesh, sintered metal, or porous ceramic.
25. The compact fuel processor as claimed in claim 24, wherein the permeable plate is of a material selected from the group consisting of inconel, carbon steel, stamless steel, hastelloy, and other material suitable for the temperature, pressure, and composition.

Documents:

1774-chenp-2003 abstract-duplicate.pdf

1774-chenp-2003 abstract.jpg

1774-chenp-2003 abstract.pdf

1774-chenp-2003 claims-duplicate.pdf

1774-chenp-2003 claims.pdf

1774-chenp-2003 correspondence-others.pdf

1774-chenp-2003 correspondence-po.pdf

1774-chenp-2003 description (complete)-duplicate.pdf

1774-chenp-2003 description (complete).pdf

1774-chenp-2003 drawings-duplicate.pdf

1774-chenp-2003 drawings.pdf

1774-chenp-2003 form-1.pdf

1774-chenp-2003 form-18.pdf

1774-chenp-2003 form-26.pdf

1774-chenp-2003 form-3.pdf

1774-chenp-2003 form-5.pdf

1774-chenp-2003 pct.pdf

1774-chenp-2003 petition.pdf

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Patent Number

224898

Indian Patent Application Number

1774/CHENP/2003

PG Journal Number

49/2008

Publication Date

05-Dec-2008

Grant Date

24-Oct-2008

Date of Filing

11-Nov-2003

Name of Patentee

TEXACO DEVELOPMENT CORPORATION

Applicant Address

6001 BOLLINGER CANYON ROAD, SAN RAMON, CALIFORNIA 94583,

Inventors:

#	Inventor's Name	Inventor's Address
1	KRAUSE, CURTIS, L	15802 LAKECLIFFE DRIVE, HOUSTON, TX 77095,
2	PHAN, JENNIFER, L	3031 COUNTY ROAD 81, ROSHARON, TX 77583,
3	DESHPANDE, VIJAY, A	5313 NAVARRO, HOUSTON, TX 77056,
4	MARTIN, PAUL	239 BOGERT AVENUE, TORONTO, ONTARIO M2N 1L2,

PCT International Classification Number

BO1J8/04

PCT International Application Number

PCT/US02/13128

PCT International Filing date

2002-04-26

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	60/286,684	2001-04-26	U.S.A.