Title of Invention	A STRUCTURED CATALYST FOR STEAM REFORMING OF METHANE FOR PRODUCTION OF SYN GAS
Abstract	The present invention relates to steam reforming of methane for production of syn gas and, in particular, to a meso-scale channeled structured catalyst (PS-CAT) comprising a plurality of square thin-walled rectangular channels obtained of cordierite coated with a selective transition metal or noble metal based catalyst formulation adapted to favour continuous and intimate contact of gas feed with the active catalyst with improve feed rate and conversion in steam reforming. Advantageously, the structured catalyst functionally favour ready use in conventional reformer tubes used in steam reforming for increased conversion to syn gas. The meso-structured catalyst achieve good conversion > 90% of methane for a molar ratio of steam to methane of >2.5 and up to 7 and steam reforming of methane is carried out preferably at a steam to methane molar ratio of 3:1 at atmospheric pressure and a temperature of 700 to 850 °C preferably about 775°C to 840°C for more than hundred hours on stream and is directed to favour wide scale application and use as a beneficial catalyst in steam reforming of methane for production of syn gas.

Title of Invention

A STRUCTURED CATALYST FOR STEAM REFORMING OF METHANE FOR PRODUCTION OF SYN GAS

Abstract

The present invention relates to steam reforming of methane for production of syn gas and, in particular, to a meso-scale channeled structured catalyst (PS-CAT) comprising a plurality of square thin-walled rectangular channels obtained of cordierite coated with a selective transition metal or noble metal based catalyst formulation adapted to favour continuous and intimate contact of gas feed with the active catalyst with improve feed rate and conversion in steam reforming. Advantageously, the structured catalyst functionally favour ready use in conventional reformer tubes used in steam reforming for increased conversion to syn gas. The meso-structured catalyst achieve good conversion > 90% of methane for a molar ratio of steam to methane of >2.5 and up to 7 and steam reforming of methane is carried out preferably at a steam to methane molar ratio of 3:1 at atmospheric pressure and a temperature of 700 to 850 °C preferably about 775°C to 840°C for more than hundred hours on stream and is directed to favour wide scale application and use as a beneficial catalyst in steam reforming of methane for production of syn gas.

Full Text	FIELD OF THE INVENTION The present invention relates to steam reforming of methane for production of syn gas and, in particular, to a structured catalyst for steam reforming of methane for production of syn gas. Importantly, the structured catalyst involving selective catalyst coating is adapted to favour continuous and intimate contact of gas feed with the active catalyst and is directed to improve feed rate and conversion under steam reforming. Advantageously, the structured catalyst is developed such as to favour ready use in conventional reformer tubes used in steam reforming for increased conversion or processing capacity of the steam reforming plant. Importantly, the structured catalyst of the invention achieve good conversion > 90% of methane for a molar ratio of steam to methane of >2.5 and up to 7 and is directed to favour wide scale application and use as a beneficial catalyst in steam reforming of methane for production of syn gas. BACKGROUND ART Catalytic steam reforming of hydrocarbons, alcohols, and light oil fractions involves the reaction of steam with methane, ethane, natural gas, LPG, naphtha, gasoline, alcohols such as methanol, ethanol, propanol over catalysts at elevated temperatures (200-900 °C) and elevated pressures (1-30 atm) to produce syn gas which is a mixture of hydrogen, carbon monoxide and carbon dioxide. The technology has matured over the years. However, still the major concerns are the endothermic nature of the reactions making the process energy intensive, and coke formation that results in catalyst deactivation. Work is still in progress to use lower or more ambient operating parameters, and to minimise coke formation thereby increasing catalyst life and hence reducing reformer down time. It is reported that 90% of hydrogen generated today is produced by the steam reforming of natural gas and light oil fractions. The major reason for this is the commercial viability of such plants by which hydrogen can be produced at $2.11/kg of H2. This is by far the most energy efficient process available in comparison to other processes like, carbon dioxide reforming, coal gasification, pyrolysis, water electrolysis and photobiochemical techniques. Recent trends in industries like Chevron Texaco have shown an increased use of processes such as partial oxidation or the energy-neutral autothermal process, both of which are modifications of the basic steam reforming process. In these processes, either oxygen (air) and / or steam in different ratios are added to the feed during operation of the steam reformer unit. 2 The reactions occurring during the steam reforming process are as given by equations (1) through (4): The conventional, bulk, steam methane reforming (SMR) system for hydrogen production is composed of a steam reformer, a shift converter, and a hydrogen purifier based on the pressure swing adsorption (PSA) or membrane separation unit. A mixture of natural gas and steam is introduced into a catalyst bed in the steam reformer, where the steam reforming reaction proceeds on nickel-based catalyst at 700-800°C. The reformed gas is supplied to a shift converter, where carbon monoxide is converted into carbon dioxide to produce more hydrogen by the shift reaction. Next the reformed gas is passed to PSA unit to separate hydrogen. Nickel possesses hydrogenation activity but limited water gas shift activity. It is a low-cost but effective catalyst for cleavage of O—H, —CH2—, —C— C— and —CH3 bonds. It is these properties that make nickel a favourable choice as a steam reforming catalyst. The use of the catalyst is to reduce the temperature of operation and to increase the conversion of the feed hydrocarbon. A typical steam reformer unit consists of a reformer block containing 40 to 400 tubes of height 6 to 12 metres having an inner diameter of 0.7 to 0.16 m and a thickness of 0.01 to 0.02 m. The tubes are generally made of high alloy nickel chromium steel. As the process is endothermic, the required heat needs to be supplied to the reformer unit. The tubes can be heated externally or internally. In external heating, part of the reed is combusted outside the reformer tube to reach the desired reaction temperature. In internal heating part of the feed is combusted inside the tube of the reformer. This latter 3 process is known as partial oxidation or autothermal reforming depending on the energy supplied to the process. Conventional catalysts are available in the form of cylindrical pellets, tablets and spheres and are simply dumped in the reformer tube. This is called as a conventional fixed bed or packed bed reformer. The catalyst pellets are randomly placed in the reformer tube and so do not contribute to a defined structure to the bed. There is no structure to the bed as a whole and it can imagined as a bed containing a large number of convoluted or tortuous paths through which the feed gas flows. The quantity of catalyst and its composition is determined on the basis of the feed quantity and quality or composition. The role of the catalyst is to achieve maximum possible conversion of the feed to syn gas, a constant pressure drop and to have sufficient mechanical and thermal strength to provide a long process cycle. Conventionally, in all fertiliser plants, supported nickel catalysts are used. The support is generally silica, alumina, and/or magnesia. The properties of the catalyst are further modified by addition of components like, calcium oxide, aluminium, molybdenum, special carbides, zirconia, ceria, other alkali earth metals like potassium, etc. to make the catalyst coke resistant, and to increase its mechanical and thermal strength. Effect of promoters such as Cu, La, Mo, Ca, Ce, Y, K, Cr, Mg, Mn, Sn, V, Rh, Pd, and their combinations have been used for improving the stability of Ni catalysts supported on alumina for steam methane reforming. Recently, the use of platinum, rhodium, and palladium, along with nickel has also been reported. However, industrial catalysts are usually nickel based catalysts. The most commonly used catalysts are nickel-alumina, nickel-alumina-magnesia, nickel-magnesia, etc. The percentage of nickel varies from as low as 3 % to as high as 52% by weight. Nickel possesses hydrogenation activity but limited water gas shift activity. It is a low-cost but effective catalyst for cleavage of 0— H, —CH2—, —C—C— and —CH3 bonds. It is these properties that make nickel a favourable choice as a steam reforming catalyst. However, nickel alone cannot be used as a steam reforming catalyst due to its limited water gas shift activity. In order to exploit this secondary reaction, nickel or other metal catalysts are coupled (or supported on) with another metal oxide such as alumina or magnesia. Conventional catalysts are available in the form of cylindrical pellets, tablets, and spheres, and are simply dumped in the reformer tube. The catalyst pellets are randomly placed in the reformer tube and so do not contribute to a defined structure to the bed. There is no structure to the bed as a whole and it can imagined as a bed containing a large number of convoluted or tortuous paths through which the feed gas flows. As the gas flows through the path, there is an increased pressure drop (relative to the use of structured catalysts). The 4 conversion of the feed is also less at identical process conditions of temperature, molar ratio of steam to methane and feed flow rate (residence time). OBJECTS OF THE INVENTION It is thus the basic object of the present invention to provide for the development of a catalyst suitable for steam reforming of methane which is targeted to improve the conversion of feed (methane) while using the steam reforming processes and existing available plant infrastructure. Another object of the present invention is directed to provide for the development of structured catalyst useful for steam reforming of methane which can be readily used in place of currently used industrial catalyst and would provide increased conversion in comparison to the existing commercial nickel based catalyst at identical process conditions. A further object of the present invention is directed to the development of a catalyst for steam reforming of methane which would not involve any change in the reformer tube design and can be used with conventional reformer tubes to achieve increased conversion/throughput. A further object of the present invention is directed to the development of a catalyst suitable for steam reforming of methane, which would achieve increased conversion and therefore enable higher flow rate of the feed relative to that achieved with existing commercial catalyst at the same molar ratio of steam to hydrocarbon feed and temperature. Yet another object of the present invention is directed to the development of a structured catalyst involving selective combination of basic structure and coating catalyst formulation directed to achieve improved feed conversion and thereby make steam reforming of methane beneficial and cost effective. A further object of the present invention is directed to the development of a structured catalyst involving selective combination of basic structure and coating formulation with selective coating procedure which would enable achieving increased specific surface area of structured catalyst and thereby favour providing for more sites for reaction and jn the 5 process increase the conversion within the thermodynamic limits and consequently achieve higher plant throughput for identical process conditions. A further object of the present invention is directed to the development of a meso- channeled structured (PS-CAT) which would be most effective in the process of reforming of methane for the production of syn gas. Another object of the present invention is directed to the development of meso-scale channeled structured catalyst adapted to favour achieving lower pressure drop as compare to pellet type packed (or fixed) bed reactor involving selective dimension of channels to further favour improved catalyst coating with higher catalyst loading to enable feeding more methane to the same tubular reformer as compared to the tube packed with pellet type catalyst. Yet another object of the present invention is directed to the development meso- channeled structured PS-CAT catalyst wherein the gas flow would be distributed in the channels at inlet of the reformer tube and thereafter follow through the entire straight length of the channel without changing its direction till reaching the bottom of the reformer tube, thereby achieving desired lesser drop in pressure energy and favouring selective use of channel dimension for effective catalyst loading for desired intimate contact of gas with catalyst and resulting increased conversion. Another object of the present invention is directed to the development of meso- channeled structured PS-CAT catalyst involving catalyst loading of 3-10% for steam reforming of methane which would achieve good conversion (>90%) of methane for a molar ratio of steam to methane of 2.5 to up to 7. A further object of the present invention is directed to a simple and cost effective manner of production of syn gas involving steam reforming of methane using a meso-channeled structured PS-CAT catalyst favouring improved conversion and throughput which would beneficially favour achieving better conversion efficiency of methane to generate syn gas through conventional reformer units. 6 SUMMARY OF THE INVENTION Thus according to the basic aspect of the invention there is provided a structured catalyst for steam reforming of methane for production of syn gas comprising: A meso scaled channeled structure obtained of cordierite with selective catalyst coating spread over the channel dimensions adapted to favour continuous and intimate contact of the gas feed with the active catalyst content of the coating for increased feed rate and conversion under said steam reforming. According to another aspect of the invention there is provided a structured catalyst for steam reforming of methane for production of syn gas comprising: meso-scale channeled structured catalyst (PS-CAT) comprising a plurality of square thin- walled rectangular channels obtained of cordierite coated with a selective transition metal or noble metal based catalyst formulation, said coating spread over the all the channel dimensions adapted to favour continuous and intimate contact of the gas feed with the active content of the coating for increased feed rate and conversion under said steam reforming. According to yet further aspect of the invention there is provided a structured catalyst for steam reforming of methane for production of syn gas comprising: meso-scale channeled structured catalyst (PS-CAT) comprising a plurality of square thin- walled rectangular channels obtained of cordierite coated with a selective transition metal or noble metal based catalyst formulation , said coating spread over the all the channel dimensions having porous material for increased surface area and adapted to favour continuous and intimate contact of the gas feed with the active content of the coating for increased feed rate and conversion under said steam reforming. In the above disclosed structured catalyst for steam reforming of methane for production of syn gas of the invention, the said selective catalyst is obtained of a nitrate salt of a transition or noble metal. In accordance with a preferred aspect, the said selective catalyst is selectively obtained of nickel nitrate solution, nitrate salt of another transition metal preferably copper, zinc or any noble metal preferably rhodium, platinum and palladium. 7 According to a further preferred aspect the structured catalyst for steam reforming of methane for production of syn gas comprises porous material coating comprises alumina sol and a binder. Importantly, the effectiveness of the structured catalyst is selectively achieved by selective change in catalyst formulation preferably rhodium-nickel combination, increasing the surface area of the coated catalyst to provide more active sites for increased conversion and plant throughput and variation in the coating thickness to achieve higher conversions. In accordance with an aspect of the invention, the structured catalyst for steam reforming of methane for production of syn gas comprises: Macrostructure obtained of Cordierite (ceramic), specifications 100 to 400 cpsi preferably about 100 cpsi (cells per square inch), wall thickness 50 to 300 microns preferably about 270 microns (average) and cell dimension 500 X 500 microns to 2000 X 2000 microns preferably 1500 X 1500 microns; BET surface area comprising uncoated (raw) cordierite substrate 0.5 to 20 m2/g preferably about 0.72 m2/g/ coated substrate (PS-CAT) 0.25 to 15 m2/g preferably about 0.49 m2/g;and Catalyst loading of Nickel Oxide in the range of 3 to 10%. According to yet another aspect of the invention there is provided a process for the manufacture of structured catalyst for steam reforming of methane for production of syn gas comprising: i) Providing cordierite blocks; ii) Providing a nitrate salt solution of a transition metal or a noble metal; iii) Soaking the said cordierite blocks in said nitrate salt solution; iv) Removing the blocks from the solution and subjecting the blocks to drying such as to obtain dry blocks ready for calcination; 8 v) Subjecting the dry blocks to calcination such as to reduce the metal nitrate to metal oxide; and v) finally, the blocks are reduced from metal oxide content to said metal catalyst contained structured catalyst suitable for steam reforming. In accordance with a preferred aspect the above process for the manufacture of structured catalyst for steam reforming of methane for production of syn gas comprises: i) providing cordierite blocks; ii) providing a nickel nitrate salt solution; iii) soaking the said cordierite blocks in said nickel nitrate salt solution; iii) removing the blocks from the solution and subjecting the blocks to drying such as to obtain dry blocks ready for calcinations; iv) subjecting the dry blocks to calcinations such as to reduce the nickel nitrate to nickel oxide; and v) finally, the blocks are reduced from nickel oxide content to said nickel catalyst contained structured catalyst suitable for steam reforming. Preferably, in the above process for the manufacture of structured catalyst for steam reforming of methane for production of syn gas the said nickel nitrate solution is obtained using nickel nitrate hexahydrate salt and distilled water under stirring; said blocks is dried in an oven at a temperature of 100 to 130 °C preferably 120°C for a period of 1 to 1.5 hours preferably 1 hour and then dipped again in the same nickel nitrate solution for 5 to 20 min preferably about 15 min., removed and again dried as said above; the said step of dipping and drying being repeated, if necessary, such that the blocks are ready for calcination. According to yet further aspect in the above process for the manufacture of structured catalyst for steam reforming of methane for production of syn gas the said step of calcination is carried out in a temperature controlled furnace following the steps of: placing the coated blocks in the furnace and raising the temperature to 350 to 400 °C preferably about 400 °C at a rate of 7 to 12 °C per min. preferably about 10°C per min., 9 thereafter the temperature was maintained at 350 to 400 °C preferably 400 °C for a period of 4 to 6 preferably 4 Hrs., next the temperature was increased to 550 to 650 °C preferably about 600 °C at a rate of 1 to 2 per min. preferably about 1 °C per min. , after which the blocks were allowed to cool in the furnace whereby nickel nitrate is reduced to nickel oxide and finally the blocks are reduced from nickel oxide to nickel just ahead of its use in the reformer unit using a hydrogen stream of flow rate of preferably about 40 N ml/min. Preferably, in the above process the said cordierite blocks are wash coated using sol gel process with alumina and thereafter coated with said nickel nitrate solution. Importantly following the above process of the invention, the effectiveness of the structured catalyst is selectively achieved by selective change in catalyst formulation preferably rhodium-nickel combination, increasing the surface area of the coated catalyst to provide more active sites for increased conversion and plant throughput , variation in the coating thickness to achieve higher conversions , modifying the catalyst solution preferably adding promoters selected from rhodium, ceria to the nickel nitrate solution and selecting the strength of the catalyst formulation preferably 3M or 4M solution of nickel nitrate. According to a further aspect of the invention there is disclosed a simple and cost- effective manner of the steam reforming of methane for the production of syn gas comprising carrying out the said process of steam reforming using the structured catalyst as above. In such process, a number of said structured catalysts in the form of blocks are stacked one above the other to fill the length of the reformer tube. The diameter of the structured catalyst blocks are selectively varied based on the process requirements. Preferably, in said steam reforming of methane the same is carried out preferably at a steam to methane molar ratio of 3:1 at atmospheric pressure and a temperature of 700 to 850 °C preferably about 775°C to 840°C for more than hundred hours on stream. Advantageously, the above process of steam reforming of methane for the production of syn gas of the invention involving the said selective use of catalyst provided for a conversion of > 90 % for a molar ratio of steam to methane of >2.5 and up to 7. 10 The meso-scale channeled structured catalyst (PS-CAT) consists of a number of square thin-walled rectangular channels (made of cordierite), which are coated with our formulation (or composition) of nickel based catalyst. This structured catalyst enables us to achieve higher conversion of methane to syn gas (mixture of hydrogen, carbon monoxide and carbon dioxide) in comparison with the conventional pellet-type nickel based catalysts (used in a conventional packed bed tubular reactor) under identical process conditions. The essential features of this catalyst are the meso-scaled rectangular channels with the specific coating. The coating is spread over all the channel dimensions, thus allowing a continuous contact of the gas feed with the active ingredient (nickel) of the coating formulation. Also, the contacting pattern between the feed and the wall-coated channels is such that it allows for more intimate contact. This contacting pattern is the direct result of the structured nature of the catalyst. The structured nature also causes a lower pressure drop when compared to pellet type packed (or fixed) bed reactors. The small dimension of the channels allows more coating to be applied to the walls of the cordierite blocks. More the number of channels within the same cross-sectional area (of the reformer tube) higher will be the catalyst loading. This allows us to feed more methane to the same tubular reformer when compared to a tube packed with a pellet type catalyst. Increasing the feed rate with increased conversion results in increased throughput of the reformer unit without any change in the equipment (reactor) used in the earlier process. Figures 1 and 2 included in this document demonstrate the contacting flow pattern and the arrangement of the channels of PS-CAT. Possible alternatives to increase the effectiveness of PS-CAT include a change in the coating formulation which is applied to the cordierite blocks. The coating can be applied such that we can increase the specific surface area of the structured catalyst by using a porous material like alumina sol and a binder for the same. More surface area means more sites for reaction increasing the conversion within thermodynamic limits and consequently the plant throughput for identical process conditions. The coating thickness can be manipulated to obtain higher conversions. This however is an active field of research, and work is underway across the globe on some of these cptional characteristics. Possible alternatives to increase the effectiveness of PS-CAT include a change in the coating formulation (different active ingredient like rhodium-nickel combination) which is applied to the cordierite blocks. The coating can be applied such that we can increase the specific surface area of the structured catalyst by using a porous material like 11 alumina sol and a binder for the same. More surface area means more active sites for reaction, thereby increasing the conversion within thermodynamic limits, and consequently the plant throughput for identical process conditions. The coating thickness can be manipulated to obtain higher conversions. This however is an active field of research, and work is underway across the globe on some of these optional characteristics. Thus, a change in the coating formulation and the coating procedure can significantly change the effectiveness of PS-CAT. The cordierite blocks can be wash coated using a sol gel process with alumins and then coated with the nickel nitrate solution. The strength of the nickel nitrate solution can be increased to 3M or 4M. This will result in a thicker coating on the surface of the cordierite blocks. But the solution is much denser hence the penetration of the solution inside the pores of the cordierite block will be limited. Nickel nitrate solution can be modified by adding promoters such as rhodium, ceria, etc. Nickel nitrate solution can be completely replaced by the solution of a nitrate salt of another transition metal such as copper, zinc or a noble metal such as rhodium, platinum and palladium. The use of noble metals is however, expensive. Details of the invention, its objects and advantages are explained hereunder in greater detail in relation to non-limiting exemplary illustration of the meso-channeled structured catalyst of the invention and its beneficial use in steam reforming of methane for production of syn gas with reference to the following accompanying figures:- BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES: Figure 1: is a typical schematic illustration of a meso-channeled structured monolith catalyst and further illustrates its ready disposition in a reactor tube for steam reforming; Figure 2: is a schematic illustration of a 4-channeled coated PS-CAT in accordance with the present invention; Figure 3(a) and 3(b): illustrate the structured flow through the PS-CAT of the present invention and the irregular flow through a packed bed of pellet type catalyst respectively; 12 Figure 4: illustrates the product gas composition of the exit gases when PS-CAT comprising of 4-channels (5 blocks) in series under conditions feed to steam molar ratio = 1:3, W/F = 56 gm-cat/min-mol, pressure = 1 atm and temperature = 775°C; and Figure 5: illustrates the product gas composition of the exit gases when PS-CAT comprising of 4-channels (5 blocks) under conditions of feed to steam molar ratio = 1:3, W/F = 56 gm-cat/min-mol, pressure = 1 atm, temperature = 840°C. DETAILED DESCRIPTION OF THE ACCOMPANYING FIGURES: References is invited to accompanying figures 1 to 2 which shows the PS-CAT according to the invention for steam reforming process involving the meso-channeled structured catalyst. As clearly apparent from said Figures 1 & 2, in case of the meso-channeled structured PS-CAT of the invention the gas flow is distributed in the channels at the inlet of the reformer tube and then the gas flows through the entire straight length of the channel without changing its direction till it reaches the bottom of the reformer tubes. Such possible straight line flow of gas through the structured catalyst of the invention is further illustrated in accompanying Figure 3(a) in such straight path flow of gas in the meso-channeled structured catalyst; there is lesser drop in pressure energy which in turn favour higher feed rate and conversion. The advantages of such structured catalyst vis-a-vis the conventional catalyst for such steam reforming which are usually in the form of cylindrical pellets, tablets and spheres can be appreciated further in relation to Figures 3(a) and 3(b). As would be apparent from Figure 3(b), in case of conventional catalyst the same are available in the form of cylindrical pellets, tablets and spheres and are simply dumped in the reformer tube. The catalyst pellets in such case assume random disposition in the reformer tube and cannot contribute to a define structure to the bed. There is no structure to the bed as a whole and it can be imagined as a bed containing large number of convoluted or tortuous paths through which the feed gas is required to flow. As the gas flows through such tortuous paths provided by such conventional catalyst in reformer tubes, there is an increased pressure drop relative to the pathway (channelised) provided by the structured catalyst of the invention. Thus, due to the presence of the tortuous path in the conventional catalyst as shown in Figure 3(b), the gas has to constantly 13 change its direction of flow with the changing direction causing it to loose part of its energy due to the change in its flow paths. As a consequence, there is a drop in the pressure energy of the gas as the flow of gas is largely pressure driven. On the other hand, in case of the meso-channeled structured PS-CAT of the invention as shown in Figure 3(a), the gas flow is distributed in the channels at the inlet of the reformer tube and then the gas follows through entire straight length of the channel without changing its directions till it reaches the bottom of the reformer tube. Thus, there is no change in direction of the gas flow after the initial gas distribution. So, relative to the conventional fixed bed catalyst, in the structured catalyst of the invention there is a lesser drop in pressure energy. Simultaneously, as the channel size is small and channels are coated with active nickel coating, the gas comes in intimate contact with the catalyst and this results in the substantial increase in conversion. Therefore, under identical process conditions, the structured catalyst of the invention can be fed more methane to the same reformer tube as the conversion is substantially more and thus favours increasing the throughput or plant capacity using the same infrastructure to produce more syn gas. An exemplary process for the manufacture of the structured catalyst PS-CAT and the coating procedure followed are further illustrated hereunder by way of the following example. EXAMPLE I: Manufacture of catalyst: PS-CAT Coating Procedure The cordierite blocks (100 cpsi) were procured from a reputed manufacturer from the open market, cleaned, and cut to desired sizes as per our reactor tube dimensions. Each block was weighed before being dipped into the solution, and after the calcination, to find out the amount of catalyst (nickel oxide) loading on the block. 2M solution of nickel nitrate was prepared using nickel nitrate hexahydrate salt and distilled water. The solution was stirred using a magnetic stirrer for 15 minutes to completely dissolve the nickel nitrate in water. Clean dust-free cordierite blocks were then soaked in this solution for three hours. This is a modification of the conventional dip coating or wall coating procedure and allows for higher soaking or loading of nickel nitrate on the cordierite blocks. The blocks were then removed from the solution and the excess liquid from the wet blocks was removed by blowing air using an air blower. The blocks were dried in an oven at a temperature of 120 °C for one hour. The blocks were 14 then dipped again in the same nickel nitrate solution for 15 minutes, removed and dried in the oven at 120 °C for one hour. These last two steps were repeated once more to obtain dry blocks ready for calcination. Calcination of the blocks was carried out in a temperature controlled furnace using a specific procedure. The coated blocks were placed in the furnace and the temperature was raised to 400 °C at a rate of 10 °C per minute. Then the temperature was maintained at 400 °C for 4 hours. The temperature was then increased to 600 °C at a rate of 1°C per minute. The blocks were then allowed to cool in the furnace. The high temperature calcination reduces the nickel nitrate to nickel oxide. There is a visible change in colour from green to steel grey when the blocks are finally removed from the furnace. The blocks are reduced (from nickel oxide to nickel) just before use in the steam reformer unit using a hydrogen stream of flow rate 40 N ml/minute. The thus manufactured structured catalyst of the invention was further identified to have the following preferred selective features: Physical Dimensions (Macrostructure) Raw substrate : CORDIERITE (ceramic) Specification : 100 cpsi (cells per square inch) Wall Thickness: ~270 microns (average) Cell dimension: 1500 x 1500 microns BET surface area Uncoated (raw) cordierite substrates : 0.72 m2/g Coated substrate- PS-CAT : 0.49 m2/g Used (post-run) PS-CAT : 0.18 m2/g EDS- X-Ray (Energy Dispersive Spectroscopic X ray Analysis) Composition Nickel Oxide content: ~8.5% 15 Catalyst loading Nickel Oxide Loading: ~ 3-10% The structured catalysts obtained in accordance with the present invention were further tested in steam reforming of methane as further detailed hereunder:- EXAMPLE II: The structured catalysts obtained according to the invention were extensively tested for steam reforming of methane at a steam to methane molar ratio of 3:1 at atmospheric pressure and a temperature of 775 ° C and 840 ° C for a long duration of time (more than hundred hours on stream). The resulting exit gas composition have been analysed and the results of the same have been plotted in the form of graphs with the process conditions as illustrated under accompanying Figures 4 and 5. The conversion of methane (feed hydrocarbon) observed with the said conditions (feed to steam molar ratio of 1:3, W/F of 56 gm-cat/min-mol, pressure of 1 atm, and temperatures of 775 °C and 840°C ) using PS-CAT is > 97 %. At similar conditions (feed to steam molar ratio of 1:3, W/F of 56 gm-cat/min-mol, pressure of 1 atm, and temperatures of 775 °C), when a commercial nickel based steam reforming catalyst was tested for steam reforming of methane in a 6 mm packed bed reactor the conversion observed was only 79.73%. In both these cases, (for the 4-channeled PS-CAT and the commercial nickel based catalyst), the same reactor tube of 6 mm inner diameter was used. The peripheral pumps, steam generator and the measurement devices were identical in all three cases compared. Range of Parameters for which the above advantages residing in the provision of structured catalyst remain valid preferably include: Temperature The catalyst exhibits a conversion (of methane) of > 90% for a temperature above 700 °C. The catalyst shows nearly complete conversion (> 98 %) of methane at a temperature above 775 °C. 16 Other Parameters W/F CH4 ~ 55.0 gm-cat min/mol Molar Ratio (CH4:H2O) ~ 3.0 Space-time fW/F CH* ratio! The catalyst exhibits a conversion of > 90% for a W/F CH4 ratio above 37.3 gm-cat min/mol for temperature above 650 °C Time-on-stream The catalyst has been extensively tested for more than hundred hours on-stream at a steam to methane molar ratio of 3:1, atmospheric pressure, temperature of 775 ° C, and W/F CH4 ~ 56 gm-cat min/mol. It was found to perform consistently giving an average conversion of ~ 97-98%. Molar Ratio of Steam to Methane The catalyst shows good conversion (> 90%) of methane for a molar ratio of steam to methane of > 2.5 and up to 7. The best results (methane conversion > 97%) are for a molar ratio of steam to methane between 2.5 and 4. EXAMPLE III: The performance of the present steam reforming catalyst PS-CAT of the invention was further compared with the performance of a commercial Nickel-Alumina-Magnesia catalyst. The commercial available catalyst (RKNGR catalyst) was used for such purpose. This catalyst was crushed to 1 mm particle size and tested with the same feed, namely, methane at the same flow rate and molar ratio of steam to hydrocarbon. The conversion of methane using PS-CAT was nearly 20 % more than the conversion of methane obtained by using the commercial catalyst. The details of the experimental runs are tabulated in Table 1. 17 Table 1: Experimental details of the comparison run It is thus found by way of the development of the structured catalyst of the invention that the base structure (the cordierite block) plays the role of providing a solid structure to the catalyst coating and also importantly the straight length flow of the gas through the catalyst structure. Moreover, the selective contact surface based on the selective catalyst coating predominantly controlled the gas reforming process. When an uncoated cordierite block was tested for steam reforming of methane, only about 20% conversion of methane was obtained at a temperature of 775 °C and identical flow rate. This conversion was attributed to thermal cracking of the feed methane at this temperature. Thus, the superior performance using PS-CAT is clearly due to the combination of the catalyst coating and the catalyst structured. The cordierite structure, favours for the uninterrupted flow pattern developed and the resultant lower pressure drop while the conversion of methane being predominantly due to the catalyst coating. Importantly, the catalyst according to the invention has a structured shape and is not irregular. The illustrations provided hereinbefore clearly show the regular and straight nature of the square channels of the structured catalyst of the invention vis-a-vis the irregular channels formed in case of the packed bed catalyst used conventionally in the steam reforming process. 18 It is thus possible by way of the present invention to provide for the development of a catalyst suitable for steam reforming of methane and targeted to improve the conversion of feed (methane) and more importantly using the steam reforming processes and existing available plant infrastructure. Thus the developed meso-channeled structured (PS-CAT) is found to be most effective in the process of reforming of methane for the production of syn gas. Importantly, the developed meso-channeled structured PS-CAT catalyst achieve catalyst loading of 3-10% for steam reforming of methane which in turn favour good conversion (>90%) of methane for a molar ratio of steam to methane of 2.5 to up to 7 which would favour beneficial and cost-effective steam reforming of methane gas for the production of syn gas. 19 WE CLAIM: 1. A structured catalyst for steam reforming of methane for production of syn gas comprising: a meso scaled channeled structure obtained of cordierite with selective catalyst coating spread over the channel dimensions adapted to favour continuous and intimate contact of the gas feed with the active catalyst content of the coating for increased feed rate and conversion under said steam reforming. 2. A structured catalyst for steam reforming of methane for production of syn gas comprising: meso-scale channeled structured catalyst (PS-CAT) comprising a plurality of square thin-walled rectangular channels obtained of cordierite coated with a selective transition metal or noble metal based catalyst formulation, said coating spread over the all the channel dimensions adapted to favour continuous and intimate contact of the gas feed with the active content of the coating for increased feed rate and conversion under said steam reforming. 3. A structured catalyst for steam reforming of methane for production of syn gas comprising: meso-scale channeled structured catalyst (PS-CAT) comprising a plurality of square thin-walled rectangular channels obtained of cordierite coated with a selective transition metal or noble metal based catalyst formulation , said coating spread over the all the channel dimensions having porous material for increased surface area and adapted to favour continuous and intimate contact of the gas feed with the active content of the coating for increased feed rate and conversion under said steam reforming. 4. A structured catalyst for steam reforming of methane for production of syn gas as claimed in anyone of claims 1 to 3 wherein said selective catalyst is obtained of a nitrate salt of a transition or noble metal. 5. A structured catalyst for steam reforming of methane for production of syn gas as claimed in claim 4 wherein said selective catalyst is selectively obtained of nickel nitrate solution, nitrate salt of another transition metal preferably copper, zinc or any noble metal preferably rhodium, platinum and palladium. 20 6. A structured catalyst for steam reforming of methane for production of syn gas as claimed in anyone of claims 3 to 5 wherein said porous material coating comprises alumina sol and a binder. 7. A structured catalyst for steam reforming of methane for production of syn gas as claimed in anyone of claims 1 to 6 wherein said the effectiveness of the structured catalyst is selectively achieved by selective change in catalyst formulation preferably rhodium-nickel combination, increasing the surface area of the coated catalyst to provide more active sites for increased conversion and plant throughput and variation in the coating thickness to achieve higher conversions. 8. A structured catalyst for steam reforming of methane for production of syn gas as claimed in anyone of claims 1 to 7 comprising: Macrostructure obtained of Cordierite (ceramic), specifications 100 to 400 cpsi preferably about 100 cpsi (cells per square inch), wall thickness 50 to 300 microns preferably about 270 microns (average) and cell dimension 500 X 500 microns to 2000 X 2000 microns preferably 1500 X 1500 microns; BET surface area comprising uncoated (raw) cordierite substrate 0.5 to 20 m2/g preferably about 0.72 m2/g, coated substrate (PS-CAT) 0.25 to 15 m2/g preferably about 0.49 m2/g;and Catalyst loading of Nickel Oxide in the range of 3 to 10%. 9. A process for the manufacture of structured catalyst for steam reforming of methane for production of syn gas as claimed in anyone of claims 1 to 8 comprising: i) providing cordierite blocks; ii) providing a nitrate salt solution of a transition metal or a noble metal; iii) soaking the said cordierite blocks in said nitrate salt solution; iii) removing the blocks from the solution and subjecting the blocks to drying such as to obtain dry blocks ready for calcination; iv) subjecting the dry blocks to calcinations such as to reduce the metal nitrate to metal oxide; and 21 v) finally, the blocks are reduced from metal oxide content to said metal catalyst contained structured catalyst suitable for steam reforming. 10. A process for the manufacture of structured catalyst for steam reforming of methane for production of syn gas as claimed in claim 8 comprising: i) providing cordierite blocks; ii) providing a nickel nitrate salt solution; iii) soaking the said cordierite blocks in said nickel nitrate salt solution; iii) removing the blocks from the solution and subjecting the blocks to drying such as to obtain dry blocks ready for calcination; iv) subjecting the dry blocks to calcination such as to reduce the nickel nitrate to nickel oxide; and v) finally, the blocks are reduced from nickel oxide content to said nickel catalyst contained structured catalyst suitable for steam reforming. 11. A process for the manufacture of structured catalyst for steam reforming of methane for production of syn gas as claimed in claim 10 wherein said nickel nitrate solution was obtained using nickel nitrate hexahydrate salt and distilled water under stirring; said blocks were dried in an oven at a temperature of 100 to 130 °C preferably 120°C for a period of 1 to 1.5 hours preferably 1 hour and then dipped again in the same nickel nitrate solution for 5 to 20 min preferably about 15 min., removed and again dried as said above ; the said step of dipping and drying being repeated, if necessary, such that the blocks are ready for calcination. 12. A process for the manufacture of structured catalyst for steam reforming of methane for production of syn gas as claimed in claim 11 wherein said step of calcinations is carried out in a temperature controlled furnace following the steps of: 22 placing the coated blocks in the furnace and raising the temperature to 350 to 450 °C preferably about 400 °C at a rate of 7 to 12 °C per min. preferably about 10°C per min., thereafter the temperature was maintained at 350 to 450 preferably 400 °C for a period of 4 to 6 preferably 4 Hrs., next the temperature was increased to 550 to 650 °C preferably about 600 °C at a rate of 1 to 2 ° per min. preferably about 1 °C per min. , allowing the blocks to cool in the furnace whereby nickel nitrate is reduced to nickel oxide and finally the blocks are reduced from nickel oxide to nickel just ahead of its use in the reformer unit using a hydrogen stream of flow rate of preferably about 40 ml/min. 13. A process for the manufacture of structured catalyst for steam reforming of methane for production of syn gas as claimed in anyone of claims 9 to 12 wherein said cordierite blocks are wash coated using sol gel process with alumina and thereafter coated with said nickel nitrate solution. 14. A process for the manufacture of structured catalyst for steam reforming of methane for production of syn gas as claimed in anyone of claims 9 to 13 wherein said the effectiveness of the structured catalyst is selectively achieved by selective change in catalyst formulation preferably rhodium-nickel combination, increasing the surface area of the coated catalyst to provide more active sites for increased conversion and plant throughput , variation in the coating thickness to achieve higher conversions , modifying the catalyst solution preferably adding promoters selected from rhodium, ceria to the nickel nitrate solution and selecting the strength of the catalyst formulation preferably 3M or 4M solution of nickel nitrate. 15. A process for the steam reforming of methane for the production of syn gas comprising carrying out the said process of steam reforming using the structured catalyst as claimed in anyone of claims 1 to 8. 16. A process for the steam reforming of methane for the production of syn gas as claimed in claim 15 wherein a number of said structured catalysts in the form of blocks are stacked one above the other to fill the length of the reformer tube. 17. A process for the steam reforming of methane for the production of syn gas as claimed in anyone of claims 15 or 16 wherein said steam reforming of methane 23 is carried out at a steam to methane molar ratio of 3:1 at atmospheric pressure and a temperature of 700 to 850 °C preferably about 775°C to 840°C for more than hundred hours on stream. 18. A process for the steam reforming of methane for the production of syn gas as claimed in anyone of claims 15 to 17 wherein the said selective use of catalyst provided for a conversion of > 90 % for a molar ratio of steam to methane of >2.5 and up to 7. 24 19. A process for the steam reforming of methane for the production of syn gas as claimed in anyone of claims 15 to 18 wherein the diameter of the structured catalyst blocks are selectively varied based on the process requirements. 20. A structured catalyst for steam reforming of methane for production of syn gas, its process of manufacture and a process for the steam reforming of methane for the production of syn gas using the said structured catalyst substantially as herein described and illustrated with reference to the accompanying examples and figures. The present invention relates to steam reforming of methane for production of syn gas and, in particular, to a meso-scale channeled structured catalyst (PS-CAT) comprising a plurality of square thin-walled rectangular channels obtained of cordierite coated with a selective transition metal or noble metal based catalyst formulation adapted to favour continuous and intimate contact of gas feed with the active catalyst with improve feed rate and conversion in steam reforming. Advantageously, the structured catalyst functionally favour ready use in conventional reformer tubes used in steam reforming for increased conversion to syn gas. The meso-structured catalyst achieve good conversion > 90% of methane for a molar ratio of steam to methane of >2.5 and up to 7 and steam reforming of methane is carried out preferably at a steam to methane molar ratio of 3:1 at atmospheric pressure and a temperature of 700 to 850 °C preferably about 775°C to 840°C for more than hundred hours on stream and is directed to favour wide scale application and use as a beneficial catalyst in steam reforming of methane for production of syn gas.

Full Text

FIELD OF THE INVENTION
The present invention relates to steam reforming of methane for production of syn gas
and, in particular, to a structured catalyst for steam reforming of methane for production
of syn gas. Importantly, the structured catalyst involving selective catalyst coating is
adapted to favour continuous and intimate contact of gas feed with the active catalyst
and is directed to improve feed rate and conversion under steam reforming.
Advantageously, the structured catalyst is developed such as to favour ready use in
conventional reformer tubes used in steam reforming for increased conversion or
processing capacity of the steam reforming plant. Importantly, the structured catalyst of
the invention achieve good conversion > 90% of methane for a molar ratio of steam to
methane of >2.5 and up to 7 and is directed to favour wide scale application and use as
a beneficial catalyst in steam reforming of methane for production of syn gas.
BACKGROUND ART
Catalytic steam reforming of hydrocarbons, alcohols, and light oil fractions involves the
reaction of steam with methane, ethane, natural gas, LPG, naphtha, gasoline, alcohols
such as methanol, ethanol, propanol over catalysts at elevated temperatures (200-900
°C) and elevated pressures (1-30 atm) to produce syn gas which is a mixture of
hydrogen, carbon monoxide and carbon dioxide. The technology has matured over the
years. However, still the major concerns are the endothermic nature of the reactions
making the process energy intensive, and coke formation that results in catalyst
deactivation. Work is still in progress to use lower or more ambient operating
parameters, and to minimise coke formation thereby increasing catalyst life and hence
reducing reformer down time. It is reported that 90% of hydrogen generated today is
produced by the steam reforming of natural gas and light oil fractions. The major reason
for this is the commercial viability of such plants by which hydrogen can be produced at
$2.11/kg of H2. This is by far the most energy efficient process available in comparison
to other processes like, carbon dioxide reforming, coal gasification, pyrolysis, water
electrolysis and photobiochemical techniques. Recent trends in industries like Chevron
Texaco have shown an increased use of processes such as partial oxidation or the
energy-neutral autothermal process, both of which are modifications of the basic steam
reforming process. In these processes, either oxygen (air) and / or steam in different
ratios are added to the feed during operation of the steam reformer unit.
2

The reactions occurring during the steam reforming process are as given by equations
(1) through (4):

The conventional, bulk, steam methane reforming (SMR) system for hydrogen production
is composed of a steam reformer, a shift converter, and a hydrogen purifier based on the
pressure swing adsorption (PSA) or membrane separation unit. A mixture of natural gas
and steam is introduced into a catalyst bed in the steam reformer, where the steam
reforming reaction proceeds on nickel-based catalyst at 700-800°C. The reformed gas
is supplied to a shift converter, where carbon monoxide is converted into carbon dioxide
to produce more hydrogen by the shift reaction. Next the reformed gas is passed to PSA
unit to separate hydrogen. Nickel possesses hydrogenation activity but limited water gas
shift activity. It is a low-cost but effective catalyst for cleavage of O—H, —CH2—, —C—
C— and —CH3 bonds. It is these properties that make nickel a favourable choice as a
steam reforming catalyst. The use of the catalyst is to reduce the temperature of
operation and to increase the conversion of the feed hydrocarbon.
A typical steam reformer unit consists of a reformer block containing 40 to 400 tubes of
height 6 to 12 metres having an inner diameter of 0.7 to 0.16 m and a thickness of 0.01
to 0.02 m. The tubes are generally made of high alloy nickel chromium steel. As the
process is endothermic, the required heat needs to be supplied to the reformer unit. The
tubes can be heated externally or internally. In external heating, part of the reed is
combusted outside the reformer tube to reach the desired reaction temperature. In
internal heating part of the feed is combusted inside the tube of the reformer. This latter
3

process is known as partial oxidation or autothermal reforming depending on the energy
supplied to the process. Conventional catalysts are available in the form of cylindrical
pellets, tablets and spheres and are simply dumped in the reformer tube. This is called
as a conventional fixed bed or packed bed reformer. The catalyst pellets are randomly
placed in the reformer tube and so do not contribute to a defined structure to the bed.
There is no structure to the bed as a whole and it can imagined as a bed containing a
large number of convoluted or tortuous paths through which the feed gas flows. The
quantity of catalyst and its composition is determined on the basis of the feed quantity
and quality or composition. The role of the catalyst is to achieve maximum possible
conversion of the feed to syn gas, a constant pressure drop and to have sufficient
mechanical and thermal strength to provide a long process cycle.
Conventionally, in all fertiliser plants, supported nickel catalysts are used. The support is
generally silica, alumina, and/or magnesia. The properties of the catalyst are further
modified by addition of components like, calcium oxide, aluminium, molybdenum, special
carbides, zirconia, ceria, other alkali earth metals like potassium, etc. to make the
catalyst coke resistant, and to increase its mechanical and thermal strength. Effect of
promoters such as Cu, La, Mo, Ca, Ce, Y, K, Cr, Mg, Mn, Sn, V, Rh, Pd, and their
combinations have been used for improving the stability of Ni catalysts supported on
alumina for steam methane reforming. Recently, the use of platinum, rhodium, and
palladium, along with nickel has also been reported. However, industrial catalysts are
usually nickel based catalysts. The most commonly used catalysts are nickel-alumina,
nickel-alumina-magnesia, nickel-magnesia, etc. The percentage of nickel varies from
as low as 3 % to as high as 52% by weight. Nickel possesses hydrogenation activity but
limited water gas shift activity. It is a low-cost but effective catalyst for cleavage of 0—
H, —CH2—, —C—C— and —CH3 bonds. It is these properties that make nickel a
favourable choice as a steam reforming catalyst. However, nickel alone cannot be used
as a steam reforming catalyst due to its limited water gas shift activity. In order to
exploit this secondary reaction, nickel or other metal catalysts are coupled (or supported
on) with another metal oxide such as alumina or magnesia. Conventional catalysts are
available in the form of cylindrical pellets, tablets, and spheres, and are simply dumped
in the reformer tube. The catalyst pellets are randomly placed in the reformer tube and
so do not contribute to a defined structure to the bed. There is no structure to the bed
as a whole and it can imagined as a bed containing a large number of convoluted or
tortuous paths through which the feed gas flows. As the gas flows through the path,
there is an increased pressure drop (relative to the use of structured catalysts). The
4

conversion of the feed is also less at identical process conditions of temperature, molar
ratio of steam to methane and feed flow rate (residence time).
OBJECTS OF THE INVENTION
It is thus the basic object of the present invention to provide for the development of a
catalyst suitable for steam reforming of methane which is targeted to improve the
conversion of feed (methane) while using the steam reforming processes and existing
available plant infrastructure.
Another object of the present invention is directed to provide for the development of
structured catalyst useful for steam reforming of methane which can be readily used in
place of currently used industrial catalyst and would provide increased conversion in
comparison to the existing commercial nickel based catalyst at identical process
conditions.
A further object of the present invention is directed to the development of a catalyst for
steam reforming of methane which would not involve any change in the reformer tube
design and can be used with conventional reformer tubes to achieve increased
conversion/throughput.
A further object of the present invention is directed to the development of a catalyst
suitable for steam reforming of methane, which would achieve increased conversion and
therefore enable higher flow rate of the feed relative to that achieved with existing
commercial catalyst at the same molar ratio of steam to hydrocarbon feed and
temperature.
Yet another object of the present invention is directed to the development of a structured
catalyst involving selective combination of basic structure and coating catalyst
formulation directed to achieve improved feed conversion and thereby make steam
reforming of methane beneficial and cost effective.
A further object of the present invention is directed to the development of a structured
catalyst involving selective combination of basic structure and coating formulation with
selective coating procedure which would enable achieving increased specific surface area
of structured catalyst and thereby favour providing for more sites for reaction and jn the
5

process increase the conversion within the thermodynamic limits and consequently
achieve higher plant throughput for identical process conditions.
A further object of the present invention is directed to the development of a meso-
channeled structured (PS-CAT) which would be most effective in the process of reforming
of methane for the production of syn gas.
Another object of the present invention is directed to the development of meso-scale
channeled structured catalyst adapted to favour achieving lower pressure drop as
compare to pellet type packed (or fixed) bed reactor involving selective dimension of
channels to further favour improved catalyst coating with higher catalyst loading to
enable feeding more methane to the same tubular reformer as compared to the tube
packed with pellet type catalyst.
Yet another object of the present invention is directed to the development meso-
channeled structured PS-CAT catalyst wherein the gas flow would be distributed in the
channels at inlet of the reformer tube and thereafter follow through the entire straight
length of the channel without changing its direction till reaching the bottom of the
reformer tube, thereby achieving desired lesser drop in pressure energy and favouring
selective use of channel dimension for effective catalyst loading for desired intimate
contact of gas with catalyst and resulting increased conversion.
Another object of the present invention is directed to the development of meso-
channeled structured PS-CAT catalyst involving catalyst loading of 3-10% for steam
reforming of methane which would achieve good conversion (>90%) of methane for a
molar ratio of steam to methane of 2.5 to up to 7.
A further object of the present invention is directed to a simple and cost effective manner
of production of syn gas involving steam reforming of methane using a meso-channeled
structured PS-CAT catalyst favouring improved conversion and throughput which would
beneficially favour achieving better conversion efficiency of methane to generate syn gas
through conventional reformer units.
6

SUMMARY OF THE INVENTION
Thus according to the basic aspect of the invention there is provided a structured catalyst
for steam reforming of methane for production of syn gas comprising:
A meso scaled channeled structure obtained of cordierite with selective catalyst coating
spread over the channel dimensions adapted to favour continuous and intimate contact of
the gas feed with the active catalyst content of the coating for increased feed rate and
conversion under said steam reforming.
According to another aspect of the invention there is provided a structured catalyst for
steam reforming of methane for production of syn gas comprising:
meso-scale channeled structured catalyst (PS-CAT) comprising a plurality of square thin-
walled rectangular channels obtained of cordierite coated with a selective transition metal
or noble metal based catalyst formulation, said coating spread over the all the channel
dimensions adapted to favour continuous and intimate contact of the gas feed with the
active content of the coating for increased feed rate and conversion under said steam
reforming.
According to yet further aspect of the invention there is provided a structured catalyst for
steam reforming of methane for production of syn gas comprising:
meso-scale channeled structured catalyst (PS-CAT) comprising a plurality of square thin-
walled rectangular channels obtained of cordierite coated with a selective transition metal
or noble metal based catalyst formulation , said coating spread over the all the channel
dimensions having porous material for increased surface area and adapted to favour
continuous and intimate contact of the gas feed with the active content of the coating
for increased feed rate and conversion under said steam reforming.
In the above disclosed structured catalyst for steam reforming of methane for
production of syn gas of the invention, the said selective catalyst is obtained of a nitrate
salt of a transition or noble metal.
In accordance with a preferred aspect, the said selective catalyst is selectively obtained
of nickel nitrate solution, nitrate salt of another transition metal preferably copper, zinc
or any noble metal preferably rhodium, platinum and palladium.
7

According to a further preferred aspect the structured catalyst for steam reforming of
methane for production of syn gas comprises porous material coating comprises alumina
sol and a binder.
Importantly, the effectiveness of the structured catalyst is selectively achieved by
selective change in catalyst formulation preferably rhodium-nickel combination,
increasing the surface area of the coated catalyst to provide more active sites for
increased conversion and plant throughput and variation in the coating thickness to
achieve higher conversions.
In accordance with an aspect of the invention, the structured catalyst for steam
reforming of methane for production of syn gas comprises:
Macrostructure obtained of Cordierite (ceramic), specifications 100 to 400 cpsi preferably
about 100 cpsi (cells per square inch), wall thickness 50 to 300 microns preferably about
270 microns (average) and cell dimension 500 X 500 microns to 2000 X 2000 microns
preferably 1500 X 1500 microns;
BET surface area comprising uncoated (raw) cordierite substrate 0.5 to 20 m2/g
preferably about 0.72 m2/g/ coated substrate (PS-CAT) 0.25 to 15 m2/g preferably about
0.49 m2/g;and
Catalyst loading of Nickel Oxide in the range of 3 to 10%.
According to yet another aspect of the invention there is provided a process for the
manufacture of structured catalyst for steam reforming of methane for production of syn
gas comprising:
i) Providing cordierite blocks;
ii) Providing a nitrate salt solution of a transition metal or a noble metal;
iii) Soaking the said cordierite blocks in said nitrate salt solution;
iv) Removing the blocks from the solution and subjecting the blocks to drying such as
to obtain dry blocks ready for calcination;
8

v) Subjecting the dry blocks to calcination such as to reduce the metal nitrate to metal
oxide; and
v) finally, the blocks are reduced from metal oxide content to said metal catalyst
contained structured catalyst suitable for steam reforming.
In accordance with a preferred aspect the above process for the manufacture of
structured catalyst for steam reforming of methane for production of syn gas comprises:
i) providing cordierite blocks;
ii) providing a nickel nitrate salt solution;
iii) soaking the said cordierite blocks in said nickel nitrate salt solution;
iii) removing the blocks from the solution and subjecting the blocks to drying such as
to obtain dry blocks ready for calcinations;
iv) subjecting the dry blocks to calcinations such as to reduce the nickel nitrate to
nickel oxide; and
v) finally, the blocks are reduced from nickel oxide content to said nickel catalyst
contained structured catalyst suitable for steam reforming.
Preferably, in the above process for the manufacture of structured catalyst for steam
reforming of methane for production of syn gas the said nickel nitrate solution is obtained
using nickel nitrate hexahydrate salt and distilled water under stirring;
said blocks is dried in an oven at a temperature of 100 to 130 °C preferably 120°C for a
period of 1 to 1.5 hours preferably 1 hour and then dipped again in the same nickel
nitrate solution for 5 to 20 min preferably about 15 min., removed and again dried as
said above; the said step of dipping and drying being repeated, if necessary, such that
the blocks are ready for calcination.
According to yet further aspect in the above process for the manufacture of structured
catalyst for steam reforming of methane for production of syn gas the said step of
calcination is carried out in a temperature controlled furnace following the steps of:
placing the coated blocks in the furnace and raising the temperature to 350 to 400 °C
preferably about 400 °C at a rate of 7 to 12 °C per min. preferably about 10°C per min.,
9

thereafter the temperature was maintained at 350 to 400 °C preferably 400 °C for a
period of 4 to 6 preferably 4 Hrs., next the temperature was increased to 550 to 650 °C
preferably about 600 °C at a rate of 1 to 2 per min. preferably about 1 °C per min. , after
which the blocks were allowed to cool in the furnace whereby nickel nitrate is reduced to
nickel oxide and finally the blocks are reduced from nickel oxide to nickel just ahead of
its use in the reformer unit using a hydrogen stream of flow rate of preferably about 40 N
ml/min.
Preferably, in the above process the said cordierite blocks are wash coated using sol gel
process with alumina and thereafter coated with said nickel nitrate solution.
Importantly following the above process of the invention, the effectiveness of the
structured catalyst is selectively achieved by selective change in catalyst formulation
preferably rhodium-nickel combination, increasing the surface area of the coated catalyst
to provide more active sites for increased conversion and plant throughput , variation in
the coating thickness to achieve higher conversions , modifying the catalyst solution
preferably adding promoters selected from rhodium, ceria to the nickel nitrate solution
and selecting the strength of the catalyst formulation preferably 3M or 4M solution of
nickel nitrate.
According to a further aspect of the invention there is disclosed a simple and cost-
effective manner of the steam reforming of methane for the production of syn gas
comprising carrying out the said process of steam reforming using the structured
catalyst as above. In such process, a number of said structured catalysts in the form of
blocks are stacked one above the other to fill the length of the reformer tube. The
diameter of the structured catalyst blocks are selectively varied based on the process
requirements.
Preferably, in said steam reforming of methane the same is carried out preferably at a
steam to methane molar ratio of 3:1 at atmospheric pressure and a temperature of 700
to 850 °C preferably about 775°C to 840°C for more than hundred hours on stream.
Advantageously, the above process of steam reforming of methane for the production of
syn gas of the invention involving the said selective use of catalyst provided for a
conversion of > 90 % for a molar ratio of steam to methane of >2.5 and up to 7.
10

The meso-scale channeled structured catalyst (PS-CAT) consists of a number of square
thin-walled rectangular channels (made of cordierite), which are coated with our
formulation (or composition) of nickel based catalyst. This structured catalyst enables us
to achieve higher conversion of methane to syn gas (mixture of hydrogen, carbon
monoxide and carbon dioxide) in comparison with the conventional pellet-type nickel
based catalysts (used in a conventional packed bed tubular reactor) under identical
process conditions. The essential features of this catalyst are the meso-scaled
rectangular channels with the specific coating. The coating is spread over all the channel
dimensions, thus allowing a continuous contact of the gas feed with the active ingredient
(nickel) of the coating formulation. Also, the contacting pattern between the feed and
the wall-coated channels is such that it allows for more intimate contact. This
contacting pattern is the direct result of the structured nature of the catalyst. The
structured nature also causes a lower pressure drop when compared to pellet type
packed (or fixed) bed reactors. The small dimension of the channels allows more coating
to be applied to the walls of the cordierite blocks. More the number of channels within
the same cross-sectional area (of the reformer tube) higher will be the catalyst loading.
This allows us to feed more methane to the same tubular reformer when compared to a
tube packed with a pellet type catalyst. Increasing the feed rate with increased
conversion results in increased throughput of the reformer unit without any change in the
equipment (reactor) used in the earlier process. Figures 1 and 2 included in this
document demonstrate the contacting flow pattern and the arrangement of the channels
of PS-CAT.
Possible alternatives to increase the effectiveness of PS-CAT include a change in the
coating formulation which is applied to the cordierite blocks. The coating can be applied
such that we can increase the specific surface area of the structured catalyst by using a
porous material like alumina sol and a binder for the same. More surface area means
more sites for reaction increasing the conversion within thermodynamic limits and
consequently the plant throughput for identical process conditions. The coating thickness
can be manipulated to obtain higher conversions. This however is an active field of
research, and work is underway across the globe on some of these cptional
characteristics.
Possible alternatives to increase the effectiveness of PS-CAT include a change in the
coating formulation (different active ingredient like rhodium-nickel combination) which is
applied to the cordierite blocks. The coating can be applied such that we can increase
the specific surface area of the structured catalyst by using a porous material like
11

alumina sol and a binder for the same. More surface area means more active sites for
reaction, thereby increasing the conversion within thermodynamic limits, and
consequently the plant throughput for identical process conditions. The coating thickness
can be manipulated to obtain higher conversions. This however is an active field of
research, and work is underway across the globe on some of these optional
characteristics. Thus, a change in the coating formulation and the coating procedure can
significantly change the effectiveness of PS-CAT.
The cordierite blocks can be wash coated using a sol gel process with alumins and then
coated with the nickel nitrate solution.
The strength of the nickel nitrate solution can be increased to 3M or 4M. This will result
in a thicker coating on the surface of the cordierite blocks. But the solution is much
denser hence the penetration of the solution inside the pores of the cordierite block will
be limited.
Nickel nitrate solution can be modified by adding promoters such as rhodium, ceria, etc.
Nickel nitrate solution can be completely replaced by the solution of a nitrate salt of
another transition metal such as copper, zinc or a noble metal such as rhodium, platinum
and palladium. The use of noble metals is however, expensive.
Details of the invention, its objects and advantages are explained hereunder in greater
detail in relation to non-limiting exemplary illustration of the meso-channeled structured
catalyst of the invention and its beneficial use in steam reforming of methane for
production of syn gas with reference to the following accompanying figures:-
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES:
Figure 1: is a typical schematic illustration of a meso-channeled structured monolith
catalyst and further illustrates its ready disposition in a reactor tube for steam reforming;
Figure 2: is a schematic illustration of a 4-channeled coated PS-CAT in accordance with
the present invention;
Figure 3(a) and 3(b): illustrate the structured flow through the PS-CAT of the present
invention and the irregular flow through a packed bed of pellet type catalyst respectively;
12

Figure 4: illustrates the product gas composition of the exit gases when PS-CAT
comprising of 4-channels (5 blocks) in series under conditions feed to steam molar ratio
= 1:3, W/F = 56 gm-cat/min-mol, pressure = 1 atm and temperature = 775°C; and
Figure 5: illustrates the product gas composition of the exit gases when PS-CAT
comprising of 4-channels (5 blocks) under conditions of feed to steam molar ratio = 1:3,
W/F = 56 gm-cat/min-mol, pressure = 1 atm, temperature = 840°C.
DETAILED DESCRIPTION OF THE ACCOMPANYING FIGURES:
References is invited to accompanying figures 1 to 2 which shows the PS-CAT according
to the invention for steam reforming process involving the meso-channeled structured
catalyst. As clearly apparent from said Figures 1 & 2, in case of the meso-channeled
structured PS-CAT of the invention the gas flow is distributed in the channels at the inlet
of the reformer tube and then the gas flows through the entire straight length of the
channel without changing its direction till it reaches the bottom of the reformer tubes.
Such possible straight line flow of gas through the structured catalyst of the invention is
further illustrated in accompanying Figure 3(a) in such straight path flow of gas in the
meso-channeled structured catalyst; there is lesser drop in pressure energy which in turn
favour higher feed rate and conversion.
The advantages of such structured catalyst vis-a-vis the conventional catalyst for such
steam reforming which are usually in the form of cylindrical pellets, tablets and spheres
can be appreciated further in relation to Figures 3(a) and 3(b).
As would be apparent from Figure 3(b), in case of conventional catalyst the same are
available in the form of cylindrical pellets, tablets and spheres and are simply dumped in
the reformer tube. The catalyst pellets in such case assume random disposition in the
reformer tube and cannot contribute to a define structure to the bed. There is no
structure to the bed as a whole and it can be imagined as a bed containing large number
of convoluted or tortuous paths through which the feed gas is required to flow. As the
gas flows through such tortuous paths provided by such conventional catalyst in reformer
tubes, there is an increased pressure drop relative to the pathway (channelised) provided
by the structured catalyst of the invention. Thus, due to the presence of the tortuous
path in the conventional catalyst as shown in Figure 3(b), the gas has to constantly
13

change its direction of flow with the changing direction causing it to loose part of its
energy due to the change in its flow paths. As a consequence, there is a drop in the
pressure energy of the gas as the flow of gas is largely pressure driven. On the other
hand, in case of the meso-channeled structured PS-CAT of the invention as shown in
Figure 3(a), the gas flow is distributed in the channels at the inlet of the reformer tube
and then the gas follows through entire straight length of the channel without changing
its directions till it reaches the bottom of the reformer tube. Thus, there is no change in
direction of the gas flow after the initial gas distribution. So, relative to the conventional
fixed bed catalyst, in the structured catalyst of the invention there is a lesser drop in
pressure energy. Simultaneously, as the channel size is small and channels are coated
with active nickel coating, the gas comes in intimate contact with the catalyst and this
results in the substantial increase in conversion. Therefore, under identical process
conditions, the structured catalyst of the invention can be fed more methane to the same
reformer tube as the conversion is substantially more and thus favours increasing the
throughput or plant capacity using the same infrastructure to produce more syn gas.
An exemplary process for the manufacture of the structured catalyst PS-CAT and the
coating procedure followed are further illustrated hereunder by way of the following
example.
EXAMPLE I:
Manufacture of catalyst: PS-CAT Coating Procedure
The cordierite blocks (100 cpsi) were procured from a reputed manufacturer from the
open market, cleaned, and cut to desired sizes as per our reactor tube dimensions. Each
block was weighed before being dipped into the solution, and after the calcination, to find
out the amount of catalyst (nickel oxide) loading on the block.
2M solution of nickel nitrate was prepared using nickel nitrate hexahydrate salt and
distilled water. The solution was stirred using a magnetic stirrer for 15 minutes to
completely dissolve the nickel nitrate in water. Clean dust-free cordierite blocks were
then soaked in this solution for three hours. This is a modification of the conventional dip
coating or wall coating procedure and allows for higher soaking or loading of nickel
nitrate on the cordierite blocks. The blocks were then removed from the solution and the
excess liquid from the wet blocks was removed by blowing air using an air blower. The
blocks were dried in an oven at a temperature of 120 °C for one hour. The blocks were
14

then dipped again in the same nickel nitrate solution for 15 minutes, removed and dried
in the oven at 120 °C for one hour. These last two steps were repeated once more to
obtain dry blocks ready for calcination.
Calcination of the blocks was carried out in a temperature controlled furnace using a
specific procedure. The coated blocks were placed in the furnace and the temperature
was raised to 400 °C at a rate of 10 °C per minute. Then the temperature was
maintained at 400 °C for 4 hours. The temperature was then increased to 600 °C at a
rate of 1°C per minute. The blocks were then allowed to cool in the furnace. The high
temperature calcination reduces the nickel nitrate to nickel oxide. There is a visible
change in colour from green to steel grey when the blocks are finally removed from the
furnace.
The blocks are reduced (from nickel oxide to nickel) just before use in the steam
reformer unit using a hydrogen stream of flow rate 40 N ml/minute.
The thus manufactured structured catalyst of the invention was further identified to have
the following preferred selective features:
Physical Dimensions (Macrostructure)
Raw substrate : CORDIERITE (ceramic)
Specification : 100 cpsi (cells per square inch)
Wall Thickness: ~270 microns (average)
Cell dimension: 1500 x 1500 microns
BET surface area
Uncoated (raw) cordierite substrates : 0.72 m2/g
Coated substrate- PS-CAT : 0.49 m2/g
Used (post-run) PS-CAT : 0.18 m2/g
EDS- X-Ray (Energy Dispersive Spectroscopic X ray Analysis) Composition
Nickel Oxide content: ~8.5%
15

Catalyst loading
Nickel Oxide Loading: ~ 3-10%
The structured catalysts obtained in accordance with the present invention were further
tested in steam reforming of methane as further detailed hereunder:-
EXAMPLE II:
The structured catalysts obtained according to the invention were extensively tested for
steam reforming of methane at a steam to methane molar ratio of 3:1 at atmospheric
pressure and a temperature of 775 ° C and 840 ° C for a long duration of time (more
than hundred hours on stream). The resulting exit gas composition have been analysed
and the results of the same have been plotted in the form of graphs with the process
conditions as illustrated under accompanying Figures 4 and 5.
The conversion of methane (feed hydrocarbon) observed with the said conditions (feed to
steam molar ratio of 1:3, W/F of 56 gm-cat/min-mol, pressure of 1 atm, and
temperatures of 775 °C and 840°C ) using PS-CAT is > 97 %. At similar conditions (feed
to steam molar ratio of 1:3, W/F of 56 gm-cat/min-mol, pressure of 1 atm, and
temperatures of 775 °C), when a commercial nickel based steam reforming catalyst was
tested for steam reforming of methane in a 6 mm packed bed reactor the conversion
observed was only 79.73%.
In both these cases, (for the 4-channeled PS-CAT and the commercial nickel based
catalyst), the same reactor tube of 6 mm inner diameter was used. The peripheral
pumps, steam generator and the measurement devices were identical in all three cases
compared.
Range of Parameters for which the above advantages residing in the provision of
structured catalyst remain valid preferably include:
Temperature
The catalyst exhibits a conversion (of methane) of > 90% for a temperature above 700
°C. The catalyst shows nearly complete conversion (> 98 %) of methane at a
temperature above 775 °C.
16

Other Parameters
W/F CH4 ~ 55.0 gm-cat min/mol
Molar Ratio (CH4:H2O) ~ 3.0
Space-time fW/F CH* ratio!
The catalyst exhibits a conversion of > 90% for a W/F CH4 ratio above 37.3 gm-cat
min/mol for temperature above 650 °C
Time-on-stream
The catalyst has been extensively tested for more than hundred hours on-stream at a
steam to methane molar ratio of 3:1, atmospheric pressure, temperature of 775 ° C, and
W/F CH4 ~ 56 gm-cat min/mol. It was found to perform consistently giving an average
conversion of ~ 97-98%.
Molar Ratio of Steam to Methane
The catalyst shows good conversion (> 90%) of methane for a molar ratio of steam to
methane of > 2.5 and up to 7.
The best results (methane conversion > 97%) are for a molar ratio of steam to methane
between 2.5 and 4.
EXAMPLE III:
The performance of the present steam reforming catalyst PS-CAT of the invention was
further compared with the performance of a commercial Nickel-Alumina-Magnesia
catalyst. The commercial available catalyst (RKNGR catalyst) was used for such purpose.
This catalyst was crushed to 1 mm particle size and tested with the same feed, namely,
methane at the same flow rate and molar ratio of steam to hydrocarbon. The conversion
of methane using PS-CAT was nearly 20 % more than the conversion of methane
obtained by using the commercial catalyst. The details of the experimental runs are
tabulated in Table 1.
17

Table 1: Experimental details of the comparison run

It is thus found by way of the development of the structured catalyst of the invention
that the base structure (the cordierite block) plays the role of providing a solid structure
to the catalyst coating and also importantly the straight length flow of the gas through
the catalyst structure. Moreover, the selective contact surface based on the selective
catalyst coating predominantly controlled the gas reforming process. When an uncoated
cordierite block was tested for steam reforming of methane, only about 20% conversion
of methane was obtained at a temperature of 775 °C and identical flow rate. This
conversion was attributed to thermal cracking of the feed methane at this temperature.
Thus, the superior performance using PS-CAT is clearly due to the combination of the
catalyst coating and the catalyst structured. The cordierite structure, favours for the
uninterrupted flow pattern developed and the resultant lower pressure drop while the
conversion of methane being predominantly due to the catalyst coating.
Importantly, the catalyst according to the invention has a structured shape and is not
irregular. The illustrations provided hereinbefore clearly show the regular and straight
nature of the square channels of the structured catalyst of the invention vis-a-vis the
irregular channels formed in case of the packed bed catalyst used conventionally in the
steam reforming process.
18

It is thus possible by way of the present invention to provide for the development of a
catalyst suitable for steam reforming of methane and targeted to improve the conversion
of feed (methane) and more importantly using the steam reforming processes and
existing available plant infrastructure. Thus the developed meso-channeled structured
(PS-CAT) is found to be most effective in the process of reforming of methane for the
production of syn gas.
Importantly, the developed meso-channeled structured PS-CAT catalyst achieve catalyst
loading of 3-10% for steam reforming of methane which in turn favour good conversion
(>90%) of methane for a molar ratio of steam to methane of 2.5 to up to 7 which would
favour beneficial and cost-effective steam reforming of methane gas for the production
of syn gas.
19

WE CLAIM:
1. A structured catalyst for steam reforming of methane for production of syn gas
comprising:
a meso scaled channeled structure obtained of cordierite with selective catalyst
coating spread over the channel dimensions adapted to favour continuous and
intimate contact of the gas feed with the active catalyst content of the coating
for increased feed rate and conversion under said steam reforming.
2. A structured catalyst for steam reforming of methane for production of syn gas
comprising:
meso-scale channeled structured catalyst (PS-CAT) comprising a plurality of
square thin-walled rectangular channels obtained of cordierite coated with a
selective transition metal or noble metal based catalyst formulation, said coating
spread over the all the channel dimensions adapted to favour continuous and
intimate contact of the gas feed with the active content of the coating for
increased feed rate and conversion under said steam reforming.
3. A structured catalyst for steam reforming of methane for production of syn gas
comprising:
meso-scale channeled structured catalyst (PS-CAT) comprising a plurality of
square thin-walled rectangular channels obtained of cordierite coated with a
selective transition metal or noble metal based catalyst formulation , said
coating spread over the all the channel dimensions having porous material for
increased surface area and adapted to favour continuous and intimate contact of
the gas feed with the active content of the coating for increased feed rate and
conversion under said steam reforming.
4. A structured catalyst for steam reforming of methane for production of syn gas
as claimed in anyone of claims 1 to 3 wherein said selective catalyst is obtained
of a nitrate salt of a transition or noble metal.
5. A structured catalyst for steam reforming of methane for production of syn gas
as claimed in claim 4 wherein said selective catalyst is selectively obtained of
nickel nitrate solution, nitrate salt of another transition metal preferably copper,
zinc or any noble metal preferably rhodium, platinum and palladium.
20

6. A structured catalyst for steam reforming of methane for production of syn gas
as claimed in anyone of claims 3 to 5 wherein said porous material coating
comprises alumina sol and a binder.
7. A structured catalyst for steam reforming of methane for production of syn gas
as claimed in anyone of claims 1 to 6 wherein said the effectiveness of the
structured catalyst is selectively achieved by selective change in catalyst
formulation preferably rhodium-nickel combination, increasing the surface area
of the coated catalyst to provide more active sites for increased conversion and
plant throughput and variation in the coating thickness to achieve higher
conversions.
8. A structured catalyst for steam reforming of methane for production of syn gas
as claimed in anyone of claims 1 to 7 comprising:
Macrostructure obtained of Cordierite (ceramic), specifications 100 to 400 cpsi
preferably about 100 cpsi (cells per square inch), wall thickness 50 to 300
microns preferably about 270 microns (average) and cell dimension 500 X 500
microns to 2000 X 2000 microns preferably 1500 X 1500 microns;
BET surface area comprising uncoated (raw) cordierite substrate 0.5 to 20 m2/g
preferably about 0.72 m2/g, coated substrate (PS-CAT) 0.25 to 15 m2/g
preferably about 0.49 m2/g;and
Catalyst loading of Nickel Oxide in the range of 3 to 10%.
9. A process for the manufacture of structured catalyst for steam reforming of
methane for production of syn gas as claimed in anyone of claims 1 to 8
comprising:
i) providing cordierite blocks;
ii) providing a nitrate salt solution of a transition metal or a noble metal;
iii) soaking the said cordierite blocks in said nitrate salt solution;
iii) removing the blocks from the solution and subjecting the blocks to drying
such as to obtain dry blocks ready for calcination;
iv) subjecting the dry blocks to calcinations such as to reduce the metal
nitrate to metal oxide; and
21

v) finally, the blocks are reduced from metal oxide content to said metal
catalyst contained structured catalyst suitable for steam reforming.
10. A process for the manufacture of structured catalyst for steam reforming of
methane for production of syn gas as claimed in claim 8 comprising:
i) providing cordierite blocks;
ii) providing a nickel nitrate salt solution;
iii) soaking the said cordierite blocks in said nickel nitrate salt solution;
iii) removing the blocks from the solution and subjecting the blocks to drying
such as to obtain dry blocks ready for calcination;
iv) subjecting the dry blocks to calcination such as to reduce the nickel nitrate
to nickel oxide; and
v) finally, the blocks are reduced from nickel oxide content to said nickel
catalyst contained structured catalyst suitable for steam reforming.
11. A process for the manufacture of structured catalyst for steam reforming of
methane for production of syn gas as claimed in claim 10 wherein said nickel
nitrate solution was obtained using nickel nitrate hexahydrate salt and distilled
water under stirring;
said blocks were dried in an oven at a temperature of 100 to 130 °C preferably
120°C for a period of 1 to 1.5 hours preferably 1 hour and then dipped again in
the same nickel nitrate solution for 5 to 20 min preferably about 15 min.,
removed and again dried as said above ; the said step of dipping and drying
being repeated, if necessary, such that the blocks are ready for calcination.
12. A process for the manufacture of structured catalyst for steam reforming of
methane for production of syn gas as claimed in claim 11 wherein said step of
calcinations is carried out in a temperature controlled furnace following the
steps of:
22

placing the coated blocks in the furnace and raising the temperature to 350 to
450 °C preferably about 400 °C at a rate of 7 to 12 °C per min. preferably about
10°C per min., thereafter the temperature was maintained at 350 to 450
preferably 400 °C for a period of 4 to 6 preferably 4 Hrs., next the temperature
was increased to 550 to 650 °C preferably about 600 °C at a rate of 1 to 2 ° per
min. preferably about 1 °C per min. , allowing the blocks to cool in the furnace
whereby nickel nitrate is reduced to nickel oxide and finally the blocks are
reduced from nickel oxide to nickel just ahead of its use in the reformer unit
using a hydrogen stream of flow rate of preferably about 40 ml/min.
13. A process for the manufacture of structured catalyst for steam reforming of
methane for production of syn gas as claimed in anyone of claims 9 to 12
wherein said cordierite blocks are wash coated using sol gel process with
alumina and thereafter coated with said nickel nitrate solution.
14. A process for the manufacture of structured catalyst for steam reforming of
methane for production of syn gas as claimed in anyone of claims 9 to 13
wherein said the effectiveness of the structured catalyst is selectively achieved
by selective change in catalyst formulation preferably rhodium-nickel
combination, increasing the surface area of the coated catalyst to provide more
active sites for increased conversion and plant throughput , variation in the
coating thickness to achieve higher conversions , modifying the catalyst solution
preferably adding promoters selected from rhodium, ceria to the nickel nitrate
solution and selecting the strength of the catalyst formulation preferably 3M or
4M solution of nickel nitrate.
15. A process for the steam reforming of methane for the production of syn gas
comprising carrying out the said process of steam reforming using the
structured catalyst as claimed in anyone of claims 1 to 8.
16. A process for the steam reforming of methane for the production of syn gas as
claimed in claim 15 wherein a number of said structured catalysts in the form of
blocks are stacked one above the other to fill the length of the reformer tube.
17. A process for the steam reforming of methane for the production of syn gas as
claimed in anyone of claims 15 or 16 wherein said steam reforming of methane
23

is carried out at a steam to methane molar ratio of 3:1 at atmospheric pressure
and a temperature of 700 to 850 °C preferably about 775°C to 840°C for more
than hundred hours on stream.
18. A process for the steam reforming of methane for the production of syn gas as
claimed in anyone of claims 15 to 17 wherein the said selective use of catalyst
provided for a conversion of > 90 % for a molar ratio of steam to methane of
>2.5 and up to 7.
24
19. A process for the steam reforming of methane for the production of syn gas as
claimed in anyone of claims 15 to 18 wherein the diameter of the structured
catalyst blocks are selectively varied based on the process requirements.
20. A structured catalyst for steam reforming of methane for production of syn gas,
its process of manufacture and a process for the steam reforming of methane for
the production of syn gas using the said structured catalyst substantially as herein
described and illustrated with reference to the accompanying examples and
figures.

The present invention relates to steam reforming of methane for production of syn gas
and, in particular, to a meso-scale channeled structured catalyst (PS-CAT) comprising a
plurality of square thin-walled rectangular channels obtained of cordierite coated with a
selective transition metal or noble metal based catalyst formulation adapted to favour
continuous and intimate contact of gas feed with the active catalyst with improve feed
rate and conversion in steam reforming. Advantageously, the structured catalyst
functionally favour ready use in conventional reformer tubes used in steam reforming for
increased conversion to syn gas. The meso-structured catalyst achieve good conversion
> 90% of methane for a molar ratio of steam to methane of >2.5 and up to 7 and steam
reforming of methane is carried out preferably at a steam to methane molar ratio of 3:1
at atmospheric pressure and a temperature of 700 to 850 °C preferably about 775°C to
840°C for more than hundred hours on stream and is directed to favour wide scale
application and use as a beneficial catalyst in steam reforming of methane for production
of syn gas.

Documents:

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Patent Number

271334

Indian Patent Application Number

1515/KOL/2007

PG Journal Number

08/2016

Publication Date

19-Feb-2016

Grant Date

17-Feb-2016

Date of Filing

02-Nov-2007

Name of Patentee

INDIAN INSTITUTE OF TECHNOLOGY

Applicant Address

SPONSORED RESEARCH & INDUSTRIAL CONSULTANCY, KHARAGPUR

Inventors:

#	Inventor's Name	Inventor's Address
1	SAHA, RANAJIT KUMAR	DEPARTMENT OF CHEMICAL ENGINEERING, INDIAN INSTITUTE OF TECHNOLOGY, KHARAGPUR-721302
2	MATHURE, PANKAJ V.	PH.D. RESEARCH SCHOLAR(S.R.F.), DEPARTMENT OF CHEMICAL ENGINEERING, INDIAN INSTITUTE OF TECHNOLOGY, KHARAGPUR-721302
3	GANGULY, SHOUVIK	ASSISTANT ENVIRONMENTAL ENGINEER, DURGAPUR REGIONAL OFFICE, WEST BENGAL POLLUTION CONTROL BOARD
4	PATWARDHAN, ANAND VINAYAK	DEPARTMENT OF CHEMICAL ENGINEERING, INDIAN INSTITUTE OF TECHNOLOGY, KHARAGPUR-721302
5	SWAMY, BALAIAH	DEPARTMENT OF CHEMICAL ENGINEERING, INDIAN INSTITUTE OF TECHNOLOGY. KHARAGPUR-721302

PCT International Classification Number

C01B3/40; C01B3/00; C01B17/16; C01B3/32;

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA