Title of Invention


Abstract The invention relates to a process for the regeneration of a deactivated wax covered Fischer-Tropsch catalyst, a pumpable suspension of deactivated catalyst being injected into a hot gas stream and the regenerated catalyst then being separated off from the gas stream, optionally further treated by calcination and/or reduction.
Full Text Process for the regeneration of a Fischer Tropsch catalyst
Natural gas, found in deposits in the earth, is an abundant
energy resource. For example, natural gas commonly serves
as a fuel for heating, cooking, and power generation, among
other things. The process of obtaining natural gas from an
earth formation typically includes drilling a well into the
formation. Wells that provide natural gas are often remote
from locations with a demand for the consumption of the
natural gas.
Thus, natural gas is conventionally transported large
distances from the wellhead to commercial destinations in
pipelines. This transportation presents technological
challenges due in part to the large volume occupied by a
gas. Because the volume of an amount of gas is so much
greater than the volume of the same number of gas molecules
in a liquefied state, the process of transporting natural
gas typically includes chilling and/or pressurizing the
natural gas in order to liquefy it. However, this
contributes to the final cost of the natural gas and is not
Formations that include small amounts of natural gas may
include primarily oil, with the natural gas being a
byproduct of oil production that is thus termed associated
gas. In the past, associated gas has typically been flared,
i.e., burned in the ambient air. However, current
environmental concerns and regulations discourage or
prohibit this practice.
Further, naturally occurring sources of crude oil used for
liquid fuels such as gasoline, jet fuel, kerosene, and
diesel fuel have been decreasing and supplies are not
expected to meet demand in the coming years. Fuels that are
liquid under standard atmospheric conditions have the

advantage that in addition to their value, they can be
transported more easily in a pipeline than natural gas,
since they do not require liquefaction.
Thus, for all of the above-described reasons, there has
been interest in developing technologies for converting
natural gas to more readily transportable liquid fuels,
i.e. to fuels that are liquid at standard temperatures and
The above is also known as GTL (gas to liquid), i.e. the
conversion of natural gas into other, heavier hydrocarbons.
Instead of using gas, also coal or biomass can be used as
the feed stock for making synthesis gas. For the coal
feedstock, the process is known as CTL, when based on
biomass the abbreviation BTL is commonly used. The general
principle is to convert the feedstock into synthesis gas
which is then converted into the desired hydrocarbons. The
term XTL is also sometimes used to describe the general
process, X stands in this case for any feedstock that can
be converted into synthesis gas.
One method for converting natural gas, coal and/or biomass
to liquid fuels involves two sequential chemical
transformations. In case of GTL, the first transformation,
natural gas or methane, the major chemical component of
natural gas, is reacted with oxygen and/or steam to form
syngas, which is a combination of predominantly carbon
monoxide gas and hydrogen gas. Syngas (or synthesis gas)
can also contain carbon dioxide. In case of CTL, coal is
gasified to syngas. In case of BTL, biomass is gasified to
syngas. The production of syngas itself can normally
includes multiple steps. After making the CO/H2 containing
gas mixture, the syngas often needs to be purified to
remove certain substances that would cause problems
downstream in the Fischer-Tropsch section. After the syngas
has been optionally purified, the second transformation,
known as the Fischer-Tropsch process takes place. The

predominant reaction is between carbon monoxide and
hydrogen to form organic molecules containing carbon and
hydrogen. Those molecules containing only carbon and
hydrogen are known as hydrocarbons. Those molecules
containing oxygen in addition to carbon and hydrogen are
known as oxygenates. Hydrocarbons having carbons linked in
a straight chain are known as aliphatics and are
particularly desirable as the basis of synthetic diesel
The Fischer-Tropsch process is commonly facilitated by a
catalyst. Catalysts desirably have the function of
increasing the rate of a reaction without being consumed by
the reaction. Common catalysts for use in the Fischer-
Tropsch process contain at least one metal from Groups 8,
9, or 10 of the Periodic Table (in the new IUPAC notation,
which is used throughout the present specification). The
molecules react to form hydrocarbons while confined on the
surface of the catalyst. The hydrocarbon products then
desorb from the catalyst and can be collected. H. Schulz
(Applied Catalysis A: General 1999, 186, p 3) gives an
overview of trends in Fischer-Tropsch catalysis.
The catalyst may be contacted with synthesis gas in a
variety of reaction zones that may include one or more
reactors. Common reactors include packed bed (also termed
fixed bed) reactors, slurry bed reactors, and fluidized bed
reactors. Originally, the Fischer-Tropsch synthesis was
carried out in packed bed reactors. These reactors have
several drawbacks, such as poor temperature control, that
can be overcome by gas-agitated slurry reactors or slurry
bubble column reactors. Gas-agitated multiphase reactors
sometimes called "slurry reactors" or "slurry bubble
columns," operate by suspending catalytic particles in
liquid and feeding gas reactants into the bottom of the
reactor through a gas distributor, which produces small gas
bubbles. As the gas bubbles rise through the reactor, the

reactants are absorbed into the liquid and diffuse to the
catalyst where, depending on the catalyst system, they are
typically converted to gaseous and liquid products. The
gaseous products formed enter the gas bubbles and are
collected at the top of the reactor. Liquid products are
recovered from the suspending liquid by using different
techniques like filtration, settling, hydrocyclones,
magnetic techniques, etc. Gas-agitated multiphase reactors
or slurry bubble column reactors (SBCRs) inherently have
very high heat transfer rates; therefore, reduced reactor
cost and the ability to remove and add catalyst online are
principal advantages of such reactors in Fischer-Tropsch
synthesis, which is exothermic. Sie and Krishna (Applied
Catalysis A: General 1999, 186, p. 55) give a history of
the development of various Fischer Tropsch reactors.
Typically the Fischer-Tropsch product stream contains
hydrocarbons having a range of numbers of carbon atoms, and
thus having a range of molecular weights. Thus, the
Fischer-Tropsch products produced by conversion of
synthesis gas commonly contains a range of hydrocarbons
including gases, liquids and waxes. It is highly desirable
to maximize the production of high-value liquid
hydrocarbons, such as hydrocarbons with at least 5 carbon
atoms per hydrocarbon chain (C.sub.5+ hydrocarbons).
The composition of a catalyst influences the relative
amounts of hydrocarbons obtained from a Fischer-Tropsch
catalytic process. Cobalt metal is particularly desirable
in catalysts used in converting synthesis gas to
hydrocarbons suitable for the production of diesel fuel.
Further, iron, nickel, and ruthenium have been used in
Fischer-Tropsch catalysts. Nickel catalysts favor
termination of the chain growth and are useful for aiding
the selective production of methane from syngas. Iron has
the advantage of being readily available and relatively
inexpensive but the disadvantage of a water-gas shift

activity. Ruthenium has the advantage of high activity but
is quite expensive.
One of the limitations of a Fischer-Tropsch process is that
the activity of the catalyst will, due to a number of
factors, deteriorate over time.
The commercial incentives for a process to convert
synthesis gas to liquid fuels and other products are
increasing as the need for energy sources increases. One
successful approach to meeting this need has been to make
synthesis gas and then synthetically convert the synthesis
gas into heavier hydrocarbons (C5+) through the Fischer-
Tropsch (F-T) process. The synthetic production of
hydrocarbons by the catalytic reaction of synthesis gas is
well known and is generally referred to as the Fischer-
Tropsch reaction. This F-T process was developed
approximately eighty years ago in Germany, and since then,
it has been practiced commercially in Germany during World
War II and later in South Africa. In recent times, very
large, new GTL and CTL complexes are built in other
countries as well.
Fischer-Tropsch hydrocarbon conversion systems typically
have a synthesis gas generator and a Fischer-Tropsch
reactor unit. In the case of starting with a gas feed
stock, the synthesis gas generator receives light, short-
chain hydrocarbons such as methane and produces synthesis
gas. The synthesis gas is then delivered to a Fischer-
Tropsch reactor. In the F-T reactor, the synthesis gas is
primarily converted to useful C5+ hydrocarbons. Recent
examples of Fischer-Tropsch systems are included in U.S.
Pat. Nos. 4,973,453; 5,733,941; and 5,861,441.
Numerous types of reactor systems have been used for
carrying out the Fischer-Tropsch reaction. See generally
the many examples found on www.fischertropsch.org. The
commercial development of the Fischer-Tropsch reactor

systems has included conventional fixed-bed and three-phase
slurry bubble column designs or other moving-bed designs.
But, due to the complicated interplay between heat and mass
transfer and the relatively high cost of Fischer-Tropsch
catalysts, no single reactor design has dominated the
commercial developments to date.
Fischer-Tropsch three-phase bubble column reactors or the
like appear to offer distinct advantages over the fixed-bed
design in terms of heat transfer and diffusion
characteristics. One particular type of three-phase bubble
column is the slurry bubble column, wherein the catalyst
size is generally between 10 and 200 microns (urn). Three-
phase bubble column reactors present a number of technical
The technical challenges associated with three-phase bubble
columns include solids management. One particular challenge
in this area is to efficiently rejuvenate slurry catalysts.
When a slurry Fischer-Tropsch catalyst is used over time,
it has a disadvantage of slowly, but reversibly,
deactivating compared to its initial catalytic activity. As
the synthesis gas (primarily H2 and CO) is fed to the
Fischer-Tropsch reactor and converted with the F-T
catalyst, the catalyst experiences deactivation caused by
carbon build up, physical degradation, and the effects of
trace compounds other than CO and H2, such as by nitrogen
containing species or oxygenated byproducts. "Carbon build
up" references the accumulation of heavy hydrocarbons and
carbonaceous type material that can have a hydrogen content
less than that of F-T products. To remedy the deactivation,
the catalyst is regenerated, or rejuvenated, using any of a
number of techniques.
Rejuvenation is different from the initial activation of
the Fischer-Tropsch catalyst. For cobalt catalysts, the
initial activation involves converting the cobalt to a
reduced state. An example of an initial activation

technique is found U.S. Pat. No. 4,729,981, entitled "ROR-
Activated Catalyst for Synthesis Gas Conversion," which
describes the initial preparation of a cobalt or nickel
based Fischer-Tropsch catalyst by reducing it in hydrogen,
oxidizing it in an oxygen-containing gas, and then reducing
it in hydrogen. The catalyst is then ready for its initial
use. Once in use, it will begin to deactivate, and it will
need regeneration.
Regeneration of a Fischer-Tropsch catalyst after activation
and operation has long been known to restore the activity
of the catalyst. See, e.g., H. H. Storch et al., The
Fischer-Tropsch And Related Synthesis (Wiley: New York
1951), 211 222. Storch describes using hydrogen treatments
to restore the catalyst activity. There are many other
examples. For example, U.S. Pat. No. 2,159,140 describes
pulling the catalyst from the reactor (where it appears to
have been fluidized) and removing the catalyst and treating
it with hydrogen to regenerate the catalyst. U.S. Pat. No.
2,238,726 indicates that the non-volatile reaction products
can be removed from the catalyst by treating it with
hydrogen or gases or vapors containing hydrogen and that
this can be done in the midst of oil circulation. Col. 2:34
54. As another example, U.S. Pat. No. 2,616,911 describes
oxidizing the catalyst and then reducing it while
maintaining it in suspension or a fluidized state. Other
examples relating to regenerating and/or de-waxing Fischer-
Tropsch catalysts include U.S. Pat. Nos. 6,323,248 Bl;
6,201,030 Bl; 5,844,005; 5,292,705; 2,247,087; 2,259,961;
2,289,731; 2,458,870; 2,518,337; and 2,440,109.
Regenerating a slurry catalyst presents particular
challenges, because the catalyst is in slurry form.
Elaborate efforts have been made to separate the catalyst
to allow regeneration outside the Fischer-Tropsch reactor
or to regenerate it in-situ. The rejuvenation can be
carried out intermittently or continuously.

As an example of a regeneration process, U.S. Pat. No.
5,973,012 describes a reversibly deactivated, particulate
slurry catalyst that is rejuvenated by circulating the
slurry from a slurry body through (i) a gas disengaging
zone to remove gas bubbles from the slurry, (ii) a catalyst
rejuvenation zone in which a catalyst rejuvenating gas
contacts the catalyst in the slurry to rejuvenate it and tc
form a rejuvenated catalyst slurry, and (iii) a means for
returning catalyst to the slurry body. This design appears
to be primarily for use as in-situ regeneration design. The
"in-situ" regeneration offers the advantage of keeping the
catalyst in the slurry matrix; however, it presents many
challenges. Amongst other challenges in-situ regeneration,
the H2 partial pressure in the process is limited due to
the low solubility of H2 in the liquid phase. Typically,
the H2 partial pressure exposed to the catalyst within the
liquid phase is less than about 10% of that in the gas
phase. In addition, the hydrogen used to regenerate may
modify the H2:CO ratio in the reactor for some time.
Further still, the temperature may be limited by the
boiling point and/or cracking properties of the liquid
slurry constituents. For these reasons, "in situ"
regeneration has real limitations.
Further on it is known to regenerate a Fischer-Tropsch-
Catalyst by a process for converting light hydrocarbons
into heavier hydrocarbons (C5+) that includes regenerating
a slurry Fischer-Tropsch catalyst in need of regeneration,
the process comprising the steps of: preparing a synthesis
gas using light hydrocarbons; converting the synthesis gas
to Fischer-Tropsch products in a slurry Fischer-Tropsch
reactor containing a slurry Fischer-Tropsch catalyst;
removing Fischer-Tropsch products from the slurry Fischer-
Tropsch reactor; regenerating the slurry Fischer-Tropsch
catalyst that needs regeneration; and wherein the step of
regenerating the slurry Fischer-Tropsch catalyst comprises
the steps of: removing the catalyst from the slurry

Fischer-Tropsch reactor; de-waxing and drying the catalyst
sufficiently to produce a free-flowing catalyst powder that
is fluidizable; fluidizing the catalyst powder; treating
the catalyst powder with an oxygen treatment to remove
hydrocarbons from the catalyst powder, reducing the
catalyst powder with a reducing gas, re-slurring the
catalyst powder to form a regenerated slurry catalyst; and
returning the regenerated slurry catalyst to the slurry
Fischer-Tropsch reactor (US 6,989,403).
Accordingly, one object of the present invention is to
provide a process for the regeneration of a deactivated,
wax covered Fischer-Tropsch catalyst which is safe and with
which there is no risk either of self-ignition of the
catalyst or of a dust explosion.
It has now surprisingly been found that a deactivated, wax
covered Fischer-Tropsch catalyst can be completely
regenerated by injecting a pumpable suspension of the
deactivated wax covered Fischer-Tropsch catalyst into a hot
gas stream and then separating off the regenerated catalyst
from the gas stream. Self-ignition of the catalyst and dust
explosions are excluded from this process.
The present invention provides a process for the
regeneration of a deactivated, wax covered Fischer-Tropsch
catalyst, comprising injecting a pumpable suspension of the
deactivated wax covered Fischer-Tropsch catalyst into a hot
gas stream and subsequently separating off the regenerated
catalyst from the gas stream.
The process according to the invention is particularly
advantageous for the regeneration of a deactivated wax
covered Fischer-Tropsch catalyst. Since in this case, the
catalyst is already present in from of a slurry.

In the process according to the invention, the regenerated
catalyst can be separated off dry from the gas stream or it
can be scrubbed out from the gas stream with formation of e
Deactivated catalysts suitable for regeneration according
to the present invention preferably have a mean particle
size between 1 urn and 300 urn.
Fischer-Tropsch catalysts means all typs of FT-catalysis
especially cobalt-contaiming catalysts.
The process according to the invention can be particularly
advantageously carried out if the hot gas stream, into
which the suspension of the deactivated wax covered
Fischer-Tropsch catalyst is injected, is in a turbulent
flow state.
The oxygen content of the hot gas stream is preferably 5 to
20% by volume, particularly preferably 8. to 12% by volume.
The temperature of the hot gas stream is preferably 300 °C.
to 1050 °C, particularly preferably 600 °C to 850 °C.
The residence time of the deactivated catalyst in the hot
gas stream is preferably 0.01 to 10 sec, particularly
preferably 0.1 to 2 sec.
The thus regenerated catalyst can be further treated by a
calcination step and/or reduction step.
The process of the present invention can suitably be
carried out as follows: A pumpable suspension of the
deactivated wax covered Fischer-Tropsch catalyst is
continuously injected into an oxygen-containing, turbulent,
preheated gas stream having a temperature of about 700 °C
to 900 °C. Water, if present at all, evaporates very
rapidly. Immediately thereafter a sudden degassing of the
deactivated catalyst takes place. The escaping gas burns

immediately and reheats the gas stream which has lost heat
by the evaporation of water and/or lighter hydrocarbons. A
very rapid burning off of the carbon compounds in the
catalyst particles then takes place, since the catalyst
particles are freely suspended in the gas stream and the
gas exchange proceeds extremely rapidly. By equally rapid
release of the energy of the particles to the gas stream,
via heat conduction and particle impact, overheating of the
particles, as could occur in the case of uncontrolled
oxygen feed to a packed bed of catalyst material as a
result of heat transmission by radiation, is reliably
prevented. The particles are then separated off from the
gas stream. It is possible to insert a further step for
heat recovery, for example for preheating the combustion
The regeneration according to the invention of a
deactivated catalyst can be carried out, for example, in a
TURAKTOR (an apparatus available from the Eisenmann company
for the thermal treatment of waste materials). In such an
apparatus, an annular channel is impinged tangentially by a
hot gas from a burner. The hot gas flows from the annular
channel through vanes into the interior and in the course
of this is set in rapid circulation.
The circulating hot gas travels upwards in a spiral motion
along the walls in the actual turbulator chamber. As a
result of the high gas velocity at the bottom, a part-
stream is sucked back into the center where it mixes with
fresh hot gas. The suspension of the deactivated catalyst
is injected into this central backflow via a spray nozzle
furnished with a water cooling jacket and having a two-
component nozzle. Because of the high gas velocities and
turbulences achieved after a short pathway, the catalyst
particles are very finely distributed, the lighter
hydrocarbons of the wax evaporate virtually instantaneously
and the burning off of the heavier hydrocarbons of the wax

or of hydrogen-deficient hydrocarbons on the catalyst
particles proceeds extremely rapidly as a result of the
minimized mass transport limitation. At the same time, good
heat exchange is ensured between the hot gas and the
catalyst particles. The temperatures are measured in the
clean, hot gas in the annular channel and at the outlet of
the equipment. Air can be additionally added into the
equipment chamber by a further annular channel. An
inspection glass permits observation of the flame vortex.
The exhaust gas stream passes through a delay time section
of generally approximately 3 m in length. The first
separation of burnt-out, regenerated catalyst particles
then proceeds in a hot cyclone. The exhaust gas is then
cooled via an air preheater before the exhaust gas is freed
from the residual catalyst particles by circulating a
liquid like for instance water or a suitable hydrocarbon in
a venturi scrubber and is conducted away into the stack by
a downstream suction fan. The current oxygen content of the
exhaust gas is measured there via an oxygen analyzer.
The process according to the invention can be used to
remove the wax from the deactivated wax-covered Fischer-
Tropsch catalysts. Furtheron, it can be used to oxidize the
catalyst or/and to reduce the catalyst after having been
freed from the wax.
The calcination and/or reduction step can be done in a
separate kiln or a separate fluidbed reactor.
According to the invention it is possible to combine the
steps of the removing of the wax and the oxidation of the
catalyst into one single step, if the process is done with
an oxygen containing gas stream.
The process according to the invention is much faster than
the known methods to regenerate the deactivated wax covered
Fischer-Tropsch catalysts.

1. A process for the regeneration of a deactivated, wax
covered Fischer-Tropsch catalyst, comprising:
injecting a pumpable liquid suspension of a deactivated
wax covered Fischer-Tropsch catalyst into a gas stream
at from 600 °C to 1050 °C. to regenerate said catalyst,
separating off the regenerated catalyst from the gas
wherein the residence time of said deactivated catalyst
in said qas stream is from 0.01 to 10 sec.
2. The process according to claim 1, wherein the
regenerated catalyst is further treated by a
calcintration step and/or reduction step.
3. The process according to claim 1, wherein said
regenerated catalyst is separated off dry from the gas
4. The process according to claim 1-3, wherein said
regenerated catalyst is scrubbed out from the gas stream
forming a suspension.
5. The process according to claim 1-4, wherein said gas
stream is in a turbulent flow state.
6. The process according to claim 1-5, wherein the oxygen
content of said gas stream is of from 5 to 20% by
volume, based on the total volume of said hot gas

7. The process according to claim 1-6, wherein the oxygen
content of said gas stream is of from 8 to 12% by
volume, based on the total volume of said hot gas
8. The process according to claim 1, wherein the
temperature of said hot gas stream is of from 600 °C to
850 °C.
9. The process according to claim 1, wherein the residence
time of said deactivated Fischer-Tropsch catalyst in
said gas stream is of from 0.1 to 2 sec.
10. The process of claim 1, wherein said liquid suspension
is a suspension comprising hydrocarbons and catalyst.
11. The process of claim 1, wherein said liquid suspension
contains 10 to 80% by weight solids.

The invention relates to a process for the regeneration of a deactivated wax covered Fischer-Tropsch catalyst, a pumpable suspension of deactivated catalyst being injected into a hot gas stream and the regenerated catalyst then being separated off from the gas stream, optionally further treated by calcination
and/or reduction.



1818-KOLNP-2009-(02-04-2014)-ANNEXURE TO FORM 3.pdf






1818-KOLNP-2009-CORRESPONDENCE 1.2.pdf



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Patent Number 263886
Indian Patent Application Number 1818/KOLNP/2009
PG Journal Number 48/2014
Publication Date 28-Nov-2014
Grant Date 26-Nov-2014
Date of Filing 15-May-2009
Applicant Address RELLINGHAUSER STRASSE 1-11, 45128 ESSEN
# Inventor's Name Inventor's Address
PCT International Classification Number C10G 2/00,B01J 38/30
PCT International Application Number PCT/EP2007/061708
PCT International Filing date 2007-10-30
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 06124432.3 2006-11-21 EUROPEAN UNION