U.S. patent application number 11/945161 was filed with the patent office on 2008-03-27 for process for the production of compression ignition engine, gas turbine, and fuel cell fuel and compression ignition engine, gas turbine, and fuel cell fuel by said process.
Invention is credited to Luis Pablo Dancuart, Delanie Lamprecht, Ian Stradling Myburgh.
Application Number | 20080076949 11/945161 |
Document ID | / |
Family ID | 34437338 |
Filed Date | 2008-03-27 |
United States Patent
Application |
20080076949 |
Kind Code |
A1 |
Dancuart; Luis Pablo ; et
al. |
March 27, 2008 |
PROCESS FOR THE PRODUCTION OF COMPRESSION IGNITION ENGINE, GAS
TURBINE, AND FUEL CELL FUEL AND COMPRESSION IGNITION ENGINE, GAS
TURBINE, AND FUEL CELL FUEL BY SAID PROCESS
Abstract
The invention provides a Fischer-Tropsch derived compression
ignition engine, gas turbine, and fuel cell fuel which is
interchangeably useable in compression ignition engines, gas
turbines, and fuel cells, said fuel selected from a substantially
C5 to C9 cut, a substantially C5 to C9 cut blended with a
substantially C9 to C14 cut, a substantially C5 to C9 cut blended
with a substantially C9 to C14 cut and a substantially C14 to C22
cut, and a substantially C5 to C9 cut blended with a substantially
C14 to C22 cut. The invention extends to a process for preparing
said fuel and the use of such a fuel in a CI engine, and HCCI
engine, a turbine, and/or a fuel cell.
Inventors: |
Dancuart; Luis Pablo;
(US) ; Lamprecht; Delanie; (US) ; Myburgh;
Ian Stradling; (US) |
Correspondence
Address: |
HAHN AND MOODLEY, LLP
P.O. BOX 52050
MINNEAPOLIS
MN
55402
US
|
Family ID: |
34437338 |
Appl. No.: |
11/945161 |
Filed: |
November 26, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11406016 |
Apr 18, 2006 |
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11945161 |
Nov 26, 2007 |
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PCT/ZA04/00125 |
Oct 14, 2004 |
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11406016 |
Apr 18, 2006 |
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60512330 |
Oct 17, 2003 |
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Current U.S.
Class: |
585/14 |
Current CPC
Class: |
C10L 1/08 20130101; C10G
2/30 20130101; F02B 1/12 20130101 |
Class at
Publication: |
585/014 |
International
Class: |
C10L 1/16 20060101
C10L001/16 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 17, 2003 |
ZA |
ZA20038080 |
Claims
1-12. (canceled)
13. A compression ignition engine, gas turbine, and fuel cell fuel
which is interchangeably useable in compression ignition engines,
gas turbines, and fuel cells, said fuel comprising a substantially
C5 to C9 hydroconverted cut blended with a substantially C9 to C14
hydroconverted cut, which cuts have the Fischer-Tropsch process as
their origin, said blend having, an H:C molar ratio from 2.18 to
2.24.
14. A compression ignition engine, gas turbine, and fuel cell fuel
which is interchangeably useable in compression ignition engines,
gas turbines, and fuel cells, said fuel comprising a substantially
C5 to C9 hydroconverted cut blended with a substantially C9 to C14
hydroconverted cut and a substantially C14 to C22 hydroconverted
cut, which cuts have the Fischer-Tropsch process as their origins
said blend having an H:C ratio from 2.12 to 2.18.
15. A compression ignition engine, gas turbine, and fuel cell fuel
which is interchangeably useable in compression ignition engines,
gas turbines, and fuel cells, said fuel comprising a substantially
C5 to C9 hydroconverted cut blended with a substantially C14 to C22
hydroconverted cut, which cuts have the Fischer-Tropsch process as
their origin, said blend having an H:C molar ratio from 2.13 to
2.19.
16. A compression ignition engine, gas turbine, and fuel cell fuel
as claimed in claim 13, having an oxidation stability of equal or
less than 0.2 mg/100 ml.
17. A compression ignition engine, gas turbine, and fuel cell fuel
as claimed in claim 14, having an oxidation stability of equal or
less than 0.2 mg/100 ml.
18. A compression ignition engine, gas turbine, and fuel cell fuel
as claimed in claim 15, having an oxidation stability of equal or
less than 0.2 mg/100 ml.
19-21. (canceled)
Description
CROSS RELATED APPLICATION(S)
[0001] This application is a continuation of PCT Patent Application
PCT/ZA2004/000125 filed Oct. 14, 2004 and published on Apr. 4, 2005
as WO 2005/035695, which claims priority to ZA 2003/8080 filed Oct.
17, 2003 and U.S. Provisional Application 60/512,330 filed Oct. 17,
2003.
FIELD OF THE INVENTION
[0002] The invention relates to the production of compression
ignition engine, gas turbine, and fuel cell fuels.
BACKGROUND TO THE INVENTION
[0003] In this specification, the term "multipurpose
hydrocarbonaceous energy sources" is abbreviated to MES and is used
in both the singular and the plural.
[0004] The term MES thus encompasses compression ignition engine,
gas turbine, and fuel cell fuels.
[0005] An MES usable in gas turbines, compression ignition (CI)
engines, including Homogeneous Charge Compression Ignition (HCCI)
systems or fuel cells is an attractive option for many energy
users, especially for those operating in remote stranded locations
where a single form of supply of energy is required and simplified
logistics are necessary. These entities include users in many
classes of human activity.
[0006] U.S. Pat. No. 6,475,375, discloses the process for the
production of a synthetic naphtha fuel usable in CI engines. This
patent, however, does not contemplate the use of such a fuel as an
MES having broader application other than use thereof in a CI
engine. Thus, the disclosure in this patent does not provide any
indication of how the problems associated with the production of an
MES may be overcome or what characteristics or properties such an
MES should have.
[0007] A synthetic multi-purpose fuel useful as a fuel cell fuel,
diesel engine fuel, gas turbine engine fuel and furnace or boiler
fuel are disclosed in PCT WO 01/59034. The multi-purpose fuel
produced ranged from C9 to C22.
[0008] The inventor has now identified a need and a process for at
least partially satisfying such an MES need.
[0009] The Fischer-Tropsch (FT) process is a well known process in
which carbon monoxide and hydrogen are reacted over an iron,
cobalt, nickel or ruthenium containing catalyst to produce a
mixture of straight and branched chain hydrocarbons ranging from
methane to waxes with molecular masses above 1400 and smaller
amounts of oxygenates. The feed for the FT process may be derived
from coal, natural gas, biomass or heavy oil streams. The term
Gas-to-Liquid (GTL) process refers to schemes based on natural gas,
which is mainly methane, to obtain the synthesis gas, and its
subsequent conversion using in most instances an FT process. The
quality of the GTL FT synthetic products is essentially the same
obtainable from the FT process here defined once the synthesis
conditions and the product work-up are defined.
[0010] The complete process can include gas reforming which
converts natural gas to synthesis gas (H.sub.2 and CO) using
well-established reforming technology. Alternatively, synthesis gas
can also be produced by gasification of coal or suitable
hydrocarbonaceous feedstocks like petroleum based heavy fuel oils.
The synthesis gas is then converted into synthetic hydrocarbons.
The process can be effected using, among others, a fixed-bed
tubular reactor or a three-phase slurry reactor. FT products
include waxy hydrocarbons, light liquid hydrocarbons, a small
amount of unconverted synthesis gas and a water-rich stream. The
waxy hydrocarbon stream and, almost always, the light liquid
hydrocarbons are then upgraded in the third step to synthetic fuels
such as diesel, kerosene and naphtha. Heavy species are
hydrocracked and olefins and oxygenates are hydrogenated to form a
final product that is highly paraffinic. Hydrocracking and
hydrogenation processes belong to the group sometimes generally
named hydroconversion processes.
SUMMARY OF THE INVENTION
[0011] According to a first aspect of the invention, there is
provided a multipurpose carbonaceous energy source (MES fuel) which
is a compression ignition engine, gas turbine, and fuel cell fuel
which fuel is interchangeably useable in compression ignition
engines, gas turbines, and fuel cells, said energy source selected
from: [0012] a substantially C5 to C9 cut blended with a
substantially C9 to C14 cut, said blend having an H:C molar ratio
from 2.18 to 2.24; [0013] a substantially C5 to C9 cut blended with
a substantially C9 to C14 cut and a substantially C14 to C22 cut,
said blend having an H:C ratio from 2.12 to 2.18; and [0014] a
substantially C5 to C9 cut blended with a substantially C14 to C22
cut, said blend having an H:C molar ratio from 2.13 to 2.19.
[0015] The MES fuel options as defined in this invention are
summarised in Table 1. TABLE-US-00001 TABLE 1 MES Fuels Carbon
Number Range H:C CO.sub.2 Fuel Cut A Cut B Cut C Ratio Emissions
MES Cut C5-C9 C9-C14 C14-C22 Molar g CO.sub.2/g fuel 1 C5-C9 X 2.29
3.080 2 C5-C14 X X 2.20 3.098 3 C5-C22 X X X 2.14 3.111 4 C5-C9
& X X 2.17 3.105 C14-C22
[0016] The MES fuel may, when combusted, have a CO.sub.2 emission
below 3.115 g CO.sub.2/g fuel combusted.
[0017] One or more of the C5 to C9, C9 to C14, and C14 to C22 cuts
may be synthetic in origin.
[0018] One or more of the C5 to C9, C9 to C14, and C14 to C22 cuts
may be Fischer-Tropsch process in origin.
[0019] The MES Fuel may be a partially or totally synthetic
fuel.
[0020] The MES Fuel may be a Fischer-Tropsch process derived
fuel.
[0021] According to a second aspect of the invention, there is
provided a process for the production of synthetic multipurpose
carbonaceous energy source (MES fuels) which is a compression
ignition engine, gas turbine, and fuel cell fuel, which fuel is
interchangeably useable in compression ignition engines, gas
turbines, and fuel cells, said process including the steps of:
[0022] a) oxidising a carbonaceous material to form a synthesis
gas; [0023] b) reacting said synthesis gas under Fischer-Tropsch
reaction conditions to form Fischer-Tropsch reaction products;
[0024] c) fractionating the Fischer-Tropsch reaction products to
form one or more MES blending components selected from the group
including: [0025] A. a C5 to C9 cut; [0026] B. a C9 to C14 cut; and
[0027] C. a C14 to C22 cut; and [0028] d) using said blending
components in the production of the MES, provided that where at
least one of the blending components is a blending component in the
C9 to C14 or in the C14 to C22 boiling range then at least two
blending components are used in the production of the MES, one of
which is the C5 to C9 cut.
[0029] The C5 to C9 cut may be a light hydrocarbon blend, typically
in the 35-160.degree. C. distillation range.
[0030] The C9 to C14 cut may be a medium hydrocarbon blend,
typically in the 155-250.degree. C. distillation range.
[0031] The C14 to C22 cut may be a heavy hydrocarbon blend,
typically in the 245-360.degree. C. distillation range.
[0032] To obtain the MES fuels of Table 1, the blending components
A, B and C, as described above, may be blended in a volumetric
ratio of A:B:C of:
1.0:0.0:0.0 for MES 1
and
1.2:1.0:0.0 for MES 2
1.8:1.0:2.3 for MES 3
1.0:0.0:2.1 for MES 4
to
1.0:1.2:0.0 for MES 2
1.0:1.2:1.8 for MES 3
1.0:0.0:1.5 for MES 4
[0033] To obtain the MES fuels of Table 1, the blending components
A, B and C may be blended in a volumetric ratio of A:B:C,
wherein:
A may be from 1 to 2;
B may be from 0 to 1.5; and
C may be from 0 to 2.5.
[0034] One or more of the blending components may be
hydroconverted.
[0035] Thus, the MES may be a blend of both hydroconverted and
unhydroconverted blending components.
[0036] The MES may be a product of one or more of only
unhydroconverted blending components.
[0037] The MES may be a product of one or more only hydroconverted
blending components.
[0038] The Fischer-Tropsch process of step b) may be the Sasol
Slurry Phase Distillate.TM. process.
[0039] The carbonaceous material of step a) may be a natural gas
stream, a natural gas derivatives stream, a petroleum gas stream, a
petroleum gas derivatives stream, a coal stream, a waste
hydrocarbons stream, a biomass stream, and in general any
carbonaceous material stream.
[0040] Optionally, hydrogen may be separated from the synthesis gas
either during or after step a).
[0041] This hydrogen may be used in the hydroconversion of FT
primary products, namely FT condensate and FT wax.
[0042] Table 2 below gives a typical composition of the FT
condensate and FT wax fractions. TABLE-US-00002 TABLE 2 Typical
Fischer-Tropsch product after separation into two fractions (vol %
distilled) FT Condensate FT Wax (<270.degree. C. fraction)
(>270.degree. C. fraction) C.sub.5-160.degree. C. 44 3
160-270.degree. C. 43 4 270-370.degree. C. 13 25 370-500.degree. C.
40 >500.degree. C. 28
[0043] In one embodiment of the invention, the hydroconverted
products are fractionated in a common distillation unit where at
least three blending components are recovered: [0044] (1) a light
hydrocarbon blend, typically in the 35-160.degree. C. ASTM D86
distillation range, i.e. C5 to C9; [0045] (2) a medium hydrocarbon
blend, typically in the 155-250.degree. C. ASTM D86 distillation
range, i.e. C9 to C14; and [0046] (3) a heavy hydrocarbon blend,
typically in the 245-360.degree. C. ASTM D86 distillation range,
i.e. C14 to C22.
[0047] However, in other embodiments, the FT condensate and FT wax
are blended together before being fractionated into the blending
components.
[0048] In some embodiments the FT condensate is transferred
directly to the products fractionator without any hydroconversion
stage.
[0049] When processing using this approach, the MES products
benefit from the synergy of the composition and quality of the wax
and condensate fractions.
[0050] MES fuels of the invention meet the fuel requirements of
many classes of energy conversion systems including gas turbines,
CI engines, including HCCI systems and fuel cells.
[0051] The MES compositions may have the following properties which
make it suitable for fuel cells, gas turbine engine and CI engines
(as shown in Table 3 below): TABLE-US-00003 TABLE 3 Quality of the
Multipurpose Energy Sources Light HC Medium Heavy HC Blend HC Blend
Blend MES-1 MES-2 MES-3 Yield (est.) wt % 28% 25% 47% 28% 53% 100%
Density @ 15.degree. C. kg/l 0.690 0.752 0.782 0.690 0.723 0.747
Cetane Number (IQT) 44 64 >72 44 60 64 Sulphur wt ppm <1
<1 <1 <1 <1 <1 ASTM D86 Distillation range .degree.
C. 35-160 155-250 245-360 35-160 35-250 35-360 Cold Filter Plugging
Point .degree. C. <-30 <-30 -12 <-30 <-30 <-30
Freezing point .degree. C. <-60 -48 -9 <-60 <-60 <-60
Flash Point .degree. C. <0 50 114 <0 <0 14 Aromatics wt %
1.0-2.0 0.5-1.0 <0.5 1.0-2.0 1.0-1.5 0.5-1.0 Biodegradabily Test
pass pass pass pass pass pass Thermal stability Visual rating 1
(Excellent) 1 (Excellent) 1 (Excellent) 1 (Excellent) 1 (Excellent)
1 (Excellent) (Octel F21-61) (relative stability) Oxidation
Stability mg/100 ml 0.1 0.1 0.2 0.1 0.1 0.1 Viscosity @ 40.degree.
C. cSt 0.98 1.14 3.3 0.98 1.10 1.34 HC = Hydrocarbon
[0052] High Cetane Number: Fuels with a high cetane number ignite
quicker and hence exhibit a milder uncontrolled combustion because
the quantity of fuel involved is less. A reduction of the
uncontrolled combustion implies an extension of the controlled
combustion, which results in better air/fuel mixing and more
complete combustion with lower NOx emissions and better cold start
ability. The shorter ignition delay implies lower rates of pressure
rise and lower peak temperatures and less mechanical stress.
[0053] The cetane number of the MES compositions was determined
according to ASTM D613 test method and an Ignition Quality Tester
(IQT--ASTM D6890).
[0054] Near Zero-Sulphur Content: The sulphur content was
determined according to the ASTM D5453 test method. The less than 1
ppm sulphur present in the MES compositions not only make the
components suitable for a fuel cell reformer catalyst, but also
contribute to the lower exhaust emission in engines, such as CI
engines. The less than 1 ppm sulphur present in the MES composition
either ensure compatible with certain exhaust catalyst devises or
give improved compatibility with other.
[0055] Good Cold Flow Properties: Cold Filter Plugging Point (CFPP)
is the lowest temperature at which the fuel can pass through a
standard test filter under standard conditions (requires more than
1 minute for 20 ml to pass through a 45-.mu.m filter). This test is
done accordingly to the Institute of Petroleum IP 309 method or
equivalent. Inadequate cold flow performance will lead to
difficulties with starting and blockage of CI engine fuel filters
under cold weather conditions.
[0056] Freezing point is one of the physical properties used to
quantitatively characterise gas turbine engine fuel fluidity. The
low freezing point, determined in accordance with the automated
ASTM 5901 test method, or equivalent, can be attributed to the more
than 60 mass % iso-paraffins present in MES compositions.
[0057] Excellent Thermal and Oxidation Stability: The thermal
stability of the MES compositions was determined according to the
Octel F21-61 test method where a visual rating was used to describe
the relative stability. The FT products lead to significantly less
carbon deposition on the fuel cell reformer catalyst than would be
expected from a conventional diesel type feedstock under
comparative reaction conditions.
[0058] Oxygen stability is tested through the calculation of the
amount of insolubles formed in the presence of oxygen. It measures
the fuel's resistance to degradation by oxygen by the ASTM D2274
test method or equivalent. The MES compositions are stable in the
presence of oxygen with the formation of insolubles of less than
0.2 mg/100 ml.
[0059] High Hydrogen To Carbon Content: The highly paraffinic
nature of the FT products and very low aromatic concentration
contribute to the high H:C ratios of the MES compositions.
[0060] In Table 1, four illustrative MES formulations are shown
which have been found compatible with their proposed use in gas
turbines, CI engines, including HCCI systems and fuel cells. The
expected quality and estimated yields of the MES formulations of
Table 1 are presented in Table 3.
[0061] The MES compositions may be suitable for use in fuel cells,
gas turbine engine and Cl engines, including HCCI systems as they
contain FT reaction derived products which are highly saturated
with less than 2 volume % olefins, have ultra-low levels of sulphur
with an almost zero aromatic hydrocarbon content, high linearity,
high hydrogen to carbon ratio, very good cold flow properties, and
high cetane number.
[0062] Lower reformer temperatures in fuel cells are required with
the use of FT naphtha, kerosene or diesel. The FT products lead to
significantly less carbon deposition on the catalyst than would be
expected from a conventional diesel type feedstock under
comparative reaction conditions and produce more steam. The MES
components have good cold flow properties as well as a high cetane
number because of the predominantly mono-, and to a lesser extent
other, branched forms of the paraffins which make these components
suitable for application in gas turbine engines, Cl engines,
including HCCI systems and fuel cells.
[0063] The highly paraffinic related properties such as high H:C
ratio, high cetane number and low density together with virtually
zero-sulphur and very low aromatics content give the FT products
their very good emission performance
DESCRIPTION OF THE DRAWINGS
[0064] The invention will now be described by way of non-limiting
example only with reference to the accompanying drawings. In the
drawings,
[0065] FIG. 1 shows a flow sheet for a process for the production
of a fuel of the invention;
[0066] FIG. 2 shows a flow sheet for an alternative process to that
in FIG. 1 but based on Natural gas;
[0067] FIG. 3 shows a flow sheet for a process using high molecular
mass feedstocks; and
[0068] FIG. 4 shows a flow sheet for a process such as that of FIG.
3 using use of coal, biomass or heavy oil as feedstock.
PROCESS DESCRIPTION
[0069] This invention includes four possible processes for the
production of MES components i.e. components for Fischer-Tropsch
derived compression ignition engine, gas turbine, and fuel cell
fuel which is interchangeably useable in compression ignition
engines, gas turbines, and fuel cells. Two of them are based in the
use of natural gas as feed and, the other two make use of any
hydrocarbonaceous feedstock possible of been gasified. Therefore,
feeds for the latter include coal, waste, biomass and heavy oil
streams.
[0070] The first process matter of this invention, presented in
FIG. 1, makes use of natural gas 11 which is converted to synthesis
gas at suitable process conditions in reformer 1. The reforming
reaction makes use of oxygen 13 obtained from an air separation
step 2 from atmospheric air 12. Water in the form of steam can also
be used in the reforming process.
[0071] Syngas 14 from the reformer stage is converted in FT unit 3
to synthetic hydrocarbons including at least two liquid streams, as
well as a gas stream and reaction water not shown. A portion of the
syngas might be derived from the hydrogen separation plant 4 where
a hydrogen rich stream 17 is produced for use in hydroconversion.
Alternatively, hydrogen can be produced in an independent facility
and transferred as stream 17.
[0072] The light synthetic hydrocarbons stream 15, sometimes named
FT Condensate, includes paraffins, olefins and some oxygenates,
mostly alcohols. This stream is transferred to hydrotreating unit 6
where olefins and oxygenates are hydrogenated into, mostly, the
corresponding paraffin hydrocarbons. The process is completed at
conditions such that the average carbon number of the feed remains
essentially unchanged in hydrotreated product 18.
[0073] The heavy synthetic hydrocarbons 16, sometimes named FT Wax,
has a similar chemical composition as that of the lighter stream
15; however, under normal processing these species are solid at
room temperature. This stream is transferred to the hydroconversion
unit 5, preferably a hydrocracker system, where (1) olefins and
oxygenates are hydrogenated to the corresponding paraffins which in
turn and together with the original long chain paraffins (2)
undergo cracking reactions resulting in a significant reduction of
its average carbon number compared with that of the feed. The
resulting hydrocracked product 19 is a mixture of normal and
iso-paraffins.
[0074] The combined hydroconverted products 18 and 19 are
fractionated in distillation unit 7 resulting in at least four
process streams. Stream 20 is a light hydrocarbon blend, typically
in the 35-160.degree. C. ASTM D86 distillation range. Stream 21 is
a medium hydrocarbon blend, typically in the 155-250.degree. C.
ASTM D86 distillation range. Stream 22 is a heavy hydrocarbon
blend, typically in the 245-360.degree. C. ASTM D86 distillation
range. Stream 23 includes unconverted species whose boiling points
are above 360.degree. C. and is recycled to the hydrocracker to
increase the production of the valuable species. The separation
process also results in collecting a gas stream--not shown.
[0075] The MES products are produced using these streams on their
own or in blends as shown in Table 1 above.
[0076] An alternative second process scheme based on natural gas is
presented in FIG. 2. From a process standpoint it differs from the
one described before in that the light synthetic hydrocarbons 15 is
not hydrotreated. Instead it is blended with the hydrocracked
product 18. The resulting stream 19 is fractionated then in
distillation unit 7 resulting in products 20-22 similar to those
above described. However, while these products can be used in the
same blends, they include some olefins and oxygenates in their
composition.
[0077] Using alternative high molecular mass feedstocks this
invention provides the process scheme shown in FIG. 3. This concept
makes use of coal, biomass or heavy oil which in the form of stream
11 is converted to synthesis gas at suitable process conditions in
gasifier 1. The gasification process makes use of oxygen 13
obtained from an air separation step 2 from atmospheric air 12.
Water in the form of steam can also be used in the process. This
process is then substantially similar to the one discussed before
with reference to FIG. 1. However, and as an additional stream,
some liquids are produced during the gasification process and
separated as stream 24. These might be recovered as a product or
recycled to the gasifier to enhance production of the valuable
streams. Other than this, process units and streams in FIG. 3
correspond to those in FIG. 1 and its associated process
description
[0078] Finally, and as an alternative to this concept, it is
provided a fourth process scheme similar in essence to the second
option discussed here above. As the one just discussed, this makes
use of coal, biomass or heavy oil as feedstock and makes use of
gasifier 1 as described in the previous paragraph. This process is
then substantially similar to the one discussed before with
reference to FIG. 2. However, and as an additional stream, some
liquids are produced during the gasification process and separated
as stream 24. These might be recovered as a product or recycled to
the gasifier to enhance production of the valuable streams. Other
than this, process units and streams in FIG. 4 correspond to those
in FIG. 2 and its associated process description.
* * * * *