System
Studies
The following are reports documenting
system studies performed for gasification technologies:
Destec Gasifier
IGCC Base Cases (June 2000) [PDF-278KB]
Two IGCC Base Cases have been developed based on the Destec gasification
process. The cases differ primarily in how the generated fuel syngas is cooled
and in the gas cleanup sections. The Destec process uses a two stage,
oxygen-blown, entrained flow, slagging gasifier. Both cases use a raw gas
cooler (which is integrated with the gasifier and other heat exchangers) to
generate high pressure superheated steam and a cyclone to remove particulates,
which are recycled to the gasifier. The syngas leaves the cyclone at 650 oF
for Case 1 and at 1004 oF for Case 2. For Case 1, the fuel gas is
further cooled and scrubbed before entering a cold gas cleanup unit (CGCU)
using the MDEA/Claus/Scot process for sulfur removal and recovery. For Case 2,
fuel gas enters a chloride guard bed that is followed by a hot gas cleanup
unit (HGCU) using a transport absorber/regenerator process. The sulfur dioxide
generated from the transport regenerator is sent to an acid plant for
producing sulfuric acid. Power is recovered for both cases using a modified
W501G gas turbine and a three-pressure level reheat steam cycle.
KRW Gasifier IGCC
Base Cases (June 2000) [PDF- 335KB]
Three IGCC Base Cases have been developed based on the KRW gasification
process. The primary differences are dependent on the approach for removing
sulfur. Case 1 uses in-bed sulfur capture and a polishing hot gas cleanup
section to provide clean fuel gas. Cases 2 and 3 use no in-bed sulfur capture.
All cases use a raw gas cooler (which is integrated with the gasifier and
other heat exchangers) to generate high pressure superheated steam and
cyclones to remove particulates, which are recycled to the gasifier. Gas
filters are then used for further cleaning with the fuel gas stream exiting at
1004 oF for all cases. For Case 2, the fuel gas is further cooled
and scrubbed before entering a cold gas cleanup unit (CGCU) using the MDEA/Claus/Scot
process for sulfur removal and recovery. For Cases 1 and 3, fuel gas enters a
chloride guard bed that is followed by a hot gas cleanup unit (HGCU) using a
transport absorber/regenerator process. For Case 1, the HGCU section is a
polishing process with the sulfur dioxide rich waste stream from the
regenerator being combined with the solid waste stream from the gasifier and
sent to a sulfator. For Case 3, the sulfur dioxide generated from the
transport regenerator is sent to an acid plant for producing sulfuric acid.
Power is recovered for all cases using a modified W501G gas turbine and a
three-pressure level reheat steam cycle.
Shell Gasifier
IGCC Base Cases (June 2000) [PDF-275KB]
Two IGCC Base Cases have been developed based on the Shell gasification
process. The cases differ primarily in how the generated fuel syngas is cooled
and in the gas cleanup sections. The Shell process uses an oxygen-blown,
entrained flow, slagging gasifier. Both cases use a raw gas cooler (which is
integrated with the gasifier and other heat exchangers) to generate high
pressure superheated steam and a ceramic filter to remove particulates, which
are recycled to the gasifier. The syngas leaves the ceramic filter at 640 oF
for Case 1 and at 1004 oF for Case 2. For Case 1, the fuel gas is
further cooled and scrubbed before entering a cold gas cleanup unit (CGCU)
using the MDEA/Claus/Scot process for sulfur removal and recovery. For Case 2,
fuel gas enters a chloride guard bed, which is followed by a hot gas cleanup
unit (HGCU) using a transport absorber/regenerator process. The sulfur dioxide
generated from the transport regenerator is sent to an acid plant for
producing sulfuric acid. Power is recovered for both cases using a modified
W501G gas turbine and a three-pressure level reheat steam cycle.
Texaco Gasifier
IGCC Base Cases (June 2000) [PDF-349KB]
IGCC Base Cases have been developed for three Texaco Gasifier cases that
differ primarily in how the generated fuel syngas is cooled and in the gas
cleanup sections. For Case 1, the gasifier system includes a high-pressure
water quench section that rapidly reduces the solid/gas mixture to
approximately 425 oF (605 psia). The Texaco Radiant/Convective
design is used in Cases 2 and 3. In this design, the mix of gas/solids from
the gasifier enters a radiant syngas cooling (RSC) system, (perhaps larger in
size than the gasifier vessel), where cooling to approximately 1500 oF
is accomplished by generating high-pressure steam. For Case 2, a convective
syngas cooling (CSC) /gas scrubbing system cools the raw fuel stream to about
305 oF (400 psia) by generating additional steam and by reheating
the clean fuel gas from the CGCU section. For Case 3, the CSC is used only to
generate steam and cools the syngas to approximately 1004 oF. Cases
1 and 2 use a gas scrubber and a low temperature gas cooling/heat recovery
section to reduce the raw fuel gas stream to 103 oF prior to
entering a CGCU section for sulfur removal. In Case 3, the raw fuel gas is
cleaned for particulates using cyclones and gas filters before entering a
chloride guard bed. The sulfur removal is accomplished in a HGCU section and
sulfur is recovered using a sulfuric acid plant.
Transport
Gasifier IGCC Base Cases (June 2000) [PDF-256KB]
Two IGCC Base Cases have been developed based on the Transport gasification
process. The cases differ primarily in the oxidant used for the gasification
section. Both cases use a raw gas cooler (which is integrated with the
gasifier and other heat exchangers) to generate high pressure superheated
steam and a ceramic filter to remove particulates, which are recycled to the
gasifier. The syngas leaves the gas cooler at 1004 oF for both
Cases. The fuel gas enters a chloride guard bed that is followed by a hot gas
cleanup unit (HGCU) using a transport absorber/regenerator process. The sulfur
dioxide rich waste stream from the HGCU is sent to a sulfator. Power is
recovered for both cases using a modified W501G gas turbine and a
three-pressure level reheat steam cycle.
British Gas /
Lurgi Gasifier IGCC Base Cases (June 2000) [PDF-273KB]
Two IGCC Base Cases have been developed based on the BGL gasification process.
The BGL process uses an oxygen-blown, moving-bed, slagging gasifier. The
Illinois #6 Coal is fed to the gasifier as a mixture of coarse coal (i.e.
above 1/4"), fines, and coal briquettes. The oxygen is supplied from a
cryogenic air separation plant (ASU) that is integrated with the gas turbine
compressor. The steam requirements are furnished from the bottoming steam
cycle. In Case 1, the raw fuel gas produced is cooled to remove the heavy
hydrocarbon components (tars, oils, naphtha) which are recirculated to the
gasifier. After additional cooling, the fuel gas then enters a cold gas
cleanup unit (CGCU) using the MDEA/Claus/Scot process for sulfur removal and
recovery. The cleaned fuel gas is reheated, resaturated and combined with
recirculated nitrogen from the ASU and sent to the gas turbine section. In
Case 2, the raw fuel gas is sent through a filter, to remove any particulates,
and then through a chloride guard bed before being sent to the transport
desulfurization unit. The sulfur dioxide generated from the transport
regenerator is sent to an acid plant for producing sulfur dioxide. The cleaned
hot fuel gas is combined with recirculated nitrogen from the ASU and sent to
the gas turbine section. Power is recovered for both cases using a modified
W501G gas turbine and a three-pressure level reheat steam cycle.
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