초록 ▼

A process (10) for co-producing power and hydrocarbons includes gasifying (16, 70) coal to produce a synthesis gas (36) and a combustion gas (86) both comprising at least CO1H2 and CO2 and being at elevated pressure, separating CO2 (18, 48) from the synthesis gas, and synthesizing (20, 22) hydrocarb

A process (10) for co-producing power and hydrocarbons includes gasifying (16, 70) coal to produce a synthesis gas (36) and a combustion gas (86) both comprising at least CO1H2 and CO2 and being at elevated pressure, separating CO2 (18, 48) from the synthesis gas, and synthesizing (20, 22) hydrocarbons from the synthesis gas. Power (1 14) is generated from the combustion gas, including by combusting (78) the combustion gas in the presence of oxygen and in the presence of at least a portion of the separated CO2 as moderating agent to produce a hot combusted gas (106) which includes CO2. The CO2 is recycled (1 12) or recovered from the combusted gas. In certain embodiments, the process (10) produces a CO2 exhaust stream (134) for sequestration or capturing for further use.

대표청구항 ▼

1. A process for co-producing power and hydrocarbons, the process including gasifying coal to produce a synthesis gas and a combustion gas both comprising at least CO, H2 and CO2 and being at elevated pressure; separating CO2 from the synthesis gas; synthesizing hydrocarbons from the synthesis gas;

1. A process for co-producing power and hydrocarbons, the process including gasifying coal to produce a synthesis gas and a combustion gas both comprising at least CO, H2 and CO2 and being at elevated pressure; separating CO2 from the synthesis gas; synthesizing hydrocarbons from the synthesis gas; generating power from the combustion gas, including combusting the combustion gas in the presence of oxygen and in the presence of at least a portion of said separated CO2 as moderating agent to produce the combusted gas which includes CO2; and recovering or recycling the CO2 from the combusted gas or a gas derived therefrom. 2. The process as claimed in claim 1, in which coal is gasified in a wet gasification stage to produce the combustion gas and in a dry gasification stage to produce the synthesis gas. 3. The process as claimed in claim 1, in which the molar ratio of H2 and CO in the combustion gas is higher than the molar ratio of H2 and CO in the synthesis gas. 4. The process as claimed in claim 1, in which the molar ratio of H2/CO in the combustion gas is at least 0.6. 5. The process as claimed in claim 1, in which the molar ratio of H2/CO in the synthesis gas is between about 0.3 and about 0.6. 6. The process as claimed in claim 1, which includes enriching a first portion of the combustion gas with H2 to produce an H2-enriched gas. 7. The process as claimed in claim 6, which includes purifying a portion of the H2-enriched gas to produce essentially pure hydrogen. 8. The process as claimed in claim 6, which includes mixing at least a portion of the H2-enriched gas with the synthesis gas, prior to synthesizing hydrocarbons from the synthesis gas, to provide synthesis gas with a higher molar ratio of H2/CO. 9. The process as claimed in claim 8, in which the H2-enriched gas is at elevated pressure and in which mixing at least a portion of the H2-enriched gas with the synthesis gas includes passing the H2-enriched gas through an expansion turbine to generate power. 10. The process as claimed in claim 1, in which generating power from the combustion gas includes expanding the combusted gas through a gas turbine expander to generate power and to produce hot exhaust gas, and recovering heat from the hot exhaust gas in a waste heat recovery stage which includes a waste heat boiler generating steam. 11. The process as claimed in claim 10, in which the waste heat boiler is a co-fired waste heat boiler and in which the synthesising of hydrocarbons from the synthesis gas produces a fuel gas, the waste heat boiler being co-fired with the fuel gas to raise the pressure and/or the temperature of the steam generated by the waste heat boiler. 12. The process as claimed in claim 1, in which the synthesising of hydrocarbons from the synthesis gas includes Fischer-Tropsch synthesis using one or more Fischer-Tropsch hydrocarbon synthesis stages, producing one or more hydrocarbon product streams and a Fischer-Tropsch tail gas which includes CO2, CO and H2. 13. The process as claimed in claim 1, which includes compressing at least a portion of the separated CO2 to exceed the operating pressure of a combustor used to generate power from the combustion gas, and mixing the compressed CO2 with oxygen already at pressure, before feeding the CO2 and oxygen to the combustor. 14. The process as claimed in claim 10, in which recovering or recycling the CO2 from the combusted gas includes treating exhaust gas from the waste heat boiler, comprising predominantly CO2 and water, to remove the water, leaving a CO2 exhaust stream, which is sequestrated or captured for further use.