Method of treating a gaseous mixture comprising hydrogen and carbon dioxide

A method of producing power, said method comprising:

• partially oxidizing or reforming a fuel selected from the group consisting of carbonaceous fuel, hydrocarbonaceous fuel and biomass fuel, to produce synthesis gas;
• reacting at least a portion of the CO in the synthesis gas with H2O in a shift conversion reaction to produce a gaseous mixture comprising H2, CO2 and at least one combustible gas selected from the group consisting of H2S, CO and CH4;
• separating H2 from said gaseous mixture to produce a separated H2 gas and a crude CO2 gas comprising said combustible gas(es);
• combusting at least a portion of said combustible gas(es) in said crude CO2 gas in an oxyfuel combustion process using an excess of oxidant gas consisting essentially of O2 and, optionally, at least one fuel selected from the group consisting of carbonaceous fuel, hydrocarbonaceous fuel and biomass fuel, to produce heat and a CO2 product gas comprising combustion products of said combustible gas(es);
• recycling a portion of said CO2 product gas as feed to the oxyfuel combustion process;
• recovering at least a portion of said heat from at least a portion of said CO2 product gas by indirect heat exchange with at least a portion of said separated H2 gas or a gas derived therefrom, to produce warmed turbine fuel gas and cooled CO2 product gas;
• and
• feeding warmed turbine fuel gas to a gas turbine for power generation.

An apparatus for treating a gaseous mixture comprising H2, CO2 and at least one combustible gas selected from the group consisting of H2S, CO and CH4, said apparatus comprising:

• a separator for separating H2 from said gaseous mixture to produce a separated H2 gas and a crude CO2 gas comprising said combustible gas(es);
• a combustion reactor for combusting at least a portion of said combustible gas(es) in at least a portion of said crude CO2 gas in the presence of O2 to produce heat and a CO2 product gas comprising combustion products of said combustible gas(es);
• conduit means for feeding at least a portion of said crude CO2 gas from said separator to said combustion reactor;
• heat exchange means for providing indirect heat exchange between at least a portion of said CO2 product gas and at least a portion of said separated H2 gas or a gas derived therefrom to produce warmed H2-containing gas and cooled CO2 product gas;
• conduit means for feeding at least a portion of said CO2 product gas from said combustion reactor to said heat exchange means;
• and
• conduit means for feeding at least a portion of said separated H2 gas or a gas derived therefrom from said separator to said heat exchange means.

An apparatus for producing power, said apparatus comprising:

• a reactor selected from the group consisting of a partial oxidation reactor and reformer for producing synthesis gas comprising CO from a fuel selected from the group consisting of carbonaceous fuel, hydrocarbonaceous fuel, biomass fuel and liquid H2;
• a shift conversion reactor for reacting at least a portion of said CO with H2O to produce a gaseous mixture comprising H2, CO2 and at least one combustible gas selected from the group consisting of H2S, CO and CH4;
• conduit means for feeding said synthesis gas from said reactor to said shift conversion reactor;
• a separator for separating H2 from said gaseous mixture to produce a separated H2 gas and a crude CO2 gas comprising said combustible gas(es);
• conduit means for feeding said gaseous mixture from said shift conversion reactor to said separator;
• an oxyfuel combustion reactor for combusting at least a portion of said combustible gas(es) in said crude CO2 gas in an oxyfuel combustion process using an excess of oxidant gas consisting essentially of O2 and, optionally, at least one fuel selected from the group consisting of carbonaceous fuel, hydrocarbonaceous fuel and biomass fuel, to produce heat and a CO2 product gas comprising combustion products of said combustible gas(es);
• conduit means for feeding said crude CO2 gas from said separator to said oxyfuel combustion reactor;
• conduit means for feeding said oxidant gas to said oxyfuel combustion reactor;
• conduit means for recycling a portion of said CO2 product gas as feed to said oxyfuel combustion reactor;
• heat exchange means for providing indirect heat exchange between CO2 product gas and separated H2 gas or a gas derived therefrom to produce warmed turbine fuel gas and cooled CO2 product gas;
• conduit means for feeding CO2 product gas from said combustion reactor to said heat exchange means;
• conduit means for feeding separated H2 gas or H2-containing gas derived therefrom to said heat exchange means;
• a gas turbine for producing power;
• and
• conduit means for feeding warmed turbine fuel gas from said heat exchange means to said gas turbine.