A comparative analysis of IGCCs with CO2 sequestration

This paper compares five Integrated Gasification Combined Cycles (IGCC) concepts where CO2 is sequestered and made available for permanent storage before it is discharged into the atmosphere. Three concepts comprise CO2 separation from the gas turbine exhaust: another one shift reaction and physical absorption of the syngas fuel; the fifth a semiclosed CO2-H2O gas turbine where the syngas is burnt in pure oxygen. The five schemes, all centred around a Texaco gasifier and a large, heavy-duty gas turbine, are compared on the basis of their technological features, their performance and projected costs of electricity. Compared to a conventional Texaco IGCC, CO2 removal reduces net plant efficiency by 6.5 to more than 8 percentage points, reduces net power output by 10 to 20% and increases the cost of electricity by approximately 20 to 40%. The scheme with shift reaction and physical absorption of the syngas fuel appears the most appealing option for the short-term implementation of low-CO2 emission IGCCs.