Leading options for the capture of CO2 at power stations

In recent years there has been a considerable improvement in the cost and efficiency of large-scale power generation technology. Some progress has also been made in the development of technologies for the capture Of CO2. There is therefore a need to reassess the methods most likely to be used today if deep reductions in CO2 emissions are required in power generation. The processes assessed in this paper are generally regarded as the leading process options for capture of CO2. State-of-the-art technology for construction of a new power station starting in year 2000 is assumed. Five CO2 capture processes are discussed: a pulverised coal (p/f) power plant working on a super-critical steam cycle with CO2 capture by scrubbing the flue gas with monoethanolamine (MEA); coal feed to an integrated gasification combined cycle (IGCC) with shift conversion of the synthesis gas and CO2 capture by a physical solvent; a natural gas combined cycle (NGCC) with CO2 capture by MEA scrubbing; a NGCC with MEA scrubbing and partial re-circulation of the flue gas; partial oxidation of natural gas, followed by shift conversion, CO2 capture in a physic-chemical solvent, and combustion of hydrogen in a combined cycle. All these processes reduce emissions Of CO2 to atmosphere by 80% or more compared to reference power generation technologies in which CO2 is not captured. The 3 natural gas processes in which CO2 is captured incur similar penalties in terms of increased cost of electricity and cost per tonne of CO2 emission avoided. For coal, CO2 capture in an IGCC process incurs smaller penalties than capture from the flue gas of a supercritical p/f plant.