An overview of these capture strategies is shown in Figure 7.A.1. All three are available, in principle, for all hydrocarbon sources, but relative costs differ, as do the energy-conversion routes that are favored. Gasification is probably the most competitive for high-rank coals, but this may reflect the lack of investment thus far in the development of gasifiers for low-rank coals. Petcoke is similar to a high-rank coal. Biomass may be co-fired with coal or petcoke, but to gasify a combination in which biomass represents a significant fraction of the total thermal input, there may need to be a separate biomass gasifier with its own feed-handling strategies.
CO2 capture from natural-gas-fired power plants can be accomplished using any of the three strategies. One proposed project design features autothermal reforming of natural gas to make hydrogen, with combustion of the hydrogen