Coal hybrid advanced systems are under development. These combine the best features of both gasification and combustion technologies, using coal in a two-stage process. The first stage gasifies the majority of the fuel and runs a gas turbine, the second stage combusts the residual ‘char’ to produce steam. Efficiencies greater than 50% are possible.
In addition to these CCTs, a development which can apply to all of the generating systems is the co-firing with coal of biomass or wastes. This involves burning or gasifying such materials together with the primary fossil fuel. Benefits can include reductions in CO2, SOx and NOx emissions relative to coal-only fired plants, and recovery of useful energy from biomass and wastes at high efficiencies can be achieved, without the need for building dedicated plant. In this way, the coal-fired power industry can utilise waste from industries.