CO2 mitigation from coal-fired power generation

Following Kyoto, it is inevitable that there will be intense focus on power stations in Australia and elsewhere to generate electricity in ways that minimise the release of CO2 to the atmosphere. This article reviews the technologies available and the comparative costs for one option - the capture of CO2. The applicability, limitations, cost, power generating efficiency penalties and issues related to their use in Australia, including any research issues, are described. The review of C02 recovery and disposal option suggests that: 1. C02 capture and disposal technologies, although expensive and energy intensive, are commercially available. C02 removal plants are currently operated using MEA scrubbing to produce C02 for industrial utilisation. Although the basic technology is well understood, further research and development are still required on advanced capture methods such as PSA, TSA and use of membranes if these are to be applied to large power generation plants; 2. For coal fired power plants, known retrofit technologies to recover C02 together with subsequent disposal would more than double the cost of electricity and decrease power plant net efficiency significantly. Hence, to make responsible decisions, accurate and consistent economic and environmental analysis of all alternatives for atmospheric C02 mitigation is required; 3. IGCC power plants will have to be modified for C02 capture by adding high/low shift reactors and Selexol scrubbing units upstream of combustion turbines. However, when compared with a conventional power plant retroffited for C02 recovery there is little difference in terms of C02 emissions and cost of C02 emissions avoided. It is concluded that with emissions trading and carbon trading regimes likely be in place in the future, conventional power plant technology need not be ruled out completely