SYSTEM STUDIES ON CO2 ABATEMENT FROM POWER-PLANTS

British Coal Corporation is taking a proactive stance in researching the issues associated with the possibility of enhanced global warming. One aspect of this research is the evaluation of the options which might conceivably be required if it tums out to be necessary to reduce CO2 emissions from coal fired power plants more than can be achieved by improved efficiency. A programme of assessment studies has been undertaken to evaluate the impacts on plant thermal efficiency of various options for CO2 removal for ultimate storage in some form of long term repository. Preliminary screening studies of the integration of CO2 recovery into coal fired power generation processes have indicated that routes based on Integrated Gasification Combined Cycles (IGCC) are preferred to those based on combustion. A series of options based on IGCC with CO shift is presented which compares alternative means of separating hydrogen from CO2, as required by this process route. Technologies evaluated include chemical and physical solvent scrubbing and membrane separation. This work was carried out with the intention of identifying thermally efficient flowsheets and the associated process development needs. The paper concludes by presenting economic considerations and describing British Coal's future research programme in this area.