THERMOECONOMIC ANALYSIS OF TECHNICAL GREENHOUSE WARMING MITIGATION

A model process is presented for carbon dioxide removal from the flue gases of hard coal fired power plants by refrigeration under pressure. Retention of 90% of the CO2 decreases overall plant efficiency from 38% to 26%. Deep sea deposition or decomposition of the CO2 in solar-thermal processes with solar hydrogen may complete the removal. CO2 emissions can also be curbed by reduced fossil fuel consumption at constant energy services. Heat cascading via heat exchangers, cogeneration and heat pumps are the appropriate conservation technologies. On the basis of given energy demand profiles and by means of vector optimization combined with the methods of Second Law Analysis we investigate the trade-offs between fossil fuel conservation, CO2 emissions and the total cost of the energy system. Without CO2 removal, the maximum saving potentials of primary energy in the industrial sector turn out to be about 25% in Germany, 30% in the U.S.A., and 45% in The Netherlands and Japan. Including CO2 removal techniques for power plants and cogeneration units in the energy-cost-CO2 optimization program, we find that in the combined German sectors of industry and households one may reduce overall emissions of CO2 by more than 70% and energy consumption by more than 20% at a total cost increase of 50-100%. Thus, continued use of fossil fuels and greenhouse warming mitigation seem to be possible, albeit at considerably enhanced cost.