Production of electric power from fossil fuel with almost zero air pollution

摘要

The present system produces electrical power from burning coal or natural gas, with almost zero air pollution. In its lack of air pollution is similar to air and wind power, but less costly. Its power may be produced day and night and when the wind is not blowing. Its power is less costly than nuclear power, and without the possibility of radiation damage, melt down, and log-term radiation storage.;The US tax law provides a $10 or $20 credit per ton CO2 for sequestration in “Secure geological storage”. See 26 USC §45Q. The estimated cost of this system's CO2 carbon capture is below that tax credit. The tax credit of $20/ton (large coal power station—800K tons of CO2) would generate a profit of millions of dollars.;This system's capture cost for CO2 is about the same in gas or coal plants. However, coal plants generate about 3 times the CO2 tonnage of gas plants per unit of electric power. In one example, the system uses combined cycle gas turbine-steam units (CCGT) thermal efficiency of 50-60%. CCGT exhaust gas is relatively cool and clean, with almost no particulates, nitrogen oxide, or mercury;The CO2 is separated from nitrogen (N2) using at least two cascaded stages of membrane separators. The permeance of the membranes of the first stage is at least 800 and preferably 2000-10,000. This permits low gas compression which saves the cost of larger compressors and electrical power. Also the area of the membranes are small due to their high permeance. The membranes of the second stage have a lower permeance with higher selectivity and higher pressure may be used. This does not add much to cost because the volume of gas separated is only 2-7% (gas) or 12-14% (coal) of the volume of CCGT exhaust gas. The over 90% pure separated CO2 is then compressed and sold or sequested in geological formations.