Magnetohydrodynamics--low Air Pollution Power Generation.
Bienstock-D; Bergman-PD; Henry-JM; Et Al
Pres Asme Ann Winter Mtg 11/11-15/73 Detroit Michigan Preprint 73-WA/ENER-3 :12 pages
Magnetohydrodynamics has very low air pollution potential. In pilot plant tests in which a 2.2 Wt.-Pct sulfur coal was burned in a cyclone furnace at 200 lb/hr and 4000 deg f at a seed concentration of 1 g-mole k2co3/kg coal, 99.8 pct removal of so2 was obtained with only 5 ppm so2 in the gaseous effluent. Operating the combustor with 95 pct of stoichiometric oxygen and ambient air admitted at 2000 deg f, NO2 emissions decreased to 150 ppm or 0.12 Lb NO2/million btu. This represents a 94 pct reduction from single- stage operation at 102 pct of stoichiometric oxygen. As the gas- cooling rate in the experimental unit is higher than projected for a commercial plant, it is expected that a commercial plant would experience even lower nox emissions. A mathematical model using the zeldovich mechanism was adequate to follow the nox decomposition in the air-rich system; an extended zeldovich was more appropriate in the fuel-rich regime. Experiments showed that at high slag- rejection rates of greater than 90 pct recovery of the potassium seed by aqueous extraction was better than 99 pct. Cost estimates of a 1,000-mwe mhd-steam plant, in which the spent seed is recovered by aqueous extraction and then regenerated with reducing gases to remove the sulfur, showed an operating cost of the seed recovery- sulfur removal steps of 9 pct of the overall power costs of 9.1 Mills/kw-hr.
Pres. Asme Ann. Winter Mtg., 11/11-15/73, Detroit, Michigan, Preprint No. 73-WA/ENER-3