Sepg. hydrogen sulphide and nitrogen oxide simultaneously - from gas mixts., using chelated iron salt with iron at least, partly ter-valent

摘要

Elimination of H2S and nitrogen oxide contained as impurities in a gas which is low in uncombined O2 is described, in which the number of moles of H2S is at least half the number of moles of nitrogen oxide. The method comprises washing the gas with an absorbing soln. in the water or an organic solvent contg. a chelated iron salt at least partly in the ferric form, to leave the gas free of its impurities, and with an aq. or organic soln. contg. S in solid state, which is sepd., the soln. being then treated with a gas contg. free O2 to regenerate it prior to returning it to contact the impure gas. For treating neutral, inert or reducing gases which are prods. of combustion in stoichiometric conditions or in insufficiency of air, of hydrocarbon gases, such as methane propane, fuel, contg. sulphurous prods., but also each be derived from the gasification of coal.