Patent ID: 6033637
Filing Date: 2000-03-07
Classification: B01D,C01G

Abstract:
A method for the recovery of products from the combustion ashes of petroleum fuels, collected by a dust collector disposed in an exhaust gas fire flue of a boiler using petroleum fuels, wherein the combustion ashes contain ammonium sulfate, said method comprisingpreparing a slurry by mixing water with said combustion ashes;injecting either calcium oxide or calcium hydroxide into said slurry and reacting the ammonium sulfate with either calcium oxide or calcium hydroxide to form gypsum and ammonia;recovering ammonia from the gypsum slurry by flowing said gypsum slurry down from an upper portion of a packed column and blowing air or steam from a lower portion of the packed column to bring the air or steam into counter-current contact with said gypsum slurry and thereby stripping ammonia therefrom; andseparating gypsum from said gypsum slurry.