Waste water processing
AssigneeCogas Development Company
InventorLouis D. Friedman
Life of this patent
Estimating the term…
Abstract
Waste water formed in the gasification of coal and containing ammonia, H.sub.2 S, and phenolic compounds is treated to remove H.sub.2 S and a substantial proportion of its ammonia, while leaving sufficient ammonia in the water to maintain a pH of at least 8 (such as up to about 10.5, preferably about 8.5 to 9), the ammoniacal water is then flashed into a stream of superheated steam being fed to gasification zone. At the high temperatures in the gasification zone the organic impurities are decomposed.
Claims2
In a system of synthesis gas manufacture including a gasifier wherein fluidized char is reacted with steam using a particulate heat exchange material to sustain the endothermic steam-carbon reaction to produce a synthesis gas stream which on cooling gives water contaminated with H.sub.2 S and NH.sub.3 and a carbonizer wherein fluidized coal is carbonized below about 700.degree.C to provide said char and vapors which on cooling give oil and water contaminated with H.sub.2 S and NH.sub.3 and organic materials, the improvement which comprises steam-stripping the contaminated waters to remove the H.sub.2 S but retaining sufficient ammonia to keep the pH between about 8.5 to 10.5 and introducing the resulting treated water into the gasifier to provide at least a portion of the steam requirement therefor while consuming the organic materials.
Dependencies are inferred from the claim text.