Treatment of a waste sludge to produce a non-sticking fuel

Abstract

A waste sludge that contains water, oil and solids is subjected to filtration under vacuum or an applied inert gas pressure, preferably no more than 50 psia while utilizing a filter aid, to retain the maximum amount of oil in the filter cake. The filter cake is then dried at a relatively low temperature, slightly above the boiling point of water, to selectively remove water and produce a high heating value non-sticking solid. The product thus obtained in suitable for use as a solid fuel for a cement kiln or other combustion facilities. Depending on the amount of oil present in the original sludge, the applied pressure can be varied to retain different amounts of oil and to produce different heating values desired in the final solid fuel.

Dependencies are inferred from the claim text.