Dewatering of petroleum-containing sludges with recovery of the oil component

US4417976A · kind A · utility

Assignee

• BASF SE

Inventors

• Bruno Sander · Ludwigshafen, DE
• Friedrich Hovemann · Hockenheim, DE
• Kurt Scherling · Hemsbach, DE

Key dates

• Filing date: Dec 22, 1981
• Grant date: Nov 29, 1983
• Expiry date: Dec 22, 2001

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C02F11/12
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process for dewatering petroleum-containing sludges by a two-stage method using finely divided additives and organic flocculants, wherein PA1 (a) finely divided additives, such as ash, coal, sand or mixtures of these, in a free-flowing form or as an aqueous suspension, are homogeneously dispersed in the petroleum-containing sludge, in an amount such that the total solids content of the resulting mixture is from 10 to 30% by weight, especially from 12 to 20% by weight, PA1 (b) this sludge mixture is treated with an aqueous solution of an organic flocculant, preferably of anionic nature, PA1 (c) the greater part of the sludge water is removed by gravity filtration, PA1 (d) the pre-dewatered sludge mixture is treated with an aqueous solution of aluminum salts or trivalent iron salts and PA1 (e) this mixture is substantially dewatered by pressure filtration, in the course of which the greater part of the petroleum present is also removed.