OIL SEPARATION METHOD

摘要

1531804 Separating oil and water; coated particles BRITISH PETROLEUM CO Ltd 28 Feb 1977 [9 March 1976] 09311/76 Headings BID and B2E [Also in Division Cl] Oil is separated from water contaminated therewith by passing a contaminated water stream through one or more purification beds containing solid particles treated with solution of a dispersant additive and a hydrocarbon activating agent. The particles may be of anthracite, charcoal, vermiculite, sand, glass beads, polystyrene, polyethylene or polypropylene. Dispersant additives are additives used in the formulation of lubricating oil, serving to maintain contaminants in fine suspension and prevent them from coagulating. They include (a) copolymers containing a carboxylic ester function and one or more additional polar functions (b) hydrocarbon polymers treated with various reagents to introduce polar functions (c) N-substituted long chain alkenyl succinimides (d) high molecular weight amides and polyamides (e) high molecular weight esters and polyesters (f) amine salts of high molecular weight organic acids, and (g) branched chain alkyl or aralkenyl polyamines in which the alkyl or alkenyl group has a number average molecular weight of 300 to 2100 and which has a total base number of at least 200. Preferred dispersants additives are polyisobutenyl diethylene triamine, polyisobutenyl triethylene tetramine and polyisobutenyl tetraethylene pentamine. Hydrocarbon activating agents include gasoline, naphtha, kerosene, light gas oil and heptane. In a preferred embodiment, the contaminated water stream is first filtered, and through the beds and then the coalesced oil droplets and water are allowed to separate by settling. Anthracite particles, pre-treated by reaction with diazomethane to convert labile hydrogen atoms to methyl groups, and then treated as above, are preferred. Suitably the water flows through the beds at an angle thereto, as where the direction of flow is horizontal and the beds are mounted vertically. Suitable apparatus comprises a container with an inlet and an outlet and one or more purification beds disposed between plates having passages therethrough, and a settling zone positioned after the last bed in the direction of flow of liquid through the container. A filter may be positioned upstream of the container and the settling zone may have two outlets, one for the discharge of oil and one for the discharge of water.