Continuous processing of oil sludge - to recover clean oil by removing water, salts and solids

摘要

(A) Continuous processing of a water and salt contg. oil sludge stream involves (a) treating the heated stream in a three-phase decanter (1) for removal of solids and for sepn. into a water stream contg. residual oil and and oil stream contg. residual water; (b) separating the oil stream in a distillation column (2) into an oil fraction stream and a water fraction stream contg. low boiling hydrocarbons; (c) feeding the water stream and the oil fraction stream into a wash column (3) contg. an aq. washing phase (4) with an s.g. at 20 deg.C of more than 1100 kg/cu.m.; (d) withdrawing practically salt-free oil contg. residual washing phase from the top (5) of the wash column (3); (e) separating the residural washing phase from the oil in a separator (b); and (f) discharging excessive aq. washing phase from the washing column. A plant for carrying out the process is also claimed. USE/ADVANTAGE - The process is useful for processing crude oil extracted from formations associated with salt-ocntg. water or for processing oil sludges from sea spills. It provides continuous recovery of water- and salt-free clean oil and a waste water which can be treated by conventional clarification plants. The process is reliable and can process oil sludges of varying s.g.