Patent ID: 6039880
Filing Date: 2000-03-21
Classification: B01D

Abstract:
A method for dehydrating a waste hydrocarbon sludge, comprising the steps of:(a) providing a waste hydrocarbon sludge comprising oil, water and sediment wherein the content of water and sediment is greater than or equal to about 10% vol;(b) providing a formation water;(c) adding to the formation water a clarifying agent in an amount of less than or equal to 250 ppm based on the volume of the formation water so as to provide a solution;(d) washing the waste water hydrocarbon sludge by mixing the waste hydrocarbon sludge with the solution so as to provide a sludge-water mixture having a ratio of water to hydrocarbon of at least about 1:1;(e) holding the sludge-water mixture at rest for at least two hours so as to obtain partial separation of water from oil to provide a partially dewatered sludge-water mixture;(f) adding a demulsifier to the partially dewatered sludge-water mixture to provide a sludge-water-demulsifier mixture;(g) heating the sludge-water-demulsifier mixture to a sufficient temperature and holding for a time sufficient to provide a hydrocarbon phase having a water content of less than or equal to about 1% vol.