Patent ID: 6248910
Filing Date: 2001-06-19
Classification: A23C,A23L,B01D,C11B

Abstract:
A multi-stage extraction process for removing oil from oil-bearing organic materials, which process comprises:(a) introducing the oil-bearing organic material into an extraction zone;(b) introducing an effective solvent into said extraction zone;(c) maintaining said solvent in contact with said organic material at an effective temperature and pressure so that the solvent is in liquid form, and for an effective amount of time to remove a fraction of the oil, thereby resulting in a partially extracted organic material;(d) passing the resulting oil-laden solvent, in liquid form, from said extraction zone to a separation zone, wherein solvent is separated from the oil for recycle to the extraction zone;(e) collecting the oil from the separation zone;(f) reducing the pressure of said extraction zone to a point where at least a fraction of any remaining solvent will vaporize;(g) introducing an effective solvent into said extraction zone;(h) maintaining said solvent in contact with said partially extracted organic material at an effective temperature and pressure so that the solvent is in liquid form, and for an effective amount of time to remove a predetermined amount of oil;(i) passing the resulting oil-laden solvent, in liquid form, from said extraction zone to a separation zone, wherein solvent is separated from the oil for recycle to the extraction zone;(j) collecting the oil from the separation zone;(k) reducing the pressure of said extraction zone to a point where at least a fraction of any remaining solvent will vaporize;(l) repeating steps (g) through (k) until the desired level of oil extraction of said organic material is reached; and(m) removing the extracted organic material from the extraction zone.