Abstract: A method and a system for purification of oil, said method comprising the steps of: -providing separation aid and oil to be purified to at least one sedimentation tank; -waiting for allowing a sludge phase to sediment to a bottom part of the sedimentation tank, said sludge phase comprising the separation aid together with impurities from the oil; -removing an oil phase not comprising said sludge phase from the at least one sedimentation tank; and -filtering said oil phase through a depth filter for removing any possible remaining separation aid and impurities.

Abstract: A method and a system for purification of oil, said method comprising the steps of: —providing separation aid and oil to be purified to at least one sedimentation tank; —waiting for allowing a sludge phase to sediment to a bottom part of the sedimentation tank, said sludge phase comprising the separation aid together with impurities from the oil; —removing an oil phase not comprising said sludge phase from the at least one sedimentation tank; and —filtering said oil phase through a depth filter for removing any possible remaining separation aid and impurities.

Abstract: A system (1; 101) and a method for purification of oil, said system comprising:—at least one feed tank (3) comprising oil to be purified;—a separation aid dosing device(13);—at least one basic sedimentation tank (21a, 21b) comprising at least one inlet (23a, 23b) connected to the feed tank (3) and to the separation aid dosing device (13) for receiving oil to be purified and separation aid, said at least one basic sedimentation tank (21a, 21b) further comprising at least one sludge phase outlet (41a, 41b) provided in a bottom part (37a, 37b) of the basic sedimentation tank and at least one oil phase outlet (39a, 39b);—at least one advanced sedimentation tank (121) comprising at least one sludge phase inlet (122) connected to the at least one sludge phase outlet (41a, 41b) of the at least one basic sedimentation tank (21a, 21b), said advanced sedimentation tank (121) further comprising at least one sludge phase outlet (141; 141a, 141b) connected to a sludge tank (143) and at least one oil phase outlet (139a, 13

Abstract: A method and a system for purification of contaminated oil. Said method comprises the steps of: —providing contaminated oil and a separation aid in a tank (3); —waiting for allowing a sludge phase comprising the separation aid together with impurities from the oil to settle in a bottom part (4) of the tank (3); —reusing the sludge phase for purification of new contaminated oil.