The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 23, 1982
Filed:
Oct. 28, 1980
Laird C Fletcher, Natchitoches, LA (US);
Harold J Beard, Baton Rouge, LA (US);
Richard O'Blasny, Natchitoches, LA (US);
Delta Central Refining, Inc., Natchitoches, LA (US);
Abstract
Used oil is rerefined by distillation and extraction with tetrahydrofurfuryl alcohol. In accordance with the process, used oil is rerefined by distillation to remove a volatile forecut followed by further distillation with recirculation provisions to obtain the desired fractions of lubricating oil products while reducing the vaporization temperature of the oil. The recycle effect tends to reduce coking and cracking while providing a greater recovery of lubricating oil products through the carrier effect of the light ends. After the desired fractions of lubricating oil have been obtained by the distillation phase of the process, tetrahydrofurfuryl alcohol is utilized in an extraction process to remove impurities remaining in the distilled oil. The tetrahydrofurfuryl alcohol-lube oil mixture is separated into a raffinate and extract stream for distilling and steam stripping the tetrahydrofurfuryl alcohol therefrom. In one embodiment of the invention, a waste oil feedstock has water, gasoline and other similarly volatile components removed in a first stage evaporator (16). Heavier fuel, such as fuel oil is then removed in the second stage evaporator (28). A light lube oil fraction is then obtained by distillation with a third stage wiped-film evaporator (40). Finally, a heavy lube oil fraction is obtained by distillation of the bottoms from the evaporator (40) in a fourth-stage with a wiped-film evaporator (64). The heavy and light lube oil fractions are then treated in the fifth stage of the process in which each of the lube oil fractions mix with tetrahydrofurfuryl alcohol in extraction columns (80) and (96). Each of the tetrahydrofurfuryl alcohol and oil fractions are then separated into raffinate and extract streams for further treatment to further separate and recover the finished light and heavy lube oil products and tetrahydrofurfuryl alcohol which is reused in the fifth stage of the process.