Method for dewaxing extract oil and rubber oil

Abstract

A method for dewaxing of an extract oil and a rubber oil is provided, where a composite solvent including a polar solvent and a solubilizer is used as a dewaxing solvent, the polar solvent is N-methylpyrrolidone (NMP), and the solubilizer is at least one selected from the group consisting of benzene, toluene, and xylene. The method includes: mixing the composite solvent with the extract oil or the rubber oil at a temperature higher than a precipitation temperature of a wax, subjecting a resulting mixture to cooling crystallization and filtration to obtain a wax paste and a filtrate, and then independently subjecting the wax paste and the filtrate to solvent recovery by heating evaporation to obtain a wax and a dewaxed oil, respectively.

What is claimed is: 
     
         1 . A method for dewaxing of an extract oil and a rubber oil, comprising the following steps:
 (1) mixing a polar solvent and a solubilizer to obtain a composite solvent, and then mixing the composite solvent with the extract oil or the rubber oil to obtain a mixed solution, wherein a temperature for the mixing the composite solvent with the extract oil or the rubber oil is higher than a precipitation temperature of a wax in the extract oil, wherein the polar solvent is N-methylpyrrolidone, and the solubilizer is at least one selected from the group consisting of benzene, toluene, and xylene;   (2) cooling the mixed solution to a temperature of −20° C. to 10° C. and then holding at the temperature of −20° C. to 10° C. for 5 minutes to 30 minutes to obtain a cooled mixed solution;   (3) filtering the cooled mixed solution to obtain a wax paste and a filtrate;   (4) subjecting the wax paste to a first solvent recovery by a first heating evaporation to obtain the wax; and   (5) subjecting the filtrate to a second solvent recovery by a second heating evaporation to obtain a dewaxed oil.   
     
     
         2 . The method for dewaxing of the extract oil and the rubber oil of  claim 1 , wherein a volume ratio of the polar solvent to the solubilizer is in a range of 30-70:70-30. 
     
     
         3 . The method for dewaxing of the extract oil and the rubber oil of  claim 1 , wherein a volume ratio of the composite solvent to the extract oil is in a range of 2:1 to 4:1.