Method for preparing low-pour point, high-aromatic, and environmental-friendly rubber oil by combining extraction and dewaxing

Abstract

A method for preparing an environmental-friendly rubber oil, including: conducting extraction in an extraction tower, where a primary extraction solvent is introduced into an upper section of the extraction tower, a raw oil is introduced into a middle-lower section of the extraction tower, and a secondary extraction solvent is introduced into a lower section of the extraction tower; subjecting a material at a bottom of the extraction tower to solvent recovery to obtain a secondary extract oil; mixing a substance flowing out from a top of the extraction tower, a solubilizer and a part of the primary extraction solvent, cooling to −15° C. to 10° C., and filtering to obtain a wax paste and a filtrate; subjecting the wax paste to heating evaporation and solvent recovery to obtain a wax; and subjecting the filtrate to heating evaporation and solvent recovery, obtaining the environmental-friendly rubber oil.

What is claimed is: 
     
         1 . A method for preparing an environmental-friendly rubber oil by combining extraction and dewaxing,
 comprising the following steps:   (1) conducting the extraction in an extraction tower, wherein a primary extraction solvent is introduced into an upper section of the extraction tower, a raw oil is introduced into a middle-lower section of the extraction tower, and a secondary extraction solvent is introduced into a lower section of the extraction tower, wherein the primary extraction solvent is N-methylpyrrolidone (NMP), the raw oil is an extract oil, and the secondary extraction solvent is a C7-C12 alkane;   (2) subjecting a material at a bottom of the extraction tower to a first solvent recovery to obtain a secondary extract oil;   (3) mixing a substance flowing out from a top of the extraction tower, a solubilizer and a part of the primary extraction solvent sent by a pump in a static mixer, subjecting a resulting mixture to cooling to a temperature of −15° C. to 10° C. in a cooler, and then filtering in a filter to obtain a wax paste and a filtrate, wherein the solubilizer is at least one selected from the group consisting of benzene, toluene, and xylene;   (4) subjecting the wax paste to a second solvent recovery by a first heating evaporation to obtain a wax; and   (5) subjecting the filtrate to a third solvent recovery by a second heating evaporation to obtain a dewaxed oil, namely the low-pour point, environmental-friendly rubber oil.   
     
     
         2 . The method for preparing the environmental-friendly rubber oil by combining extraction and dewaxing of  claim 1 , wherein a mass ratio of the primary extraction solvent introducing into the upper section of the extraction tower to the raw oil is in a range of 2:1 to 3.5:1. 
     
     
         3 . The method for preparing the environmental-friendly rubber oil by combining extraction and dewaxing of  claim 1 , wherein the lower section of the extraction tower is at a temperature of 40° C. to 60° C., and the upper section of the extraction tower is at a temperature of 60° C. to 80° C. 
     
     
         4 . The method for preparing the environmental-friendly rubber oil by combining extraction and dewaxing of  claim 1 , wherein a volume ratio of the part of the primary extraction solvent to the solubilizer mixed with the substance flowing out from the top of the extraction tower is in a range of 40-50:60-50. 
     
     
         5 . The method for preparing the environmental-friendly rubber oil by combining extraction and dewaxing of  claim 1 , wherein a volume ratio of the solubilizer to the raw oil is in a range of 1:1 to 3:1.