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.

Claims

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.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The present disclosure will be described in detail below with reference to specific examples to facilitate further understanding of the present disclosure.

EXAMPLE 1

[0018] 100 g of an extract oil with a pour point of 28 C. was added into 300 mL of a composite solvent consisting of NMP and benzene at a volume ratio of 50:50. A resulting mixture was heated to 40 C., stirred evenly, cooled to 16 C. at a cooling rate of 2 C./min and held at the 16 C. for 10 min. A resulting system was vacuum-filtered with an acid-resistant glass funnel of model G3 at a rate of 37 mL/min for 11 min. A resulting wax paste and a filtrate were subjected to heating evaporation, respectively, resulting solvents were removed, to obtain a wax having a melting point of 45 C. and a dewaxed oil having a pour point of 2 C., respectively. A yield of the wax is 10.25%.

COMPARATIVE EXAMPLE 1

[0019] An extract oil and a filter the same as those in Example 1 were used. 100 g of the extract oil was added into 300 mL of a composite solvent consisting of butanone and toluene at a volume ratio of 50:50. A resulting mixture was heated to 40 C., stirred evenly, cooled to 16 C. at a cooling rate of 2 C./min and held at the 16 C. for 10 min. A resulting system was vacuum-filtered with an acid-resistant glass funnel the same as that in Example 1 (re-washed and dried before use) at a rate of 24 mL/min for 17 min. A resulting wax paste and a filtrate were subjected to heating evaporation respectively, resulting solvents were removed to obtain a wax having a melting point of 42 C. and a dewaxed oil having a pour point of 5 C. A yield of the wax is 15.2%.

[0020] It can be seen from the Example 1 and the Comparative Example 1 that the method according to the present disclosure could increase the dewaxing rate, reduce the oil content in the wax, and improve the dewaxing effect.

EXAMPLE 2

[0021] An extract oil and a filter the same as those in Example 1 were used. 100 g of the extract oil was added into 300 mL of a composite solvent consisting of NMP and toluene at a volume ratio of 30:70. A resulting mixture was heated to 40 C., stirred evenly, cooled to 16 C. at a cooling rate of 3 C./min and held at the 16 C. for 5 min. A resulting system was vacuum-filtered with an acid-resistant glass funnel the same as that in Example 1 (re-washed and dried before use) at a rate of 34 mL/min for 12 min. A resulting wax paste and a filtrate were subjected to heating evaporation respectively, resulting solvents were removed to obtain a wax having a melting point of 45 C. and a dewaxed oil having a pour point of 1 C. A yield of the wax is 11.6%.

EXAMPLE 3

[0022] An extract oil and a filter the same as those in Example 1 were used. 100 g of the extract oil was added into 300 mL of a composite solvent consisting of NMP and xylene at a volume ratio of 70:30. A resulting mixture was heated to 40 C., stirred evenly, cooled to 16 C. at a cooling rate of 3 C./min and held at the 16 C. for 10 min. A resulting system was vacuum-filtered with an acid-resistant glass funnel the same as that in Example 1 (re-washed and dried before use) at a rate of 45 mL/min for 9 min. A resulting wax paste and a filtrate were subjected to heating evaporation respectively, resulting solvents were removed to obtain a wax having a melting point of 45 C. and a dewaxed oil having a pour point of 0 C. A yield of the wax is 12.3%.

EXAMPLE 4

[0023] 100 g of a rubber oil having a pour point of 36 C. was added into 300 mL of a composite solvent consisting of NMP, benzene, and toluene at a volume ratio of 40:30:30. A resulting mixture was heated to 50 C., stirred evenly, cooled to 10 C. at 1 C./min and held at the 10 C. for 20 min. A resulting system was vacuum-filtered with an acid-resistant glass funnel the same as that in Example 1 (re-washed and dried before use) at a rate of 40 mL/min for 10 min. A resulting wax paste and a filtrate were subjected to heating evaporation respectively, resulting solvents were removed to obtain a wax having a melting point of 46 C. and a dewaxed oil having a pour point of 9 C. A yield of the wax was 15.2%.

EXAMPLE 5

[0024] 100 g of a rubber oil having a pour point of 36 C. was added into 400 mL of a composite solvent consisting of NMP, benzene, toluene, and xylene at a volume ratio of 50:20:20:10. A resulting mixture was heated to 50 C., stirred evenly, cooled to 10 C. at a cooling rate of 1 C./min and held at the 10 C. for 30 min. A resulting system was vacuum-filtered with an acid-resistant glass funnel the same as that in Example 1 (re-washed and dried before use) at a rate of 42 mL/min for 12 min. A resulting wax paste and a filtrate were subjected to heating evaporation respectively, resulting solvents were removed to obtain a wax having a melting point of 46 C. and a dewaxed oil having a pour point of 10 C. A yield of the wax was 12.3%.

[0025] Using the rubber oil, a butanone-toluene mixed solvent as a dewaxing solvent, with a same solvent-oil ratio and cooling rate, a filtration time was 17 min, a filtration rate was 29.8 ml/min, and the pour point of the dewaxed oil was 12 C. This indicates that the method according to the present disclosure has a higher filtration rate.

[0026] Certainly, the present disclosure may further include other various embodiments. A person skilled in the art could make various corresponding modifications and variations according to the present disclosure without departing from the spirit and essence of the present disclosure, but all these corresponding modifications and variations shall fall within the scope defined by the appended claims in the present disclosure.