CN102070749B - Method for preparing wax-containing crude oil pour point depressant - Google Patents

Abstract

A kind of preparation method of waxy crude oil point depressant, this point depressant is formed by ternary copolymerization of maleic anhydride, styrene and vinyl acetate, comprises the following steps: (1) is equipped with condenser, adds maleic anhydride Acid anhydride and 75ml toluene, styrene and vinyl acetate are added dropwise, and the toluene solution of initiator benzoyl peroxide (BPO) is added dropwise simultaneously, and solvent is removed by distillation under reduced pressure to obtain solution A; (2) terpolymer A , tetracosyl alcohol, add in the there-necked flask that toluene, hydroquinone are housed, after heating and stirring until reactant dissolves completely, pressure distillation removes solvent toluene, obtains product B; (3) product B is first used 5% Neutralize the remaining acid with a sodium carbonate solution, wash with water until neutral, and finally vacuum-dry to constant weight to obtain the crude oil pour point depressant. Provided is a ternary polymer pour point depressant with wide application range, stable performance and excellent pour point depressing effect on crude oil with a pour point higher than 40°C.

Description

A kind of preparation method of waxy crude oil pour point depressant

technical field

The invention relates to a preparation method of a pour point depressant, in particular to a preparation method of a waxy crude oil pour point depressant.

Background technique

Most high-condensation crude oils in my country have high wax content, high freezing point, and poor low-temperature fluidity, which brings a lot of inconvenience to the transportation, mining and processing of crude oil, and increases production and transportation costs. For several years, the heating transportation process has been the only choice for crude oil pipeline transportation. It is relatively easy to implement and enables smooth and safe transportation of crude oil to its destination. But the process also has many disadvantages: (1) the fuel consumption is large; (2) once the pipeline stops for some reason, it cannot continue to add heat to the crude oil, and the pipeline is in danger of "condensation pipe"; (3) the middle The investment in the heating station is relatively large.

Therefore, the application of pour point depressants is an effective way to save energy and reduce consumption. Pour point depressant (PPD) is a kind of oil additive. When it is added in a small amount, it can greatly change the crystal form of paraffin in the oil, the interface state of the system and the rheological properties, reduce the freezing point and viscosity of crude oil, and improve The quality and efficiency of crude oil in oil production, gathering, storage and other work.

There are many kinds of crude oil pour point depressants studied at home and abroad, which can be generally divided into three categories: alkyl naphthalene, polyolefin and polyester. Although researches on pour point depressants have been active in various countries in recent years, they are relatively single in nature, and there are few reports on pour point depressants for crude oil with a freezing point higher than 40 °C.

Contents of the invention

The object of the present invention is to provide a kind of preparation method of waxy crude oil pour point depressant, the polymer high pour point crude oil pour point depressant that is formed by the polymerization of three kinds of monomers of maleic anhydride, styrene, vinyl acetate, provides a kind of Terpolymer pour point depressant with wide application range, stable performance and excellent pour point depressing effect on crude oil with pour point higher than 40°C.

The purpose of the present invention is achieved through the following technical solutions:

A preparation method of a waxy crude oil point depressant, the point depressant is formed by ternary copolymerization of maleic anhydride, styrene and vinyl acetate, comprising the steps of:

(1) In a four-necked flask equipped with a condenser and a stirrer, add maleic anhydride and 75 ml of toluene, pass nitrogen to replace the oxygen in the reactor, and raise the temperature to 80 °C, add styrene and vinyl acetate dropwise, Add the toluene solution of initiator benzoyl peroxide (BPO) dropwise simultaneously, control the flow rate for about 1 h to complete the dropwise addition, after constant temperature reaction for 4-6 h, desolventize under reduced pressure to obtain solution A;

(2) Add terpolymer A and tetracosyl alcohol into a three-necked flask equipped with toluene and hydroquinone, heat and stir until the reactants are completely dissolved, then add catalyst p-toluenesulfonic acid, heat up and react, and wait until When the amount of water is equivalent to the theoretical value, the reaction is stopped; the solvent toluene is removed by distillation under pressure to obtain the product B;

(3) Product B is first neutralized with remaining acid with 5% sodium carbonate solution, then washed to neutrality, and finally vacuum-dried to constant weight to obtain the crude oil pour point depressant.

The preparation method of described a kind of waxy crude oil point depressant, its described polymerization reaction: maleic anhydride, styrene, the mol ratio of vinyl acetate is 1.5:1.5:1; Solvent consumption is 95 ml, initiator The consumption is 1.5% of the total amount of reactants.

The preparation method of the described a kind of waxy crude oil point depressant, its described esterification reaction: the molar ratio of ternary polymer and tetracosanol is 1:2; Catalyst dosage is polymer and alcohol total amount 1.5%; the amount of polymerization inhibitor is 0.5% of the total amount of polymer and alcohol.

Advantage and effect of the present invention are:

The invention solves the problems of single property and freezing point higher than 40°C, and provides a ternary polymer pour point depressant with wide application range, stable performance and excellent pour point depressing effect on crude oil with freezing point higher than 40°C.

Detailed ways

The present invention will be described in detail below.

Example:

(1) Add 9.806 g of maleic anhydride and 150 ml of toluene into a four-necked flask equipped with a condenser and agitator, pass nitrogen to replace the oxygen in the reactor, and raise the temperature to 80 °C, add 78 ml of styrene dropwise, Vinyl acetate 5.768 g, and at the same time, 40 ml of toluene solution containing 0.8 g of initiator was added dropwise, and the flow rate was controlled for about 1 h to complete the dropwise addition. After reacting at a constant temperature of 80 °C for 4 h, the solvent was distilled off under reduced pressure to obtain product A.

(2) Purify the above-mentioned A and add it into a three-necked flask equipped with 70.624 g of tetracosyl alcohol, 80 ml of toluene and 0.772 g of hydroquinone, heat and stir until the reactants are completely dissolved, and add 2.613 g of catalyst p-toluenesulfonic acid , heated to 120-130 ℃ for 3 h to obtain product B.

(3) Product B is first neutralized with remaining acid with 5% sodium carbonate solution, then washed to neutrality, and finally vacuum-dried to constant weight to obtain the pour point depressant for high pour point crude oil of the present invention.

Claims (1)

1. A preparation method of a waxy crude oil point depressant, the point depressant is formed by terpolymerization of maleic anhydride, styrene and vinyl acetate, and alcoholysis with tetracosanol, it is characterized in that, comprising Follow the steps below: (1) In a four-necked flask equipped with a condenser and a stirrer, add maleic anhydride and 75 ml of toluene, pass nitrogen to replace the oxygen in the reactor, and raise the temperature to 80 °C, add styrene and vinyl acetate dropwise, Add dropwise the toluene solution of initiator benzoyl peroxide (BPO) simultaneously, control flow rate 1 h dropwise, after constant temperature reaction 4-6 h, desolventize under reduced pressure, obtain ternary polymer A; (2) Add terpolymer A and tetracosyl alcohol into a three-necked flask equipped with toluene and hydroquinone, heat and stir until the reactants are completely dissolved, then add catalyst p-toluenesulfonic acid, heat up and react, and wait until When the amount of water is equivalent to the theoretical value, the reaction is stopped; the solvent toluene is removed by distillation under pressure to obtain the product B; (3) Product B is first neutralized with remaining acid with 5% sodium carbonate solution, then washed to neutrality, and finally vacuum-dried to constant weight to obtain the crude oil pour point depressant; Described polyreaction: maleic anhydride, styrene, the mol ratio of vinyl acetate is 1.5:1.5:1; Toluene consumption is 95 ml, and initiator consumption is 1.5% of reactant total amount; Described esterification reaction: the molar ratio of terpolymer A and tetracosanol is 1:2; The amount of catalyst is 1.5% of the total amount of polymer and alcohol, and the amount of hydroquinone is the total amount of polymer and alcohol 0.5%.