Synthesis method of polyester polyol

Abstract

The invention discloses a synthesis device of polyester polyol. The synthesis device comprises a reaction kettle, a reflux condenser, an intermediate tank and a second condenser, wherein the reaction kettle is provided with a heat conduction oil inlet and a heat conduction oil outlet; the reflux condenser is provided with a coolant inlet and a coolant outlet; the second condenser is provided with the coolant inlet and the coolant outlet; the reaction kettle is communicated with the intermediate tank, the intermediate tank is communicated with the reflux condenser; the intermediate tank is filled with a water-absorbing substance; the outlet of the reflux condenser is provided with a temperature control point; the reflux condenser is communicated with the second condenser, the reaction outlet of the second condenser is divided into two paths to be respectively communicated with a vacuum device and an empty valve. The synthesis device of the polyester polyol is characterized in that the intermediate tank filled with the water-absorbing substance is added between the reaction kettle and the reflux condenser. Compared with the traditional process device, the synthesis device has the advantages that the reaction speed is fast, the reaction time is short, the energy consumption is low, the equipment utilization rate is improved, the investment is saved, the wastewater treatment is simple and the treatment cost is low.

Description

technical field [0001] The invention belongs to the technical field of polyester polyol synthesis, in particular to a polyester polyol synthesis device. Background technique [0002] Polyester polyols are formed by polycondensation of small molecule polyols and dibasic acids. This is an equilibrium reversible reaction. During the reaction process, the small molecule water produced during the reaction must be continuously removed to disrupt the balance before the reaction can continue. To make the reaction proceed quickly, the reaction temperature must be increased and the water generated during the reaction must be removed in time. [0003] The dibasic acids used mainly include: [0004] (1) Saturated fatty acids: monooxalic acid, succinic acid, adipic acid, suberic acid, etc.; [0005] (2) Unsaturated fatty acids: maleic acid, fumaric acid, etc.; [0006] (3) Aromatic acids: terephthalic acid, isophthalic acid, phthalic acid or anhydrides. [0007] Polyols are: [0008...

AI Technical Summary

Problems solved by technology

[0015] 2. Lose a certain amount of small molecule polyols

Even if the top temperature of the reflux condenser B1 can be precisely controlled at 100-105°C, a certain amount of small molecule polyols will still be entrained by water vapor, so the excess of small molecule polyols is about 5% higher than the theoretical value

[0016] 3. High energy consumption

resulting in high energy consumption in the entire reaction process

[0017] 4. Long response time

During the reaction process, the condensed water is continuously refluxed and cannot be discharged in time, which inhibits the reaction, and there is water, the temperature of the material rises slowly, the reaction speed of the material is slow, and the reaction time is prolonged

[0018] 5. High cost of wastewater treatment

However, due to the high COD of small molecule polyols entrained by water vapor, the cost of wastewater treatment is high

[0019] At present, some more advanced devices are figure 2 The reflux condenser B1 is changed to a distillation column, which can effectively reduce the discharge of small molecular polyols with water vapor, but it also has problems such as long reaction time and high energy consumption.

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