Trimethylamine tail gas recovery system and method in parylene production process

Abstract

The invention discloses a trimethylamine tail gas recovery system and method, and belongs to the technical field of chemical engineering and waste gas treatment. Trimethylamine tail gas generated by areaction kettle enters from the top of an absorber through a gas pipe; an absorbent in a circulating tank is pumped into the upper part of an absorber through a pump to form a liquid film; absorptionliquid after reaction is discharged into the circulating tank from the lower part of the absorber; and tail gas is discharged into a vacuum unit from the bottom of the absorber; the tail gas is pumped to an exhaust funnel through a vacuum unit, and is discharged at high altitude after being detected to reach the standard by an on-line monitor; when the discharge rate of trimethylamine in the online monitor is greater than 80% of the discharge standard, the absorption liquid in the circulating tank is pumped into the reaction kettle to realize recovery of trimethylamine in the tail gas, and finally p-methylbenzyl chloride in a metering tank is pumped into the circulating tank. According to the system and the method, the recovery of trimethylamine in the tail gas is realized, the tail gas emission can reach the standard, and gas-liquid parallel flow is controlled; the method can be carried out at room temperature without heating, so that the energy consumption is reduced, and the comprehensive economic benefit is improved.

Description

technical field [0001] The invention relates to a system and method for recovering trimethylamine tail gas, and belongs to the technical fields of chemical industry and waste gas treatment. Background technique [0002] Trimethylamine tail gas is produced in the synthesis and cyclization sections of the Parylene production process. This type of waste gas has a small air volume, high concentration, and single component, which has a high recovery value. Trimethylamine is a colorless gas at room temperature, with a fishy smell and foul odor, soluble in water, ethanol, etc., flammable and toxic, with a boiling point of 3-4°C. Because of its low boiling point, the volatilization amount is large during use; the smell threshold is low, and the stench seriously affects the ambient air quality around the factory area. [0003] At present, the trimethylamine tail gas produced in the production process of parylene often uses water or dilute sulfuric acid as the absorbent. When water i...

AI Technical Summary

Problems solved by technology

But in this invention, trimethylamine is used in excess, and the reaction process requires heating, and the reaction time is long. A small part of the excess trimethylamine volatilizes to produce harmful exhaust gas, and most of it needs to be neutralized by acid to produce waste salt, resulting in waste of resources.

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