Method for treating waste gas from dimethylamine recovery by synthetic leather dimethyl formamide

Abstract

The present invention is a treatment method of synthesizing the leather dimethyl formamide and recycling the dimethylamine emission. The method comprises the preheating, de-amine and drainage to form the top water de-amine technology of the DMF recycling tower; the concentration of the top water dimethylamine of the dehydration tower I and the dehydration tower II in the recycling of the three towers is relatively low and the top water dimethylamine is sent into the middle section of the de-amine tower; the concentration of the top water dimethylamine of the distillation column is relatively high and the top water dimethylamine is sent into the upper section of the de-amine tower for filtering downward; the dimethylamine in the water on the tower top is taken away by the lifting steam in the de-amine tower; the purified water after the removal of the dimethylamine is collected in the tower kettle and then enters the storage tank for the recycling in the wet production; the inside of the de-amine tower consists of four sections of high-efficient wire packing; the pressure of the vacuum work is 16 KPa; the temperature on the tower top is 50 DEG C; the tower reactor is 55 DEG C; the tower reactor of the de-amine tower is heated with the vapor on the top of the dehydration tower II and the distillation column, or is directly heated with the left steam of the boiler; the dimethylamine exhaust is pumped out by the vacuum pump; the concentration of the dimethylamine is 20 percent to 30 percent; and the dimethylamine exhaust is sent to the boiler for burning; the energy-saving and exhaust-discharging effects are good. Compared with the device of the same category, the required heat and cooling water are greatly lowered; the economic benefit and social benefit are obvious.

Description

technical field [0001] The invention relates to a treatment method for dimethylamine waste gas in the recovery process of polyurethane synthetic leather dimethylformamide. Background technique [0002] In recent years, domestic polyurethane (PU) synthetic leather industry manufacturers have increased equipment production lines, increased product output year after year, increased variety of designs and colors, and increasingly broadened product markets. They are widely used in various industries of the national economy. According to statistics, there are currently more than 2,000 artificial leather and synthetic leather enterprises in China, more than 516 dry-process production lines above designated size, more than 364 wet-process production lines, and more than 100 recycling devices. The industry's largest annual production capacity will reach 5.6 billion meters. PU leather The industry is developing rapidly. [0003] Dimethylformamide (DMF) is a solvent widely used in PU ...

AI Technical Summary

Problems solved by technology

Although dimethylamine is not very toxic, it has a low boiling point, is volatile, and is easily soluble in water. It has a strong foul smell, which will make people feel very unpleasant. At present, domestic synthetic leather enterprises basically do not treat it, and directly discharge it into the atmosphere. It pollutes the environment, damages the surrounding air quality, and affects human health. Therefore, it is necessary to treat the dimethylamine waste gas recovered from PU synthetic leather DMF.

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