Ammonia gas absorption device for tert-butyl alcohol reduced pressure recovery tower and ammonia gas absorption method

Abstract

The invention discloses an ammonia gas absorption device for a tert-butyl alcohol reduced pressure recovery tower and an ammonia gas absorption method. The device comprises a primary cooler 2, a storage tank 3, a vacuum buffer tank 4, a deep cooling device 5, a vacuum pump 6, a gas-liquid separator 7 and a reflux pump 8. A pipe connected to the top of a tert-butyl alcohol reduced pressure tower is orderly connected to the primary cooler, the storage tank and the reflux pump and then is connected to a tert-butyl alcohol reduced pressure tower return pipe. A noncondensable gas outlet of the primary cooler is orderly connected to the vacuum buffer tank, the vacuum pump and the gas-liquid separator by pipes and then is connected to the storage tank by a pipe. The storage tank is orderly connected to the deep cooler and the vacuum pump by pipes and then is connected to the storage tank by a pipe. The bottom of the storage tank is provided with a tower top finished product collection hole of the tert-butyl alcohol reduced pressure tower. An overflow plate is arranged in the storage tank or a liquid level automatic control valve is arranged at the finished product collection hole. The ammonia gas absorption device realizes recovery of a noncondensable tert-butyl alcohol vapor phase from a tert-butyl alcohol reduced pressure tower, absorbs ammonia gas in the system, satisfies rectifying tower separation requirements, improves a product yield and realizes stable caprolactam ammoximation.

Description

technical field [0001] The invention relates to an ammonia absorption device and method for a tert-butanol decompression recovery tower. Background technique [0002] In the production process of caprolactam, in order to reduce the problem of high energy consumption of single-column rectification in the tert-butanol recovery tower, multi-effect distillation has been gradually applied to industrial production because it greatly reduces the energy consumption of single-column distillation. The multi-effect rectification system consists of columns with different operating pressures. The higher-pressure tower overhead steam is used as the heat source for the reboiler of the adjacent lower-pressure rectification tower, so that in the multi-effect rectification, only the first tower Heat needs to be added to the tower kettle, and the top steam of the last tower is condensed with a cooling medium, while the rest of the towers no longer need external heating and cooling, so it has a...

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Problems solved by technology

[0003] Chinese patent CN103214346 provides a multi-effect rectification process for tert-butanol recovery. The steam consumed in the tert-butanol recovery process is only 45-65% of that of single-column rectification, which greatly reduces the cost of the rectification process. Energy consumption, but because the treated substance contains ammonia gas, a volatile component, the last effective distillation tower is operated under vacuum, causing ammonia gas to enter the working fluid of the vacuum pump or be discharged into the atmosphere, while ammonia gas is produced by caprolactam The raw material of the ammoximation reaction process in the device, the ammonia gas does not condense, resulting in waste of ammonia gas raw materials, and the tert-butanol product at the top of the tower is unqualified due to the low content of ammonia gas, and pollutes the environment

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