Device and process applied to reinforced absorption of methyl iodide in acetic acid tail gas

Abstract

The invention relates to a device and a process applied to reinforced absorption of methyl iodide in acetic acid tail gas. The device comprises two reinforced absorption devices, two stages of absorption liquid pumps, two stages of absorption liquid storage tanks, a demister and an absorption liquid cooler which are connected with one another in series, wherein a gas inlet of a first-stage reinforced absorption device is communicated with an acetic acid tail gas source; a gas outlet of the first-stage reinforced absorption device is communicated with a gas inlet of a second-stage reinforced absorption device; a liquid inlet is communicated with a second-stage absorption liquid storage tank by virtue of a first-stage absorption liquid pump; a liquid outlet is directly communicated with a first-stage absorption liquid storage tank; a gas outlet of the second-stage reinforced absorption device is communicated with an inlet of the demister; a liquid inlet is communicated with a liquid outlet of the absorption liquid cooler by virtue of a second-stage absorption liquid pump; the liquid outlet is directly communicated with a second-stage absorption liquid storage tank; a liquid discharging hole of the demister is communicated with the second-stage absorption liquid storage tank. The device is simple in structure, small in size, easy to operate, low in operation cost and high in production efficiency.

Description

technical field [0001] The invention belongs to the technical field of energy saving and environmental protection, and in particular relates to a device and a process for strengthening the absorption of methyl iodide in acetic acid tail gas. Background technique [0002] No matter what kind of main catalyst is used to produce acetic acid by methanol carbonylation, methyl iodide or other iodine-containing compounds are used as cocatalysts and stabilizers. The introduction of iodine, on the one hand, makes the carbonylation reaction easier to occur, on the other hand, it brings great difficulties to the recovery and utilization of the subsequent acetic acid tail gas. [0003] Acetic acid tail gas has two working conditions of high pressure and low pressure, which contains a relatively high content of CO and has a high recycling value. For an acetic acid plant with an annual output of 100,000 tons of acetic acid, the tail gas volume is about 1500-2000m 3 / h. Because the methy...

AI Technical Summary

Problems solved by technology

Because the methyl iodide in the acetic acid tail gas cannot be reduced to a very small amount, the enterprise can only give up the recycling of the tail gas, remove the methyl iodide to the emission standard and send it to the torch for combustion, resulting in great waste

CO is the basic raw material for the production of acetic acid. A large amount of CO is vented and burned, which not only wastes energy, increases the production cost of acetic acid, but also pollutes the environment.

At the same time, the tail gas contains a small amount of highly corrosive methyl iodide, which restricts most of the CO separation and purification process

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