Continuous low-energy consumption acetonitrile refining process

Abstract

The invention relates to a continuous low-energy consumption acetonitrile refining process which comprises the following steps of: continuously refining crude acetonitrile in a decyanation tower, a chemical treatment kettle, a drying tower, a finished product tower and a tail gas absorbing tower and removing impurities to obtain a qualified acetonitrile product. The chemical treatment kettle comprises three same kettles which are connected with one another in parallel; the three kettles respectively run through process control to accept feeding, reacting and discharging and circularly operate, so that the whole chemical treatment kettle continuously feeds and discharges and continuously refines acetonitrile; and the drying tower and the finished product tower are used for heat integration. Compared with the prior art, the continuous low-energy consumption acetonitrile refining process has the advantages of continuous and stable operation, reduced production energy consumption, reduced operation expense, improved economic benefit and the like.

Description

technical field [0001] The invention relates to a process for refining acetonitrile, in particular to a process for refining acetonitrile by-products produced in the process of producing acrylonitrile by propylene ammoxidation or propane ammoxidation. Background technique [0002] Acetonitrile, the molecular formula is CH 3 CN is a widely used organic chemical raw material and a solvent with excellent performance. It can be used as an extraction solvent in butadiene devices and isoprene devices, and can also be used as organic synthesis, medicine, pesticides, surfactants, fuels, etc. Synthetic raw materials for fine chemicals, and mobile phase solvents for high performance liquid chromatography. [0003] At present, acetonitrile produced by acrylonitrile by ammoxidation of propylene is the main source of acetonitrile product, and the output of acetonitrile is about 3% of the output of acrylonitrile product. A device with an annual output of 130,000 tons of acrylonitrile ca...

AI Technical Summary

Problems solved by technology

[0006] In the current acetonitrile refining process, the chemical treatment tank is single or double tank, and the chemical treatment tank is actually operated in batches. The content of impurities such as hydrocyanic acid in the output of the chemical treatment tank is difficult to control stably, which affects the subsequent unit operation. Continuous and stable operation

[0007] In addition, the existing acetonitrile refining process does not fully integrate and utilize heat, and the energy consumption is relatively high.

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