Acetonitrile double-effect pressure-swing refining separation system

Abstract

The invention discloses an acetonitrile double-effect pressure-swing refining separation system. The system comprises an atmospheric pressure tower, preheaters, a high pressure tower and a reboiler, wherein a tower kettle pipeline of the atmospheric pressure tower is provided with an inter-stream heat exchanger and a flash evaporation tank, the tower kettle pipeline of the atmospheric pressure tower is successively connected with the inter-stream heat exchanger and a third preheater, and then introduced into the flash evaporation tank, the top of the evaporation flash tank is connected with atower kettle of the atmospheric pressure tower through a pipeline, a bottom pipeline of the flash evaporation tank is connected with a public water pipe network, the tower top of the high pressure tower is connected with the inter-stream heat exchanger through a pipeline, a pipe path of the inter-stream heat exchanger is further connected with the tower top of the high-pressure tower through a pipeline in a circulating manner, a communication pipeline is arranged between a pipe path of the inter-stream heat exchanger and a first preheater, a pressure reducing valve is arranged on the communication pipeline, and a second preheater is further arranged between a material inlet pump and the high pressure tower. The inter-stream heat exchanger and the flash evaporation tank are added in the process system, energy consumption of the separation system is reduced, load of a subsequent wastewater treatment unit is reduced, and benefits of environmental maintenance are significantly increased.

Description

technical field [0001] The invention relates to the technical field of acetonitrile refining process, in particular to an acetonitrile double-effect pressure swing refining separation system. Background technique [0002] In the production of chemical products, using liquefied petroleum gas with low added value of resources produced in the petrochemical process as raw material, the integrated process technology plan for the production of acrylonitrile by-product acetonitrile can effectively broaden the organic chemical industry chain and improve chemical resources. Added value and enhanced market competitiveness and many other advantages. The main process is as follows: First, the liquefied petroleum gas is removed from the raw material by the pretreatment unit to obtain propane with a mass purity of 97.1%. Propane is produced by two-stage catalytic dehydrogenation (reaction temperature 600°C) in the propane dehydrogenation reaction unit Propylene, propylene enters the ammo...

AI Technical Summary

Problems solved by technology

The mixture of acetonitrile and water forms different azeotropes under normal pressure and high pressure, so the traditional process uses normal and high-pressure distillation towers to separate the mixture system of acetonitrile and water. In the traditional process system, the balance of the high-pressure tower system It cannot be reasonably coupled with the atmospheric tower, and the energy utilization efficiency is low; the wastewater generated by the atmospheric tower still needs to enter the wastewater treatment unit for treatment, and the amount of wastewater circulation is greatly increased

The traditional production process is relatively inefficient in terms of energy consumption, environment, and resource utilization in the actual production process

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