Methylbenzene tower fractionation device and method driven by heat pump

Abstract

The invention provides a methylbenzene tower fractionation device and method driven by a heat pump. The methylbenzene tower fractionation device driven by the heat pump comprises a methylbenzene tower, a compression preheater, a compressor, a heat pump reboiler, a pressure relief valve, a tower top heat output heat exchanger, a tower top waste heat recovery heat exchanger, a tower top reflux tank,a tower top reflux pump and a tower bottom reboiler, wherein the compression preheater communicates with the tower top of the methylbenzene tower through a first stop valve; the compressor communicates with the compression preheater; the heat pump reboiler communicates with the compressor and the compression preheater and communicates with the bottom of the methylbenzene tower; the pressure relief valve communicates with the compression preheater; the tower top heat output heat exchanger communicates with the pressure relief valve through a second stop valve and communicates with the tower top of the methylbenzene tower through a third stop valve; the tower top waste heat recovery heat exchanger communicates with the tower top heat output heat exchanger; the tower top reflux tank communicates with the tower top waste heat recovery heat exchanger; the tower top reflux pump communicates with the tower top reflux tank and the tower top of the methylbenzene tower; and the tower bottom reboiler communicates with the bottom of the methylbenzene tower. According to the methylbenzene tower fractionation device and method driven by the heat pump, methylbenzene and C7-C9 aromatics are separated by the methylbenzene tower, the methylbenzene tower is driven by the heat pump, energy consumption of a single-tower system is reduced by 50%-70%, and the methylbenzene tower fractionation deviceand method driven by the heat pump have obvious advantages of energy saving and consumption reduction.

Description

technical field [0001] The invention relates to the technical field of separation of aromatics, and more specifically, to a heat pump-driven toluene tower fractionation device and method. Background technique [0002] Aromatics extraction is an important device for petrochemical enterprises to separate aromatics from reformed products. Liquid-liquid solvent extraction and solvent extraction distillation are widely used in industrial production. Among them, domestic petrochemical companies mostly use extractive distillation technology for aromatics recovery, and its working principle is to use highly selective solvents to change the relative volatility of feed components. In the mixture of aromatics and non-aromatics, due to the action of solvent, the relative volatility of non-aromatic components is increased. This promotion allows non-aromatic components to be evaporated to the top of the column in a traditional distillation column, while aromatics enriched at the bottom o...

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