Method for separating C6 mixed hydrocarbon by two-stage PSA

Abstract

The invention relates to a method for separating C6 mixed hydrocarbon by two-stage PSA (Pressure Swing Adsorption). Methyl cyclopentane, n-hexane and cyclohexane with the purity higher than 99.0% arerespectively extracted from C6 mixed hydrocarbon with different sources. The method comprises a two-stage PSA separation process, wherein the first-stage PSA separation process comprises the followingsteps: mixing a polar separation adsorbent with C6 hydrocarbon mixture steam, adsorbing and separating a component A under a first pressure condition to obtain a high-purity component B, and desorbing and liquefying the component A adsorbed by the adsorbent under a second pressure condition to obtain a first-stage desorbed substance A-rich mixed hydrocarbon. In the second-stage PSA separation process, a selective separation adsorbent is mixed with A-rich mixed hydrocarbon steam of a first-stage desorbed substance, a component B is adsorbed and separated under a first pressure condition to obtain a high-purity component A, and the component B adsorbed by the adsorbent is desorbed and liquefied under a second pressure condition to obtain a second-stage desorbed substance. And the second-stage desorbed substance is mixed with the original C6 hydrocarbon mixture, and the two-stage PSA separation and adsorption separation process is repeated.

Description

technical field [0001] The invention relates to the technical field of two-stage pressure swing adsorption (PSA) separation, in particular to a method for separating C6 mixed hydrocarbons by PSA. Background technique [0002] Industrially, methylcyclopentane is used as an organic solvent to dissolve resins, waxes, asphalt, rubber and drying oils. It has recently been found that methylcyclopentane is a good refrigerant and can replace Freon as a refrigerant in fluorine-free and environmentally friendly refrigeration equipment. n-Hexane is mainly used as a solvent to prepare viscose to bond shoe leather or bags. It is often used in wiping and cleaning operations in the production process of the electronic information industry, as well as crude oil leaching in the food manufacturing industry, propylene solvent recovery in the plastics manufacturing industry, and chemical industry. extractant, solvent extraction of floral fragrance produced by daily chemicals, etc. Cyclohexane...

AI Technical Summary

Problems solved by technology

Since the separation factor of the separated C8 aromatics molecules on the K, Ba-Y zeolite polar separation zeolite molecular sieve adsorbent is generally relatively low, no more than 5, so the annual processing capacity is as high as tens to millions of tons of mixed C8 aromatics separation to produce PX The project uses a simulated moving adsorption bed with isothermal operation, and realizes its separation operation with a very precise, complex and expensive multi-way rotary valve, and the equipment investment is high.

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