Purification method for deep dehydration and impurity removal of olefin by full-temperature range adsorptive extraction

Abstract

The invention discloses a purification method for deep dehydration and impurity removal of olefin by full-temperature range adsorptive extraction. The purification method is characterized in that crude olefin feed gas (liquid) enters a gas / liquid phase adsorption process, an extraction and desorption process and an extracting agent regeneration process sequentially, moisture and trace impurity components are absorbed by an absorbing agent, and an olefin product with a purity of more than or equal to 99.9-99.99 percent (v / v) flows out from the top of an adsorption tower; after the adsorption process is completed, an extracting agent is introduced into the adsorption tower for the extraction and desorption process to dissolve out the moisture and the trace impurity components. Extraction anddesorption gas enters the extracting agent regeneration process, and the extracting agent is recovered and recycled after treatment. The purification method disclosed by the invention has the benefits that by adopting an adsorption-extraction and desorption process and in combination with an adsorption mechanism and an extraction and desorption dissolving mechanism, the whole operation process ismore stable and safer, the energy consumption is low, the product purity is high, the equipment investment cost is low, the purity of the olefin product is more than or equal to 99.9-99.99 percent, and the yield is more than or equal to 99 percent.

Description

technical field [0001] The technical field of purification and refining of olefins of the present invention, more specifically relates to a method for purification of olefins through adsorption, extraction, dehydration, dehydration and impurity removal throughout the temperature range. Background technique [0002] Olefin monomers required for polyolefin production, especially ethylene propylene, which has a wide range of uses, have more and more production methods, such as petroleum cracking, hydrocarbon steam thermal cracking, hydrocarbon dehydrogenation, methanol to olefins, ethanol condensation and dehydration Olefins, and petrochemical dry gas recovery of olefins, etc. However, different production methods have different impurity components contained in olefin products. When used to polymerize high-purity polyolefin products, various trace or trace impurities must be removed. Therefore, the selected The methods of purifying are also different. [0003] There are two w...

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Problems solved by technology

[0007] The present invention provides a purification method for deep dehydration and impurity removal of olefins through adsorption and extraction in the full temperature range. ") The extraction and separation process is coupled together. The adsorption mechanism and the desorption mechanism in the adsorption and desorption regeneration cycle are not the same. CCO2), carbon three and above components (C3+), methanol, ethanol, and water are used as extractants, and the extractant has a strong selective solubility for the adsorbate and the adsorbate has a large diffusion in the extractant fluid. The ability makes the desorption and regeneration completely complete, without considering the difficult situation of desorption caused by the deep adsorption of the adsorbate in the adsorption process, breaking through the traditional pressure swing adsorption (PSA), temperature swing adsorption (TSA), temperature swing adsorption (TPSA) and the whole The temperature range pressure swing adsorption (FTrPSA) process is limited to matching and solving the balance and contradiction between adsorption and desorption by changing pressure, temperature or pressure and temperature, making adsorption easy and desorption easy, thus solving the problem of existing olefins In dehydration and impurity removal methods, such as prominent contradictions between adsorption and desorption, short service life of adsorbent, incomplete regeneration, co-adsorption of water, oxygen-containing compounds and azeotropes, high-temperature heat carrier regeneration is required, troublesome subsequent treatment of regeneration gas, and high operating costs , Olefin yield and purity indicators are easily affected by the selection of purification process and other defects

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