Extraction method for a segment of butadiene with NMP method

Abstract

The invention discloses a NMP butadiene sectional extraction method with a forward hydrogenation technology. The invention solves the problems existed in the prior NMP butadiene sectional extraction method that the tower top of a leaching and rectifying tower has large load, needs a circulated pressure compressor and has high requirement on the grade of refrigerant. The invention provides a butadiene section extraction method of leading a slight tower and canceling the circulated pressure compressor in the sectional extraction technology, and the invention comprises the steps of hydrogenation,releasing the slight components, leaching and rectifying, adsorption stripping, refining and so on. The invention is characterized in that the forward hydrogenation technology is adopted so that theacetylene hydrocarbon is released before leaching and rectifying, thereby increasing the operational safety, and the slight components are released in advance before leaching and refining so that thematerial positioned on the tower top of the adsorption stripping tower can be condensed to liquid phase, thereby being able to be transported to a refining tower through a pump; the invention cancelsthe compressor, thereby saving the device investment, decreasing the energy consumption, simplifying the operation, and being high in safety. Besides, with strong adaptive capacity on raw material, the operation of the device is not influenced by the regeneration period of catalyst.

Description

technical field [0001] The present invention relates to a kind of butadiene extraction method, more specifically, the present invention relates to a kind of one-stage extraction of butadiene using NMP (N-methylpyrrolidone, N-methylpyrrolidone) as solvent using pre-hydrogenation technology ene method. Background technique [0002] Butadiene is an important petrochemical basic organic raw material and synthetic rubber monomer, and is one of the most important components in the C4 fraction. At present, butadiene in the world is mainly extracted from the mixed C4 fraction produced by the ethylene cracking unit. This type of method is low in cost and has economic advantages. [0003] The traditional butadiene extraction process uses a two-stage extractive distillation process, but as the depth of ethylene cracking increases, the content of alkynes in the by-product C4 fraction of ethylene cracking gradually increases. The increase in alkyne content and the increase in the purit...

AI Technical Summary

Problems solved by technology

[0008] In order to solve the problems of large heat load at the top of the extractive distillation tower in the one-stage extraction process of NMP butadiene, the need for a circulating gas compressor and high requirements for refrigerant grade, the present invention proposes to introduce a A new method for one-stage extraction of butadiene with the removal of the tower and the cycle gas compressor

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