Novel extraction process for aromatic hydrocarbons

Abstract

The invention relates to a novel extraction process for aromatic hydrocarbons. Key improvements in the novel extraction process are that a depentanizing tower, an extracting and rectifying tower, a solvent recovering tower and a benzene tower employ novel inward-bending arc fin flat-ring filling material and a unique liquid distribution apparatus and filling material support apparatus are cooperatively used, so resistance drop, a pressure drop ratio and loads of the towers are effectively reduced and production capacity is substantially improved. The depentanizing tower and the extracting and rectifying tower employ main and assistant reboilers for heat adjustment, so optimization of heat supply is realized and long-period stale operation of the towers is guaranteed. Meanwhile, since a sulfonic acid ionic liquid is used as a cosolvent, influence of decomposition and corrosion of the solvent is reduced, usage cost of equipment is lowered, the service life of the solvent is prolonged, the problems of high contents of aromatic hydrocarbons and napthene and easy azeotropy of aromatic hydrocarbons in the extracting process of aromatic hydrocarbons are effectively overcome, investment cost and operation cost of the facilities are substantially reduced, and substantial economic benefits are obtained.

Description

technical field [0001] The invention belongs to the technical field of petrochemical industry and coal chemical industry, and specifically relates to the research and improvement of a new process for extracting aromatic hydrocarbons. Background technique [0002] Light aromatics, namely benzene, toluene, and xylene (BTX), are not only important chemical raw materials, but also the basic raw materials for the three major synthetic materials and fine chemicals. The world's BTX resources mainly come from reformed oil from petroleum fractions, ethylene by-product pyrolysis gasoline and coal tar. With the establishment and development of large-scale ethylene plants, the proportion of BTX recovered from pyrolysis gasoline will continue to rise. Whether recovering BTX from reformed oil or pyrolysis gasoline, aromatics extraction technology has become an indispensable means. Aromatics extraction provides high yields and high purity of benzene, toluene and various isomeric C8 aroma...

AI Technical Summary

Problems solved by technology

However, the degradation products of sulfolane are easy to polymerize into macromolecular acidic substances at high temperatures, corrode equipment, block pipelines, reduce product quality, and increase equipment maintenance costs and difficulties.

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