Abstraction distillation system special for carbonization benezene or sulfureous containing benezene, and fine purification method

Abstract

The present invention relates to a special extractive and distillation system of coked pure benzene or sulfur-containing pure benzene, and a refining method thereof. The basic equipment consists of a raw material preheater, a CS2-doffing tower, an extractive and doffing tower, a main extractive tower, a extractant regenerating tower, an auxiliary extractant regenerating tower and a thiophene refining and recovery tower which are connected orderly. The CS2-doffing tower and the extractive and doffing tower are provided with a reboiler; the main extractive tower and the auxiliary extractant regenerating tower are provided with a middle reboiler. The refining method comprises pre-extractive distillation, extractive distillation and refining of the thiophene. The process is simple. The method can be used for preparing both high-purity low-sulfur benzene and expensive thiophene. The whole process has no waste discharge and no environmental pollution, and belongs to the technology conducive to the environment. The materials has no serious corrosion to the equipment; the cost is low; the yield is high; and the method has broad prospects for application, and is an excellent method for steel enterprises and coking enterprises to further process and make use of by-products.

Description

technical field [0001] The invention belongs to the refining technology of coking benzene in the field of chemical industry, and in particular relates to a special extraction and rectification system for coking pure benzene or sulfur-containing pure benzene and a refining method thereof. Background technique [0002] As we all know, benzene is an important basic organic chemical raw material. As an intermediate of organic chemical and fine chemical raw materials, the consumption of benzene accounts for about 45% to 50% of benzene resources. The domestic petroleum benzene raw material has been in short supply, and the price is relatively high. , which makes coking benzene an important source of local fine chemical raw materials, and its demand is increasing year by year. Coking benzene has a complex composition and contains various impurities, among which sulfide thiophene affects the deep processing of coking benzene, and thiophene is also a very expensive chemical raw mater...

AI Technical Summary

Problems solved by technology

[0005] In addition, each tower in the whole separation system is equipped with facilities such as tower bottom heating and tower top condensation, so it needs to consume a lot of heat energy and circulating cooling water; some processes (such as German patent 4586986) adopt pressurized operation in the preheating rectification tower , and then use the high-temperature steam at the top of this tower as the heat source for other towers. Although this can save energy, due to the high operating pressure and high temperature of the pre-rectification tower, the investment in equipment will be greatly increased, and a high-temperature heat source will be required. Investing in the construction of a high-temperature heat carrier system leads to high production costs

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