Method for preparing BTX and co-producing tetramethylbenzene from C9<+> heavy aromatic hydrocarbons

Abstract

The invention relates to a method for preparing BTX and co-producing tetramethylbenzene from C9<+> heavy aromatic hydrocarbons. The method comprises: carrying out catalytic cracking conversion on C9<+> heavy aromatic hydrocarbons to obtain a first-stage hydrocarbon mixing product using BTX and trimethylbenzene as main components, and separating respectively with an ethane removing tower, a butane removing tower, a hexane removing tower, a BTX removing tower and a trimethylbenzene removing tower to obtain dry gas, liquefied gas, C5-C6 non-aromatic hydrocarbons, BTX, trimethylbenzene and C10<+> heavy aromatic hydrocarbons, wherein the dry gas, the liquefied gas, the C5-C6 non-aromatic hydrocarbons and the BTX are adopted as products; carrying out a reaction on the trimethylbenzene and a certain amount of methanol to obtain a tetramethylbenzene-rich second-stage mixing product, and separating the products to obtain dry gas, wastewater and liquid-state hydrocarbons, wherein the liquid-state hydrocarbon products return to the ethane removing tower so as to be separated; and carrying out crystallization separation on the C10<+> heavy aromatic hydrocarbons to obtain tetramethylbenzene and a heavy component residue liquid, wherein the tetramethylbenzene and the part of the heavy component residue liquid are adopted as the product, and the remaining heavy component residue liquid return to a catalytic cracking reactor. According to the present invention, with the method, the moving bed non-hydrogen cracking and the tetramethylbenzene preparation using trimethylbenzene alkylation are compounded, such that the BTX is produced at a maximum while the high added value tetramethylbenzene can be co-produced.

Description

Technical field [0001] The invention belongs to the technical field of aromatics chemical production, and specifically relates to a C 9 + Method for preparing BTX and co-producing mesitylene from heavy aromatics. Background technique [0002] BTX (benzene, toluene, xylene) is an important primary organic raw material, and its output and scale are second only to ethylene and propylene. At present, my country has become the world's largest producer, consumer and importer of BTX. In the future, with the further growth of the national economy, my country's demand for BTX will further increase. [0003] BTX is mainly derived from catalytic reforming. While catalytic reforming produces BTX, it will produce a part of C by-product. 9 + Heavy aromatics, C 9 + Heavy aromatics account for approximately 20% of reforming processing capacity. According to statistics, the current domestic reforming capacity is 120 million tons / year, C 9 + The production of heavy aromatics is approximately 25 mi...

AI Technical Summary

Problems solved by technology

[0006] The present invention mainly solves the current C 9 + The processing technology of heavy aromatics requires hydrogen operation, high hydrogen consumption, low conversion rate of raw materials, large dry gas output, and low added value of products. BTX and homogeneous Tetramethylbenzene, which has the advantages of high conversion rate of raw materials, high yield of target products, and high added value of products

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