Technological process of desulfurizing coking benzene to co-produce refined benzene and nitro benzene

Abstract

The technological process of desulfurizing coking benzene to co-produce refined benzene and nitro benzene includes the following steps: adding (68-80) % concentration sulfuric acid solution, nitric acid and coking benzene in the volume ratio of (1-5) to (0.01-1.1) to 1 into a nitrifying reactor and continuous nitrification at 5-75 deg.c; separating the resultant in a separator before neutralizing and water washing; rectifying in a rectifying tower with top temperature 50-80 deg.c and top pressure of 0.05-0.1 MPa to produce nitro benzene in the tower bottom; desulfurizing the mixture of benzene and CS2 from the top of the rectifying tower in a desulfurizing tower with top temperature of 35-75 deg.c to produce benzene in the tower bottom while eliminating CS2 from the top; and other steps. The process has less benzene loss and high economic utility.

Description

technical field [0001] The invention belongs to the technical field of coking benzene desulfurization, and more specifically relates to the innovation of coking benzene desulfurization process method of co-production of refined benzene and nitrobenzene. Background technique [0002] Coking benzene is a by-product of iron and steel enterprises and coking enterprises. Due to its high sulfur content (mainly in the form of thiophene, its content is generally around 4000ppm), its comprehensive application is severely limited. For example, it affects the life of equipment and catalysts used in the processing of subsequent products of benzene, and also affects the quality of subsequent products. With the continuous rise of oil prices and the development of coal deep processing industry, more and more coking benzene will be supplied to the market. The research and improvement of coking benzene desulfurization process is of great significance. [0003] The...

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Problems solved by technology

For example, the catalytic hydrogenation method can completely remove thiophene in coking benzene, and the quality of the product benzene is comparable to that of petroleum benzene, but the one-time investment is high, the reaction conditions are harsh, and the operating cost is high, and it is only suitable for large-tonnage coking benzene Refining process; extractive distillation method is separated by adding appropriate solvent to increase the relative volatility of benzene and thiophene, but this method is not suitable for dealing with coked benzene containing trace thiophene; freeze crystallization method utilizes the difference in the crystallization point of benzene and thiophene to separate Separation and purification of coking benzene, but because benzene and coking benzene will form mixed crystals, it is very difficult to completely remove thiophene from benzene; the adsorption method uses the difference in molecular size and molecular polarity of thiophene and benzene to separate and remove thiophene in coking benzene Thiophene, but its adsorption capacity is small, and it is yet to find a suitable regeneration method for the adsorbent

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