Device and method for continuously producing mixed dinitrobenzene by using coking benzene

Abstract

The invention discloses a device and method for continuously producing mixed dinitrobenzenes by using coking benzene. The production device is composed of nitrating kettles, pre-washing kettles, neutralization kettles and washing kettles which are reversely connected in series, wherein the number of the nitrating kettles is 5-7, the number of the pre-washing kettles is 1-2, the number of the neutralization kettles is 2-4, the number of the washing kettles is 2-4, and an oil-water separator is connected in front of each kettle. The method disclosed by the invention comprises the following steps: nitrating coking benzene into dinitrobenzene in the nitrating kettles by using mixed acid consisting of sulfuric acid and nitric acid, and simultaneously carrying out ring-opening oxidation on thiophene so as to obtain carbon disulfide; then, sequentially processing a mixture by using the pre-washing kettles, the neutralization kettles and the washing kettles so as to obtain hetero-dinitrobenzene. In the invention, based on the characteristics of a benzene nitration process and the reaction characteristics of thiophene and the mixed acid, the mixed dinitrobenzene production process is a reverse continuous nitration process; the sulfur-free mixed dinitrobenzene is produced directly by using coking benzene, therefore, the energy consumption and material consumption of the traditional coking benzene desulfurization process are reduuced; because the step of pre-desulfurization is not required, the desulfurization cost is low, and the nitrification is safe; meanwhile, because the whole system is in reverse series connection, the conversion rate of the nitration reaction is high, the consumption of the sulfuric acid is low, and less wastewater is generated.

Description

technical field [0001] The invention belongs to the technical field of coking benzene application, and more specifically relates to a device and a method for continuously producing mixed dinitrobenzene from coking benzene. Background technique [0002] Coking benzene is a by-product of coking enterprises and coal deep processing. 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 direct application research of coking benzene is of great significance. [0003] Coking benzene contains sulfur-containing compounds mainly including thiophene. Thi...

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Problems solved by technology

All these methods require coking benzene to be pretreated before using it, which requires adding a new process, resulting in material consumption, energy consumption, and increased equipment investment

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