Method for refining carbonization crude benzole

Abstract

The present invention relates to a refining method of coking crude benzol. The method has four following sequential steps as follows: thepretreatment process of raw materials, the refining process of doffing non-arene and doffing othiophene, the deep desulfurization process of thiophene alkyl, and the refining process of toluene and xylene. The products of high-purity sulfur-free benzene, toluene and xylene can be made. The detailed technological process can be referred to the specification munual. Compared with the traditional pickling method, the present invention has the following advantages: the whole process has no production of acid tar, no serious pollution to the environment and no serious corrosion of equipment; at the same time, the present invention avoids sulfonate loss of arene, effectively improves the reclamation rate of arene and belongs to an environmental friendly technology. Besides, the products of coking benzene category are obviously superior in quality to the traditional pickling. Compared with the catalytic hydrogenation process, the process is simple and not only can save a substantial amount of investment costs, but also the operation cost of device is low. The quality of benzene products is equivalent to hydrogenated benzene. The present invention provides an environmentally protective and economical process for the reasonable development and utilization of coking benzene resources, and has quite broad application prospects.

Description

technical field [0001] The invention relates to the fields of chemical separation engineering and catalytic reaction engineering, in particular to an environment-friendly coking crude benzene refining method, which adopts extractive distillation technology to remove impurities such as non-aromatic hydrocarbons and thiophenes in coking benzene, Alkylation means deep desulfurization of coke benzene. Background technique [0002] Benzene and toluene are important basic organic chemical raw materials, and one of their important sources is coking crude benzene, a by-product of iron and steel enterprises and coking enterprises. Due to the complex composition of crude benzene and containing many impurities, especially thiophene and saturated alkanes, these impurities cannot be completely removed when crude benzene is purified by the traditional pickling process, thereby affecting the quality of coking aromatic products, especially Many quality indicators of coking benzene have a b...

AI Technical Summary

Problems solved by technology

The pickling process is simple, the production cost is low, and the technology is relatively mature, but the fatal defect of this process is that it produces a large amount of acid tar and waste sulfuric acid while removing impurities such as thiophene and unsaturated hydrocarbons, which causes serious pollution to the environment. Moreover, the purification depth of coking benzene and toluene is not enough in this process, and some saturated hydrocarbons whose relative volatility is close to that of benzene and toluene will enter the product as impurities, affecting the purity of the product. At the same time, the thiophene in benzene cannot be completely removed. In addition, these impurities will affect the subsequent production processes related to the catalytic process, such as the synthesis of cyclohexanone by coking benzene, the synthesis of maleic anhydride by oxidation of coked benzene, and the production of nitrobenzene by nitration and then hydrogenation to produce aniline. It must be deeply desulfurized

[0005] There are many methods for deep desulfurization of coking benzene. The typical one is to use adsorbents to selectively adsorb trace thiophene impurities in coking benzene. For example, zeolite molecular sieves such as A, 13X, and Y are used for adsorption and desulfurization of coking benzene through metal ion exchange modification. Currently reported The adsorption capacity of the adsorbent is generally low, the regeneration cycle is short, and the regeneration process often uses high-temperature hot nitrogen purge or roasting with oxygen-containing gas. Therefore, there is no report on the industrial application of the process of selectively adsorbing thiophene for deep purification of coked benzene.

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