Coking benzene deep desulfuration purification method

Abstract

The invention discloses a method of coking benzene deep desulfurizing refined method, which comprises the following steps: adopting catalytic alkylthiophene desulfuration and selective adsorption desulfurizing associated craft; generating alkylthiophene with higher boiling point; rebuilding alkylthiophene through rectifying abscission; selective-adsorbing with desulfurizer; stripping excess un-reaction thiophene; reaching the demand of deep purifying harmful sulfur impurities in coking benzene. This invention possesses small corrosion, low cost and high earning rate, which is a better method for deep processing by-product of steel company and coking plant.

Description

technical field [0001] The invention relates to a refining method for removing a small amount of thiophene in coking benzene, in particular to a combined method of catalytic thiophene alkylation desulfurization and selective adsorption desulfurization. Background technique [0002] Coking benzene is a by-product of iron and steel enterprises and coking enterprises, and it is also a valuable resource for the development of organic and fine chemicals. However, because it contains a certain amount of thiophene impurities, its comprehensive development and utilization are largely restricted, especially in the field of catalysis. For a long time, the deep processing and utilization of this coking by-product has not been greatly developed. Removal of sulfide in coking benzene is the key to rational development of this resource. At present, the catalytic hydrogenation method is used for the treatment of large-tonnage coking benzene. This method generally uses Co-Mo and Ni-W serie...

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Problems solved by technology

At present, the catalytic hydrogenation method is used for the treatment of large-tonnage coking benzene. This method generally uses Co-Mo and Ni-W series catalysts to hydrogenate and saturate thiophene into hydrogen sulfide for removal under high temperature and high pressure conditions. After hydrogenation treatment The sulfide index in the final benzene product can reach the standard of petroleum benzene. Because the reaction conditions of this method are very harsh, the desulfurization process consumes hydrogen, and the process is very complicated. Therefore, the cost of producing sulfur-free benzene from coking benzene is generally high, and the process Suitable for large tonnage coking benzene treatment

For the vast majority of small and medium-sized coking enterprises and iron and steel enterprises, the traditional pickling method is still adopted, that is, thiophene in coking benzene reacts with sulfuric acid to generate thiophene sulfonic acid, and under the catalytic action of sulfuric acid, thiophene reacts with unsaturated olefins in coking benzene. The process is simple, the production cost is low, and the technology is very mature. Therefore, most coking benzene products in my country are produced by this method, but this process cannot completely remove the coking benzene. Thiophene, especially for coking benzene with relatively high thiophene content, even after two-stage pickling process, coking benzene still contains a small amount of thiophene impurities (generally, the concentration of thiophene is about 300 mg / L), and these small amounts of thiophene impurities will also It affects the subsequent production process related to the catalytic process (such as the process of coking benzene to catalyze the oxidation of maleic anhydride and the process of nitration to produce nitrobenzene and hydrogenation to produce aniline), so it must also be deeply desulfurized

There are many methods for deep desulfurization of coking benzene, and the representative one is to use adsorbent to selectively adsorb trace thiophene impurities in coking benzene, such as using A, X, Y, ZSM-5 and their modified zeolites for coking benzene adsorption desulfurization, The adsorption capacity reported in the research is generally low, and the regeneration cycle of the adsorbent is short, especially for the coking benzene adsorption desulfurization process with high thiophene content, and the regeneration process needs to be regenerated by high-temperature hot nitrogen purge or roasting. This desulfurization method has not been reported on industrial application so far, and the development trend is to develop adsorbents with large adsorption capacity.

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