Coal tar whole fraction hydrotreatment process

Abstract

The invention discloses a hydrocracking treatment technique for coal tar total distillate, which comprises: first mixing with homogeneous catalyst, or adding impurity, gum, asphaltene and coal oil total distillate contained much oxygen element directly into suspended-bed hydrogenation device; cutting the stream with distilling plant to discharge water, distillate less than 370Deg that enters fixed bed reactor for hydrorefining reaction to cut gasolene less than 150Deg and diesel oil 150-370Deg, and tail oil less than 370Deg that recycles to said reactor and converts into light oil product. Compared with prior art, this invention is simple, but high conversion rate and stability.

Description

technical field [0001] The invention relates to a process for treating coal tar, in particular to a process for producing clean light fuel by using the whole fraction of coal tar as a raw material and using a hydrogenation process. Background technique [0002] Coal tar is a by-product of coal coking, carbonization and gasification. The whole fraction of coal tar is different from natural petroleum, with complex composition, high content of aromatics, colloids and asphaltenes, high oxygen content of 8-9wt%, especially solid impurity content of 2-7wt%. The impurities in coal tar include inorganic impurities and organic impurities, and the inorganic impurities are mainly iron filings and oxide powders with a particle diameter of about 10 μm. The high-temperature thermal polymer of aromatic hydrocarbon molecules in coal with the main average particle size of organic impurities of 0.5 μm. Among the organic impurities, some coke powder is also included, and its particle size is...

AI Technical Summary

Problems solved by technology

CN1351130A firstly fractionates the coal tar, and carries out hydrogenation upgrading on the light fraction, but its main disadvantage is that the raw materials are not fully utilized

Although the process also mentions the use of a suspended bed reactor, for the processing of untreated coal tar, it is actually a combined process of fixed bed and suspended bed, and due to the high content of impurities in untreated coal tar, bed formation is prone to occur. In order to maintain long-term operation, the catalyst must be replaced frequently. The amount of catalyst is large, which increases the cost and complicates the process, and the product from the switching reactor contains a considerable amount of water, which directly enters the hydrogenation reactor without treatment. Catalysts (especially catalysts containing molecular sieves) have a great influence on the activity, which will lead to a great reduction in catalyst activity

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