Method for producing tetrahydronaphthalene through naphthalene hydrogenation

Abstract

The invention discloses a method for producing tetrahydronaphthalene by hydrogenating naphthalene. The method adopts a fixed-bed reactor, and naphthalene is subjected to a hydrogenation reaction under hydrogenation reaction conditions in the presence of a presulfurized hydrogenation catalyst to obtain tetrahydronaphthalene, wherein the composition of the hydrogenation catalyst used is as follows: Based on weight, the content of ZSM-5 molecular sieve is 10.0%~80.0%, the content of alkali metal is 0.1%~10.0%, the content of nickel oxide is 10.0%~80.0%, and the content of molybdenum trioxide is 0.5%~5.0%. , and the balance is silicon dioxide. The method of the invention adopts a specific hydrogenation catalyst and adopts a fixed bed to continuously produce tetrahydronaphthalene under suitable hydrogenation reaction conditions, so that the conversion rate of naphthalene is high and the selectivity of tetrahydronaphthalene is good.

Description

technical field [0001] The invention relates to a method for hydrogenating naphthalene to produce tetrahydronaphthalene. Background technique [0002] Tetrahydronaphthalene (also known as tetrahydronaphthalene, tetralin), is an alicyclic aromatic hydrocarbon. Tetrahydronaphthalene is insoluble in water and miscible with all common solvents. It is an ideal high-boiling solvent and can be widely used in industrial fields such as paint, coating, ink, hard alloy, medicine, and papermaking. Tetralin is mainly used to produce tetralone, and is also used as a solvent for grease, wax, resin and paint, and can be mixed with benzene and ethanol as a fuel for internal combustion engines, and also as a substitute for turpentine in glazing agents and paints. supplies. At present, the production of tetrahydronaphthalene in the market mainly comes from the hydrogenation of naphthalene, so it has strong practicability and considerable economic value to investigate the hydrogenation of nap...

AI Technical Summary

Problems solved by technology

[0005] Naphthalene hydrogenation generally uses alumina as the catalyst carrier, transition metals, such as nickel, molybdenum, tungsten, cobalt, etc., as active components, or noble metals such as Pt, Pd, etc. Precious metals are active metal components, and the cost is high. Especially in recent years, the price of precious metals has been rising, resulting in high catalyst costs, which limits its use and promotion; moreover, because precious metals are very sensitive to impurities, even a small amount of impurities, such as Compounds such as sulfur and nitrogen can easily lead to poisoning of precious metal catalysts, shorten the service life, and increase the cost of use; (2) Most of the refined catalyst supports currently used are alumina, and contain some elements such as silicon and titanium. There are different degrees of acidity on the catalyst, which often leads to side reactions such as the cracking of aromatics in the hydrogenation process, and the selectivity of the target product is low; In the process, the conversion rate of naphthalene will be low. If the temperature is increased, side reactions such as cracking will occur, and the selectivity of the target product will be low; Neither the reactant nor the product has binding capacity, so that a variety of products will be produced, and the selectivity of the target product is low; (5) Some catalysts are added with stronger acidic molecular sieves, such as BETA or Y-type molecular sieves, which will lead to side effects. The reaction increases, which not only reduces the selectivity of tetrahydronaphthalene, but also causes a significant loss of naphthalene with a higher price