Production Of1,4-cyclohexanediol From Catalytic Hydrogenation Of Hydroquinone

Chemical product1,4-cyclohexanediol monomer is a kind of important material and pharmaceutical intermediates. It is anti-cancer drug, reduced enzyme HMGCoA, Gp Ⅱb/Ⅲa antagonist, succinyl sulfathiazole and benzotriazole and other important drug intermediates, spectrum of pure1,4-cyclohexanediol is one of the key new material which could be made such as liquid crystal, electroluminescent materials or biological control markers and other items, so it is of great importance in the production of1,4cyclohexanediol.1,4-cyclohexanediol would be received by the reaction of catalytic hydrogenation of hydroquinone, the reaction will produce by-products such as cyclohexanol and cyclohexanone, the experiment is a reaction of taking hydroquinone as a raw material to produce1,4-cyclohexanediol.Taking the hydroquinone as the initial reactants, hydrogenation catalysts were mixed to produce1,4-cyclohexanediol, the specific problems existed in the pr℃ess in current, such as the hydrogenation reaction time so long, hydrogenation catalyst deactivation so easy, lack of catalytic activity of hydrogenation catalysts, catalytic efficiency was not high, the reaction mechanism was not very clear shortcoming.There were few studies in this regard.This study used on the precious metals platinum, palladium, ruthenium, and Raney Ni catalyst in these types of hydroquinone in the catalytic hydrogenation reaction, the results showed that the Ru/C was taken as the catalytic, its activity and selectivity would give good efficient and more aim products on the target. At the same time a kind of carrier-supported catalyst was prepared, which made Ru as a catalyst active component and carbon, SiO2, TiO2as carrier. Experimental results showed that the hydrogenation press in the activated carbon as the load Ru/C catalyst activity and selectivity of the end products of the best. Experimental results show that the hydrogenation of suitable conditions are as follows:reactant and the catalyst material in the350:1ratio when the optimal reaction temperature was150℃, when the hydrogen pressure5MPa, access to5mL ethanol solvent, the reaction time of2h when the reaction of hydroquinone conversion rate of about98.8%, the target product1,4-cyclohexanediol selectivity of79.6%.The experiment studied the hydrogenation of hydroquinone in supercritical hydrogenation, at the same time several kinds of co-catalysts such as Pt, Pd, Ru and Rh catalyst on the reaction of the specific compound was investigated, the results showed that Ru/C catalyst was the best for the hydrogenation selectivity and catalytic performance.Experiments also studied the hydrogenation reaction system in the type of alkali such as NaOH, C2H5OK and CH3COOK several alkali such as the amount of medium, temperature, reaction time and other important factors on the hydrogenation reaction rate and catalyst for the conversion of trans-1,4-cyclohexanediol selectivity effects.