Preparation Characterization And Performance Of Copper-based Catalyst For Synthesis Of DL-γ-butyrolactone

The α-hydroxy-β,β-dimethyl-γ-butyrolactone(DL-γ-butyrolactone)with a wide range of uses is an important raw material of calcium pantothenate and panthenol.Although the copper-based catalysts have been used for many years with high activity and selectivity,but still exist many drawbacks,such as low thermal stability.The activity and stability of catalyst prepared by co-precipitation method were better.Based on this,the amount of catalyst was Scaled-up for 100 times.The preparation conditions was optimized and sability of the catalyst was researched in the hope of appling this new copper-based catalyst into industrial production.The effect of preparation conditions on activity and stability of catalyst were studied,the optimal preparation conditions were obtained as follows: the stirring speed was 150 r/min,the trickling speed was 40 ml/min,the concentration of alkali solution was 0.10 mol/L and metal solution was 0.05mol/L,the precipitating temperature 45 ℃,the pH value was 8 and the alteration time was 12 h,the calcination temperature was 500 ℃.There was no changes on activity and stability of catalysts after scaling-up for 10 times and 100 times,there was no changes on crystal form and BET surface area of catalyst,it means that the effect of scaling-up was eliminated effectively.the catalyst(500g)activity was evaluated in fixed-bed reactor and the Yield of DL-γ-butyrolactone was 98%.The stability of catalyst was studied.There was no obvious deactivation in catalyst after reacting for 500 h.There was strong interaction between copper fractions of catalyst.restored Cu crystal can be dispersed in the silica carrier after restoring and have smaller particle diameter.The Cu crystl diameter growth is low in the reaction in order to Prevent agglomeration phenomenon and change the catalyst cativity.This study investgated the impact of the molding additives and process conditions on catalyst strength,and further optimization of molding condition.The results showed the strongest intensity at binder(water)wet base content of 15%,the amount of lubricant(graphite)5%(Powder mass percentage)and loading capacity of 10 ml.