Liquid phase in-situ hydrogenation of phenol for synthesis of cyclohexanone and cyclohexanol
Based on the combination of the methanol aqueous-phase reforming(APR)and catalytic hydrogenation of phenol,a novel reaction system of liquid phase in-situ catalytic hydrogenation of phenol for the synthesis of cyclohexanone and cyclohexanol,in which hydrogen is produced from methanol aqueous-phase reforming in the same reactor over the Raney Ni catalyst,is proposed.The production,preservation and transportation of H2 in the traditional hydrogenation process could be eliminated,which leads to the decrease of cost and enhancement of safety significantly.In this coupling process,methanol is the raw material of the aqueous-phase reforming reaction.It is the solvent of the liquid-phase hydrogenation of phenol,on the other hand.While hydrogen is the product of the aqueous-phase reforming of methanol,it is at the same time the raw material of phenol hydrogenation reaction.The active hydrogen generated from the aqueous-phase reforming of methanol could be quickly removed from the active sites of the catalyst,through the in-situ hydrogenation of phenol,which could improve the selectivity of hydrogen for the APR process of methanol.Furthermore,highly selective hydrogenation of phenol to the aimed products cyclohexanone and cyclohexanol could be realized over the Raney Ni catalyst(100% of the total selectivity to cyclohexanone and cyclohexanol),which is superior to the traditional catalytic hydrogenation method by using H2.