In-Situ Reduction Of Acetophenone To α-Phenylethanol With Hydrogen From Aqueous-Phase Reforming Of Methanol

α-phenylethanol(PE) is an important chemical product which has been widely usedin pharmaceutical and perfume industries. In the synthesis ofα-phenylethanol, muchmore attentions on the hydrogenation of acetophenone(AP) has been attracted due to itsatomic economy.Both the endothermic aqueous-phase reforming of methanol for hydrogengeneration and the exothermic hydrogenation of AP to PE are performed over the sametype of catalyst under the close conditions of temperature and pressure. In the presentwork, a novel method of liquid-phase in-situ hydrogenation of AP to PE was proposed,in which the active hydrogen came directly from the aqueous-phase reforming ofmethanol.The effects of reaction conditions, such as reaction temperature, reaction pressure,AP concentration and the ratio of raw materials on the reaction of liquid-phase in-situhydrogenation of AP to PE over the Raney Ni catalyst have been explored. Theexperiment results indicated that the conversion of AP reached 66.4% and the selectivityto PE could reach 95.1% under optimal hydrogenation conditions: T=403 K; P(Ar)=0.6 MPa; LHSV=0.71 h^-1; AP concentration=0.43 mol/L and the H₂O/CH₃OH molarratio=1.33 in the tubal reactor. In addition, we had carried out macroscopical kineticstudies on the liquid-phase in-situ hydrogenation of AP under the Raney Ni catalyst.The activation energy of the reaction is 22.6 KJ/mol.The activity and selectivity to PE in the AP hydrogenation of the various methods,such as hydrogenation reduction, transfer hydrogenation with hydrogen from isopropanol, hydrogenation of AP by the active hydrogen from methanol cracking andaqueous-phase reforming of methanol, were investigated. The experimental reslutshown that the active hydrogen came from aqueous-phase reforming had higherselectivity of hydrogenation and lower selectivity of hydrogenolysis.The combination reaction system of "AP+methanol+water" could increase notonly the selectivity to PE but also improve the process of aqueous-reforming ofmethanol, that is the conversion of methanol and selectivity of hydrogen are increasedhighly. The production rate of hydrogen was higher than the reaction rate of AP in theexperimental conditions, therefore, the further study the mass matching between theaqueous-reforming of methanol and the hydrogenation of AP to PE over Raney Nicatalyst is needed. The catalytic deactivation of Raney Ni catalyst was caused due to thesintering, Ni metal loss and passive layer formation by the characterizations of BET,XRD, TPO and CO adsorption analysis.