Study On The Production Of Ethanol From Hydrogenation Of Acetic Acid

As one kind of the clean automobile fuels and gasoline additives, ethanol becomes more and more significant in the energy market. The traditional production processes for ethanol were limited by the shortage of crude oil as well as the increasing price of crops, which caused more attention to the new technology for ethanol production. The catalysts in the research were Pt-Sn/Al2O3-CaSiO3, which were prepared by the volumetric impregnation method. And then the catalysts were characterized by using different techniques:XRD, BET, H2-TPR, H2-TPD, NH3-TPD. The performance of the catalysts and the influence of reaction conditions to the acetic acid conversion and the selectivity of main products were studied.The diffraction peak of the catalyst samples were similar to those of the Al2O3support. The surface area, pore volume and average pore diameter of the catalysts had a trend of decrease with the adding of the active components. The introduction of Sn could cause structure effect with metal Pt, which made the H2reduction peak move toward the high temperature direction. The NH3-TPD result shown that the support modifier could adjust the acidity of the catalyst, reduced the strong acid sites, and almost had no influence on the structural properties of the catalysts.With the rise of Sn content, the conversion of acetic acid and the selectivity of ethanol both decreased after an increase. In condition that the temperature were225～325℃, the pressure were1.5～4.0MPa, the WHSV were0.22～1.10h-1, and the mole ratio of H2to acetic acid were6～14. The results indicated that higher conversion and selectivity could be obtained under the conditions of higher pressure, while a first increased and then downward trend appeared as the temperature increased. With the increase of the space velocity, the conversion of acetic acid dropped slowly while the selectivity of ethanol had a trend to rise. While improving the ratio of H2to acetic acid, the conversion of acetic acid and the selectivity of ethanol first increased, and then decreased.