| Catalytic Distillation (CD) is a combination of catalytic reaction and distillation in a single vessel owing to which it enjoys a number of specific advantages over conventional sequential approach of reaction followed by distillation or other separation techniques. Improved selectivity, increased conversion, better heat control, effective utilization of reaction heat, scope for difficult separations and the avoidance of azeotropes are a few of the advantages that reactive distillation offers.It was widely used in etherification, esterification, hydrogenation, hydro, desulfurisation and polymerization. CD technology is currently used by the cation exchange resin and Molecular Sieve catalyst is represented by the solid acid catalyst. Cation exchange resin catalyst not only has high selectivity, but also can reduce the corrosion of equipment and the environment more friendly, except the conditions limitations of reaction and phase. Molecular Sieve had limitation of temperature. There are two aspects at present:catalytic performance can not be given full play, and the catalyst distillation is not obvious.In my study, the CD technology and the synthesis of ethyl acetate, to develop a new, highly efficient etherification catalyst. Raschig ring packing based on this selection the catalyst, the use of aluminum to the substrate, prepared by anodic oxidation of a Raschig ring packing type of Al2O3-Al carrier, through the porous alumina film are suitable for load-MoO3 Catalytic Distillation Process Special solid catalyst MoO3/Al2O3-Al. This systematic research includes the following steps:catalyst preparation of the MoO3/Ao2O3-Al, characterization and reactivity of ethyl esterification, Nanopore with a regular array structure, specific surface area of Al2O3-Al as the carrier, ammonium molybdate as Mo source, Using the over the volume impregnation to get a supported MoO3/Al2O3-Al catalyst. In order to study the catalytic esterification, model of synthesis of ethyl acetate was established. Samples were characterized by means of XRD, BET, NH3-TPD To clarify the active component of catalyst dispersion on the carrier, BET surface area and pore structure, N2 adsorption-desorption isotherm, Acidity and so on.The results show that the appropriate of MoO3/Al2O3-Al catalyst preparation conditions were as flows:2.2% mass fraction of impregnation, dipping time 12h, seal time 2.5h, calcination temperature 450℃, calcination time 4h. The conversion rate of 62.09% acetic acid, and 100% selectivity to ethyl acetate could be got under those conditions. Reaction temperature 98℃, reaction time 8h, raw materials for the 0.3:1 ratio of acid to alcohol, catalyst mass 4.0% acetic acid, under appropriate conditions, The conversion rate of acetate about 80%,100% selectivity to ethyl acetate. Pore structure analysis shows that, MoO3/Al2O3-Al catalyst for the porous structure and smaller pore size range, pore size distribution range in the hole; NH3-TPD analysis showed that the presence of a catalyst weak activity center. |
