Study On Preparation Of ?-Al₂O₃ Carrier Material By Alkaline Process

Aluminum oxide support is one of the most popular catalyst supports.With the development of petroleum processing,the requirement for oil refining catalyst supports is more and more stringent.So it is valuable to prepare?-Al2O3 support and its precursor.In this paper,the way of preparing better quality ?-Al2O3 by nitric acid method was studied.The influences of preparation conditions on pore size,pore volume and specific surface area were investigated.Higher temperature and larger pH value is favorable for obtainingy-Al2O3 with large and equal pore size.The specific surface area is lowered along with temperature and pH value.?-Al2O3 with large pore size can be obtained with low concentration of NaAlO2 solution.In the preparation process,temperature,pH value,raw material,feed rate and stirring speed have remarkable influences on the performance of active ?-Al2O3.A suitable condition is required for preparing pseudo-boehmite and ?-Al2O3 with high quality.After a careful control of reaction condition,a few pseudo-boehmite samples with special structure;then,?-Al2O3,with desirable hardness and particle size,is prepared in oil-ammonia column.Based on the characterization of catalyst,pH value and pore size have the influences on specific surface area.The specific surface area lowers along with preparation time and pH value.Influenced by the pore size and pH,the crystal size is increased and the specific surface area is lowered.The finally prepared ?-Al2O3 was investigated in practical trichloroethylene and tetrachloroethylene production,and the product purity was increased,reaction rate was enhanced,production cost was reduced.