Modification And Its Catalytic Application Of The Y Zeolite

As worldwide demand for middle distillate has been growing steadily and rapidly, it is hard for the middle distillate yield from now methods to meet the market demand. So the study on productive middle distillate technologies has recently attracted increasing interest. As a result of the merit of the hydrocracking unit, it has a great potential in middle distillate production. But the middle distillate selectivity of catalyst, which makes the cracking component with the zeolite, is not satisfactory at present in the industry. The main purpose of this paper is to modify Y- zeolite by organic reaction, and modify it to enhance its middle distillate selectivity in order to improve its function of middle distillate production.Organic reaction is adopted to investigate the factors that influence the Modification of Y-zeolite, such as pH value,the reaction temperature, liquid-solid ratio, reaction time, the concentration of dealumination and liquid-liquid ratio. The results showed that pH value, the reaction temperature, reaction time, liquid-solid ratio, the concentration of dealumination and liquid ratio impact on the structure, and pH value ,the reaction temperature, reaction time and the concentration of dealumination made a great impact on the structure, and there existed an optimum value.Mesopore area and volume of the modified zeolite increased, and acid strength increased but acid reduced.In order to increase the degree of crystallinity of modified zeolite, we added NH4F to solution. The results showed that, it improved modified zeolite degree of crystallinity by adding NH4F.The modified zeolites were used as cracking component to obtain hydrocracking catalysts, reacting on them in 100 ml hydrogenation. The results showed that, the middle distillate selectivity of hydrocracking catalysts with modified NH4Y components for cracking was higher than its of hydrocracking catalysts with modified USY components for cracking, and the middle distillate selectivity of the modified zeolite catalyst was higher, of which mesopore area and volume was larger. And the middle distillate selectivity of hydrocracking catalysts with modified Y-zeolite components for cracking was higher than selectivity of industrial catalysts.