Alumina carrier is the most widely used catalyst carrier in the chemical industry. The current development trend is mainly reflected in the development of low-cost, green and environmentally friendly preparation processes, controlling the pore size and pore size distribution of alumina, and improving the thermal stability of alumina , Preparation of nano alumina and so on.
Due to the wide application of activated alumina and the complicated changes in structure and form, the research on the preparation and properties of γ-Al2O3 as a catalyst carrier is still a relatively active field so far. The current research progress on alumina carrier is mainly reflected in the following aspects
1. Application of pseudo-boehmite in catalyst industry
In the modern oil refining and chemical industry, more than 90% of chemical reaction processes are achieved through catalytic processes. Therefore, catalysts have become the key to the development of new refinery and chemical processes and new products. In the oil refining industry, solid catalysts are generally used, which are composed of a carrier and an active component. The carrier is a unique component of the solid catalyst, which can increase the specific surface area, improve the heat resistance and mechanical strength, and act as a dispersant, adhesive or support for the active component.
There are many types of carriers used in the catalyst, such as alumina, molecular sieves, silica gel, silica alumina gel, activated carbon, and diatomaceous earth. However, the amount of alumina carrier accounts for more than half of the total amount of catalyst carrier. There are 8 types of alumina, the most widely used is Al,0. And d-A1 0, mainly used for high temperature or external diffusion control reaction, can also be used for bed support to promote uniform distribution of airflow. 11-A1, O is sometimes used as a catalyst for petroleum reforming. 8-A1, O, used for catalytic reactions requiring only a small specific surface area. x-A1, O and P-Al, O are only used as desiccants. K-A1, O, and 0-Al, O are processes
Type, rarely used in catalysts. A1, O can also be used directly in Claus sulfur recovery, ethanol dehydration, ammoniation or lipidation reactions.
2. The application of pseudo-boehmite in the purification process of automobile exhaust