This project belongs to the synthesis and application field of mesoporous materials. The specific application fields are adsorption, catalysis, macromolecular reactions and nano-assembly. For the first time in this project, microporous molecular sieve ZSM-5 was dissolved in the presence of a template agent, then diluted acid water was used to adjust the pH value of the system, and then high-hydrothermal qualitative and long-ordered mesoporous materials were synthesized through separation, drying and calcination processes. This project aims to provide a mesoporous material with high hydrothermal stability and high long-range order that can be used in adsorption, catalysis, nanoassembly, etc. After roasting, the specific surface area of the material is 400-1200m2/g, and the pore volume is 0.1- 1.3 cm3/g. After refluxing with boiling water for 500 hours, the material still maintains a specific surface area and pore volume of about 80%.
Propylene is an important chemical raw material. Starting from propylene, many high-value-added downstream products such as acrylic acid, polypropylene, and acrylonitrile can be prepared. Demand for propylene has grown strongly in recent years. At present, propylene production technology mainly relies on petroleum resources. Today, when petroleum resources are becoming increasingly scarce, the demand for propylene is growing rapidly. In particular, my country's lack of oil and rich coal resources makes the development of methanol-to-propylene technology (MTP) using coal and natural gas as raw materials of important strategic significance and has attracted more and more widespread attention. At present, many large petrochemical companies at home and abroad are committed to technical research and process development of methanol to propylene. However, there is still a way to go for successful commercial operation of MTP.
One of the keys to MTP technology is to improve the stability and selectivity of catalysts. The focus of its research is on the structural design of catalysts and the control of surface acid properties. However, due to the problems of heat conduction, mass transfer and rapid carbon deposition of the catalyst, there is still much room for improvement in the stability and propylene selectivity of the catalyst. ZSM-5 zeolite is currently a catalyst with high propylene selectivity for the conversion of methanol to propylene, and has good industrial application prospects. The catalytic reaction performance of molecular sieves is closely related to its physical properties. Therefore, it is of great practical significance to control the morphology, pore structure, and acid properties of ZSM-5 molecular sieve through different synthesis and modification methods, thereby improving its catalytic performance in MTP reactions.
In the early 1970s, Mobil Company first developed ZSM-5 zeolite. It is a shape-selective zeolite with a unique three-dimensional channel structure and acid strength distribution. The vast majority of sub-pore diameters are about 0.55 nm, and it has high silicon-aluminum ratio. It has the characteristics of lipophilic and hydrophobic properties, as well as high thermal stability and catalytic activity. It is used in petrochemical processes to improve the quality of catalytic cracking gasoline and produce important chemical raw materials such as ethylene and propylene.
The search and expert review show that the project provides a technically feasible and economically cost-effective synthesis route for mesoporous materials. The hydrothermal stability of the obtained mesoporous materials has reached the international advanced level, laying a solid foundation for its future industrial application. Its core technology has been patented by China.
This achievement has been applied in many projects, proving that it is highly reliable, easy to use, reduced costs, strong market competitiveness, and a high degree of achievement transformation. In 2013 and 2014 alone, the new output value reached 41.84 million yuan, bringing indirect economic benefits of more than 80 million yuan. Especially in the transformation of MTP project results is of great significance.