This project belongs to the field of organic chemical engineering, involving catalyst, chemical reaction engineering and operation optimization. Styrene monomer is an important organic chemical raw material, mainly used in the production of polystyrene, ABS resin, styrene butadiene rubber and other products, which has an important impact on the development of national economy.
A new method for preparing high efficient catalyst and a new energy-saving process for ethylbenzene dehydrogenation to styrene were developed in this project. Through the compounding and creation of catalytic materials, key technological breakthroughs in the catalyst's low water ratio resistance were achieved, and a high-performance ethylbenzene dehydrogenation catalyst was successfully developed; intelligent modeling technology integrating process mechanism and operation information was used to develop the full-process model of the ethylbenzene dehydrogenation industrial production device, realizing the full-process simulation and operating parameter optimization of the industrial styrene production process. The innovation points of the project are as follows:
1)A catalyst composite pore system construction technology has been created. Aiming at the problem that the small pores of catalyst are not conducive to the diffusion of components, the project invented a new method for preparing organic compound/inorganic oxide composite channel director, which formed macropores and mesopores favorable for diffusion in the catalyst, optimized the diffusion environment of reactant molecules and product molecules, and effectively improved the operation performance of the catalyst.
2) A new water-gas reaction accelerator was discovered. In order to solve the problem of catalyst activity decaying too fast, a new type of water gas reaction promoter is adopted, which keeps the continuous self-regeneration function of catalyst, realizes the application of catalyst under the condition of low water ratio, and saves the energy consumption of dehydrogenation reaction.
3) A new energy-saving process for sequential separation of styrene and constant boiling heat recovery was developed. In response to the problem of large waste of low-temperature heat, the constant boiling evaporation process of raw materials is adopted to realize low-grade heat recovery, improve energy utilization efficiency, and save energy by 23% of the device. The constant-boiling heat recovery heat exchanger with independent intellectual property rights supports the stable operation of the device under the conditions of low temperature difference and low pressure drop.
4) Development of styrene whole process operation optimization technology. Aiming at the problem that process parameters deviate from the optimal operating conditions, based on the characteristics of styrene production process, a proxy model for the entire styrene process with high prediction accuracy was established (Kriging model). The modeling and optimization techniques that give consideration to both computational accuracy and efficiency reduce the computational resource consumption of the optimization process, making the model have the characteristics of high accuracy and fast obtaining the optimal solution. After being applied to industrial plants, the energy saving effect of reducing the steam consumption in the dehydrogenation reaction process and the reboiling steam consumption in the product separation process in real time is achieved.
Compared with similar foreign catalysts, the highly efficient and energy-saving GS series ethylbenzene dehydrogenation catalyst developed by the project has an increase in ethylbenzene conversion by 1.8% and a reduction in reaction temperature by more than 8℃; The catalyst has a service life of more than 42 months and has been successfully applied in 22 styrene units of companies such as China Petrochemical, China Petroleum, China Offshore Oil, and China Chemical. It has been exported to Taiwan Formosa Plastics Group, Guoqiao Petrochemical and the Middle East many times. The comprehensive performance has reached the international advanced level, and the low-temperature performance and stability rank among the world's leading level. The new energy-saving process coupled with azeotropic evaporation and rectification column vapor phase condensation has been successfully applied industrially in styrene plants such as Baling Petrochemical and Zhanjiang Dongxing. Compared with conventional process flows, the new process saves more than 23% of energy, reaching the international advanced level. After the styrene operation optimization technology was applied in Qilu Petrochemical's styrene plant, the energy consumption of the plant was further reduced, providing strong technical support for enterprises to improve quality and efficiency.
This project has applied for 38 invention patents, authorized 35, published 15 papers, and was cited 49 times. The project has achieved a total of 467.6769 million yuan in new output value, 107.9652 million yuan in new profit, 12.0473 million yuan in new tax revenue, and a total of 120.0125 million yuan in profits and taxes. It has achieved foreign exchange exchange through exports of US$8.336 million, saving 44.428 million yuan in funds, and remarkable economic benefits. The industrial application of the above technologies is of great significance to enhancing the international competitiveness of my country's styrene industry and promoting the sustainable development of my country's economy and society.