This project belongs to the intersection of control science and engineering and chemical engineering and technology.
The ethylene industry is the leader and development symbol of the petrochemical industry, and its development marks the development level of a country's petrochemical industry. my country's existing ethylene production capacity ranks second in the world, but the self-sufficiency rate of equivalent ethylene is only 46.1% in the past five years. Due to the complexity of ethylene raw materials and the relatively backward production and operation level, there is still a significant gap between the product yields and energy consumption of existing ethylene units and the world's advanced level. In order to maximize high value-added products during the operation of ethylene plants, this project focuses on the research and development and implementation of the following innovative technologies:
(1) For the first time, a coupled modeling technology for point-by-point flow, combustion, radiant heat transfer and free radical cracking reaction process in the furnace tube in an ethylene cracking furnace was proposed and realized. Detailed flue gas temperature, velocity, concentration and heat flux distribution in the furnace furnace of different furnace types were obtained, as well as detailed information on the outer wall temperature of the furnace tube, oil and gas temperature, velocity, pressure and product yield distribution in the furnace tube, realizing the characterization and simulation of the full-cycle operating characteristics of the cracking furnace. It provides technical support for the independent design and manufacturing of China Petroleum Daqing Petrochemical's 150,000-ton/year large cracking furnace.
(2) For the first time, the optimization configuration technology for multiple raw materials and their loads for the cracking furnace cluster of ethylene units was proposed and implemented, reaching the international leading level. The yield models of key products, fuel gas consumption models and operating cycle models characterized by the outlet temperature of the waste boiler of different cracking furnaces under different cracking raw materials and different operating conditions were established, which realized online evaluation of the operating efficiency of the cracking furnace; With the goal of maximizing high value-added products, the MINLP problem for the raw material and load configuration of the cracking furnace cluster was solved and optimized. While effectively improving the yield of diene, fuel gas consumption is reduced.
(3) For the first time, we creatively developed real-time optimization control technology for cracking furnace cracking depth and promoted it in China Petrochemical. Using oil attribute cluster analysis and neural network technology, an online prediction model for the full-component yield of cracking products with different oil attributes was established. Real-time optimization of cracking depth was realized using rolling optimization. At the same time, intelligent control technology for cracking depth was developed and implemented. Effectively increased the output of high value-added products.
The project has formed 12 national invention patents (2 authorized and 10 disclosed), and registered 10 national computer software copyrights. 32 published relevant academic papers were included in SCI and 33 were included in EI. After the implementation of the above optimized control technology, the main technical and economic indicators have reached or exceeded the international advanced level of similar devices. Among them: After the implementation of Shanghai Petrochemical's cracking depth control technology, the yield of diene increased by an average of 0.24% to 0.38% when cracking different oil products. After the implementation of the cracking feedstock load optimization technology, the overall diene yield was increased by 0.187%, and the annual fuel gas consumption was reduced by 5,296,022 Nm3; after the implementation of Yangzi Petrochemical's cracking depth control technology, the "diene" yield of the SL-II light cracking furnace increased by 0.28% year-on-year, the "diene" yield of the SL-II heavy furnace increased by 0.9% year-on-year, the GK-VI cracking furnace increased by 0.78% year-on-year, and the SRT-IV cracking furnace increased by 0.46% year-on-year. After the implementation of the cracking depth real-time optimization technology, the yield of diene increased by 0.333% when cracking naphtha, and the yield of diene increased by 0.374% when cracking hydrogenated tail oil; after the implementation of Zhenhai Petrochemical's cracking depth control technology, the yield of high-attached products increased by 0.1%; After the implementation of Tianjin Petrochemical's cracking depth control technology, the yield of diene increased by 0.24 - 0.34%.
Since January 2008, the project results have been successfully applied in million-ton large-scale ethylene plants such as China Petrochemical Yangzi Petrochemical, Shanghai Petrochemical, and Zhenhai Refining and Chemical. In the past three years, it has achieved a total of 305 million yuan in new profits, 51.174 million yuan in new taxes, and 357 million yuan in new profits and taxes. Starting from "cracking mechanism modeling-raw material load optimization-process operation optimization," this technology effectively solves key bottleneck problems in ethylene production and operation. Related technologies have been radiated and extended to China Petroleum Jilin Petrochemical and Daqing Petrochemical ethylene industry units, promoting scientific and technological progress in the ethylene industry and even the petrochemical industry.