Turn low-quality heavy oil into something \"lighter\"”

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A team led by Professor Lu Chunxi, dean of the School of Chemical Engineering at China University of Petroleum (Beijing), spent over a decade working on this project and successfully developed key technologies for new post-catalytic cracking reaction systems; last week, they were awarded the **Second Prize for Scientific and Technological Progress. This achievement successfully solved problems in the post-reaction system of heavy oil catalytic cracking units, such as excessive cracking caused by oil-gas backmixing, which led to losses of the desired products. “We achieved significant economic benefits with relatively low investment. For a medium-scale plant with a capacity of one million tons, adopting this technology requires an investment of just over 2 million yuan, and it can generate benefits of over 30 million yuan per year. ” Lu Chunxi said. The fluidized catalytic cracking process plays a crucial role in China’s petroleum processing industry; 70%–80% of gasoline and about 30% of diesel are produced through this process. How to minimize the residence time of oil and gas in the post-reaction system in order to achieve efficient separation between the oil and gas and the catalyst is key to obtaining an ideal product distribution and ensuring long-term operation of the plant; it is also a global challenge. Most of the units in our country are heavy oil catalytic cracking units, and the proportion of low-quality residue oil used in production has long been the highest in the world; therefore, there is an urgent need for advanced technologies for post-reaction systems. Previously, only large foreign oil companies such as UOP and Mobil possessed similar processes, but the cost of using these technologies was very high, and they were not well-suited for use in domestic facilities. The achievements developed by Lu Chunxi and others are a series of technologies independently developed in China with independent intellectual property rights. On June 10, 2009, an expert panel organized by the China Petroleum and Chemical Industry Federation concluded that the series of technologies as a whole had reached the international advanced level; among them, the high-efficiency gas-solid swirl separation, high-efficiency pre-vaporization, and technology for improving the oil and gas retention rate had attained the international leading level, offering broad application prospects. The core equipment of the reaction system after catalytic cracking is the rapid separation system at the riser outlet. In response to the stringent requirements across various aspects of the rapid separation system, this research team successfully developed three innovative technologies: efficient gas-solid swirl separation, efficient pre-vaporization, and high oil-gas containment capacity. They have been granted 14 patents, including 11 invention patents ； Through integrated innovation, 4 new types of fast fractionation systems with complete independent intellectual property rights have been developed, suitable for all current catalytic cracking units in China; this has led to the creation of theories and methods for the optimized design of key equipment in post-reaction systems. “Engineering research involves taking certain risks, and it is essential to persevere throughout the development process. For researchers, the testing process of the first industrial-scale setup is always very stressful, as its results determine the direction and even the fate of a project. It is gratifying that we were able to achieve success in this one-time experiment through steady efforts; this is not only an acknowledgment of the work done by the research team but also a comfort to my mentor, Academician Shi Mingxian of the Chinese Academy of Engineering, who passed away in 2009. ”Lu Chunxi said with deep feeling. Previously, domestic universities had also spent five to six years developing similar technology, but were forced to abandon it after industrial trials failed. It is understood that UOP’s VDS and VSS systems are internationally recognized as advanced rapid separation technologies. However, during their first application in China, a serious incident occurred in which 180 tons of catalyst were lost in just 20 minutes; moreover, the systems caused unplanned shutdowns 7 times within one year due to catalyst loss, indicating that they have limited operational flexibility and are not well-suited for use in Chinese plants. The key equipment technologies for the post-reactor system, which Lu Chunxi and his team developed in China for the first time, were put into industrial use in China around the same time as UOP’s technologies. However, thanks to their superior performance and lower costs – only 1/20 to 1/10 of those of foreign technologies – they quickly drove those foreign technologies out of the Chinese market. Only 4 sets of UOP’s rapid separation system have been used in China, whereas the subsequent reaction system technology has been successfully applied in 48 units of different types and scales, including China’s largest heavy oil catalytic cracking unit with an annual capacity of 3.5 million tons. Numerous application cases show that this achievement can increase the light oil yield by more than 1 percentage point, reduce the dry gas and coke yields by more than 0.5 percentage point each, and significantly extend the operation cycle of the plant while increasing the slag blending ratio. To date, the total processing capacity of catalytic cracking units that utilize this technology has exceeded 40 million tons per year, accounting for nearly 30% of the total catalytic cracking processing capacity in the country. Lu Chunxi pointed out: “The successful progress of this project is mainly due to the combination of China University of Petroleum’s traditional strengths in gas-solid separation technology and the research team’s unique expertise in the field of gas-solid fluidization.” ”Although this achievement was widely implemented in 2006, the research did not stop there; they have recently developed a new ultra-short rapid separation technology that reduces the residence time of oil and gas in the post-reaction system from 5 seconds to 4 seconds, thereby increasing the yield of gasoline and diesel by 1%. At present, the industrialization plan for the new ultra-short rapid separation technology has been finalized, and preparations are underway to conduct experiments on a unit at Yanshan Petrochemical. Currently, the total processing capacity of catalytic cracking units in our country is approximately 130 million tons per year, and it is expected to increase further to 170 million tons per year in the future. “As the oil refining industry imposes increasingly strict requirements regarding the efficient use of heavy oil, energy conservation, emission reduction, and environmental protection, it is expected that our achievements will be applied more widely, contributing further to the improvement of overall efficiency in this industry. ”Lu Chunxi said confidently. For more content, please visit the China Chemical Industry News digital edition (http://ipaper.ccin.com.cn)