Thread Content
On April 1, within the Yunnan Petrochemical Plant, the large secondary electrodialysis tanks shone brightly in the sunlight. Qin Yujian, a process engineer from the first refining department, took samples from the sampling ports and said, “After electrodialysis, the iron content in crude oil drops from 14 milligrams per kilogram to 3.2 milligrams per kilogram, with the removal rate rising from 20% to 70%, placing it at the forefront nationwide!” ”To date, after more than 8 months of technical efforts, Yunnan Petrochemical has successfully deployed an efficient iron removal agent that has been in use steadily for 3 months, thereby resolving the key technical issue of excessive iron content in crude oil. “When the iron content in crude oil is too high, it wraps around the catalyst particles like armor, significantly affecting the performance of the catalyst; this phenomenon is known as ‘catalyst iron poisoning’. ”Xu Yan, a manager in charge of the three types of reagents at the Production Operations Department, explained. In April 2024, the iron content in the catalysts used for the catalytic regeneration of heavy oil was as high as 7,000 milligrams per kilogram, which resulted in a 1.53% decrease in the liquid yield from the catalytic unit. The consumption of fresh catalysts increased from 1.1 kilograms per ton to 1.65 kilograms per ton, becoming a bottleneck that hindered production efficiency. The Production Operations Department organized Team 1 of the Refining Department to form a technical task force to tackle the challenges that hinder production. Initially, the countermeasures focused on the catalytic cracking stage, with an emphasis on using balance agents, low-magnetic agents, and freshening agents. The team examined various additive solutions on multiple occasions and found that addressing the issue by focusing on the catalytic cracking stage only provided temporary relief rather than a permanent solution; moreover, the additives were expensive and not economically viable. Therefore, the task force decided to implement a \"get to the root of the problem\" strategy, shifting the main focus to the crude oil pretreatment stage. However, removing iron from crude oil is recognized worldwide as a difficult challenge in the refining industry. The iron removal agents available on the market are expensive, difficult to apply, and their effectiveness is inconsistent; moreover, they often contain acids that can cause corrosion in the equipment. The technical problem-solving team found itself in a difficult situation, but it did not give up. On the one hand, attempts are made to reduce the iron content by adjusting the process parameters of electrodialysis ； On the other hand, efforts should be intensified to communicate with related organizations, seek advice from industry experts, and find more suitable additives. “The turning point came last September. ”Xu Yan recalled. At that time, the analysis results of crude oil and desulfurized residue oil came in, confirming that the form of iron in the crude oil was mainly inorganic iron, with most of it concentrated in the emulsion layer at the oil-water interface. “We immediately found the direction and approach to tackle this problem! ”Xu Yan said. Focusing on the form and distribution of iron, the team innovatively proposed a technical approach of \"targeted deposition–directional removal\". After three months of additive screening tests, the team tried various different additives. After comparative screening, a scheme involving the mixed use of various additives was ultimately selected, achieving the optimal balance between cost-effectiveness and iron removal efficiency. In January this year, the new iron removal process was officially put into industrial use. “This technological breakthrough fills the gap in the field of iron removal from heavy crude oil in China! This method has also been successfully applied in enterprises such as Sichuan Petrochemical, Dalian Xitai, and Dalian Petrochemical.