Desulfurization aids make oil refinery pollution resources

On the one hand, the price of sulphur rose exponentially, and downstream industries such as domestic phosphate fertilizers and sulphuric acid suffered enormous cost pressures. On the other hand, millions of tons of valuable sulphur resources in the domestic oil refining industry were exhausted indiscriminately with exhaust gas, or were only recovered inefficiently. Not only caused a waste of resources, but also caused serious environmental pollution. This situation raises a question for the industry: Can we efficiently recover sulfur resources that can be used for production from refinery flue gas, eliminate pollution and save resources?
At present, many companies and research institutes are working hard to achieve this goal.
The catalytic cracking (FCC) device is a relatively serious device for pollution emission from refineries. The flue gas contains a large amount of sulfur oxides and nitrogen oxides, and is the main source of pollution for acid rain formation. In recent years, the gravity and inferior quality of catalytic cracking feedstocks have increased the sulfur content of the catalytically cracked flue gas. About 5% to 10% of the sulfur in the raw material is brought into the regenerator with coke, and sulfur oxides are generated during combustion. Currently, the content of sulfur oxides in untreated flue gas emitted from catalytic cracking units of domestic refineries is usually in the range of 500 to 4000 mg/m3.
At present, the common refinery flue gas desulfurization pathways include equipment desulfurization (construction of a desulfurization tower), desulfurization of additives, and the like. The construction of a desulfurization tower requires a large amount of equipment investment, daily maintenance costs are also high, and economical performance is poor. The desulfurization aids are not only simple to use, but also very economical, and they are increasingly being taken seriously by the industry.
In recent years, research on desulfurization aids has accelerated at home and abroad. Domestic research institutes include East China University of Science and Technology, China University of Petroleum, Sinopec Petrochemical Research Institute, and Luoyang Petrochemical Engineering Company. However, the results of industrialization are few, and the desulfurization effect of industrial applications is not ideal. The reason is that these desulfurization auxiliary products cannot effectively convert sulfur dioxide to sulfur trioxide, thereby greatly affecting its deep desulfurization performance and sulfur recovery rate.
The catalytic cracking sulfur transfer agent FP-DS developed by Beijing Sanju Environmental Protection New Materials Co., Ltd. and China University of Petroleum (East China) is the first solid sulfur transfer agent to achieve industrial production and application in China. The sulfur transfer agent can transfer the sulfur oxides in the catalytically cracked flue gas to the riser and be reduced to hydrogen sulfide and enter the dry gas or liquefied gas. The removal rate of sulfur oxides is more than 60%, and can effectively reduce the amount of regenerated tobacco smoke. The acid dew point temperature of the gas delays the cracking of the equipment. Beijing Petrochemical Research Institute and Lanzhou Petrochemical Company's catalyst plant also jointly developed a new green environmental protection catalyst sulfur transfer additive LRS-25. The sulfur transfer auxiliaries can effectively reduce the sulfur emissions in the catalytic cracking process and also have a good trapping effect on nickel and antimony in the material.
A batch of FCC refining desulfurization auxiliary newly developed by Albemarle not only does not affect the cracking activity of the main agent of the refining catalyst, and the desulfurization rate reaches more than 80%. The additive can effectively convert sulphur dioxide into sulphur trioxide, resulting in more sulphur products. At present, the product has been industrialized in China. According to Yang Dajun, catalyst sales manager of Alpha Chemicals (Shanghai) Co., Ltd. in China, Albemarle is a global leader in the field of sulfur transfer agents. In the 1980s, Albemarle made breakthroughs in hydrotalcite technology and is currently sold globally. 70% of sulfur transfer agents use this technology.
In terms of application, the popularity and effectiveness of desulfurization aids applied in refineries in developed countries and regions are clearly superior to those in China. However, the price of international sulphur has skyrocketed in the past two years. The recent domestic price has approached 6,000 yuan/ton. The awareness of sulfur resources recovery and utilization has been greatly enhanced in domestic refineries. It is understood that Alcan's desulfurization aids have been successfully applied to a set of FCC units at the Hainan refinery, with a desulfurization rate of over 80%. At present, Jinan Refinery, Guangzhou Petrochemical, Dalian West Pacific Petrochemical and other refining companies are all planning to try Yabao's desulfurization auxiliary products. The application of homemade FP-DS and LRS-25 sulfur transfer additives has also achieved certain results.