Advanced oxidative desulfurization technology is about to enter China
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As an important fossil fuel, diesel is being used more and more widely around the world due to its high engine thermal efficiency and excellent power performance. However, the pollutant SOx generated during diesel combustion forms acid rain when emitted into the atmosphere. To this end, countries have introduced increasingly strict sulfur content standards for diesel, and low-sulfur diesel is receiving growing attention worldwide; as a result, there is an urgent need to develop new desulfurization technologies. Sulfur in diesel exists mainly in the forms of thiol, thioether, and thiophene; among these, thiophene accounts for over 85% of the total sulfur content in diesel. These thiophenes are highly stable and difficult to remove through hydrodesulfurization processes ； Hydrodesulfurization units require huge investment and high operating costs ； Hydrodesulfurization requires a large amount of hydrogen, posing safety risks ； Gasoline hydrogenation also saturates the olefins, reducing the octane rating. The oxidation desulfurization process features mild reaction conditions, a high desulfurization efficiency; it does not require high temperatures or pressures, results in low investment costs for the equipment, and does not need hydrogen. The products resulting from the reaction of sulfur are sulfones and sulfoxides, which are easy to store, cause little pollution, are safe, and can be easily recycled. It is one of the new desulfurization technologies that are being actively studied both domestically and internationally. Despite many years of research on oxidation desulfurization technology both domestically and internationally, various factors have made it difficult to commercialize this technology. Initially, ultrasonic oxidation desulfurization was used, but ultrasonic waves could not be applied stably on a large scale, so it remained only at the laboratory stage ； Secondly, many research institutions have attempted to use standard reactors in place of ultrasonic devices, but the oxidants and catalysts used in this approach cannot be recycled, resulting in high desulfurization costs and preventing commercialization. To this end, Fushilan International Company, in collaboration with Zibo Fushilan Technology Group, has developed a commercially viable oxidation desulfurization technology. This technology holds multiple international patents and was nominated for the Global Energy Award in 2018. The Fushilan oxidation desulfurization technology uses standard chemical equipment; it requires no high temperature or pressure, nor does it need a large number of auxiliary devices, thereby reducing construction costs ； This technology successfully enables the recycling of oxidants and catalysts, minimizing reagent consumption and significantly reducing production costs ； No hydrogen is required, making it safer than conventional hydrodesulfurization units. At a temperature of 80°C and with low asphaltenes content, this technology can process any fuel with a viscosity below 5 CPS; it is suitable for sulfur levels ranging from 3500 ppm to 15 ppm, achieving a desulfurization rate of up to 99.9%. In addition to significantly reducing the sulfur content, this process can also remove other pollutants such as soil, water, and acute chemical contaminants, meeting EPA regulations; at present, this technology is fully ready for commercial use. The oxidation desulfurization process of Fushilan is briefly described as follows: fuel, oxidant, catalyst, and pH regulator are fed into the reactor in certain proportions and in a specific sequence to mix together; the sulfur in the fuel is oxidized, resulting in oxidized fuel and sulfides—sulfoxides ； The oxidized fuel and sulfides enter the next reactor where an adsorbent is added, resulting in desulfurized fuel and an adsorbent containing sulfides ； The equipment is used to recover excess oxidants, catalysts, and adsorbents, and to separate out sulfides ； The recovered oxidants, catalysts, and adsorbents are recycled; sulfides can be sold as products, and no harmful substances are emitted during the entire production process, making it safe and environmentally friendly. Features of Fushilan oxidation desulfurization technology: ● Low investment cost – no need for high temperature or pressure ● Requires very little space ● Utilizes a proven industrial process with a unique and patented mixing/extraction method ● The operating cost of the desulfurized distillate oil is equal to or lower than that of HDS ● Thanks to these advantages, the production unit can be installed in smaller locations, such as refineries and fuel distributors, or even on ships
Regarding matters in the R&D phase, I’m not sure about their reliability If it’s true, then it would indeed be a groundbreaking technology in the field of petroleum refining!
Learning about it*, thanks to the original poster for sharing
This post was last edited by Catalyzing a Grain on 2019-8-26 23:17. It may be suitable for LPG desulfurization, as it contains only simple sulfur-containing compounds such as H2S, COS, and CS2. For diesel, if the oxidation desulfurization process cannot simultaneously remove nitrogen-containing compounds (alkyl amines, indoles, pyridines, etc.), oxygen-containing compounds (phenols, naphthenic acids, etc.), and organometallic compounds, hydrorefining is required after oxidation desulfurization. Furthermore, for diesel fractions produced by non-hydrocracking, the bromine number specification cannot be met without hydrorefining.
Sorry! A typo was made in the previous post (Building 6#): “diesel fractions produced by waste hydrocracking” should be understood as “diesel fractions produced by non-hydrocracking”.
However, this is only effective for desulfurization; it has no effect on olefin saturation, nor on deoxygenation and denitration, and cannot completely replace hydrogenation. Additionally, the distillation energy consumption after desulfurization is high. But my idea is to carry out oxidation desulfurization before hydrogenation; in that case, less advanced technology will be needed for hydrogenation, and perhaps hydrogenation refining alone will suffice?
You are very professional in what you say. I said the same thing in the last reply. If oxidation desulfurization is carried out first and hydroprocessing later, it’s not clear whether this will meet the requirements for deoxygenation, denitration, etc. that you mentioned. I don’t know much about this area. Does hydrogen cracking need to be used in order to reduce sulfur levels to below 10?
Oxidative desulfurization is carried out first, followed by hydrogenation refining; otherwise, parameters such as the bromine value of diesel produced via non-hydrocracking will not meet the required standards. This discussion does not cover hydrocracking.
If oxidation desulfurization is carried out first and hydroprocessing later, will it meet the current National VI standards?