Diesel as a petroleum refinery products, in the fuel structure of countries have a higher share, has become an important power fuel, with the accelerated development of the world economy and the increase of diesel-fueled vehicles, the future demand for diesel will gradually increase, but the exhaust of diesel combustion on the environment is also increasingly serious harm.
Given the wide range of applications of petroleum products in production and life, it is very important to remove the hazardous sulfur from them. The non-hydrogenated desulfurization methods currently used in industry include acid-base refining, solvent extraction and adsorption desulfurization. Defects and inadequacies. The acid-base refining has a large amount of waste acid and waste alkali, which will cause serious environmental pollution; the solvent extraction desulfurization process consumes a lot of energy, and the oil products are not suitable for use in the production process. Low yield; low adsorption capacity of the adsorbent in adsorption and frequent regeneration. Other non-hydrogenated desulphurization technologies are still at the experimental stage, including biological desulphurization, ultrasonic oxidative desulphurization and ultraviolet light irradiation and plasma-based desulphurization. The application of desulfurization technology is an attractive prospect and may be an effective way to achieve future clean fuel oil production.
In the oxidation and desulfurization process, it is difficult to mix the water phase and oil phase by general mechanical stirring. The ultrasonic intervention reaction can form microemulsions between the water phase and the oil phase through mechanical, cavitation and thermal effects, which can increase the efficiency of the fuel oil production. Intermolecular contact, the formation of local high temperature and pressure, and the simultaneous generation of free radicals and excited reactive oxygen species, not only rapid oxidation of sulfides. Improves oxidation of oxidants, improves reaction selectivity, significantly shortens oxidation reaction time, and can also change the reaction path and direction, allowing the oxidation reaction to proceed more completely. In the extraction stage, the ultrasonic intervention induces an effective mixing of the extractant and the partially oxidized diesel phase, which promotes the oxidized sulfide The full contact between the molecule and the extractant makes the sulphone effectively removed. The main by-products of ultrasonic desulfurization are dibenzothiophene sulfone compounds, a class of important organic synthesis intermediates, which are widely used in pesticides, pharmaceuticals, pharmaceuticals, and other industries. Biological, dyes and other synthesis has an important role, the whole reaction process without three waste emissions. After ultrasonic oxidation treatment, the sulphur content of diesel with different sulphur content can be reduced to below 10ppm.
Ultrasonic oxidation desulfurization process: raw materials and water containing oxidants and catalysts mixed in the reactor, under the action of ultrasound, small bubbles are rapidly generated and burst, so that the oil phase and the water phase mixed violently, in a short period of time, ultrasound can also make the local temperature and pressure within the mixture material rapidly increased, and produce hydrogen peroxide in the mixture material, participate in the reaction of sulfide; solvent extraction to remove sulfone and sulfate, solvent recycling after recycling, sulfone and sulfate can produce other chemical products.
Commonly used techniques for ultrasonic oxidative desulfurization:
Ultrasonic-H2O2-inorganic acid oxidation and desulfurization technology
Ultrasonic-H2O2-Organic Acid Oxidation and Desulfurization Technology
Ultrasonic-H2O2-Solid Acid Oxidation and Desulfurization Technology
Ultrasonic-H2O2-Fenton reagent oxidative desulfurization technology