Method for removing sulfur in diesel by photo catalytic oxidation

Abstract

The invention relates to a method for removing the sulfur in gasoline and diesel oil through photocatalytic oxidation; a catalyst is dissolved into an accessory ingredient and then is added into an oil product; under the irradiation of light, the sulfur-compounds in the oil product are selectively oxidized by molecular oxygen and generated into sulfur dioxide which escapes from a reaction liquid; the accessory ingredient is methanol, ethanol or acetonitrile; the catalyst is phosphotungstic acid, phosphotungstate, phosphomolybdate, phosphomolybdate or any mixture thereof or a derivative thereof; the light refers to artificial light or sunshine which can inspire the catalyst or a complex compound thereof; the molecular oxygen refers to the molecular oxygen or pure compressed oxygen in the air; the dosage of the catalyst is 0.01 to 5g for each L of fuel; the dosage of the accessory ingredient is 1 to 500g for each L of fuel; the pressure of the oxygen is 0.02 to 1.0 MPa; the method is carried out under normal temperature and pressure and does not need the treatment of extraction and concentration; the sulfur is separated in the mode of SO2 without products of organic sulfur like sulfone, sulphoxide, thioether, and the like, thereby having no loss of organic carbon; the yield of the oil product can achieve more than 99 percent.

Description

technical field [0001] The invention relates to a method for catalytically oxidizing sulfur in oil products into SO by using molecular oxygen 2 It is a mild photocatalytic oxidation method for removing sulfur from gasoline and diesel by directly escaping to achieve no loss of organic carbon in oil products. Background technique [0002] Fuel oil such as gasoline, diesel and heavy oil is still the main form of combustion and energy release at present, and the sulfide content in it is tens to thousands of ppm, which is the main source of air pollution and acid rain. At present, various desulfurization methods can effectively eliminate sulfide in fuel oil within a certain range, such as the commonly used hydrodesulfurization, because the selectivity of the catalyst is continuously improved, it can selectively reduce the sulfur in the oil to h 2 S is thus separated from oil products, and the technical route is very mature, which has always been the main process in the oil refi...

AI Technical Summary

Problems solved by technology

Since there is no means of catalytic oxidation, the defect of this technology based on the stoichiometric organic peroxyacid oxidation reaction is inevitable. For example, it must be reacted in an organic acidic medium, and the extraction of a polar solvent must be strengthened. No oxidation effect on thiophene, etc.

In addition, the biggest disadvantage of oxidative desulfurization at present is that sulfur-containing compounds can only be oxidized to sulfone or sulfoxide products. In addition to the loss of organic hydrocarbons in extraction, the removal of sulfone and sulfoxide itself is also a loss of organic carbon.

A big improvement is to use oil-water two-phase layering to remove oxidized organic sulfur. For example, Japanese patent JP200430588A uses water-soluble heteropolyacids to photocatalytically react in oil-water two-phase to oxidize sulfur into strongly polar The organic sulfur component enters the water phase and separates in layers after the reaction, but this method can only oxidize benzothiophene or substituted dibenzothiophene organic sulfur into the corresponding sulfone or sulfoxide, the other is if the original sulfide If it is an alkyl-substituted benzothiophene or dibenzothiophene, the oxidized alkyl group will become a highly polar carboxylic acid. Due to the limitation of oxygen / oil phase / water phase diffusion, the oxidation efficiency is very low, and the oxygen pressure must be increased to Oxidation is complete and there is still loss of organic components

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