چكيده به لاتين
Oxidative desulfurization is one of the most effective and important methods in the field of desulfurization, which has attracted a lot of attention. In this study, oxidative desulfurization was performed experimentally in the presence of microwave irradiation and was compared with desulfurization method in hot water bath (conventional heating). In this study, formic acid was used as a catalyst and hydrogen peroxide as an oxidant to oxidize sulfur compounds. The behavior of material under microwave-dependent depends on the dielectric properties of the material. The more polar the material, more affected by the microwave irradiation, and whatever the dielectric constant of the material is more, the more it stores the electromagnetic field, and depending on the dielectric loss factor, it converts the electromagnetic energy into thermal energy inside the material. In other words, the dielectric loss factor is larger, the material is warmer. Simulation of pure materials in coil reactor were investigated. The results simulation of fluid flow in a coil- reactor were investigated. The results show that toluene do not absorb the irradiation and are not heated, while the oxidation system (formic acid and hydrogen peroxide) is strongly affected by the microwave irradiation and are heated. Oxidation desulfurization of real fuel (diesel) with an initial sulfur content of 2760ppmw was performed in the MicroSYNTH microwave device and in conventional heating (hot water bath). It was observed that by increasing the formic acid to oxidant molar ratio from 6 to 6.6 at a constant temperature of 50%and applying microwave irradiation pulse and constant formic acid concentration by 85% decreased from 82.93% to 73.9% and under the same operating conditions at conventional heating (hot water bath reduced the efficiency of the process from 84.78% to 71.7%. The results showed that the efficiency of the process did not different significantly between the two heating methods at the same temperature. In other words, because the temperature of the reaction bulk is equal in the two methods, so the efficiency in the two methods is the same. The results of model fuel studies (dibenzothiophene in toluene) with an initial sulfur content of 500ppmw in a home microwave device showed that with increasing oxidant to sulfur molar ratio to sulfur from 5 to 40 at a constant power value of 800w and a constant formic acid to sulfur molar ratio of 120, the conversion rate of dibenzothiophene was reduced from 60% to 19%. Increasing the temperature also raises the reaction temperature, but a temperature of 50 degrees Celsius is considered the optimal temperature.
