چكيده به لاتين
The pyrolysis process is one of the methods of polymer waste management, which, in addition to reducing their environmental hazards, is economically feasible and can produce part of the fuel needs of the community by producing valuable materials. Liquid fuel from pyrolysis contains a lot of sulfur, so the desulfurization of this fuel is necessary.
A combination of oxidation and extraction desulphurisation methods, due to high efficiency and suitable operating conditions, can be considered as an acceptable alternative to conventional desulphurisation methods. In this study, the oxidation/extraction desulphurisation method was used to remove sulfur compounds from liquid fuel produced by this pyrolysis. A liquid fuel with a total sulfur content of 8500 ppmw was selected for studies. With the evaluation of different oxidation systems, the hydrogen peroxide-formic acid system was used to oxidize the sulfur compounds in the gas oil. The solvent used for the extraction of this system was made of dimethylformamide, because it had a high percentage of desulphurisation and affordable price. The results of this experimental study are in accordance with the results reported by other researchers. Based on this study, it was found that increasing the ratio of solvent to fuel and the number of extraction stages of more than two stages will not have much effect on the rate of desulphurisation of the fuel and will only increase the operating costs of the process. The reaction time was considered optimally for 150 minutes. Taking into account the temperature changes, the amount of hydrogen peroxide as oxidant and the amount of formic acid as a catalyst, experiments were carried out using the Central Composite algorithm and the Design Questionnaire design software to obtain the highest percentage of desulphurisation. The optimum conditions that the software used to maximize the percentage of desulphurisation indicated the temperature of 100° C, the amount of 5.6% of the fuel in the test chamber for hydrogen peroxide, and the 7.4% fuel in the test chamber for the formic acid. The amount of dehydration that was specified for these conditions was 74.7%. In order to validate the optimum point obtained by the software, the above conditions were tested experimentally; with the percentage of desulfurization obtained from the experiment was 73.5%. These two numbers were very close to the difference of less than one percent, which indicates the accuracy of the optimized point.
Keywords: Pyrolysis, Design Expert, Desulphurisation, Extraction, Formic Acid, Hydrogen peroxide, Dimethylformamide, Liquid Fuel
