Study On The Desulfurization Of Gasoline By The Method Of Adsorption And Extraction

In this paper, the sulfur removal in gasoline was studied by the method of extraction and adsorption. And the related factors on the desulfurization ratio and the yield of gasoline were researched. The researching contents were as follows:1. The modified ZSM-5 zeolite was prepared by ion exchange of ZSM-5 zeolite with metallic ions. The factors on the desulfurization ratio were investigated and the chemical and physical characterization of modified ZSM-5 zeolite were studied. For the adsorption studies, using 93# gasoline as feed stuff, the mass ratio of the adsorbent and gasoline was 0.10, the adsorption time was 1h, and the samples were placed in a fixed bed using a glass column at ambient temperature and pressure. Under these conditions, the CuO-ZSM-5 zeolite showed the best desulfurization ratio which can reach 85%.2. The adsorbents for desulfurization were also prepared by conventional co-precipitation method. In this investigation, the calcination temperature was 350℃and the calcination time was 5h. For the adsorption studies, using 93# gasoline as feed stuff, the mass ratio of the adsorbent and gasoline was 0.05, the adsorption time was 2h, and the samples placed in a fixed bed using a glass column at ambient temperature and pressure. Under these conditions, the desulfurization performance can be ranked as follows: CuO/Al₂O₃/ZnO> CuO/Al₂O₃> ZnO / Al₂O₃>CuO, the CuO/Al₂O₃/ZnO showed the best desulfurization performance which can reach a ratio of 87%.3. In the investigation of desulfurization by the method of extraction, N-methylpyrrolidone(NMP) was employed as extracting agent. Using 93# gasoline, type A gasoline, type B gasoline as feed stuff in the experiment, through the one-stage extraction, the desulfurization ratio of NMP showed a good result which can reach 52% and the yield of gasoline was 98%. And then, the other related factors were investigated by the extraction with NMP. The optimum conditions were obtained as follows: the volume ratio of gasoline and extracting agent is 2:1; the volume ratio of water and NMP is 0.10; the best extraction stage is 3.Through the extraction, the desulfurization ratio can reach 82% and the yield of gasoline was above 88%.