Mesoporous Carbon Materials Prepared From Waste Polystyrene And Its Adsorptivity For Thiophenic Sulfurs In Model Oil

In recent years, with the increasingly severe haze, more and more people began to look toward the vehicle exhaust pollution. Vehicle exhaust pollution is mainly due to some sulfur compounds and nitrogen compounds in the fuel. The resulting SOx impose significant impact on air quality. Therefore, the low-sulfur fuel will become the inevitable trend in oil refinery. Conventional hydrodesulfurization process has some problems for removing thiophene compounds, especially dibenzothiophene (DBT), e.g. the demanding reaction conditions, as well as the loss of octane value. The adsorption desulfurization can be achieved efficiently in a mild reaction conditions with low cost and little effect on the fuel quality. Activated carbon as a cheap and efficient adsorbent can selectively remove thiophene compounds in fuel oil. Waste expanded polystyrene foam (WEPS) recycling is another environmental problem to be solved. These two problems may be solved simultaneously by using WEPS as the feedstock for the synthesis of activated carbon for oil desulfurization.In this paper, crosslinked polystyrene CPS1and CPS2were synthesized by using carbon tetrachloride and chloroform as the crosslinking agent of WEPS with the catalyst anhydrous AlCl3. New carbon materials, ACCPS1and ACCPS2, are prepared via calcination of CPS1and CPS2, respectively, with high surface area and microporous structure. In order to get the optimal reaction conditions, we have researched the effect of catalysts, crosslinking agents, and other reaction conditions on the structure and properties of CPS. CPS1is a mesoporous material with surface area of370m2/g, while ACCPS2is a microporous material with doubled surface area of CPS1, and80%of the surface area and65%of the pore volume are arising from the microporous pores.The isothermal adsorption data of CPS1, CPS2, ACCPS1and ACCPS2were measured for dibenzothiophene (DBT)-Octane DBT-Toluene, and DBT-Gasoline systems at30℃. The adsorptivity of these materials for DBT follow the order of CPS2<CPS1<AC<Y-zeolite<AAC<ACCPS2<ACCPS1<Cr-BTC<Cu-BDC. The ACCPS1’s adsorption capacity is better than AC, AAC and Y-zeolite, and a little worse than MOF’s. The higher adsorptivity of ACCPS1than ACCPS2is in accordance with their microporous surface areas. Further, ACCPS1has good regeneration performance, and its equilibrium adsorptivity can also reach16.8mg/g after5cycles reuses, which is higher than conventional fresh active carbon materials. Through precise controlling of the pore structure and surface chemistry, the ACCPS’s desulfurization capability may be improved further, and thus prospect for the real application.