Behavior Of Desulfurization Of3-Dimensionally Ordered Macroporous Fe₂O₃-SiO₂Compound Desulfurizer

Coal is the main source of energy and plays an important role in energy structure in China. The efficient using of coal have been becoming the chief aim in the development of energy in our country. Integration gasification combine cycle(IGCC) technology and coal poly-generation technology are the main orientation of clean energy technology in the future. During coal gasification process, the sulfur in the coal release in the form of H2S, which will not only corrode the mechanical sections and structural materials, but also poison the downstream catalysts. Therefore, H2S must be removed, and coal gas purification is the key step in the entire system. Removal of H2S by metal oxide desulfurizer is a typical non-catalytic gas-solid reaction in which diffusion has important influences on the performance of desulfurizer and the role of texture which can affect diffusion is crucial in the process of desulfurization.The3-dimensionally ordered macroporous (3DOM) materials have unique pore diameters, and they are arrayed highly periodically. The macropores keep interconnected through small windows. The structure can improve diffusion because of its high surface area and pore size.This work employed the typical structure of3DOM into the preparation of desulfurizers. The performance of desulfurization of3DOM Fe2O3-SiO2compound desulfurizers were investigated. Firstly, PS microspheres with different particle diameters were prepared by emulsion ploymerization, which were used as colloidal crystal templates. Secondly,3DOM Fe2O3-SiO2compound desulfurizers with different pore diameters were synthesized with iron nitrate and TEOS as the precursor. The desulfurization performance of3DOM Fe2O3-SiO2compound desulfurizers with different pore diameters were investigated by means of minitype fixed-bed reactor. The desulfurizational law of desulfurizers were investigated with the changes of pore diameters of desulfurizer, reactive temperature, content and ratio of mixtural gas, space velocity. The advantage of performance of3DOM desulfurizers were investigated by means of comparing with GH Fe2O3desulfurizers. The regenerative behaviors were investigated using minitype fixed-bed reactor.The main conclusions from the experimental results are followed.1.3DOM Fe2O3-SiO2compound desulfurizers not only obtain longer breakthrough time, but also have more sulfur capacity than GH Fe2O3desulfurizers, which shows the advantage of3DOM Fe2O3-SiO2compound desulfurizers in the field of H2S remove. The investigation conclusion of desulfurization performance of3DOM Fe2O3-SiO2compound desulfurizers with different pore diameters shows that the175nm desulfurizer display the best performance. The optimum temperature area of3DOM Fe2O3-SiO2desulfurizer is300℃.2.3DOM Fe2O3-SiO2compound desulfurizers exhibit more excellent desulfurizational behavior than3DOM Fe2O3desulfurizers from the charactisic results and minitype fixed-bed reactor experiments.3. The sulfided desulfurizers can not regenerate at100℃.They exhibit good regenerative performance at200℃,300℃,500℃. They can not regenerate totally at200℃and may be sintered at500℃. So300℃is the optimum temperature area of3DOM Fe2O3-SiO2compound desulfurizers. Regenation reaction is good under the condition of water/oxygen. When there is only oxygen,it can obtain high SO2release and fast reaction,but it will make the desulfurizers sintering. When there is only water, it can not obtain total regenation even reacting with long hours. And at this condition, it will produce SO2as well as H2S.