反应条件对Co/SBA-15催化剂Fischer-Tropsch合成性能的影响

采用初湿浸渍法制备了 Co/SBA—15催化剂,采用 N_2物理吸附、X 射线衍射和透射电子显微镜等方法对载体和催化剂进行了表征;在小锈钢固定床反应器中,对 Co/SBA—15催化剂的 Fischer—Tropsch 合成性能进行r评价,考察了反应温度、反应压力及合成气空速对 CO 转化率和产物选择性的影响,得到了 CO 转化率与反应温度、反应压力和合成气空速间的定量关系,并给出了数学表达式。实验结果表明,CO 转化率与反应温度呈指数关系、与反应压力呈线性关系、与合成气空速呈反比关系,过高或过低的反应温度、低反应压力和大合成气空速都不利于长链烃的生成。同时考察了反应时间对 Co/SBA-15催化剂 Fischer-Trop-sch 合成性能的影响。随反应时间的延长,CO 转化率降低,产物选择性变化不大,在考察反应温度、反应压力及合成气空速的影响时,可以忽略反应时间的影响。

Effect of Reaction Conditions on Performance of Co/SBA-15 Catalyst in Fischer-Tropsch Synthesis

Co/SBA-15 catalyst was prepared by incipient wetness impregnation. The support and the catalyst were characterized by means of N2 physical adsorption,XRD and TEM. Performance of Co/SBA-15 catalyst in Fischer-Tropsch synthesis was evaluated in a fixed-bed stainless steel reactor. Effects of reaction conditions,namely reaction temperature,reaction pressure and GHSV of syngas,on CO conversion and selectivities to products were investigated. Quantitative relations of CO conversion with reaction temperature,reaction pressure and GHSV of syngas were obtained. Their mathematic expressions were derived. CO conversion varied exponentially with reaction temperature,linearly with reaction pressure and in inverse ratio with GHSV of syngas. Too high and too low reaction temperature,low reaction pressure and high GHSV of syngas are all negative for production of long chain hydrocarbon. Concerning the effect of reaction time on performance of the catalyst in Fischer- Tropsch,the change of CO conversion and selectivities to products along with the reaction time can be ignored when the effects of reaction conditions are discussed.