低温高活性熔铁催化剂上的超临界相费托合成反应

在固定床反应器中超临界相条件下研究了熔铁催化剂上的费托合成反应,发现在超临界介质中反应物和产物更容易扩散,较好地抑制了催化剂表面非活性碳的沉积,从而提高了费托合成反应中的CO转化率和烯烃选择性,增加了链增长因子,降低了甲烷选择性.同时,考察了超临界介质、反应温度、压力、H2/CO比和空速等条件对费托合成反应的影响.结果表明,C5-8正构烷烃在催化剂活性温度下都是适宜的超临界介质.当温度和压力都在介质的临界点以上时,介质表现出较好的传质与传热性能,可改善费托合成反应性能.

Supercritical Phase Fischer-Tropsch Synthesis Reaction over Highly Active Fused Iron Catalyst at Low Temperature

The Fischer-Tropsch synthesis (FTS) reaction over the fused iron catalyst in the presence of supercritical media was investigated in a fixed-bed reactor. Compared with the gas-phase FTS reaction,the presence of supercritical media resulted in an increase in CO conversion,olefin selectivity,and C5 selectivity,but a decrease in CH4 selectivity owing to the fact that diffusion was easier in the supercritical media and less inactive carbon was deposited on the catalyst surface. The effects of supercritical media,temperature,pressure,H2/CO ratio,and syngas flow rate on the supercritical phase FTS reaction were investigated. The n-pentane,n-hexane,n-heptane,and n-octane had similar effects on the FTS reaction. The performance of FTS reaction could be improved when the reaction temperature and pressure were higher than the critical points of the media owing to the better mass and heat transportation in supercritical media.