Effect of Recycle Gas Composition of the Performance of Fischer-Tropsch Catalyst

摘要

In this study, the influence of CO_2 and CH_4 on the performance and selectivity of Co-RU/Al_2O_3 catalyst is investigated by injection of these gases (0— 20 vol.% of feed) to the feed stream. The effect of temperature and feed flow rate are also inspected. The results show that low amounts of CO_2 in the feed stream do not change the catalyst activity, but increasing the amount of CO_2 (more than 10 vol.%), causes the CO conversion to decrease and the selectivity of heavy components to increase. Methane acts as an inert gas and does not affect the catalyst performance. Increasing feed flow rate has a negative effect on both CO conversion and heavy component selectivity. By raising the temperature, CO conversion will increase but there are more volatile components in the product. The effect of CO_2 on catalyst deactivation is also investigated and a mechanism is suggested to explain the negative influence of CO_2 on catalyst deactivation.