Fe-Mn催化剂对F-T合成反应的催化性能 Ⅱ.中后期反应性能

Catalytic Performance of Fe-Mn Catalyst for Fischer-Tropsch Synthesis Ⅱ. Performance of Catalyst during Middle and Late Period of Reaction

采用固定床积分反应器 ,详细考察了F T合成反应用Fe Mn催化剂运行 90 0和 180 0h后的中后期反应性能 .结果表明 ,该催化剂仍维持着较高的催化活性及稳定性 ;与初期反应性能相比 ,运行 90 0h后CH4选择性有明显升高的趋势 ,运行180 0h后CH4选择性进一步升高 .运行 2 2 0 0h后 ,通过降低原料气的H2 /CO比和提高反应压力 ,可明显改善烃产物的选择性 .在n(H2 ) /n(CO) =0 6 2 ,GHSV =2 30 0h-1,p =3 0 2MPa和θ=2 83℃的条件下 ,CO转化率可达 75 6 % ,总有效烃 (C=2～ 4+C+ 5)的选择性可达 89 0 % ,CH4选择性为 5 7% .这表明该催化剂具有良好的可操作性 ,且特别适合于由煤制合成气制液体燃料和C2～ 4低碳烯烃 。

The effects of reaction conditions on the performance of Fe Mn catalyst for F T synthesis during the middle and late period of the run process have been investigated in an integral fixed bed reactor. Firstly, 900 h stability test for the catalyst shows that the catalyst has relatively high activity and excellent stability, and the CH 4 selectivity apparently increases compared with in the early period. In the late period of the catalyst run for 1?800 h, the effects of reaction pressure and H 2/CO ratio on the catalyst performance have been evaluated and the CH 4 selectivity further increases to some extent. After 2?200 h, the catalyst also has relatively high activity; the selectivity for hydrocarbon products can be apparently improved by decreasing the H 2/CO ratio in feeding gas and increasing the reaction pressure. The conversion of CO and the selectivity for (C = 2～4 +C 5+ ) and CH 4 are 75 6%, 89 0% and 5 7%, respectively, under the conditions of n (H 2) / n (CO) =0 62, GHSV= 2?300 h -1 , p =3 02 MPa and θ =283 ℃. Compared with the middle period of reaction after 900 h under the conditions of n (H 2) / n (CO) =2 07, GHSV= 2?400 h -1 , p =2 30 MPa and θ =283 ℃, the selectivity for (C = 2～4 +C + 5) increases but the selectivity for CH 4 decreases, indicating that the catalyst has very good longevity and promising application in the production of light olefins and high quality liquid fuels.