催化剂活化压力对费托合成反应影响的研究

Study on impact of catalyst reduction pressure on Fischer-Tropsch(F-T) synthesis reaction

采用中国神华自主知识产权低温浆态床费托合成工业沉淀铁系催化剂SFT418-7,在神华浆态床费托合成催化剂评价中试装置(CEU)上实施了经不同活化压力处理的催化剂对费托合成反应性能影响试验。结果表明,2.8 MPa压力下还原处理的催化剂较0.5 MPa压力活化处理的催化剂合成气(H2+CO)总转化率高,CO转化率和H2转化率均略高,而C+,C3+和C5+时空产率及合成气产油率却有所降低,碳有效利用率相对降低,其原因主要受CO2选择性增加引起。催化剂活化压力提高后,反应产物CH4选择性显著增加,烃类中C3+和C5+产物选择性下降,表明提高压力活化情况下,催化剂表面水煤气变换反应活性相增加,费托合成反应向碳链缩短方向转移。

The pilot plant tests of F-T catalysts reduced at different reduction pressures were performed to investigate the impact of different reduction pressure of catalyst on the F-T synthesis reaction performance in a proprietary low-temperature slurry-bed pilot plant using Fe-based SFT-418-7 catalyst. The results show that, the total conversion of synthesis gas （ H2 ＋ CO） of catalyst reduced at 2.8 MPa pressure is higher than that of catalyst reduced at 0.5 MPa pressure, the CO conversion and H2 conversion are a little bit higher, the yields of C ＋, C3＋ , and C5 ＋ and the yield of synthesis gas are reduced, leading to lower utilization of carbons. All these are caused by the increase of CO2 selectivity. After increase of catalyst reduction pressure, the CH4 se- lectivity is apparently improved and the selectivity of C3 , and C5＋ in hydrocarbons is lowered, which indicates that the shifting reactivity of water gas on catalyst surface is increased and F-T reaction is shifting towards shortening carbon chains at the increased catalyst reduction pressure.