NH_3对Ni-Mo-W/Al_2O_3和Co-Mo/Al_2O_3催化剂上多环芳烃选择性加氢饱和的影响

以硫化态Co-Mo/γ-Al_2O_3、Ni-Mo-W/γ-Al_2O_3为催化剂,选用催化裂化柴油为原料,考察反应气氛中NH_3对多环芳烃选择性加氢饱和的影响。试验结果表明:NH_3的引入使多环芳烃饱和率略有下降,并且对不同类型催化剂的单环芳烃选择性存在不同的影响;在相同多环芳烃饱和率下,对于Ni-Mo-W/γ-Al_2O_3催化剂,NH_3浓度的提高可促进单环芳烃选择性的提高,而对加氢脱氮反应基本无影响;对于Co-Mo/γ-Al_2O_3催化剂,NH_3浓度的提高对单环芳烃的选择性基本无影响,但显著抑制了加氢脱氮反应。因此,对Ni-Mo-W/γ-Al_2O_3催化剂,可采取引入NH_3的方式来达到提高单环芳烃选择性的目的。

EFFECT OF AMMONIA ON SELECTIVE HYDROGENATION PERFORMANCE OF POLY-AROMATICS ON Ni-Mo-W/ Al2O3 AND Co-Mo/ Al2O3 CATALYSTS

The effect of ammonia on poly-aromatic selective hydrogenation saturation was studied with Ni-Mo-W/γ-Al2O3 and Co-Mo/γ-Al2O3 catalysts using LCO as a feed. The results indicate that the introduction of NH3 reduces slightly the saturation rate of poly-aromatics, and affects the mono-aromatics selectivities on different types of catalysts. At the same saturation rate of poly-aromatics, the ammonia addition increases the mono-aromatic selectivity for Ni-Mo-W catalyst, but no effect on HDN reaction is found; while for Co-Mo/γ-Al2O3 catalyst, no influence on the mono-aromatic selectivity is observed but significant inhibition of HDN reaction when increasing NH3 concentration. It is concluded that adding NH3 can improve selectivity for mono-aromatic on Ni-Mo-W/γ-Al2O3 catalyst.