Ni-P/Hβ催化剂上FCC汽油加氢改质

Improvement of FCC Gasoline Hydrogenization on Ni-P/Hβ Catalysts

采用Hβ沸石为载体,以非贵金属Ni为主剂,P为助剂合成了FCC汽油加氢改质双功能催化剂,并研究了P的质量分数对催化剂性能的影响。结果表明,加入少量的P,双功能催化剂弱酸中心下降比较明显,中等强酸中心略有增加,而强酸中心明显增多,P的引入使催化剂的金属加-脱氢活性增强,因而有效地调节了催化剂的金属加-脱氢活性中心与酸性活性中心的比例,使催化剂的加氢活性和异构化选择性明显提高。引入P的质量分数过高,催化剂的酸量大幅度减少,降低催化剂的加氢活性和异构化选择性。分析了反应温度、质量空速和氢油体积比对产品分布的影响,在反应温度为280℃、质量空速为3h-1、氢油体积比为300∶1和压力为2.5MPa的反应条件下Ni-P/Hβ催化剂具有很好的异构化和芳构化性能,使在降低催化裂化汽油烯烃的同时,能够保证汽油的辛烷值基本不下降。

FCC gasoline hydroupgrading dual function catalysts were synthesized using Hβ zeolite as carrier, non-noble metal nickel as main catalyst and phosphorus as auxiliary. Influence of mass fraction of phosphorus on catalysts has been studied. The results show that weak acid centers of dual function catalysts fall obviously, middle acid centers increase a little, and strong acid centers increase obviously when minor phosphorus is added. Activity of hydrogenization and dehydrogenation of metal in catalysts is enhanced and the rate of metal active centers to acid active centers is adjusted efficiently at the same time. Hydrogenization activity and isomerization selectivity of the catalysts are enhanced obviously. Acid content of the catalysts falls considerably, and hydrogenization activity and isomerization selectivity of the catalysts are reduced with excessive P. Influence of reaction temperature, WHSV, and V(H_2)/V(Oil) on product distributions is studied. Ni-P/Hβ catalyst has excellent properties of isomerization and aromatisation under the reaction conditions that reaction temperature is 280 ℃, WHSV is 3 h^(-1), hydrogen-to-oil volumic ratio is 300∶1, and reaction pressure is 2.5 MPa. Octane number of gasoline does not fall under condition of deceased alkene.