Mo-P/HZSM-5催化剂临氢芳构化性能研究

Study on the hydroaromatization performance of Mo-P/HZSM-5 catalyst

将硅铝原子比为38的HZSM-5分子筛在不同浓度的氢氧化钠碱溶液中处理后,通过离子交换法脱除部分硅原子,改善孔结构。以HZSM-5分子筛为载体,钼酸铵和磷酸二氢铵做钼源和磷源,用共浸渍法制备了氧化态前体,采用程序升温还原法制备出了负载型磷化钼催化剂,采用XRD和N2-吸附进行表征。在小型连续固定床反应器上以全馏分FCC汽油为原料,考察碱溶液浓度和工艺条件对芳构化反应的影响。结果表明,最佳的碱溶液浓度为0.20 mol/L,在反应温度360℃、压力2.0 MPa、空速2 h-1、氢油比400∶1时,液相产品中芳烃质量分数为32.39%,烯烃质量分数为17.18%,液体收率为93.5%。

The ZSM-5 zeolite with a SiO2/Al2O3 molar ratio of 38 was treated in NaOH alkali solution of different concentrations and then transformed into the acid state by ion exchange. HZSM-5 supported Mo-P catalyst was prepared by co-impregnation to form an oxidized precursor and followed by temperature-programming reduction （TPR） and characterized by X ray diffraction （XRD） and nitrogen-adsorption. The impacts of the concentration of alkaline solution and process conditions on aromatization reaction were investigated on a small series fixed-bed reactor using FCC gasoline as feedstock. The results showed that the optimum concentration of alkali solution was 0.20 mol/L and under the optimum process conditions： reaction temperature 360 ℃, reaction pressure 2.0 MPa, LHSV 2.0 h-1 and hydrogen/oil volumetric ratio 400： 1, the aromatics mass fraction in liquid product was 32.39%, the olefin mass fraction was 17.18% and liquid product yield was 93.5%.