摘要
在考察ZSM 5沸石晶粒大小对脱除汽油中烯烃的影响的基础上 ,用纳米ZSM 5沸石作为活性组分负载Co Mo氧化物制备了改性纳米ZSM 5沸石催化剂 ,并用XRF ,NH3 TPD和TEM等方法对催化剂进行了表征 .以脱除DCC汽油中的烯烃为探针反应 ,临氢条件下 ,在固定床反应器上对催化剂脱除烯烃的性能进行了评价 ,考察了反应温度、压力、质量空速和氢 /油比对催化剂脱除烯烃性能的影响 .结果表明 ,由于纳米ZSM 5沸石具有晶粒小、微孔短、扩散路程短以及表面酸中心数量多等特点 ,因而表现出较高的催化活性和较强的抗积碳性能 .在V(H2 ) /V(oil) =30 0 ,WHSV =3h-1,p(H2 ) =3 0MPa和θ =35 0℃的适宜条件下 ,DCC汽油中烯烃的含量由 6 0 7%下降到 40 %左右 ,芳烃和烷烃的含量增加 ;在脱除烯烃的同时可维持汽油的辛烷值不降低 .催化剂连续运行 10 0 0h以上 ,其脱除烯烃的性能稳定 .
On the basis of studying the influence of ZSM-5 with different crystal size on the removal of olefins in DCC gasoline, the modified nano-crystallite ZSM-5 catalysts for removal of olefins in gasoline were prepared by impregnating Co-Mo oxides on nano-ZSM-5 as active component, and characterized by XRF, NH 3-TPD, TEM and so on. In the presence of hydrogen, the performance of the modified nano-crystallite ZSM-5 for removal of olefins in gasoline was evaluated in a fixed-bed reactor. The influence of H 2/oil ratio, WHSV, reaction pressure and temperature on the removal of olefins in gasoline was investigated. The results indicated that the nano-ZSM-5 exhibited higher activity and higher ability to resist coking because of its smaller crystallite, shorter micropore and diffuse distance, and more acidic centers. The modified nano-crystallite ZSM-5 catalysts had also strong ability to remove the olefins in gasoline and more stable activity. Under the optimum conditions of V(H 2)/ V(oil)=300, WHSV=3 h -1, p(H 2)=3.0 MPa and θ=350 ℃, the olefin content in gasoline was decreased from 60.7% to 40.0%, the content of paraffin and aromatics was increased, while the RON of gasoline was maintained. The catalytic performance of the modified nano-crystallite ZSM-5 catalysts did hardly change during the reaction for 1*!000 h.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2003年第8期585-589,共5页
关键词
加氢精制
纳米ZSM-5沸石
烯烃
芳香族烃
烷烃
汽油
钴
钼
hydrofining, nano-ZSM-5 zeolite, alkene, aromatic hydrocarbon, alkane, gasoline, cobalt, molybdenum
