摘要
纳米HZSM-5(20～50 nm)沸石晶粒经碱性介质水热处理、负载稀土和锌氧化物组合改性后,制备成降低FCC汽油烯烃的催化剂,并用TEM,XRF,NH3-TPD及IR等手段对其进行了表征. 在温度为370 ℃, 压力3 MPa, 质量空速(WHSV)3 h-1 和氢油比(V(H2)/V(oil))为600的反应条件下, 在固定床反应器上对催化剂的降烯烃性能进行了评价. 结果表明,组合改性后的纳米HZSM-5催化剂表现出很强的降烯烃能力. 全馏分FCC汽油中烯烃含量(φ,下同)从49.6%降至15.4%, 芳烃(主要是C7～C9)含量从11.4%增加到33.5%, 异构烷烃(主要是C4～C6)含量从17.4%增加到31.1%, 异构烷烃与正构烷烃比从3.3增加到8.1, 在烯烃大量降低的同时,汽油的辛烷值(RON)有所增加. 同时汽油中苯的含量从2.84%降低到0.66%, 而硫的含量从0.02%(w)降低到0.01%. 催化剂具有降烯、除苯和脱硫的综合性能,且连续反应320 h仍保持性能稳定.
By hydrothermal treatment in alkaline medium and then loading rare earth oxide and zinc oxide, the modified nano-HZSM-5 catalysts （20-50 nm） were prepared, and they were characterized by TEM, XRF, NH3-TPD, IR and so on. Under the conditions of 370 ℃, p = 3.0 MPa, WHSV= 3 h^-1 and V（H2）/V（oil） = 600, their catalytic performance for reducing olefins in FCC gasoline was evaluated in the fixed bed reactor when the feed stock gasoline containing 49.6 % （φ, the same below） of olefins was used. The results indicated that the modified nano-HZSM-5 catalysts not only had stronger olefins reduction ability and better stability but also had stronger capability to reduce the sulfur and benzene contents simultaneously. The olefins content in the FCC gasoline decreased from 49.6% to 15.4% on the modified nano-HZSM-5 catalyst with 0.9% ZnO loading. Meanwhile, the ability of olefins reduction did not changed much within 320 h on stream. The aromatics （mainly C7 - C9） content increased from 11.4 % to 33.5 % and the i-paraffins （mainly C4 - C6 ） content increased from 17.4% to 31.1%, while the benzene content decreased from 2.84% to 0.66% and the sulfur content （w） decreased from 0.02% to 0.01%. The ratio of i-paraffins to n-paraffins increased from 3.3 to 8.1. Meanwhile, the research octane number （RON） of upgraded FCC gasoline increased while the olefins content was reduced greatly. The modified nano-HZSM-5 catalyst had integrative performance for reducing olefin, benzene and sulfur content in the FCC gasoline.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2005年第10期911-916,共6页
基金
山东省自然科学基金资助项目(Y2004B10)
