摘要
在固定床反应器上考察了哌啶对二苯并噻吩(DBT)的加氢脱硫(HDS)反应活性及反应路径的影响。反应所用催化剂为MCM-41分子筛担载的Co-Mo或Ni-Mo硫化物,MoO3的负载量为20%,Co(Ni)与Mo的摩尔比为0.75。反应前,催化剂用10% H2S和90% H2的混合气进行硫化,硫化温度为400℃,硫化时间为3 h。HDS反应压力为5.0 MPa,温度为260-340℃,催化剂用量为0.2 g。反应原料为含哌啶和DBT分别为0-0.3%和0.8%的十氢萘溶液,液时空速为27 h-1。研究结果表明,无论是在Co-Mo／MCM-41 催化剂上还是在Ni-Mo／MCM-41催化剂上进行DBT的HDS反应,少量哌啶的存在都会大幅度降低催化剂的活性。由DBT的HDS反应产物的选择性分析发现,哌啶对HDS的抑制作用主要体现在对加氢反应路径的毒害作用。随着反应温度的升高,哌啶的加氢脱氮活性提高,HDS的反应活性接近于原料中没有哌啶时的活性,说明哌啶的毒害作用可能是因为它与含硫化合物竞争吸附而低温下加氢脱氮活性较低所致。
The detrimental effects of piperidine on hydrodesulfurization ( HDS ) ofdibenzothiophene (DBT) catalyzed by Co-Mo/MCM-41 or Ni-Mo/MCM-41 were investigated in a fixed-bed reactor. A loading of 20wt% MoO3 was chosen for both catalysts, and the atomic ratio of Co or Ni to Mo was 0. 75. Prior to HDS reaction, the catalysts were presulfided at 400℃ for 3h in the presence of hydrogen containing 10vol% hydrogen sulfide. The HDS activities of the catalysts were evaluated at atemperature range of 260-340℃, a total pressure of 5. 0MPa and a LHSV of 27h-1 with a feedstock of declaim solution containing 0. 8wt% DBT and a piperidine content of 0-0. 3wt%. It was shown that the presence of trace amount of piperidine led to dramatic decrease in HDS activity of either Co-Mo/MCM-41 or Ni-Mo/MCM-41. Through the analysis of product selectivity, it was found that the detrimental effect of piperidine on HDS of DBT was mainly characterized by the inhibition of the hydrogenation route in the DBT reaction network. The hydro-denitrogenation activity of piperidine increased at elevated temperatures, and the HDS activities of both catalysts in the presence of piperidine approached those in the absence of piperidine. It is suggested that the detrimental effect of piperidine on HDS activity might result from the competitive adsorption of piperidine with DBT on the active sites.
出处
《石油炼制与化工》
CAS
CSCD
北大核心
2004年第11期9-14,共6页
Petroleum Processing and Petrochemicals
基金
国家自然科学基金青年基金(20003002)重点基金(20333030)教育部博士点基金(20030141026)CNPC中青年创新基金资助项目
