【作者】 罗运强；

【导师】 靳广洲；

【作者基本信息】 北京化工大学 ， 化学工艺， 2009， 硕士

【摘要】 随原油劣质化趋势加大和环保法规的日益严格,开发新型高效加氢脱硫、脱氮催化剂已成为加氢精制领域新的研究热点。本文采用程序升温还原碳化反应制备了碳化钼催化剂,并用TG-DTA技术对氧化钼的还原碳化机理进行了研究,借助XRD、BET、GEM、XPS等技术对制备的催化剂进行了表征,以喹啉/环己烷溶液为模型化合物,在高压微反装置上对制备的碳化钼催化剂的喹啉加氢脱氮性能进行了评价。结果表明,MoO₃可在程序升温条件下于CH₄/H₂气氛中还原碳化为β-Mo₂C,其适宜的还原碳化温度675℃,恒温保持180min。Ni助剂的加入可降低MoO₃的还原碳化始、终点温度,增大催化剂的比表面积.Co助剂的可降低MoO₃的还原碳化起始温度,但对还原碳化终点温度影响不大,并能抑制Mo₂C颗粒的生长,从而有利于提高碳化钼催化剂的比表面积。Mo₂C催化剂表现出了较高的加氢脱氮活性,其在反应压力3.0MPa,反应液时空速8h^-1,H₂/原料液体积比500:1,340℃反应温度下的喹啉加氢脱氮活性达到了41.3%,比相应MoS₂和MoO₃分别提高了约8和28个百分点。Ni、Co助剂的加入对Mo₂C喹啉加氢脱氮活性有明显的促进作用,在上述反应条件下,Ni/Mo比为0.3和Co/Mo原子比为0.4制得的Ni-Mo₂C和Co-Mo₂C催化剂的喹啉脱氮率分别达到了98.2%和98.0%,相应都提高了约47百分点。Ni-Mo₂C催化剂合成条件以还原碳化温度625℃、还原碳化时间为180min较为适宜;而Co-Mo₂C催化剂合成条件以还原碳化温度650℃、还原碳化时间为180min较为适宜。更多还原

【Abstract】 With the petroleum becoming inferior and environmental regulations growing stringent,new high-performance hydrodesulfurization and hydrodenitrogenation catalysts in hydrotreating field has become a new hotspot.Molybdenum carbide catalysts were prepared by temperatureprogrammed reaction and characterized by XRD、BET、SEM、XPS techniques.TG-DTA in-situ was used to investigate the synthesis mechanism of molybdenum carbide catalysts.The hydrodenitrogenation（HDN） performance of the catalysts were evaluated by using of quinoline/cyclohexane as model reactants.The results were as follows:MoO₃ could be carburized intoβ-Mo₂C in CH₄/H₂ mixture at carburizing temperature 675℃.The promoters Ni and Co could change the process of carburization,decrease the carburizing temperature and increase the surface area of Mo₂C.Ni could reduce it’s initial and terminal carburizing temperature,while Co could merely increase the initial temperature,but couldn’t effect the terminal carburizing temperature.Mo₂C had a higher activity of quinoline HDN than MoS₂ and MoO₃.Under the reaction conditions of 340℃,3.0MPa,space velocity 8h^-1,and H₂ / liquid volume ratio 500:1,the quinoline HDN activity of Mo₂C reached 41.3 percent,which was about 8 percent point and 24 percent point higher than that of MoS₂ and MoO₃,respectively. The quinoline HDN activity of Ni-Mo₂C at 0.3 of Ni/Mo atom ratio and Co-Mo₂C at 0.4 of Ni/Mo atom ratio reached 98.2%and 98.0%under the same reaction conditions,which was about 47 percent point higher than that of Mo₂C.It was found that Ni and Co promoters could significantly improve the quinoline HDN activity of Mo₂C.The optimal preparation conditions for Ni-Mo₂C were that the carburizing temperature was about 625℃,while for Co-Mo₂C that was 650℃,and the carburizing time was 180 min for both.更多还原