节点文献
稀土作助剂的钴系催化剂合成及费托反应性能评价
Synthesis of Co-Based Catalysts Promoted with Rare Earth Oxides and Their Catalytic Performance for Fischer-Tropsch Synthesis
【作者】 杜永;
【导师】 苏海全;
【作者基本信息】 内蒙古大学 , 无机化学, 2008, 硕士
【摘要】 以煤或天然气为原料,经由合成气通过费托(F-T)反应制液体燃料,对保障我国能源安全及解决环境污染问题具有重大的经济和现实意义;开发性能优异、低成本的新型费托催化剂对于节约投资和提高合成液体燃料的经济性具有重大的经济价值。本论文研究了以γ-Al2O3为载体制备钴系催化剂的助剂效应,通过XRD、BET、TPR、TEM等表征手段分析了催化剂性质并进行了费托反应性能评价。分析了稀土氧化物中硫含量、空速和不同助剂对费托反应性能的影响。首次用混合稀土氧化物作为费托反应钴系催化剂的助剂,提高了催化剂中钴的分散度和产物中重质烃含量。混合稀土氧化物中大量的硫会使催化剂硫中毒;不同空速影响链增长过程使产物分布发生改变;催化剂中钕的添加影响钻的还原度,导致催化费托反应的活性下降。研究了钌、混合稀土和单一稀土氧化物作为催化剂助剂对费托反应的影响及其反应机理。
【Abstract】 The synthesis of liquid fuel based on Fischer-Tropsch(F-T) synthesis through the coal or natural gas would have significant meaning in resolving the problems of the national energy-supply security and environment protection in China. To develop one kind of cheap catalyst, which has good character in liquid fuel synthesis and simplify the industrial craft or manipulation, it would cut down the investment and promote the development of liquid fuel synthesis based on F-T synthesis.This paper studied modification effects of different cobalt catalysts supported onγ-Al2O3 by XRD, BET, TPR, TEM and tested their catalytic performance for F-T synthesis. The influences of the sulfur content of rare earth oxides and various space velocity and modification effects were discussed.The catalysts promoted with mixed rare earth oxides were prepared and enhanced the dispersion of the cobalt and C5+ selectivity of products. Sulfur in the mixed rare earth oxides poisoned the catalyst. Different space velocity affected the process of chain growth and distribution of products. Neodymium in catalyst impacted on the reduction of cobalt and lowered catalytic activity. Compared mixed rare earth oxides with ruthenium with single rare earth promoter for the performance of F-T synthesis, the mechanism and effect of the different promoters were studied.
【Key words】 F-T synthesis; Co-based catalysts; rare earth promoter; mixed rare earth oxides;