合成气氢源下悬浮床加氢反应焦炭及催化剂特性分析

在高压釜中,合成气气氛下考察了克拉玛依减压渣油在不同分散型催化剂作用下的裂化反应,对反应前后催化剂的存在形态进行了光学显微扫描(SEM)分析和X射线衍射(XRD)分析。实验结果表明,催化剂存在的主要作用是抑制生焦和抑制过度裂化,改善产品分布。催化剂和焦的XRD分析谱图中没有检测到钼的硫化物形式,而在二元钼钴复合催化剂的焦XRD谱图中检测到非化学计量的CoMoS_x;焦的SEM分析表明,催化剂的存在有利于抑制焦炭颗粒的长大,水溶性催化剂作用下焦炭颗粒最小,颗粒尺寸约1μm。水溶性二元复合催化剂的总体催化性能优于相应的一元水溶性催化剂和油溶性催化剂,所选用的几种催化剂的活性从大到小的顺序为:Mo/CoMo/NiCoNaphNiNaphCo(NO_3)_2,Ni(NO_3)_2AMT。

AN ANALYSIS OF COKE AND DISPERSED CATALYSTS IN SLURRY-BED HYDROCRACKING USING SYNGAS AS HYDROGEN SOURCE

An investigation of upgrading karamay vacuum residue over various finely dispersed catalysts was carried out in a batch-type autoclave using syngas as alternative hydrogen source. The catalyst samples prior and post to reaction as well as coke samples were characterized by XRD and SEM. Results showed that the existence of catalyst could help suppress coke formation and overcracking, improve product distributions as well. From the XRD patterns of catalyst and coke, the sulfide type molybdenum was not detected; CoMoSx was found qualitatively in the coke sample with Mo-Co composite catalyst. The SEM results verified the catalyst function of inhibiting coke particles growing, with water soluble catalyst the coke particle size was only around 1µm. The overall catalytic performance of water soluble binary-metal composite catalysts was better than that of water soluble single metal catalysts and oil-soluble catalysts. The activities of catalysts used in this paper from high to low followed the order of Mo/Co＞Mo/Ni＞CoNaph＞NiNaph＞Co(NO3)2＞Ni(NO3)2＞AMT.