煤焦油加氢预处理催化剂的Fe、Ca沉积分布规律  

Distribution of Fe and Ca deposits in coal tar hydro-pretreatment catalyst

作　　者：吴艳 WU Yan(Beijing Research Institute of Coal Chemistry,China Coal Research Institute Corporation Ltd.,Beijing 100013,China;State Key Laboratory of Coal Mining and Clean Utilization,Beijing 100013,China)

机构地区：[1]煤炭科学技术研究院有限公司煤化工分院,北京100013 [2]煤炭资源高效开采与洁净利用国家重点实验室,北京100013

出　　处：《煤质技术》2022年第1期32-38,共7页Coal Quality Technology

基　　金：天地科技股份有限公司科技创新创业资金专项项目(2021-TD-MS004)。

摘　　要：为解决Fe、Ca沉积导致催化剂颗粒间被堵塞、活性中心被覆盖以及床层压降快速下降等问题,对中低温煤焦油加氢预处理催化剂(保护剂和脱金属剂)上沉积金属类型及分布规律进行研究。研究方法包括:利用ICP、SEM-EDS结合物料衡算表征Fe、Ca元素在反应器及催化剂上轴向、径向沉积分布;采用BET分析金属沉积导致的孔结构变化;利用TG-MS研究了催化剂上金属硫化物的热解行为。结果表明:加氢处理后煤焦油中Fe和Ca大部分以硫化物形式沉积在催化剂颗粒之间,其余部分沉积在催化剂上;Fe元素对催化剂的危害大于Ca元素。Fe元素在催化剂床层上的轴向沉积分布为沿反应器从上向下方向呈下降趋势,Ca元素的分布无明显规律。Fe元素未能进入保护剂内部孔道,主要沉积在保护剂的外表面,但在脱金属剂内部分布均匀。由于Fe、Ca元素覆盖和堵塞,反应器上部催化剂的比表面积和孔体积损失率更高。沿反应器从上到下的方向,3种催化剂SO_(2)的质谱信号呈减弱趋势,因上部催化剂的金属沉积量较大,由金属硫化物氧化与氧化物升华造成的失重量也就越大。In order to solve the problems such as blockage of catalyst particles,coverage of active centers and rapid drop of bed pressure drop caused by deposition of Fe and Ca,the types and distribution rules of deposited metals on the medium and low temperature coal tar hydrotreating catalysts(protective agents and demetallizing agents)were studied.The research methods include:using ICP、SEM-EDS combined with material balance to characterize the axial and radial deposition distribution of Fe and Ca elements on the reactor and catalyst,using BET to analyze the pore structure changes caused by metal deposition,using TG-MS to study the pyrolysis behavior of metal sulfides on catalysts.The results shows that most of Fe and Ca in coal tar are deposited between catalyst particles in the form of sulfides,and the rest are deposited on the catalyst.Fe is more harmful to the catalyst than Ca.The axial deposition distribution of Fe on the catalyst bed shows a downward trend from the reactor top to bottom,and there is no obvious distribution regularity of Ca.The element Fe fails to enter the inner channel of the protective agent,and mainly deposits on the outer surface,but distributes uniformly in the demetallizing agent.Due to the coverage and blockage of Fe and Ca,the specific surface area and pore volume loss rate of the catalyst in the upper part of the reactor are higher.From the reactor top to bottom,the SO_(2) mass spectrum signals of the catalysts shows a weakening trend,and the larger the amount of metal deposited on the upper catalyst,the larger the weight loss caused by oxidation of metal sulfide and sublimation of oxide.

关 键 词：煤焦油 预处理 保护剂 脱金属剂 金属沉积 催化剂 沉积分布 孔体积损失率 

分 类 号：TQ536[化学工程—煤化学工程]