仪长渣油中含钙化合物的分布及加氢脱钙反应的研究

摘要

The Yichang residues of high calcium content were analyzed and corresponding hydrotreating experiments were carried out,to study the calcium-containing compounds distribution before and after residue hydrotreating,at the same time,the calcium removal reactions were investigated.The results showed that the calcium-containing compounds in Yichang residues can be classified into easy-to-removal ones and difficult-to-removal ones.The former mainly existed in resin component and was prone to remove by adding crude decalcification agent during electric desalting or hydrotreating operation,and the letter mostly existed in asphaltene component and was tough to handle with.The removal rates of calcium were usually lower than that of both nickel and vanadium,although the increase of temperature accelerated hydrodecalcium reactions.Meanwhile,the correlation between hydrodecalcium and hydrodeasphaltene reactions was found.In order to avoid agglomeration of calcium in the front catalysts bed,before introducing residue into the fixed bed residue hydrotreating unit,crude decalcification agent should be used appropriately to remove all the easy-to-removal calcium-containing compounds.%深入分析了高钙含量仪长渣油的性质,并对其进行加氢处理,考察了渣油加氢前后含钙化合物分布规律及其加氢反应特性.结果表明,仪长渣油中含钙化合物可以分为易脱除钙和难脱除钙;前者主要分布于胶质中,较容易加氢脱除或使用脱钙剂脱除,后者则主要分布于沥青质中,采用上述2种方法均较难脱除.仪长渣油的加氢脱钙率通常低于其脱镍率和脱钒率;较高的反应温度对加氢脱钙反应有利;加氢脱钙率与沥青质加氢脱除率具有一定的相关性.在实际工业装置上,为避免易脱除钙过于集中地沉积在固定床渣油加氢前部催化剂床层,应采用适量的脱钙剂先将易脱除钙尽可能完全脱除,再进行固定床加氢处理.