镍在渣油加氢处理过程中的行为研究

采用4反应段固定床连续加氢处理装置研究了镍在渣油加氢处理过程中的变化,分析了混合渣油原料油及各步加氢处理油中镍的含量,并将各油样分离成八组分,对各组分中的元素镍进行了分析,讨论了原料油、各加氢处理油及分离组分中镍的分布变化及原因。结果表明,原料油中的镍主要集中在胶质和沥青质组分中,在保护剂段沥青质组分被大量脱除,并促使重组分中部分镍的存在形式发生一定的转化,减轻了后续床层催化剂的负荷,镍主要在加氢保护剂段和加氢脱金属段被脱除,有利于延长下游催化剂的使用寿命;经连续加氢处理后,镍含量明显降低,由25.4μg/g儋降低到5.3μg/g,镍的累积脱除率达到79.1%。

STUDY ON THE BEHAVIOR OF NICKEL IN THE HYDROTREATING OF RESIDUE FEED

The behavior of nickel in the residue feed during residue hydrotreating process was studied using a 4-zone fixed bed hydrotreating device. The Ni contents of residue feed and various treated oil samples were analyzed. Furthermore, the feed sample and treated oil samples were seperated to SARA components individually, and the Ni contents in various components were analyzed as well. The changes of total Ni content and Ni distributions during hydrotreating residue feed were discussed based on the above data. Results showed that in the residue feed, Ni was mainly in the resin and asphaltene components; at the guard catalyst zone, most of the asphaltene components were removed, besides, the forms of Ni existed in the heavy components were partly converted, which released some load for the downstream catalysts. It can be said that most of the Ni species were removed by the guard catalyst and hydrodemetallization catalyst, which could prolong the service life of downstream catalysts. Through 4-zone hydrotreating, the Ni content of residue dropped to 5.3 μg/g from the original of 25.4 μg/g, a total Ni removal rate of 79.1% was obtained.