The Research Of Anti-coking Technology In Ebullated-bed Residue Hydrocracking Unit

Petroleum resource,the non-renewable resources,is the main source for human survival and the raw material for chemical industry at the moment.With the short of petroleum resources,the processing proportion of heavy crude oil becomes larger and larger,thereof the process selection of heavy oil will impact on the economic benefit and future of the whole plant.Ebullated bed residue hydrocrackingtechnology will be adopted widely for its advantage of high efficiency of residue oil conversion rate,low pollution of environment,and high return rate on investment etc.However,this technology will destroy the stability of residue feedstock during reaction and result in asphaltene dissolve out from unconverted residue product,which will consequently lead to coking on equipment and pipes,and limit the conversion of all the residue hydrocracking units that affects the economic benefit of the whole plant or shortens unit operating cycle.Hence a better control of the relationship between the stability of unconverted oil and residue conversion ratio for the ebullated-bed residual hydrocracking units is the key for “safety,stability,long lifetime,satisfaction and excellence” of the units.Some foreign companies have been working on the studies of the anti-coking technologies of ebullated-bed residual oil hydrocracking unit many years ago.They have been carrying on a series of research from the unit conversion efficiency,the character of ingredients,catalysts,catalyst assistant,construction of units etc.And the results also have been widely used in industrial installations,besides,they enhanced the convert efficiency of the unit and reduced the unit coking.This paper studies the relationship between the coking condition of the residual oil hydrocracking unit and the operating conditions along with the combination of different highly aromatic fluxing oil,then generalize,analysis,and summarize the results at last,searching the solution of achieving the goal that make the operating steadily and long-periodic.