Study On Metal Removal Process Of Crude Oil

The crude oil contains a variety of trace metal elements,which will not only destroy the catalytic cracking catalyst,but also may cause bed blockage of the hydrocracking reactor and catalyst deactivation.The structure of metal elements in crude oil is very complex and stable,so it is difficult to remove.Although there are many kinds of demetallization agents,their effect is single.If one demetallization agent can efficiently remove multiple metal elements at the same time,the demetallization process of crude oil can be simplified and the cost of demetallization can be reduced.In this paper,the removal methods of nickel,iron,magnesium and calcium in crude oil were studied by acid extraction and chelating separation.In this paper,on the basis of previous research,Aq crude oil and Dg crude oil as the research object,first of all,the effect of single demetallization agent is investigated.The results showed that oxalic acid and EDTA-4Na were good demetallizers for iron removal.The effect of magnesium removal agent of Nas CN and acetoxamic acid are good;Tartaric acid and glyoxylic acid have good nickel removal effect.The effects of mercury and tetrasodium iminedisuccinate on the demetallization of crude oil were also investigated,but the removal rate was not high.After screening a single demetallization agent with better demetallization effect,two kinds of demetallization agent compound and three kinds of demetallization agent compound were carried out.The results show that under the two kinds of demetallization agent compound conditions,The effect of the combination of tartaric acid(1000μg/m L),nitrotriacetic acid(1000μg/m L)and glyoxylic acid(300μg/m L to 1000μg/m L)was better than that of single demetallization agent.However,the effect of the three demetallization agents of tartaric acid,glyoxylic acid and nitrotriacetic acid in the concentration range of 300μg/m L to 1000μg/m L is better than that of the two demetallization agents.The combined demetallization agent has better effect on the decalcification of Dg crude oil.In addition,the effects of conventional heating under 90℃ and in autoclave heating under 140℃ on metal removal were also investigated,which indicated that increasing the reaction temperature in autoclave was beneficial to increase the rate of metal removal.