Composition of ash from petroleum cokes in relation to quality of coker feedstock and original crude oil

1.The principal elements contributing to high ash contents of petroleum residual stocks and the cokes obtained from these stocks are sodium, iron, and magnesium, the contents of which increase with increasing content of chlorides in the crude oil.2.The contents of silicon, nickel, vanadium, and manganese in the residual stocks and in the cokes are essentially independent of the salt content of the crude oil.3.Thorough desalting of crude oil is a basic prerequisite in the production of low-ash cokes.4.In order to produce low-vanadium coke, the coker feedstock must be selected very carefully.