Patent ID: 7604731

Claim:
A process for preparing crystalline petroleum coke having needle like structure suitable for manufacturing high temperature graphite electrodes from atmospheric residue obtained from bottom of atmospheric crude distillation column, said process comprising the steps: a. preheating the atmospheric residue to a temperature in the range of 440° to 520° C. to obtain a hydrocarbon stream in which thermal cracking has been initiated; b. subjecting the hydrocarbon stream in which thermal cracking has been initiated thus obtained in step (a) to a first delayed coking step in a first coking column to form cracked hydrocarbon vapors and easily cokable material and separating the easily cokable material from the cracked hydrocarbon vapors as solid coke; c. adding quench stream to the cracked hydrocarbon vapors obtained in step (b) in a quench column to obtain a condensate containing heavier hydrocarbon fraction and vapors containing lighter hydrocarbon fractions; d. separating the vapor containing lighter hydrocarbon fractions into at least a gas component and a hydrocarbon fraction having true boiling point in the range of 380° C. to 480° C. in a first distillation column; e. mixing the condensate obtained in the step (c), the hydrocarbon fraction having boiling point in the range of 380° C. to 480° C. thus obtained in step (d) and optionally clarified oil (CLO) obtained from FCC process and/or thermal tars and/or aromatic extract to obtain a mixture having aromatics content greater than or equal to 60% and average aromatic ring per molecule in the range of 3 to 8; f. subjecting the mixture thus obtained in step (e) to a temperature in the range of 460° C. to 540° C. in a preheater in presence of steam to obtain a hydrocarbon stream in which thermal cracking has been initiated; and g. subjecting the hydrocarbon stream in which thermal cracking has been initiated thus obtained in step (f) to a second delayed coking step in a second coking column thereby obtaining crystalline petroleum coke having needle structure and a cracked hydrocarbon product mixture and separating the crystalline petroleum coke having needle structures.