Evaluation of several petroleum residues as the needle coke feedstock using a tube bomb

Nine feedstocks were carbonized at 500°C for 4 h in a tube bomb into lump cokes which can be evaluated in terms of their optical anisotropy, CTE and bulk density. The properties of some cokes were found comparable to those of commercial ones. Variable carbonization pressure allows more precise evaluation of feedstocks, since higher pressure was generally preferable for the production of better needle coke. The participation of the lighter fraction which is more emphasized under higher pressure is suggested to be very critical for the formation of needle coke. The reactivity of the feedstock measured by the coke formation in the carbonization for 1 h appears to reflect the quality of the resultant coke. The most reactive fraction may form the porous coke in the initial stage of the carbonization, separating from the matrix which can mediate the carbonization reaction.