Submitted to: Petroleum Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/10/2006
Publication Date: 2/27/2007
Citation: Sharma, B.K., Sharma, C.D., Bhagat, S.D., Erhan, S.Z. 2007. Maltenes and asphaltenes of petroleum vacuum residues: Physico-chemical characterization. Petroleum Science and Technology. 25:93-104.
Interpretive Summary: The fraction of petroleum crude oil which boils at temperature above 530 deg C are called vacuum residues. Solvent separation is used to reduce the coke forming tendencies of these residues. This process is capable of removing all or substantial amount of insolubles from these residues that are destined for further processing and thus applied as first step of refining. The soluble (maltenes) and insoluble (asphaltenes) fractions of these residues were obtained by precipitation in n-hexane, n-heptane and ethyl acetate solvents, and also by further reprecipitation of n-heptane and ethyl acetate soluble fractions by n-pentane. These soluble and insoluble fractions were characterized for their physical properties. The resulting degree of removal of insolubles ranged from 10-28 wt% of one vacuum residue and 25-50 wt% of the other vacuum residue. The chemical composition thus obtained will enable us to efficiently convert these low value products into high value fuels.
Technical Abstract: Solvent separation is frequently applied to petroleum vacuum residues to reduce the coke forming tendencies of these materials. This process is capable of removing all or substantial amounts of asphaltenes from feedstocks that are destined for further processing and thus applied as the first step of refining. Maltenes and asphaltenes obtained from vacuum residues of Heera and Jodhpur Indian crude oils using n-hexane, n-heptane, and soluble and insoluble fractions obtained using ethyl acetate, were characterized for elemental analysis, molecular weight, conradson carbon residue (CCR), specific gravity and pour points. The resulting degree of removal of asphaltenes ranged from 10-28 wt% of the HVR and 25-50 wt% of the JVR. The increasing trend of API and decreasing trend of CCR and pour point are observed with the increase in removal of asphaltenes.