Chemistry and processability of crude oil asphaltenes as studied by ultracentrifugation

Conference · Sat Sep 01 04:00:00 EDT 1979 · Am. Chem. Soc., Div. Pet. Chem., Prepr.; (United States)

OSTI ID:5720338

Weeks, Jr, R W ^[1]; McBride, W L

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1. Los Alamos Scientific Lab., NM

One of the problems encountered during high severity hydrocracking of resids is asphaltene precipitation on the catalyst, in reactor effluent lines, and in product blends. Asphaltenes from different crudes show surprising differences in their response to hydrogen processing. Some asphaltenes are remarkably refractory while others are readily destroyed. These differences are very difficult to relate to analytically determined properties for two reasons: (1) the chemistry of asphaltenes is complex and ambiguous, and (2) defining such properties as reactivity and solubility under process conditions is difficult. In the present study several crude oils were ultracentrifuged and detailed analyses were carried out on the products. The crudes studied were selected to attempt to correlate their hydroprocessability and surface chemistry to results from the ultracentrifuge study. There were substantial differences in the amounts and compositions of the precipitates obtained from various crudes by ultracentrifugation. In samples where equilibrium separations were obtained, the amount of precipitate was generally two to four times the amount of asphaltenes in the crude. This additional material was found to be primarily resins with some oils. Not all the asphaltenes were precipitated at equilibrium at 181,000 g. The amount of the total crude oil heteroatoms (S, N, Ni, and V) concentrated in the precipitates seemed to correlate with ease of hydroprocessing. Two crudes, AB and Magrip, whose resids are known to be difficult to hydroprocess, had high values of the total crude oil heteroatoms that were precipitated. Differences were noted in the nickel- and vanadium-containing compounds as a greater fraction of the total nickel-containing compounds were precipitated.

• OSTI ID: 5720338
• Report Number(s): CONF-790917-(Vol.24)(No.4)
• Conference Information: Journal Name: Am. Chem. Soc., Div. Pet. Chem., Prepr.; (United States) Journal Volume: 24:4
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400* -- Petroleum-- Processing
023000 -- Petroleum-- Properties & Composition
ASPHALTENES
ASPHALTS
BITUMENS
CENTRIFUGATION
CHEMICAL REACTIONS
CHEMISTRY
ENERGY SOURCES
FOSSIL FUELS
FUELS
HYDROGENATION
ORGANIC COMPOUNDS
ORGANIC POLYMERS
ORGANOMETALLIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
PETROCHEMICALS
PETROLEUM
PETROLEUM PRODUCTS
POLYMERS
PROCESSING
REFINING
RESINS
SEPARATION PROCESSES
TAR
ULTRACENTRIFUGATION