ABSTRACT
Solvent deasphalting processes are a major part of refinery operations (Bland and Davidson,
1967; Hobson and Pohl, 1973; Gary and Handwerk, 1994; Speight and Ozum, 2002), and are
not often appreciated for the tasks for which they are used. In the solvent deasphalting
processes, an alkane is injected into the feedstock to disrupt the dispersion of components
and cause the polar constituents to precipitate. Propane (or sometimes propane and butane
mixtures) is extensively used for deasphalting and produces a deasphalted oil (DAO) and
propane deasphalter asphalt (PDA or PD tar) (Dunning and Moore, 1957). Propane has
unique solvent properties; at lower temperatures (388C to 608C; 1008F to 1408F), paraffins are very soluble in propane and at higher temperatures (about 938C; 2008F), all hydrocarbons are almost insoluble in propane.
