Abstract: There are disclosed processes for separating waxes of different melting points from a room temperature amorphous or liquid hydrocarbon mixture in an energy conservative manner by selectively causing precipitation of crystallized waxes. The processes involve the use of a selected co-solvent totally miscible with light and intermediate hydrocarbons from a group consisting of acetone, ketene, propanone, 2-propanone, methanol, ethanol, isopropanol, N-propanol, acetic acid, formic acid, and propionic acid or combinations thereof as a precipitating agent. Hydrocarbon mixtures, especially those with elevated pour points are first diluted by solvents such as toluene and/or methylethyl ketone which must be free of any significant quantity of the aforesaid co-solvents. The diluted hydrocarbon mixture at above 50 degrees F.

Abstract: There is disclosed a process of oil recovery from tar sands or separation of hydrocarbons from a solid or viscous bitumen source wherein carboxylic acids or carboxylic acid mixtures are utilized as a solvent or diluent and are mixed with heavy crude oil, injected into an oil reservoir or mixed with tar sands in a surface vessel to reduce the viscosity of the crude oil and to increase the mobility of the oil. The process is characterized by the use of an amphiphilic phase separation induced by injection of isopropanol or other alcohol to facilitate the recovery of carboxylic acid diluent from the bitumen product, and another phase separation step may be employed to separate the carboxylic acid component from the alcohol. Sodium chloride or other brine solution is usually mixed with the alcohol and many embodiments combine a light hydrocarbon such as heptane with the carboxylic acid as an additional solvent. Carboxylic acids in the form of fatty acids with from 8 to 20 carbon atoms are preferred.