Removal of hydrocarbons from particulate solids
A process and composition for removing heavy oil and bitumen from oil sands is disclosed. The composition comprises an emulsion of d-limonene in water, with an optional anionic surfactant as an emulsifying agent. The emulsion is contacted with an oil sand slurry until the aqueous and hydrocarbon phases separate. The process may take place at temperatures less than about 80° C. and with low concentrations of the d-limonene.
1. A process for primary extraction of bitumen from oil-wet or water-wet oil sands, comprising the step of forming a mixture by mixing an effective amount of a composition comprising an emulsion of an organic phase comprising d-limonene in an aqueous phase, with an aqueous slurry of the oil sands, and recovering a hydrocarbon phase, wherein the mixing step is conducted to avoid vigorous agitation to avoid forming stabilized suspensions of clay or other fine particles.
2. The process of claim 1 wherein the mixture comprises 4% or less d-limonene by volume, and the resulting hydrocarbon recovery exceeds 90% by weight.
3. The process of claim 2 which is conducted at a temperature of less than 80° C.
4. The process of claim 2 which is conducted at a temperature of 30° C. or higher.
5. The process of claim 1 wherein the organic phase of the composition is recovered from the extracted hydrocarbon phase, and recycled in the process.
6. The process of claim 1 wherein the mixing step is performed without significant froth formation.
7. The process of claim 1 further comprising the step of removing clay and other fine particles from an aqueous phase, and recycling the aqueous phase into the process.
8. The process of claim 1 wherein the oil sands comprises oil-wet oil sands.
9. The process of claim 1 wherein the oil sands comprises water-wet oil sands.