(564d) Hose: PRESSURE-Assisted Extraction of Bitumen FROM OIL SANDS for High YIELD and Environmetally Acceptable BYPRODUCTS
Hot water extraction of bitumen from oil sands has been commercially applied for decades. The extraction process is greatly aided by the addition of caustics and other reagents, which adversely impact handling and disposal of byproducts at process end. Recent effort of increasing energy efficiency by reducing operation temperature might necessitate longer conditioning time and additional chemical additives that require further treatment downstream. In particular, Utah oil sands with high bitumen viscosity are expected to require more intensive agitation and caustic wetting agent such as sodium hydroxide.
With effective recovery of bitumen from oil sands and minimal adverse impacts of tailings to the environment as important objectives, we have developed a new heightened oil sands extraction (HOSE) process that greatly accelerates the release and collection of bitumen from oil sands, while requiring no intensive agitation, caustics, or other chemical additives that aggravate hydrocarbon contamination of the process water and subsequent treatment and disposal needs. The technique involves compression and decompression cycles, delivering a gas and oversaturating with it in the sands/water mixture during compression; this creates expanding microbubbles during decompression that helps dislodge bitumen from the sands. The new process results in high yields without chemical additives that are prone to creating problematic end products. High bitumen yields were achieved leaving spent sands that readily separate from the water column via gravity settling. The process water and spent sands contain small amounts of organics and appear to possess potential for water reuse and as construction fill material. Yields vs. specific operation parameters such as temperature, number of pressure cycles, gas type, and others for several Utahn and Canadian oil sands will be presented. An emphasis is on the process’ byproduct quality and the increased ability to treat, reuse, and dispose them post-operation.