Role of binary solvent and ionic liquid in bitumen recovery from oil sands

Abstract

A binary solvent of ethyl acetate and n‐heptane was made and applied together with ionic liquids (ILs, 1‐ethyl‐3‐methyl imidazolium tetrafluoroborate ([Emim]BF4)) to extract bitumen from oil sands at ambient conditions. Results of bottle tests show that the bitumen recovery is highly dependent on the volume ratio of ethyl acetate to n‐heptane. The maximum recovery was obtained at the ethyl acetate‐to‐n‐heptane ratio of 3:6. With external addition of ILs, an additional improvement of ∼10 % of bitumen recovery was observed (from 83 to 93 % at the ethyl acetate‐to‐n‐heptane ratio of 3:6). Based on the intensive investigation of key operational parameters (i.e. ILs‐to‐solvent ratio, agitation time, and conditioning time), a set of recommended extraction conditions were proposed to maximize the bitumen recovery. Further fractionation of the extracted bitumen together with FTIR and SEM detection on the residual solids indicated that ILs addition could increase the dissolution of bitumen fractions into solvents, while reducing the entrapment of fine particles in the solvents. The improvement of bitumen recovery by ILs addition was attributed to the enhancement of the liberation of bitumen components from mineral solids surfaces during oil sands solvent extraction. However, the asphaltenes were observed to be rejected during processing due to their accumulation at the oil‐ILs interface as a film.

Recovery of extra-heavy oil and minerals from carbonate asphalt rocks by reactive extraction

“…10 To improve this situation, great efforts have been made. [18][19][20][21][22] For example, Sui et al proposed the application of switchable solvent to recover the asphalt. They obtained a high asphalt recovery of 97% and the switchable solvent could be recovered easily.…”

“…The heavy hydrocarbons recovery was up to 93.04% and the solvent entrainment in the waste solids was highly inhibited. 20 They obtained excellent results, while these new methods were beyond applications at present due to high cost on both chemicals and operation. Some researchers believed that pyrolysis would be a potential way for the exploitation of the Indonesian asphalt rocks, 15,[23][24][25] because the asphalt could be directly cracked into light oil fractions or gases without adding external chemicals.…”

Novel treatment and value-added utilization of oily sludge using ionic liquid and pyrolysis

“…[Emim][BF4]) to enhance solvent extraction (Li et al, 2011;Sui et al, 2016;Tourvieille et al, 2017). Li et al (2011) reported the maximum bitumen recovery was 86% at the acetone-to-nheptane ratio of 2:…”

“…Since 92 % (by weight) bitumen recovery was obtained even when the IL was reused 10 times, the solvent extraction technology using composite solvent enhanced by IL was encouraged to be extended from bench scale to the oil sand industry by Li et al (2011). Sui et al (2016) examined the effect of operational parameters (i.e., IL-to-oil sands ratio, agitation time, and conditioning time) on bitumen recovery from oil sands using IL enhanced solvent extraction. It was found that bitumen recovery increased as IL-to-oil sands ratio and agitation time increased, whereas the conditioning time had a negligible effect on bitumen recovery.…”

“…Tourvieille et al (2017) assessed the impact of variables (i.e., temperature, contact time, solvent-to-oil sands ratio, IL-to-oil sands ratio, water-to-IL ratio, solvent, and IL types) on bitumen recovery and bitumen quality. It was observed that the IL-to-solids ratio (0.75-2 g/g) and type of IL had no significant effect (P > 0.05) on bitumen recovery (Tourvieille et al, 2017 (Ge et al, 2008) 1.30 (Ge et al, 2008) >90% bitumen recovery, less clean (small amounts of IL was found in the bitumen) (Painter et al, 2010a) 1-ethyl-3-methyl-imidazolium acetate ([Emim][Ac]) 141.1 (Nazet et al, 2015) 1.09 (Nazet et al, 2015) >90% bitumen recovery, less clean (small amounts of IL was found in the bitumen) (Painter et al, 2010a) 1-ethyl-3-methyl-imidazolium tetrafluoroborate ([Emim][BF4]) 66.5 (Huddleston et al, 2001) 1.25 (Seddon et al, 2002) Up to 95% bitumen recovery, relatively low viscosity, clean separation (no IL and fines in the bitumen) (Li et al, 2011;Sui et al, 2016) 32.0 (Greaves et al, 2006) 1.22 (Greaves et al, 2006) IL type had no significant effect on bitumen recovery, low aluminum content in the bitumen (Tourvieille et al, 2017) 1…”