Recovery And Mechanisms Of Asphalt Separation From Carbonate Rock Assisted By Amino Acid Ionic Liquids

Unconventional oil,such as oil sands,oil shale and tight oil,has become an important part of energy supply as a supplement of conventional energy.As an important component of unconventional oil,carbonate asphalt rock with high viscosity,high density,high content of asphaltene,is difficult to unlock since oil-solid separation.Hence,in this paper,a series of amino acid ionic liquids and derivatives were designed,screened and synthesized,to enhance separating asphalt from Indonesian carbonate asphalt rock by ionic liquid-assisted solvent extraction method,and the mechanisms of asphalt separation from carbonate rock assisted by amino acid ionic liquids were researched.In this paper,a series of choline-based amino acid ionic liquids were economically synthesized by one-pot synthesis method with cheap raw materials,and ued in ionic liquid-assisted solvent extraction for Indonesian oil sands.The results showed that the asphalt recovery of single-stage extraction was 91.26%,which was13%higher than that with pure toluene solvent extraction under the same condition.Meanwhile,the solid entrainment in the asphalt oil from ionic liquid-assisted solvent extraction was decreased by about 80%,compared to the pure toluene solvent extraction.In this paper,the mechanisms of choline-based amino acid ionic liquids in the IL-assisted solvent extraction were researched by the molecular dynamics simulation calculation and COSMO-RS theory.The simulation results showed that amino acid ionic liquids with the strong electrostatic force"competed"with asphalt to adsorb on mineral surface,then gradually"carried"asphalt from the calcite surface to the toluene solvent phase as a"carrier".In addition,according to the theory based on the simulation calculation method,the common amino acid ionic liquid was screened for IL-assisted solvent extraction,and it was predicted that choline histidine was the optimum extraction assistant.In this paper,a neutralization method was used to synthesize a kind of protic amino acid ionic liquid,ProNO₃,which was applied in separating asphalt from Indonesian carbonate asphalt rock.The experimental results showed that the asphalt recovery of single-stage extraction by the mixed system of ProNO₃-ethanol-toluene reached 95.33%.It was found ProNO₃ enhanced the liberation of asphaltenes,then improved the asphalt recovery.In this paper,a kind of amino-acid-ionic-liquid-based deep eutectic solvent,TrpBF₄/U was synthesized.TrpBF₄/U was introduced into the microemulsion system and applied in separating asphalt from Indonesian carbonate asphalt rock.The experimental results showed that the asphalt recovery of single-stage extraction by TrpBF₄/U/ethanol/toluene microemulsion was 93.04%,which was about 12%higher than the pure toluene solvent extraction under the same conditions.Meanwhile,the solid entrainment in the asphalt oil from microemulsion extraction was reduced by about 90%.compared to the pure toluene solvent extraction.It was found that when Trp BF₄/U was mixed with ethanol and toluene,a non-water and surfactant-free microemulsion with droplet size less than 10 nm was formed.This microemulsion played an important role in the interface modification between asphalt and mineral surfaces,such as improving solid wettability,lowering asphalt-microemulsion interfacial tension,and providing a phase barrier for oil-sands separation.