Showing papers by "Haifeng Dong published in 2012"

Carbon capture with ionic liquids: overview and progress

Abstract: As an emerging carbon dioxide (CO2) capture technology, separating CO2 from industrial gases with ionic liquids is increasingly attracting remarkable interests. In this paper, the research progress on CO2 capture with ionic liquids is reviewed with particular attention on the viewpoint of potential industrial applications. We investigate and compare the CO2 capture capacities of pure ionic liquids, including conventional and task-specific ionic liquids, and ionic liquid-based mixtures. The mechanisms of chemisorption and physisorption are explained with experimental characteristics and molecular simulation, which show more and more important roles for screening suitable ionic liquids from tremendous candidates. Considering the scaling up of novel units for ionic liquid-based fluids, the studies on the transport properties and hydrodynamics of ionic liquid fluids are presented. The process design and assessment of ionic liquid processes are discussed, including the research progress on thermodynamic properties and prediction models. Besides giving an overview of research for each issue above, we also provide discussions for future work to try to identify the gap between the current work and the demand by real industrial applications. Finally, we present some perspectives of ionic liquid-based novel technologies, and the challenges which will be faced while developing industrially available technologies.

Densities and Viscosities of the Binary Mixtures of 1-Ethyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide with N-Methyl-2-pyrrolidone or Ethanol at T = (293.15 to 323.15) K

Abstract: The densities and viscosities of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][NTf2]) + N-methyl-2-pyrrolidone (NMP) and [EMIM][NTf2] + ethanol mixtures were investigated over the mole fraction range from (0.1 to 0.9) and at temperatures from (293.15 to 323.15) K at intervals of 5 K. The densities can be well-represented by the quadratic equation, and the viscosities can be represented in the form of the Vogel equation. The excess molar volumes (VE) and viscosity deviations (Δη) were calculated, and the results were fitted to the Redlich–Kister equation using a multiparametric nonlinear regression method. The estimated parameters of the Redlich–Kister equation and standard deviation were also presented. The results showed that the densities and viscosities were dependent strongly on NMP or ethanol content. Comparatively, the viscosity deviation Δη was more sensitive to temperature than the excess molar volume VE.

Extraction of Asphaltenes from Direct Coal Liquefaction Residue by Dialkylphosphate Ionic Liquids

Abstract: Asphaltenes in direct coal liquefaction residue (DCLR) are important precursors for the preparation of carbon materials. Some traditional polar hydrocarbon solvents show the ability to extract asphaltenes from DCLR, but these solvents are volatile, toxic, and difficult to recycle. Dialkylphosphate ionic liquids (ILs) have been demonstrated to have the ability to extract asphaltenes fractions from DCLR environmentally friendly. In order to understand the relationship between the extractive performance and the structure of cations and anions of ILs, a series of N,N-dialkylimidazolium dialkylphosphate ILs were synthesized and used to extract asphaltenes from DCLR. The extracts were characterized by Elemental Analysis, FT-IR, C-13-NMR, etc. The results show that it is feasible to extract asphaltenes from DCLR by N, N-dialkylimidazolium dialkylphosphate ILs. The alkyl chain length of cations and anions of the ILs is one factor that influences the extraction yield and the physicochemical characteristics of the extracted asphaltenes, such as the atomic ratio of H/C, true density, aromaticity, and so on. The alkyl chain length of ILs might be modified successfully for controlling the physicochemical characteristics of the extracts from DCLR.

Novel multi-amino functionalized ionic liquid and preparation method thereof

Abstract: The invention relates to novel multi-amino functionalized ionic liquid and a general preparation method thereof, and belongs to the fields of functional materials and preparation. The preparation method comprises the following steps: allowing halogenated aliphatic amine with protective groups to react with organic amine such as imidazole, pyrrole, indole, carbazole, pyrazole, 1,2,4-1-H-triazole, 1-H-tetrazole, purine, piperidine, imidazoline, piperazine, primary aliphatic amine, and secondary aliphatic amine in an aprotic solvent, performing protective group removal of the product to obtain amino functionalized liquid with anions being halogen ions, then performing an anion displacement reaction to displace the halogen anions into other anions; the amino functionalized ionic liquid obtained in the invention is insoluble in non-polar solvents, is simple in separation, and can be used repeatedly; the amino functionalized ionic liquid is applicable to the absorption and separation of acidic gas such as carbon dioxide, sulfur dioxide, hydrogen chloride, hydrogen sulfide, and the like.

Modeling and Simulation of CO2 Absorption with Amine Component Solvent

Abstract: Blended amine solvent has been shown unique and predominant performance while used to capture CO2 compared with the single amine solvent. Calculations were compared with experimental solubility measurements of CO2 in aqueous ternary and quaternary systems of H2O, MEA and AMP. Electrolyte non-random two liquid (ENRTL) theory was employed to fit solubility data in three ternary systems CO2-H2O-MEA and CO2-H2O-AMP. The binary interaction energy parameters for the ionic species were obtained by regression of the experimental solubility data of the ternary systems. A good agreement between the calculated values and the experimental data was achieved. Process simulation for CO2 removal using an equilibrium approach was performed with newly fitted parameters. The simulation results have been compared with the pilot plant experimental data.