Anticorrosion Protection by Amine-Ionic Liquid Mixtures: Experiments and Simulations

The mixtures of aqueous amines and ionic liquids (ILs) are considered as potential solvents for CO2 capture. We report corrosion and CO2 absorption behavior of the mixed IL-amine solutions. The absorption tests were performed at 318.15 K under 0.1-2.7 MPa. The corrosion tests were carried out at 318.15 K under 2.7 MPa. Addition of [bmim][BF4] in aqueous alkanolamine solutions reduces corrosion rate for MEA by up to 72%. The CO, absorption capacity in the mixtures falls between those of aqueous MDEA and pure IL. These results allow to choose the working pressure range as a function of other parameters, such as gas pressure and mixture viscosity. According to the simulations, [bmim][BF4] participates in the gas capture through H-bonding, although the number of amine molecules is enough to capture all supplied CO, molecules. The equilibrium of the chemisorption reaction is, therefore, modified upon the stepwise IL addition. An ideal IL content for preventing corrosion is 10% w/w.CNPqHewlett-Packard Brasil LtdaCAPESPontif Catholic Univ Rio Grande Sul PUCRS, Postgrad Program Mat Engn & Technol, Ave Ipiranga 6681, BR-90619900 Porto Alegre, RS, BrazilPontif Catholic Univ Rio Grande Sul PUCRS, Sch Chem, Ave Ipiranga 6681, BR-90619900 Porto Alegre, RS, BrazilPontif Catholic Univ Rio Grande Sul PUCRS, Sch Engn, Ave Ipiranga 6681, BR-90619900 Porto Alegre, RS, BrazilUniv Fed Sao Paulo, BR-04021001 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, BR-04021001 Sao Paulo, SP, BrazilWeb of Scienc

Synthesis and physical-chemical properties of ionic liquids based on 1-n-butyl-3-methylimidazolium cation

The reaction of 1-n-butyl-3-methylimidazolium chloride (BMI.Cl) with sodium tetrafluoroborate or sodium hexafluorophosphate affords the molten salts BMI.X (1, X= BF4 and 2, X= PF6). Compounds 1 and 2 are viscous liquids within a wide range of temperature (down to 192 K). IR, NMR, density, viscosity and conductivity measurements suggest that compound 2 behaves quasi-molecular. Compound 1 is quasi-molecular below 279 K, but at higher temperatures is probably composed of imidazolium and tetrafluoroborate ions in an extended hydrogen-bonded network

Imidazolium-based ionic liquid silica xerogel as catalyst to transform CO2 into cyclic carbonate

In this work silica xerogel samples containing different imidazolium ILs (EMIM-CF3SO3, EMIM-MSO3, BMIM-Cl, MBMIM-TF2N, BMIM-TF2N and EMIM-TF2N) were synthesized, characterized and used as catalyst in cyclic carbonate synthesis. ILs mass percentage was varied from 5% to 25%. The effect fostered by the ILs mass variation in the synthesis of silica xerogel was observed both in the materials characterization as well as in the performance of these materials as solid catalysts in the cyclic carbonate synthesis from the cycloaddition reaction of CO2 with propylene epoxide. The obtained silica xerogel samples (SXs) were characterized by FTIR, RAMAN, TGA, SEM and TEM. The selectivity of the cycloaddition reaction was analyzed by GC and 1H and 13C NMR. The best results were obtained for SX-EMIM MSO3 (20% of IL) and SX-BMIM Cl (15% of IL) with propylene carbonate yields of 91.4% and 83.4% and selectivities >99% and 97.4% respectively

Synthesis and NMR characterization of aliphatic-aromatic copolyesters by reaction of poly(ethylene terephthalate) post-consumer and poly(ethylene adipate)

An aliphatic-aromatic copolyester of poly(ethylene terephthalate), PET, and poly(ethylene adipate), PEA, PET-co-PEA, was synthesized by the high temperature melt reaction of post-consumer PET and PEA. As observed by NMR spectroscopy, the reaction yielded random copolyesters in a few minutes through ester-interchange reactions, even without added catalyst. The copolyesters obtained in the presence of a catalyst presented higher intrinsic viscosity than that obtained without the addition of catalyst, due to simultaneous polycondensation and ester-interchange reactions. The structure of the aliphatic-aromatic copolyesters obtained in different PET/PEA ratio is random as observed by NMR analysis

Hybrid ionic liquid-silica xerogels applied in CO2 capture

The imidazolium-based ionic liquids (ILs) are solvents known for selectively solubilizing CO2 from a gas CH4/CO2 mixture, hence we have produced new hybrid adsorbents by immobilizing two ILs on xerogel silica to obtain a solid-gas system that benefits the ILs' properties and can be industrially applied in CO2 capture. In this work, the ILs (MeO)3Sipmim.Cl and (MeO)3Sipmim.Tf2N were used at different loadings via the sol-gel process employing a based 1-methyl-3-(3-trimethoxysylilpropyl) imidazolium IL associated to the anion Cl- or Tf2N- as a reactant in the synthesis of silica xerogel. The CO2 adsorption measurements were conducted through pressure and temperature gravimetric analysis (PTGA) using a microbalance. SEM microscopies images have shown that there is an IL limit concentration that can be immobilized (ca. 20%) and that the xerogel particles have a spherical shape with an average size of 20 μm. The adsorbent with 20% IL (MeO)3Sipmim.Cl, SILCLX20, shows greater capacity to absorb CO2, reaching a value of 0.35 g CO2/g adsorbent at 0.1 MPa (298 K). Surprisingly, the result for xerogel with IL (MeO)3Sipmim.Tf2N shows poor performance, with only 0.05 g CO2/g absorbed, even having a hydrophobic character which would benefit their interaction with CO2. However, this hydrophobicity could interfere negatively in the xerogel synthesis process. The immobilization of ionic liquids in silica xerogel is an advantageous technique that reduces costs in the use of ILs as they can be used in smaller quantities and can be recycled after CO2 desorption.publishersversionpublishe