title: Amino acids as natural inhibitors for hydrate formation in CO2 sequestration.
abstract: The motivation for this work was the potential of hydrophobic amino acids such as glycine, l-alanine, and l-valine to be applied as thermodynamic hydrate inhibitors (THIs). To confirm their capabilities in inhibiting the formation of gas hydrates, three-phase (liquid-hydrate-vapor) equilibrium conditions for carbon dioxide hydrate formation in the presence of 0.1-3.0 mol % amino acid solutions were determined in the range of 273.05-281.45 K and 14.1-35.2 bar. From quantitative analyses, the inhibiting effects of the amino acids (on a mole concentration basis) decreased in the following order: l-valine > l-alanine > glycine. The application of amino acids as THIs has several potential advantages over conventional methods. First, the environmentally friendly nature of amino acids as compared to conventional inhibitors means that damage to ecological systems and the environment could be minimized. Second, the loss of amino acids in recovery process would be considerably reduced because amino acids are nonvolatile. Third, amino acids have great potential as a model system in which to investigate the inhibition mechanism on the molecular level, since the structure and chemical properties of amino acids are well understood.
authors.affiliation: Department of Chemical Engineering, Pohang University of Science & Technology, San 31, Hyoja-Dong, Pohang-Si, Gyeongbuk 790-784, Korea.
authors.forename: Jeong-Hoon
authors.initials: JH
authors.lastname: Sa
authors.forename: Bo Ram
authors.initials: BR
authors.lastname: Lee
authors.forename: Da-Hye
authors.initials: DH
authors.lastname: Park
authors.forename: Kunwoo
authors.initials: K
authors.lastname: Han
authors.forename: Hee Dong
authors.initials: HD
authors.lastname: Chun
authors.forename: Kun-Hong
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D057965:Carbon Sequestration; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D014867:Water; D002245:Carbon Dioxide