title: Inhibition of methane and natural gas hydrate formation by altering the structure of water with amino acids.
abstract: Natural gas hydrates are solid hydrogen-bonded water crystals containing small molecular gases. The amount of natural gas stored as hydrates in permafrost and ocean sediments is twice that of all other fossil fuels combined. However, hydrate blockages also hinder oil/gas pipeline transportation, and, despite their huge potential as energy sources, our insufficient understanding of hydrates has limited their extraction. Here, we report how the presence of amino acids in water induces changes in its structure and thus interrupts the formation of methane and natural gas hydrates. The perturbation of the structure of water by amino acids and the resulting selective inhibition of hydrate cage formation were observed directly. A strong correlation was found between the inhibition efficiencies of amino acids and their physicochemical properties, which demonstrates the importance of their direct interactions with water and the resulting dissolution environment. The inhibition of methane and natural gas hydrate formation by amino acids has the potential to be highly beneficial in practical applications such as hydrate exploitation, oil/gas transportation, and flow assurance. Further, the interactions between amino acids and water are essential to the equilibria and dynamics of many physical, chemical, biological, and environmental processes.
authors.affiliation: Department of Chemical Engineering, Pohang University of Science &Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 790-784, Korea.
authors.forename: Jeong-Hoon
authors.initials: JH
authors.lastname: Sa
authors.affiliation: Department of Chemical Engineering, Pohang University of Science &Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 790-784, Korea.
authors.forename: Gye-Hoon
authors.initials: GH
authors.lastname: Kwak
authors.affiliation: CO2 Project Team, Research Institute of Industrial Science &Technology, 67 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 790-600, Korea.
authors.forename: Kunwoo
authors.initials: K
authors.lastname: Han
authors.affiliation: Beamline Division, Pohang Accelerator Laboratory, 80 Jigok-Ro 127Beon-Gil, Nam-Gu, Pohang, Gyeongbuk 790-834, Korea.
authors.forename: Docheon
authors.initials: D
authors.lastname: Ahn
authors.affiliation: Offshore Plant Resources R&D Center, Korea Institute of Industrial Technology, 30 Gwahaksandan 1-Ro 60Beon-Gil, Gangseo-Gu, Busan 618-230, Korea.
authors.forename: Seong Jun
authors.initials: SJ
authors.lastname: Cho
authors.affiliation: Offshore Plant Resources R&D Center, Korea Institute of Industrial Technology, 30 Gwahaksandan 1-Ro 60Beon-Gil, Gangseo-Gu, Busan 618-230, Korea.
authors.forename: Ju Dong
authors.initials: JD
authors.lastname: Lee
authors.affiliation: Department of Chemical Engineering, Pohang University of Science &Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 790-784, Korea.
authors.forename: Kun-Hong
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006859:Hydrogen / Q000737:chemistry; D007700:Kinetics; D008697:Methane / Q000737:chemistry*; D015394:Molecular Structure; D059206:Natural Gas; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D059206:Natural Gas; D014867:Water; D006859:Hydrogen; D008697:Methane