eprintid: 10200 rev_number: 2 eprint_status: archive userid: 1 dir: disk0/00/01/02/00 datestamp: 2023-11-09 16:36:49 lastmod: 2023-11-09 16:36:49 status_changed: 2023-11-09 16:30:49 type: article metadata_visibility: show creators_name: Khan, M.S. creators_name: Bavoh, C.B. creators_name: Partoon, B. creators_name: Nashed, O. creators_name: Lal, B. creators_name: Mellon, N.B. title: Impacts of ammonium based ionic liquids alkyl chain on thermodynamic hydrate inhibition for carbon dioxide rich binary gas ispublished: pub keywords: Carbon dioxide; Chain length; Dissociation; Electrolytes; Gases; Hydration; Ionic liquids; Solutions; Thermodynamics, Ammonium based ionic liquids (AILs); Enthalpy of dissociation; Hydrate inhibitors; Mixed gas hydrates; Tetrabutylammonium hydroxides; Tetramethyl ammonium hydroxide; Tetrapropylammonium hydroxide; Thermodynamic inhibitors, Gas hydrates note: cited By 55 abstract: In this work, the thermodynamic inhibition impact of four ammonium-based ionic liquids (AILs) on CO2 rich mixed gas hydrate system (70�30 mol CO2 + CH4) is experimentally studied, and the observed behaviour is modelled. The studied AILs are; tetramethylammonium hydroxide (TMAOH), tetraethylammonium hydroxide (TEAOH), tetrapropylammonium hydroxide (TPrAOH) and tetrabutylammonium hydroxide (TBAOH). Initially, the impact of 10 wt AILs in an aqueous solution on the CO2 enriched binary gas phase boundary is evaluated by measuring the dissociation temperature in the pressure range of 1.90�5.10 MPa. The thermodynamic inhibition influence of AILs is quantitatively analyzed by calculating the hydrate suppression temperatures for all studied systems. Further, the Clausius�Clapeyron equation is used to determine the molar hydrate enthalpy of dissociation (�Hdiss) for the studied systems. The results revealed that the inhibition influence of AILs is observed to be decreasing with the increasing alkyl chain length of AILs. Excluding TBAOH, all the other studied AILs act as thermodynamic inhibitors due to the relatively shorter alkyl chain. The �Hdiss results of the binary mixed gas system in the presence and absence of AILs revealed that the presence of TMAOH, TEAOH and TPrAOH has negligible effect in hydrate cages formation. However, TBAOH exhibited a significant change in �Hdiss which indicates the semi-clathratic nature of it. Among the considered AILs, TMAOH shown better thermodynamic impact attributed to its shortest alkyl chain length. Therefore it is further investigated for various concentrations (1, 5 and10 wt). Moreover, the measured, mixed gas hydrate phase boundaries of various aqueous AILs solutions are also predicted via electrolyte model proposed by Dickens and Quinby-Hunt and are found to be in good agreement with the experimental data apart from TBAOH. Therefore, this study is relevant for the understanding of structural variations (alkyl chain elongation) of AILs on the hydrate phase stability of the high CO2 content mixed gas system. © 2018 Elsevier B.V. date: 2018 publisher: Elsevier B.V. official_url: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85045391657&doi=10.1016%2fj.molliq.2018.04.015&partnerID=40&md5=3f8b34d57322b5fe0321865605d06e50 id_number: 10.1016/j.molliq.2018.04.015 full_text_status: none publication: Journal of Molecular Liquids volume: 261 pagerange: 283-290 refereed: TRUE issn: 01677322 citation: Khan, M.S. and Bavoh, C.B. and Partoon, B. and Nashed, O. and Lal, B. and Mellon, N.B. (2018) Impacts of ammonium based ionic liquids alkyl chain on thermodynamic hydrate inhibition for carbon dioxide rich binary gas. Journal of Molecular Liquids, 261. pp. 283-290. ISSN 01677322