Toward Economical Seawater-Based Methane Hydrate Formation at Ambient Temperature: A Combined Experimental and Computational Study

• Published in: ACS Sustainable Chemistry & Engineering
• Main Authors: Omran, Ahmed, Nesterenko, Nikolay, Paecklar, Arnold, A, Barrier, Nicolas, Valtchev, Valentin
• Other Authors: École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU), Laboratoire catalyse et spectrochimie (LCS), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS), TotalEnergies OneTech Belgium, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Normandie Université (NU)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry; [CHIM.GENI]Chemical Sciences/Chemical engineering; [SPI.MAT]Engineering Sciences [physics]/Materials; [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering; Methane hydrate
• Online Access: https://hal.science/hal-03772161; https://hal.science/hal-03772161/document; https://hal.science/hal-03772161/file/manuscript_F.pdf; https://doi.org/10.1021/acssuschemeng.2c03530

International audience Clathrate hydrates are emerging as a novel storage medium for safe and compact methane storage. However, their industrial-scale applicability is hindered by sluggish formation kinetics and intense energy cooling requirements. The present study is the first report on binary methane-tetrahydrofuran (THF) formation using seawater and an unstirred reactor at ambient temperature (298.2 K) that would improve the process economics. Acidic zeolites with different Si/Al ratios (USY-40 and USY-10) as well as aliphatic and aromatic amino acids (L-valine and L-tryptophane) are employed as environmentally benign kinetic hydrate promoters. The experimental study is combined with DFT calculations to shed light on the role of kinetic promoters in hydrates formation. The set of experimental data revealed that hydrophobic zeolites with a higher Si/Al ratio performed better than the more hydrophilic ones. Moreover, the aliphatic amino acid L-valine showed better kinetic promotion performance for hydrate formation in natural and artificial seawater than the aromatic amino acid L-tryptophan. The optimization of the experimental conditions allowed a controlled hydrate growth boosting the gas uptake to 40 mmol gas/mol water, which is the highest reported under mild conditions using seawater. In addition, the induction time is reduced to less than 10 minutes, and a methane recovery of 97% is reached without any foaming signs. Thus, this study demonstrates the possibility of controlling the stochastic nature of nucleation and hydrate growth by proper manipulation of the reaction system. Our results provide a better understanding of hydrate nucleation enhancement under realistic conditions and open the door for a possible application of these environmentally benign KHPs for synthetic natural gas (SGH) on a continuous process and industrial scale.