(128g) An L-Tryptophan and 1,3 Dioxane Synergic Study on CO2 Hydrate Kinetic with Seawater: Applicable to CO2 Sequestration Via Gas Hydrate

One of the potential carbon capture and storage [CCS] techniques is capturing CO₂ emissions from the industry and injecting them into the oceanic sediments, where, under favorable conditions, they can be stored as gas hydrates. However, the high salinity of oceanic sediments hinders the CO₂ hydrate formation kinetics, which is a major challenge in hydrate-based CCS. To address this challenge, the fundamental study of CO₂ hydrate formation, dissociation, and morphology in seawater was carried out in the static and non-static mediums. Moreover, the effect of a kinetics hydrate promoter (L-tryptophan), thermodynamic hydrate promoter (1,3 dioxane), and synergic effects of kinetics+ thermodynamics hydrate promoters on CO2 hydrate kinetics was also analyzed. Furthermore, using Raman spectroscopy, CO₂ dissolution behavior was evaluated in seawater with 1,3 dioxane.

The experimental results show that the CO₂ uptake was higher for stirred medium [ 39 (±4) to 67 (±2) mmol/mol] compared to unstirred medium [21 (±6) to 30 (±5) mmol/mol] when different combinations of the promoters (L-tryptophan and 1,3 dioxane) were used. The morphological results indicate that CO₂ hydrate formed using 1,3 dioxane has different needle-like CO₂ hydrate growth. Finally, the Raman spectroscopy analysis indicated that a maximum of CO₂ dissolved was achieved within ~280 minutes. This study's findings on CO₂ uptake and the Raman analysis with seawater provide fundamental insights into CO₂ hydrate kinetics for carbon sequestration using gas hydrates.

Acknowledgments

PL acknowledges the funding support from the Agency of Science, Technology and Research (A*STAR) under the low carbon energy research (LCER) funding initiatives (project ID: U2102d2010).