Rapid Methane Storage in Seawater Via Clathrate Hydrates

Abstract

Storing natural gas in the form of clathrate hydrates (termed as Solidified Natural Gas, SNG) is highly advantageous as it is non-explosive, environmentally benign and offers a relatively compact mode of natural gas storage with high volumetric storage capacity. Here for the first time, we demonstrate rapid methane storage in seawater and saline water (1.1 mol% NaCl solution) via clathrate hydrates aided by 5.56 mol% THF in a simple quiescent reactor configuration. We report extremely fast formation kinetics with methane uptake of 89.2 (±2.0) v/v and 88.0 (±5.4) v/v in saline water and seawater, respectively. Further, molecular insights of the hydrate formation in presence of NaCl is derived through high-pressure calorimetry, in-situ Raman, and powder X-ray diffraction analysis. Our findings render SNG technology very attractive to store/transport methane for large-scale storage needs and low production facilities like stranded gas fields or biogas manufacturing plants.