Inhibition effects of poly(N-vinylcaprolactam)/poly(ε-caprolactone) amphiphilic block copolymers on methane hydrate formation

Enrichment of gas storage in clathrate hydrates by optimizing the molar liquid water-gas ratio

Natural gas (NG) is considered a modern source of energy. Gas hydrates are anticipated to be an alternative method for gas storage and transportation applications. The process must be handy, rapid, and proficient for scale-up. In the present study, methane (CH4) and carbon dioxide (CO2) hydrates are synthesized by varying the guest (gas) to host (water) volume. The experiments are performed in a non-stirred system. The results specify that the maximum storage capacity is achieved when the molar liquid water-gas ratio is about 4.08 and 8.25 for CH4 and CO2 hydrates. At the optimal water-gas ratios, the total CH4 and CO2 gas uptake capacity is about 14.3 ± 0.4 and 9.1 ± 0.4 liters at standard temperature and pressure (STP) conditions. The gas uptake gradually increases with the solution volume and abruptly falls after a threshold point. The hydrate grows across the reactor's metal surface; when the process fully covers the surface, the growth continues horizontally (increase in thickness). With varying the liquid water-gas ratio (low to high), the formation kinetics (t 90) is delayed. The hydrate growth rate gradually decreases and does not significantly influence the hydrate formation temperatures. Optimizing the molar liquid water-gas ratio yields a high gas storage capacity and faster process kinetics.