A new ice-like material has shown potential for the safer, cleaner, and more efficient storage of natural gas and biomethane.<\/p>\n
Researchers at the National University of Singapore (NUS) have developed a reusable, biodegradable ice material called amino-acid-modified ice.\u00a0<\/p>\n
Interestingly, the testing showed the material reached 90% capacity in over two minutes, a huge speed increase compared to conventional systems that take hours.<\/p>\n
\u201cNatural gas and biomethane are important components in the energy mix today, but their storage and transport have long relied on methods that are either costly or carbon-intensive,\u201d said Professor Praveen Linga, the lead researcher. <\/p>\n
\u201cWhat we are showing is a simple, biodegradable pathway that can both work quickly and be reused. It makes gas storage safer, greener and more adaptable,\u201d Linga added in the press release on Oct 2. <\/p>\n
Faster storage <\/p>\n
The current methods for storing natural gas at scale \u2014 either under high pressure or cooled to \u2212162\u00b0C (liquefied natural gas) \u2014 are energy-intensive and costly.\u00a0<\/p>\n
An alternative storage technique, called solidified natural gas<\/a>, traps methane within an ice-like structure known as a hydrate, but this process is generally too slow to be practical for large-scale applications.<\/p>\n The team found a simple solution by freezing water with a small amount of naturally occurring amino acids \u2013 the building blocks of proteins.\u00a0<\/p>\n The \u201camino-acid-modified ice\u201d quickly captures methane gas in a matter of minutes.<\/p>\n Lab tests showed that the amino-acid-modified ice rapidly became a white, expanded solid, indicating that methane hydrate formation had occurred.<\/p>\n Remarkably, the material\u2019s storage capacity was 30 times higher than plain ice, achieved in just over two minutes.<\/p>\n The change in the ice\u2019s surface properties, driven by the amino acids, is what makes the gas capture so fast.<\/p>\n Hydrophobic amino acids (like tryptophan) cause tiny liquid layers to form when methane is injected.\u00a0<\/p>\n These layers provide an ideal surface for hydrate crystals to grow, forming a porous, sponge-like structure that rapidly captures the gas.<\/a><\/p>\n In contrast, plain ice forms a dense film that blocks methane from diffusing inward, thereby slowing the process.<\/p>\n The proof-of-concept stage<\/p>\n The team further used Raman spectroscopy to understand the process at a molecular level.\u00a0<\/p>\n Methane was observed to rapidly and efficiently pack into two types of microscopic hydrate cages, with over 90% occupancy.<\/p>\n \u201cThis gives us direct evidence that the amino acids are not only speeding up the process but also allowing methane to pack efficiently into the hydrate cages,\u201d said<\/a> Dr Ye Zhang, the lead author.<\/p>\n Although currently at the proof-of-concept stage, the modified ice shows highly promising performance.\u00a0<\/p>\n At near-freezing temperatures and moderate pressures, it outperformed advanced porous materials (like metal-organic frameworks and zeolites) in both the speed and capacity of methane<\/a> storage.<\/p>\n The system is highly valuable for its reusability and sustainability.\u00a0<\/p>\n Since amino acids are biodegradable, they avoid the risks associated with chemical surfactants. The method does not produce foaming during gas release.<\/p>\n Furthermore, the material allows for on-demand methane release via gentle heating. After which, the ice can be refrozen and reused in a closed-loop cycle.<\/p>\n This approach is especially appealing for storing renewable<\/a> biomethane from smaller sources.\u00a0<\/p>\n The team is now working to scale up the process, test it with natural gas mixtures, and adapt the technique for storing other gases, including carbon dioxide and hydrogen.<\/p>\n