Researchers from the U.S. Department of Energy found out a way to chemically enclose methane in cage-like ice crystals. This technology is much safer than current liquefied natural gas (LNG), which is transported at very low temperatures and high pressures.
Until now, methane hydrate had been made by mixing water and methane in large, pressurized containers. It took hours or days to get it, and this is why it hasn’t been used extensively. DOE’s innovation forces water and methane through a specially-designed nozzle that creates the hydrate “almost instantaneously,” says Charles Taylor, the lead researcher on the project at the DOE’s National Energy Technology Laboratory in Pittsburgh. As the mixture exits the nozzle, it quickly forms hydrate, which looks like snow.
Designing the nozzle wasn’t an easy task, because it has to create the methane hydrate at its exit. If it forms too soon, it clogs the nozzle.
Naturally, methane hydrate forms undersea at high pressures ad low temperatures. Once formed, the ice crystals keep methane trapped inside them, even if the surrounding pressure is lowered. This is another advantage, as the methane-containing ice can be transported at normal atmospheric pressure as long as it’s kept frozen (to about -10°C).