Gas Goes Solid

Roland Piquepaille writes "This innovation from Japanese researchers can potentially revolutionize the energy distribution sector. Instead of transporting liquid gas, they changed gas into a solid material which is easier, safer and cheaper to distribute. Technology Review has the story. "Rather than extracting methane from hydrates, they want to turn methane into hydrates -- essentially, transforming the colorless and odorless gas into small pellets that can be easily stored, transported, and eventually turned back into natural gas. A few months ago Mitsui, in partnership with Osaka University, opened a demonstration plant near Tokyo to promote the concept and show that it works." Check this column for an analysis."

Comments

Re:One problem from the world of ice cream

[Duke]

When the temperature of your freezer goes up by even a fraction of a degree (and it need not go anywhere near as high as 0 degrees celsius), some of the ice melts. When the temperature drops again, it re-freezes, but in a slightly different location.

Bzzt. No. But thanks for playing.

Whether a liquid or a solid, water is has a vapor pressure. If a system of ice and air is at the same temperature, there will be water vapor in the the air. The system will be (once there is enought water vapor in the air) in equilibrium - there will be no net movment of water from its ice form to its vapor form. But this is dynamic equilibrium, ice will be moving to vapor at the same rate that vapor is moving to ice. (Both processes - solid to gas and gas to solid - are called sublimation.)

If there is a temperature difference in your freezer, the ice will move from the (even slightly) warmer spot to a colder one. However, the process, for instance, of having all your ice cubes smoothing their edges and attaching themselves to each other would occur even if the contents of the freezer were all at the same temperature. The ice is trying to get itself into its minimum energy configuration, where it would be one big sphere.

If the top of the ice cream container is cooler than the rest of it, water will migrate to the top. The migration just requires a spatial temperature gradient, not a temporal temperature change.