| Gas Storage by David A. Dietzler, 2007 Hydrogen can be stored in metal hydride form. This will not require special alloys for cryogenic tanks, super insulation, special pumps and piping of superalloys, heavy cooling equipment or shielded space radiators. Simple buried metal vaults or iron or mild steel can contain the hydrides. Hydrogen can be stored in magnesium powder or FeTi alloy powder, both that can be made on the Moon. FeTi is better because it will not pack down after thousands of cycles and become incapable of storing hydrogen. Compressors are needed to drive the hydrogen into spaces between the metal powders and moderate heating combined with vacuum pumping can extract the hydrogen from metal hydride storage tanks. This kind of storage is much denser than liquid hydrogen storage but it is very heavy; however, we don't plan on moving. Carbon 60 nanotubes might also be used if they are more effective and more cost effective too for storing hydrogen. Perhaps other gases like CO, CO2, N2, O2 and He can be stored in carbon 60 nanotubes. These are soft cryogens but they will still require some fancy equipment. Carbon dioxide can be stored simply with pressure to liquefy it at room temperature and at the -20 C. (-4 F.) temp. of regolith at a depth of a few feet it will be even easier to liquefy CO2 with pressure. At 1 atmosphere (1 atm) CO2 liquefys at -78 C. Carbon monoxide must be cooled to -191.5 and N2 to -196at 1 atm to liquefy. Oxygen at 1 atm liquefys at -183 C. Helium must be cooled to just a couple of deg. above absolute zero. If C60 nanotubes can soak up these gases, it will be of immense benefit to Moon miners. Simple iron or mild steel buried tanks or vaults will be much easier to make on the Moon than cryo storage tanks and related equipment. Gas separation will be done not with cooling and fractional liquefaction but with membranes. Membrane technology is used today to separate the gases in air and to clean up natural gas. The membranes are made of sophisticated polymers. Perhaps some of these polymers or similar polymers can also be used to store gases. This would greatly simplify the challenges of gas separation from volatiles mining, the separation of cooled off gases from DRI furnaces (though C60 nanotubes would be better for separating hot off gases from furnaces) and even the purifying of air by life support systems. see: http://pubs.acs.org/cen/coverstory/83/8340membranes.html http://en.wikipedia.org/wiki/Gas_separation http://www.ripi.ir/EN/gas%20separation.asp |
 |
| to Damascus Project |
 |
| Lunar Resources |