Energy for Future Presidents
Physics for Future Presidents
by Richard Muller, physics professor at UC Berkeley
CO2 increase - don't ignore agriculture
MORE LATER
Liquid methane for aviation
First things first - before greatly expanding shale gas production, we need to manage water better:
- 1) Full public disclosure on what goes in the wells, and comes out of them 2) Mark individual wells chemically, so we can trace the source of pollution 3) Use seawater, pumped overland, rather than drain aquifers and compete with agriculture for water 4) Regulation to enforce long term responsibility for fractured shale commensurate with long term, boundary crossing effects.
Jet aircraft may be the best transportation use for methane, possibly from fractured shale. Tupolev is designing planes to run on natural gas. Unlike passenger vehicles, aircraft travel between major airports, with fuel systems operated by professionals. Aircraft fuel is stored in huge, easy to insulate tanks. Liquid methane must be kept cryogenically cold, but the heat of evaporation can maintain temperature for the duration of a flight. If the tank and liquid are pressurized, that may require wing redesign, but the pressure can help stiffen the wing, much like the thin tanks on the Atlas rocket. LCH4 is only 60% as dense as normal jet fuel, but the energy per weight is higher and fuel cost and the pollution are lower. This increases fuel economy, lowers takeoff weight, and makes aircraft operation cheaper. This reduces the need for a recooler after the intake compressor in the engine. Under pressure the boiloff displaces air from the ullage above the remaining liquid. Managed correctly, this should prevent air-fuel explosions like TWA Flight 800 in 1996.
Drawbacks: The cryogenic liquid can lead to icing, stuck valves, and mechanical problems in the wings. There may be safety problems while maintenance crews learn new techniques and procedures. Ultracold metal can be more brittle.
Wikipedia paragraph about LNG for aviation
===Power storage Loop ===