[Moltke]

Thanks for the clarification - knew that LPG and LNG are not the same chemically, but just read up on a few details that I’d forgotten/wasn’t aware of. Even so, should we ever find ourselves in a world where LNG is plentiful and LPG or petroleum isn’t, methinks we’d find ways to harness that energy for purposes including personal transport. That storage temperature of -162 °C is still somewhat above that of liquid nitrogen (-196 °C), copious amounts of which I’ve used in an earlier line of work and Linde delivered to our lab by the truckload. The question of costs will then depend on the market.

[thackney]

CNG (Compressed Natural Gas) is far more reasonable to use as a fuel for most vehicles than LNG.

The natural gas is used as fuel for vehicles today, it just is not very common.

You can purchase a compression unit to fuel a CNG vehicle at your home and CNG is available in limited areas.

http://www.afdc.energy.gov/afdc/fuels/natural_gas.html

[Smokin' Joe]

...liquid nitrogen (-196 °C), copious amounts of which I’ve used in an earlier line of work and Linde delivered to our lab by the truckload

You can vent the liquid N2 to atmosphere without any real danger, but you can't do that with LNG.