Here is a story regarding a recent deal China made with Iran to buy a great deal of liquified natural gas over the next twenty years. The story goes on to talk about how they’ve begun modifying cars to burn it in place of gasoline.
How does that work? What’s involved in that sort of a conversion? Is there any significant difference either in emissions or miles per gallon/liter for liquid natural gas over the alternative? Is it safer? Has this sort of thing been done in other countries, before?
It is common for a car to run on LPG in both NZ and Australia and I presume it is common in other western countries too. I don’t know the specifics but the LPG cars I’ve seen run on petrol as well.
Converting automobiles to LPG isn’t common in the USA on a percentage basis but is done. The conversions are straightforward - here’s one web site that explains some of it - http://www.wps.com/LPG/
Where LPG is common is in industrial settings where gas vehicles running inside buildings produce excess fumes and LPG vehicles don’t. There are other reasons LPG is a good choice - it avoids the temptation to fill vehicles that may not be company owned for instance.
Safety seems to be OK but accidents can happen because the tank is pressurized (varies depending on how much LPG is in the tank) and the contents are highly flammable. Filling the tanks requires a little training since the contents are transferred under pressure. It’s a “good idea” to not overfill tanks and to also properly bleed off lines before disconnecting them. LPG spraying onto the skin can cause severe frostbite as it vaporizes.
I worked briefly at a job that required field work in a propane powered truck. Environmental questions aside, it was a bit of a pain. The truck had poor acceleration, you had to get it filled at two specific places in the entire county, the refill process was long and required a professional to do it, and the truck stank of propane all the time.
Unless these kinks were worked out of the process, I don’t see LPG catching on here in the US any time soon.
Many taxis in Tokyo use LPG and LNG. (I’m pretty sure both exist, but I’m not sure which is more common.) They seem to accelerate just fine, judging from all the reckless driving I’ve witnessed. I’ve never noticed any smell. The only annoyance for the passenger is the huge gas tank that takes up 1/3 of the trunk space.
Back in my automotive days, I had a client that invested millions trying like hell to make an LNG-powered car.
The good: The fuel was clean and relatively inexpensive. The prototype sailed through the California emissions tests.
The bad: The necessary tank was huge compared to a gas or diesel tank.
The dealbreaker: They couldn’t get acceptable mileage. One major auto company was set to have them convert fleet Crown Victoria/Grand Marquis models for LNG. They had one non-negotiatble. The car had to go 200 miles between fill-ups.
It couldn’t be done. The tank would have taken up the entire trunk, maybe more. And the Crown Vic has a BIG trunk.
LNG has a niche for delivery vehicles and commuter cars that only travel a few miles a day, and could be refilled overnight. I’m not an engineer, but maybe LNG could be paired with hybrid technology to increase the range. But currently it just isn’t practical to convert a typical car/truck to LNG and get a commercially acceptable vehicle.