Also it is harder to get a Diesel to burn other fuels than it is to get a gas engine to burn propane, ethanol etc.
An engine that can burn anything is the way we need to go, and as far as I know only a handful of Military Diesel Tanks were Omnivorous.
These folks have the solution: www.flexdi.com
Now if they can only get it run in HCCI mode....
An Omnivorous HCCI engine running at a constant RPM in a Series Hybrid like the Chevy Volt is the solution....
Try this:
You gotta be kidding.
The diesel engine was designed to run on peanut oil.
It's much easier to run alternative fuels in a diesel engine than in a spark ignition engine.
Many industrial diesel engines already can run on any of the fuels you mentioned.
Back when starting in very cold weather was an issue a lot of construction equipment wasstarted on gasoline and then switched to diesel. They had two fuel tanks onboard.
The diesel engine is of necessity built much tougher than a gasoline engine, so it is rugged enough to use nearly any fuel.
A gasoline engine, by contrast, isn’t as mechanically as strong. Witness the GM automobile diesels which were simply modified gasoline engines. Those engines were battered to pieces in a very short time.