Tuesday, January 3, 2006

EV World: Five Chinese Cities Test Clean Hythane Fuel in Buses

This story: Five Chinese Cities Test Clean Hythane Fuel in Buses (evworld.com, Jan 3, 2006) discusses how Hythane has an agreement with five cities in China to test their fuel in city buses. They're getting ready for the 2008 Olympics to be held in China. What's Hythane? That's a good question, because this is the first I've heard of them, but the answer is very interesting.

Hythane (hythane.com) makes a fuel by adding hydrogen to natural gas. They explain it best:

Hydrogen and methane are complimentary vehicle fuels in many ways. Methane has a relatively narrow flammability range that limits the fuel efficiency and oxides of nitrogen (NOx) emissions improvements that are possible at lean air/fuel ratios. The addition of even a small amount of hydrogen, however, extends the lean flammability range significantly. Methane has a slow flame speed, especially in lean air/fuel mixtures, while hydrogen has a flame speed about 8 times faster. Methane is a fairly stable molecule that can be difficult to ignite, but hydrogen has an ignition energy requirement about 25 times lower than methane. Finally, methane can be difficult to completely combust in the engine or catalyze in exhaust aftertreatment converters. In contrast, hydrogen is a powerful combustion stimulant for accelerating the methane combustion within an engine, and hydrogen is also a powerful reducing agent for efficient catalysis at lower exhaust temperatures.

In other words it makes natural gas a better fuel. Hmmm...

Seems to me this gives an interesting adoption advantage over other systems. A battery EV or a fuel cell vehicle both require a wholesale switchover. It's hard to simply make a few changes to an existing vehicle to turn it into a battery EV or fuel cell EV.

On the other hand, vehicles running on compressed natural gas (CNG) are common. And a gasoline engine is very similar to the one which run's CNG. And finally it would allow reuse of the infrastructure that provides gasoline.