Hydrogen Combustion

"Blue Flame" by John McKee, Creative Commons license

The Circle 18SM engine can run on almost any fuel. It's uniquely suited to hydrogen combustion.

Unlike complex fuel cell systems, the Circle 18SM can easily provide loads of torque — directly from hydrogen.

Why Hydrogen?

Why Hydrogen Combustion?

  • Power to weight efficiency. Electric motors are bulky and heavy. Unfortunately, fuel cell systems rely on them. Combustion has better power-to-weight, and the circle 18SM is better at combustion.

  • Fast energy conversion. Fuel cells convert hydrogen to usable power very slowly compared to combustion. Just think of the last thing you saw explode.
  • Simple system. The Circle 18SM is shockingly simple. So are it's installed applications. This cuts life-cycle energy (i.e. not just operating fuel but all energy for gathering, assembling and distributing, and disposing of materials). By contrast, fuel cells require complex systems (high energy cost), including some toxic chemicals.

  • Competitive fuel efficiency. Fuel cells are quite efficient, but they often require electric motors (a 20% hit), heavy batteries, etc. Improving the combustion process will give mass market fuel cells real competition, if we consider the efficiency of the system as a whole.

What About Safety?

Like any fuel, hydrogen is flammable and can be dangerous. But it's not necessarily more dangerous than gasoline. It's just different. In some ways, hydrogen is safer:

  • Hydrogen is much lighter than air, so it will dissipate quickly into the upper reaches of a space, or up into the air. By contrast, gasoline pools and its fumes are heavier than air.
  • Hydrogen will not explode without oxygen, so it can be stored safely.
  • Hydrogen does have a wider flammability range than gasoline (i.e. you can burn a very lean mixture or a very rich one).
  • In case of an explosion, hydrogen flames have lower radiant heat.

Does hydrogen make you think of the Hindenburg? It's fabric envelope was coated with reactive chemicals (based on the report of Addison Bain of NASA). Most deaths were not caused directly by the fire but were from jumping from the burning ship. (Click here for more information and citation.)

In fact, there are over 700 miles of hydrogen pipeline in operation in the USA alone, and they have an extremely good safety record.

There is a lot more information on hydrogen safety at the National Hydrogen Association.