[Moose]

This is somewhat related to what I had originally started my masters research on a little over a year ago. A company that was developing hydrogen injection systems for large diesel/natural gas engines wanted computer simulation work done on the effects of different levels of added hydrogen.

Using computational fluid dynamic software and complex combustion models, I ran a series of simulations to see the effect of hydrogen addition on the autoignition of natural gas (ignition without a sparkplug). The idea is that hydrogen radicals are very diffusive, and can cause the flame front to move faster throughout the unburnt mixture with, potentially, less pollutants formed. The thought was that autoignition would occur earlier and more predictably, and the production of soot could be substantially reduced.

I didn't look at pollutant formation, since the autoignition phenomenon is complex enough for one thesis. My results showed that even with up to 20% hydrogen added to natural gas (thats a huge percentage), the effects on autoignition time and location were minimal.

I wouldn't buy any of these hydrogen addition performance claims. I imagine that if the addition of hydrogen does have any impact, it'll be on the very complicated processes of soot formation, but that's a bit out of my area.

Edit to add: Since soot isn't a concern within gasoline spark-ignition engines I would be surprised if any, even small, gains would be had from injecting hydrogen in these types of engines.