I think there are two. The first is ethanol, where you can capture the CO2 that comes off the fermentation and inject it underground, so it's carbon capture and storage. That's worth 30 g/MJ. We have ethanol plants today in the low 40 g/MJ on a full life-cycle basis. The other major factor is the fuel that's used—natural gas. Renewable natural gas or biomass combustion can get those plants down to zero.
The other fuel that has a lot of interest in Canada and in the United States is something called “renewable diesel”. It's made from vegetable oils or animal fats. It has low GHG emissions, probably in the order of 20 to 25 g/MJ. Again, more than half of that is due to the hydrogen that's used in the process.
I know that the companies that are looking at doing this are looking at two things. The first is carbon capture and storage, again, for the hydrogen. Second, those plants also produce some co-products that are biogenic in nature and can be used to produce the hydrogen. Using the biogenic components can get the hydrogen part of it down to zero, and again, you can still do the carbon capture on that biogenics to get the full life cycle down to zero without looking at some of the other things that are going to happen in the future with the use of renewable fuels, better farming practices and all of that.