The interesting thing here is that they also use waste water and reusing co2 from a waste water treatment plant. I would love to see these sort of operations set up every single place that has waste water and waste co2. You know like every single person that has a gas furnace and who has a toilet. If we all made part of our own fuel in the back yard we could make a lot of fuel. Not to mention it would cut down on transportation costs. More info here.