| Thanks for the response! So, my point is that in the bio-gas process, you are generation H2 + CO2 and using some proceeds from H2 sales to sequester the CO2 you produce. However, with electrolysis (from renewable elect. plants), you aren't generating any CO2, so any profit that you spend on Carbon sequestration (from somebody else's process) would be a much more Carbon negative proposition overall. All this depends on the H2 production cost as to which is a mor effective Carbon sequestration scheme, right? In the paper I cite (I convert SEK to $): bio-gas costs ~$4/kg H2 (let's say this produces 5 kg of CO2), and electrolysis ~$4.50/kg H2 (producing 0 kg Carbon). Now say it costs $0.50/kg for CO2 sequestration). In the biogas process, because of the cost to sequester the CO2 byproduct, your actually spending ($0.5×$5)+$4 = $6.50/kg H2 produced just to get Carbon Neutral. However, for electrolysis (without the mess) you're only spending $4 to be Carbon Neutral, and if you want you can spend $2.50 (which you avoided by chosing elect. over gas), to go Carbon negative. These are rough numbers I guessed at based on a little googling. Am I far off on the real numbers? I'm really not trying to be a pain. What you're proposing is still light years better than the greedy bastards reforming natural gas and pocketing 100% of the profits without giving a second thought to the environment. I'm just wondering if there might be a way for you guys to do even more good, more easily. |
Electrolysis also typically costs more than you'd expect as soon as you add the requirement of renewable energy supply. Usually the renewable energy supply is solar, which has a ~30% duty cycle. So 70% of the time your electrolyzer is sitting idle. This crushes your economics and makes solar-powered electrolysis untenable in all of the analyses I've seen. We didn't have any clever ideas for how to change that situation, so after looking at it ~1.5 years ago we decided to look elsewhere.