| So let's do some math. Let's consider natural gas. According to the US government [1], natural gas produced 1.358x10^12 kWh of power and 5.6x10^8 metric tons of CO2 so 1 metric ton of CO2 equates to ~2400 kWh of produced power. This post suggests the energy cost is ~230kWh/ton. This is an important sanity check because it means that (capital costs aside) and if it scales you could technically remain carbon neutral for a net output of energy. While this is of course only in a lab and they mention "battery" one should remain skeptical (since pretty much every battery "breakthrough" is nothing more than marketing for research funding). This may be in the paper but in this summary I didn't see anything about how the CO2 needs to be delivered. Does it need to be in a relatively pure form? What sort of preprocessing is required? As for the capital costs, it's hard to say anything concrete here other than if silver and Gallium are catalysts, they're both relatively cheap at that scale (Gallium seems to be <$250/kg according to some quick Googling). Catalysts tend to have a lifespan so those aren't one-time costs generally but still. It's also not clear how much of each material is required. Not to be a broken record on HN, but I've often said--and I'll repeat here--that I don't believe altruism will solve greenhouse gas emissions and global warming: it'll only be solved when it becomes economic to do so. Another way of putting that is when the cost of carbon capture and/or non-greenhouse gas emitting energy sources is profitable, that's when you'll see change. [1]: https://www.eia.gov/tools/faqs/faq.php?id=74&t=11 |
Gallium is currently supplied by reprocessing the waste from other convenient metal ores to extract the traces of gallium. Even if we maximized gallium extraction from these waste streams, we are talking about a few thousand tons of gallium per year. We produce more gold every year than there is practically available gallium.
Unfortunately this is the story with many proposed solutions to carbon capture. Many things are possible as a prototype which are completely infeasible at the industrial scales required to make a dent in atmospheric carbon because the resources don't exist to run chemistry at that scale.