[SaratogaEnergy]

thanks! in the case of the cement market, carbon nanotubes have been used in 1% concentration to improve the lifespan of cement. 4 billion tons of cement are produced every year. If carbon nanotubes where used in all new cement mixtures, that would be 40 million tons of carbon nanotubes per year, which would consume 148 million tons of CO2 per year. But perhaps more importantly, carbon nanotubes would reduce the replacement frequency of cement structures. cement production is one of the largest industrial sources of carbon dioxide emissions.

[amirhirsch]

I love this area of technology and the scale of your vision. For the battery application, do you need to use only electrically conducting nanotubes? Is your 27kWh per kg number for single-walled electrically conducting nanotubes? Do you need to filter out semi-conducting nano-tubes?

I think that the improvements to batteries will have a better value proposition than strengthening concrete, though perhaps you can get away with less filtering requirements for non-electrical applications. How much does this strengthening increase the life-time-value of the concrete? Concrete is under $100 per ton (poured cost, 50% of which is dry materials), and it seems like you're talking about 50% - 150% increased cost.

At scale, you are talking about ((40 billion kg) * 27 * (kWh per kg)) / (1 year) = 123.205917 gigawatts -- to makes 1267 kg of nanotubes per second for 40 million tons of carbon nanotubes per year. 123 GW almost certainly means hundreds of billions of dollars invested in power infrastructure for the purposes of carbon nanotube production for concrete. If you expect to scale with sustainability in mind, you should consider designing your entire reaction around the renewable energy source. Perhaps you can employ similar catalytic processes to the Co-Mo-S photo-hydrogenation from sunlight to achieve higher efficiency per area by using sunlight more directly.

[SaratogaEnergy]

We like the battery idea the best as well. We've chosen that as our first product to market. Me make multi-walled carbon nanotubes which are conductive in bulk. Its possible that there are non-conductive layers, but they are encased by conductive layers that counter act them. For concrete i've sen research showing 50% improvement in strength with 1% carbon nanotube concentration. We haven't confirmed this ourselves yet, but we are starting up a testing program soon. We are also planning on scaling with renewables like hydroelectric. If in the future carbon nanotubes can be used to replace aluminum as a structural material, there may be an opportunity to use they hydroelectric they were once operating on to power the process. But I agree, to reach a massive scale, we will need massive renewable energy. But I think we need that anyway!

[sonofgod]

Cool; so about 0.35% of yearly world production of CO2 per year from capture, and assuming 25% increased longevity, somewhere a little short of 1% due to cement reduction.

... that's pretty good, actually, might buy us another year, on its own...

[SaratogaEnergy]

maybe it'll buy us some time to figure out fusion! I think if we can get the electric car market to a more significant level as well (and power them on renewables) that would also have a big impact.