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Australian University Unveils New Carbon-Trapping Bricks
FirephoxRising writes "A research pilot plant in Newcastle will trial world-first technology that turns carbon emissions into bricks and pavers for the construction industry. More efficient and stable than storing gas in the ground, the new method will sequester carbon and can work anywhere, unlike geo-sequestration which is site specific."
From TFA: "capture carbon dioxide emissions and turn them into rock." We all know what rock is made from carbon...
So they're bringing coal to Newcastle -- specifically, artificial coal bricks and pavers!
The article fails to mention what they intend to convert the CO2 into, or how much it will cost. Maybe the primary function of the company is to win government grants.
CO2 is carbon at its maximum oxydation level (you cannot burn it anymore). Limestone is made of calcium carbonate (and magnesium carbonate in a lesser extent), it is also carbon at its maximum oxydation level. The transformation seems smart, but it requires water (easy part) and calcium. Where will that calcium come from? The usual source is limestone...
A good question, though I'm less cynical about the presumed answer. They did say something like they were recreating the Earth's natural processes, so probably something like calcium carbonate (CaCO3), the stuff that egg and seashells are made of.
Can anybody say how various carbonates compares energetically to oil and CO2? My chemistry is pretty rusty. Since the final cycle would be oil -> CO2 -> carbonate the maximum net energy would be that from a hypothetical fossil fuel -> carbonate transition, which would tell us how energetically feasible this is with the right catalysts. If it's an endothermic reaction this is a complete non-starter except as part of some hypothetical future atmosphere-scrubber (and I do really hope we have the tech ready if it comes to that).
If the reaction is exothermic though then there's hope, especially if it's a significant portion of the (presumably larger) oil -> CO2 energetic gap. If we could complete the fossil fuel -> brick transition while generating even half as much power as currently then this could be a real game-changer. Every coal- or oil-fired power plant could have it's adjacent brick factory and become carbon neutral. We could stay on fossil fuels for centuries without aggravating the global climate, even as oil and gas run out - we have truly massive coal reserves to fall back on. Of course we'd need to really shift the attention back to general environmental protection again, and get serious about that, otherwise the search for fuel could get *really* ugly. Coal mining isn't exactly environmentally friendly
--- Most topics have many sides worth arguing, allow me to take one opposite you.
I bet you could get a lot of investors on board with a plan to use solar power to convert atmospheric CO2 into building materials. Just don't tell them that the super-secret device that does so is called a "tree."
How can we continue to believe in a just universe and freedom to eat crackers if we have no ale?
The article says they have spent 6 years researching the technology. 6 years ago is also when German researchers published their discovery: http://en.wikipedia.org/wiki/Hydrothermal_carbonization (The German version of the Wikipedia article is much more informative.)
As far as I know, it started with a researcher wondering how exactly the Earth produced coal and oil and discovering that for almost a century nobody had done any new experiments. So he did some, adding some of today's knowledge.
It turns out that if you put water and basically arbitrary organic waste (wood, grass cuttings, leaves, entire weeds, whatever) into a pressure cooker, add some citric acid as a catalyser and then heat it to 200 degrees Celsius, then you get an exothermic reaction which makes the stuff keep that temperature without further input of energy. Provided you are not using an ordinary pressure cooker (which will explode) but some special thingy.
You stop the reaction after 8-12 hours and filtrate the water to get the product. Depending on the precise time you stop, you can create topsoil, oil, brown coal or low-quality stone coal. While the method doesn't seem to produce any excess heat, you can theoretically make an industrialised country CO2 neutral by treating all of its green waste that way and storing the resulting low-quality coal underground, e.g. in an old coal mine.