Good. Invent things. Try things.<p>But keep this in mind: plants evolved lignin to make their structures (trunks, branches, all that) hundreds of millions of years before bacteria and other microorganisms evolved the ability to break down that lignin. So, for hundreds of millions of years, plants captured carbon dioxide by photosynthesis and sequestered it. That's what changed earth's atmosphere from reducing to oxidizing. Fossil carbon is the geological remains of that carbon capture.<p>It's hard to imagine carbon-capture tech that has the longevity of those planet-wide lignin forests.
I have an impression that in recent years MIT produces much ado about nothing. In that particular case, capture method requires energy input from, let me guess, coal burning? Moreover, you can't trick chemistry: more efficient capture implies higher affinity of CO2 towards this "CO2 battery". Higher affinity means that more energy would be required for regeneration of the "battery".<p>From chemistry point suggested process is indistinguishable from the following process: pass air over CaO or Ca(OH)2 solution to turn it into CaCO3. Heating of CaCO3 will release CO2 thus regenerating CaO, which could be reused again. This process would require energy input — like MIT tech.<p>Excess of CO2 in atmosphere is not necessarily bad thing. More CO2 in atmosphere means more carbon will be available for capture by plants, which means more crops and trees.
Cool, but isn't it better to use naturally occurring alkaline minerals so that energy doesn't have to be expanded to re-release CO2? I suppose that energy to mine and pulverize minerals could exceed energy to cycle this battery. But minerals can potentially be put to dual use during or after capture, for example for construction or erosion control.
Burying old trees underground seems like the simplest solution to this issue. An old tree represents hundreds of years of removing carbon dioxide out of the air and converting it into a form that is convenient for storage. We only need to do the last step of making sure that invested carbon sequestration is not put back into the atmosphere through decomposition or fire.<p>Here's a link to a relevant publication (from a university that unfortunately doesn't have the prestige or marketing team of MIT): doi.org/10.1186/1750-0680-3-1
I wonder what the extra energy required to take this "pure stream of ejected CO2" into the ground is compared to using a different style of removing CO2 that just requires extra energy during capture.<p>I'm definitely not an engineer but I feel like injecting CO2 directly into the earth has to use a ton more energy.