> Not allowed by thermodynamics. Otherwise you could create free energy by continuously burning and recapturing the same carbon. That doesn't have to be the ca

> Not allowed by thermodynamics. Otherwise you could create free energy by continuously burning and recapturing the same carbon. That doesn't have to be the case; the carbon you capture may not be in a burnable form. E.g. if carbon dioxide were captured, additional energy would be required to split off the oxygen before the carbon could be 'burned' again.