See, they take seawater, and using copious amounts of electricity, turn it into HCl and NaSO4.
Now this nice gentleman thinks he can take CO2 and combine it with the HCl, to create the light petroleum products like butane.
Isn't this a bit like making a perpetual motion machine?
It would be, if he were suggesting to then run the power plant off the results of the process and use the plant's electricity to produce the HCl. However, since the system has two energy inputs, the fuel burned by this plant and the fuel burned by the plant powering the HCl factory, it's okay for the end result to contain more energy than one of the two inputs. Essentially, if this process were very efficient, it'd be like running a power plant off HCl rather than hydrocarbons.
Of course, the process won't be even remotely that efficient. Instead, the point is to combine the plant's waste products—heat and CO2—with HCl to create a product that, one hopes, has more economic value than the original HCl did. Actually, even if the petroleum products have less value than the HCl, this can still make financial sense. It transfers the pollution from this generator to the one that powered the HCl plant; varying regulations may make that worthwhile. And if the HCl plant is run off nuclear power or some other "free" electricity, then the process reduces CO2 emissions as a whole. Not that there's any objective value to that, but again, regulations may make it worthwhile.