The basic problem with carbon capture is energy, and energy is cost. When coal or oil is burned, heat and CO2 are produced. CO2 is a pretty low energy form of carbon. Turning it into something solid (calcium carbonate, graphite or coal) requires a lot of energy. Also, when CO2 is made by burning fossil fuels it disperses, and re-concentrating it requires energy. That’s why carbon capture proposals often include using exhaust gas, grabbing the CO2 before it disperses. The other main type of capture I’ve seen proposed takes the CO2, concentrates it to high pressure, and pumps it underground (and hopes it stays there). Compressors take a lot of energy, and so do pumps if the CO2 needs to be piped hundreds of miles to a place where it can be pumped underground.
The key number for carbon capture is, how much energy is required relative to the amount generated by burning the fossil fuel? I’ve never seen articles about it touting this number. A quick look shows one assessment being 30% – 35% of the energy (Zhang et al, 2014), another figures the production cost of electrcity with carbon capture being 62% – 130% higher (White et al, 2012, Table 6) Another article looks at the harder case, CO2 capture from air, and estimates the cost at $1000/ton CO2 (link). Burning the coal to generate a ton of CO2 (1/3 of a ton coal) generates about $80 of electricity.
So the best case cost of carbon capture–from power plant exhaust gas–is dismal, 25%, 75%, maybe over 100% of the value of the electricity. This number will translate directly to increased fossil fuel energy costs (+30%, +100%, etc.) if fossil fuel companies are required to capture the majority of the CO2 pollution they generate.
All the carbon capture projects are basically stalling actions. The fossil fuel companies pay small $$ to put together a pilot plant (or better yet, get the govt to fund it), run tests for years, but never implement CO2 capture on a coal or gas energy plant. This had been a very successful approach for the fossil fuel industry, they’ve managed to stall things for 50 years already!