[credit_guy]

The application doesn't really make sense the way they explain it: use CO2 from a power plant to produce syngas. If the power plant burns methane, you might as well produce syngas straight out of methane, and short-circuit the step where you produce CO2. From the net energy usage point of view, you are better off (otherwise, you just found a recipe for perpetual motion).

Where this could make sense is energy storage. Say you are next to a large solar power plant, and you want to store the excess energy produced during the day and release it at night. Batteries are too expensive, pumped water requires some mountains, etc. With this, you store a quantity of CO2 in some tanks. At day you generate syngas and consume electricity, and store it in some other tanks. At night, you burn the syngas, get some of the initial electricity back, and store the CO2 back in its tanks.

[nine_k]

This makes complete sense if you replace a power plant that produces electricity with an industrial process that produces heat, e.g. a blast furnace.

Then you can grab the waste CO₂ and turn it into something useful (ultimately liquid fuel, plastics, etc) by using the cheap solar energy, of which we often have a surplus at daytime.

This has the downside of only operating efficiently during sunshine, or needing a power transmission line from somewhere under sunshine currently (e.g. during local night).

[pm90]

You’re correct but It still makes sense as a way to get existing power plant operators on board the green energy train. It’s probably cheaper to retrofit an existing plant to harvest the generated co2.