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Beijing Unveils Supercritical CO2 Turbine That Could Upend Power Tech
China has launched the world's first carbon dioxide–based power generator, using supercritical CO2 instead of steam to produce electricity with over 50% efficiency.
The system harnesses industrial waste heat—such as from steel plants—and needs no water or fuel, reducing maintenance and equipment complexity.
Compact and versatile, the technology could revolutionize carbon capture by using CO2 for profitable energy generation, potentially lowering emissions and storage costs.
China has launched a first-of-its-kind power generator that works with carbon dioxide instead of steam, like traditional generators in power plants. Perhaps more importantly, however, the new generator works with waste heat and boasts a much higher efficiency than existing ones at doing that. According to the company that designed it, the generator is the start of a new era, the South China Morning Post reported.
Normally, thermal power generators work in one of two ways, both relying on heat to turn a turbine. In coal power plants, the burning of coal heats up water until it vaporizes, the vapor then being directed to the turbines that generate electricity. In gas-fired power plants, the turbines are activated by the heat, generated from the compression of gas and its subsequent heating.
Unlike them, the SCMP reported, the new generator uses carbon dioxide in a supercritical state, meaning the compound is subjected to a certain pressure and a certain temperature, which makes it behave simultaneously like a gas and a liquid. The state is called supercritical, hence the whole generator is called a supercritical one. Conveniently, waste heat from sintering in steelmaking plants could reach as much as 700 degrees Celsius—so the inventors of the new generator connected it to one steel works, and to the grid. Even more conveniently, the supercritical state of CO2 does not, in fact, require this high of a temperature.
(Score: 1, Touché) by whatnow on Sunday November 30, @03:51PM (2 children)
>> In gas-fired power plants, the turbines are activated by the heat, generated from the compression of gas and its subsequent heating.
Hmm, guess you learn something every day, I foolishly assumed that gas fired plants burn the gas to generate heat.
(Score: 4, Informative) by VLM on Monday December 01, @07:48PM (1 child)
I think I see where you guys are confused. Supercritical CO2 is a tolerable good working fluid, ideally it would neither flow into nor out of the power plant.
If you try to suck too much energy out of steam it turns to water and water in a turbine causes incredible wear and tear on the blades which are ideally very delicate and precise and randomly slapping into drops of condensed water is a problem. You could make an "ultra-efficient" steam turbine but the blades would be ruined in a week or so. Maybe a month. Either way they're too expensive to be abused that way. Its like the inverse of cavitation destroying a boat propeller. Supercritical fluids/gasses don't condense they just kinda get colder and denser so its "safe" to draw a heck of a lot of energy out with them.
I think people who haven't done a thermodynamic class think the output of the turbine in a steam plant is like ice cold beer too cold for UK peeps. Its not. Theoretically you could make a turbine that would cool down to blowing snow, but good luck making that light and efficient and cheap all at once. Also cooling it would be a PITA with a sane sized heat exchanger. Maybe on Neptune or something.
Believe it or not you can run supercritical steam its just like 250 Fing bars of pressure or something like that. CO2 is much chiller coolant to deal with, just keep it above 1000 psi or so (a mere 75 bar or so).
Its greenwashing not because it's sequestering CO2 (which it actually does, temporarily until it leaks out) but because the alternatives are a chore to deal with, and you can burn less fuel to extract more energy "green".
Ironically, methane from natgas would be a nice working fluid I bothered to look it up the crit pressure is only 46 bar and crit temp is -86 so no need to be weirdos about it even in the arctic. A giant ultra high pressure can of methane with a flame under it strikes me as a very bad idea. But it would be cool in the sense of I'd click to see that blow up on youtube LOL. Maybe supercritical argon would be a better idea, that needs 1000+ psi for practical use (you can't do stuff right at the triple point, has to be higher). But CO2 is cheap.
(Score: 2) by corey on Monday December 01, @09:07PM
Thanks for clarifying.
The article is an absolute mess. It makes no sense and chucks around buzzwords like CO2 capture. I thought initially it meant that the Chinese have figured how to extract CO2 from the air, compress it then burn it. But as you explain, it’s just in the closed loop between the compressor and turbine. It’s a minor improvement in efficiency, I suppose. Good. But geez, I can’t help but wonder if the article writer (hazard to day journalist in fear of smearing them such) ran it through an awful AI/LLM model.