Image Credit: Sven Dorum/VISUM
FutureGen never went past a press release. Hydrogen Energy ran out of it. But, finally, somebody is at last running an honest-to-God clean coal power station; surprise, surprise, it’s funded by Scandinavians and it’s been built in Germany:
Sweden’s Vattenfall inaugurated a prototype coal-fired power station on Tuesday which it says is almost emissions-free, but environmentalists were unimpressed. Located at the site of the massive ‘Schwarze Pumpe’ (‘Black Pump’) power station in eastern Germany, Sweden’s Vattenfall said the new technology has the potential to allow coal to be burnt without releasing harmful greenhouse gases.
While the plant has a capacity of only 30 megawatts, tiny by coal-fired power station standards, it is the first fully integrated “clean coal” plant in the world – that is coal goes in, electricity and liquified CO2 come out. How is this achieved? There are, essentially, three proposed ways to capture CO2 when producing coal-fired electricity. The first, post-combustion capture, is to simply run a conventional coal-fired power station as normal, and extract the CO2 from the exhaust gases. That’s conceptually simple – and has the advantage that you should be able to retrofit it to existing power plants – but there’s a problem. Most of the exhaust gas is the nitrogen in the air. So you have to work harder to extract the relatively dilute CO2. The second approach – the one that the Hydrogen Energy proposal used – was to use the coal to make hydrogen, which would then be burned in a gas turbine. The “process CO2″ that came from the hydrogen production process is much more concentrated and, therefore, cheaper and easier to collect and purify.
The final approach, and the one used at Schwarze Pumpe, is the “oxyfuel” process. The difficulty with post-combustion capture is all that nitrogen in the exhaust gas. The oxyfuel approach solves this problem by extracting pure oxygen from the air, and burning the coal in that. There’s a twist, however; if you burn coal in pure oxygen, it burns so hot that it’ll melt your combustion chamber. But we’d like the exhaust gas to be as pure carbon dioxide as possible, so you don’t want to mix in anything else. But we can recycle part of the exhaust gas itself to dilute the oxygen. Now everybody’s happy; the coal burns at a reasonable temperature, the exhaust gas is reasonably concentrated carbon dioxide that we can filter out without too much effort, and everything’s hunky-dory. What’s the catch? Producing the pure oxygen, of course. Extracting pure oxygen from the atmosphere takes a fair bit of effort, as anybody who’s tried to ride up mountains can tell you. While it’s not explicitly stated how it’s done, this article suggests they are using “standard industrial techniques” for it, which probably means fractional distillation of liquified air. Liquefying air involves cooling it to around -195 Celsius, a rather energy intensive process.
The big question from all this, of course, is when we might see commercial-scale applications of this technology. Vattenfall is planning to build a full-scale demonstration plant in 2010, to be completed in 2015. But, as we’ve all repeatedly seen, reality has a way of intruding into optimistic timelines. This is a complex collection of systems being used together for the first time; there’s lots of opportunities for things to not work as expected. Let alone, of course, whether it’s economically competitive with alternatives…
Coal fired power is evil. End.of.discussion.
Carbon emissions that cause global warming are evil. Discussion.still.open.
Robert, I don’t see the ‘Chemical Munitions Bunker’ in that shot. How reliable are the pictures?
BBB
It’s right next to the Wal-Mart
Reading over comments one and two, I think I got a slight case of period pain.
Thankfully, I finally figured out a way of putting a full stop to that…
Better:than:colon:pain
Thanks for the quick and informative tour of common carbon capture methods, Robert. Maybe it’ll work at scale; maybe it won’t.
One concern is the ultimate energy equation given the energy needed to cool the air to extract the oxygen for burning the coal. Another is the larger question of the appropriate balance between CCS and the development of renewables. We should also be mindful of the money going into CCS relative to supporting new coal generation – for example, the $150 million of state and federal funds going into a single new plant in Victoria’s LaTrobe Valley compared to the $100 million recently announced by Rudd for the proposed CCS institute.
Mind you, the money for CCS should be coming from the coal industry, which I would also argue should not be compensated in the forthcoming ETS.
In short, an interesting development, but we need to really ramp up the renewables and consider the potential of gas as a transitional fuel with lower carbon intensity. The continuing emphasis on coal and the lure of CCS seems to hold out the dangerous promise that once we develop a technology to mop up our power generation emissions from coal, we can then go on consuming like there’s no tomorrow.
Everyone will of course raise China in this context, and I concede that it’s a big challenge in terms of that nation’s reliance on coal. However, as a huge exporter of coal, Australia must throw itself into helping China achieve the transition to more renewable power generation. Unfortunately, people like Martin Ferguson tend to see such ideas as disastrous our coal market, rather than necessary for preventing dangerous climate change. With CCS still unproven, and the timeline for at-scale processes uncertain, we probably can’t have both.
While it may seem the best course to extract ALL the CO2 from the air, if retro-fitted plants of this type removed only 30-50% then it would still be worth doing, particularly in China.
Grendel, I tend to think that CCS will have to be part of the plan for China, but that it must be a transition measure to renewables. China has so many plants up and running and so many set to come online that we may have no choice in terms of the global emissions reductions we need. However, the reliance on coal must decline with the increasing adoption of renewables – it’s a different plan from the aim of simply perpetuating our market for coal through the use of CCS.
Grendel, that’s true, but the oxyfuel technology can’t easily be retrofitted to existing plants.
Post-combustion capture is the one that might be suitable for retrofitting.
Robert,
Oxyfuel should be able to be retrofitted as well. You could (conceivably) chill your oxygen, feed that into the fire, take the output gasses, feed some of the CO2 back into the inlet stream and capture the rest.
No doubt it would be more expensive to retrofit than a pure post burning capture process, but I see no reason why it could not be used.
When I was in high school, I was taught that solid CO2 converts directly to gas in a process called sublimation; that there is no such thing as liquid CO2. I’d like to know how Vattenfall liquefy CO2.
I also remember the astronauts on the failed Apollo 13 mission had a problem with too much CO2 in the air. They solved the problem by forcing the air through wet socks. Why can’t the power stations use millions of wet socks to extract the CO2 from their emissions? Unless of course the Apollo 13 story was a hoax.
In fact there is a proven method of removing CO2 from the atmosphere. It’s called photosynthesis.
Silkworm: have a look at this phase diagram. If you pressurize it enough you can get liquid CO2.
Your Apollo 13 story is rather garbled. The Apollo 13 had to use the lunar module as a “lifeboat” when the Command Module had a serious failure. However, the lifeboat had a problem – the Lunar Module’s CO2 “scrubbers” wouldn’t last the entire missions with the whole crew in there. Mission Control devised, and the crew implemented a jury-rig with duct tape and a cardboard box to use the CO2 scrubbers from the Command module in the LM. Unless “wet socks” is some secret code for “lithium hydroxide scrubbers” I’ve never heard…
Photosynthesis is indeed a proven method of removing CO2 from the atmosphere; however, seeing the amount in the atmosphere is going up, we have exceeded its capacity to do so.
Carbon Capture viable by 2030 today! Only £8bn in easy payments!
I think there’s a strong argument that CCS projects are evil in the sense that they assume the worst of us in the future. We would, according to this kind of relentless technocratic logic, be just homo economicii bumbling along into oblivion. I don’t see any inherent evil in CCS itself, just the premise that it’s inevitable.
Robert – interesting the Swedish company had to construct their demonstration plant in Germany. They were forced to because Swedes rely on a combination of hydro and nuclear power for their energy. Swedes are among the lowest per-capita emitters on the planet – yet they work for clean coal. I suppose they win the battle for the moral high ground.
I was unable to find if the plant’s 30MW is net electrical output or the thermal rating of the boiler. Did you find any information on the plant’s thermal efficiency?
€20 (~$35) per tonne carbon dioxide cost isn’t bad. It’s in the ballpark of other options.
Any idea what the leakage will be? Will it achieve Garnaut’s ‘near zero’ stated goal to preserve the coal economy in ’450 world’ or better?
I disagree with Mr. Lewin-Hill. Clean coal development is a must – globally. Renewables and other options deserve equal attention for the sake of supply diversity and achievement of the most aggressive reduction goals, but the development of clean coal has considerable benefits beyond environmental. Its full development will allow the production of highly reliable electricity while sustaining an existing economy with little or no job retraining etc. If a technology enables high quality, highly reliable carbon-free energy production, I am ALL for it. And once the technology is developed why not deploy it in any interested country to the maximum extent? If demonstration plants show, objectively (i.e. withstands a rigorous and diverse technical peer review), that the technology is viable – full steam ahead!
Coal isn’t evil on its own. Emissions spewing, non-captured coal combustion however is a completely different story. I look forward to the day any government declares a moratorium on the construction of any fossil station without the parallel deployment of some type of carbon capture technology.
The great unknown is will we get there in time?
It would be interesting to see what the short-run marginal cost of a low-carbon emission coal fired plant would be. If it’s low enough, you would still have coal, instead of other plant, providing baseload power.
Do carbon intensive industrial processes other than power generation (eg iron smelting) account for a significant proportion of total co2 emissions? If so, isn’t it important to develop ccs regardless of the debate regarding power generation?
dk.au. I’m not crazy about CCS for the resons I’ve outlined, but also because of concerns about CO2 pumped into the ground staying in the ground. However, what’s the game plan for China without any CCS? Are the current and soon-to-be commissioned coal-fired plants in China to continue emitting without CCS until sufficient renewables come online?
Especially should retrofitting become viable, CCS might be a pragmatic intermediate step, though not with the mindset that ongoing unlimited exploitation of fossil fuels is acceptable. The challenge is to optimise mitigation without impeding the adoption of renewables, which must replace fossil fuels as soon as possible.
Robert, is there any prospect of the CCS technology being developed for coal also applying to gas? If so, that seems to strengthen the argument for using gas as a transition fuel, though I appreciate that a single solution is unlikely.
Carbon capture and temporary storage may be worthwhile over the long term. You could imagine coal power stations being used in Europe or North America during the winter months and having the CO2 wastes stored in underground reservoirs until the warmer months. The carbon dioxide could then be changed into something less harmful when there is more energy readily available. Carbon capture technology could keep the coal power stations viable for some time yet. I don’t think long term storage of CO2 underground would work at scale though.
So apart from the energy intensive oxygen purification, we’re all good to go? Will this result in having to build a bigger power plant to produce the oxygen required to complete the CO2 removal? Won’t this end up like putting a much bigger engine in a car so it’s got the power to move both the car and the engine?
CCS works fine for gas. Any of the three options – post-combustion capture, oxyfuel, or making hydrogen – works, and most of them are easier for gas than for coal.
Ed: It’s not clear, but it seems to be 30MW electrical output. However, I’m not sure that it really matters all that much. No specific figures on thermal efficiency. I would think the most important information is the energy costs of oxygen production, and the CO2 capture and liquefaction. No quotes on the percentage of carbon leakage, either. Most of the studies on CCS I’ve seen assume 90% capture; one interesting bit in the Garnaut report is that in the long term 90% capture isn’t going to be enough to compete with zero-emission technologies.
Interesting.
.
And yet to talk to all my anti-Science environmentalist acquaintences (many active in the Greens) this sort of thing is not viable.
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It’s not viable. Close it down please. And no genetically engineered crops either. It’s not viable either. Get rid of fertilizers, pesticides. All agriculture must be organic. It’s the only viable way.
.
Famine? What does that mean?
Thanks Robert.
I am looking for the efficiency numbers to assess economic viability. However, the authors have put the €20 carbon costs there for me to do just that.
The missing detail only makes it tough to give that number a sanity check.
Koopatroopa: yes, making steel and concrete is a globally significant source of CO2. We will apparently need CCS for it.
Sam: Yes, you need to build a bigger power plant (and burn more coal) than you otherwise would to power:
the oxygen purification plant.
the co2 extractor and liquifier (you have to compress the CO2 to high pressure)
Transporting the CO2 to its final disposal site.
However, all of that uses less energy than the plant produces! Also, the net carbon emissions are still far lower than a plant without CCS would be.
Robert,
You’ve missed highlighting the big fat power cable that takes most of the energy produced by the power station directly to the CO2 hiding station, and the new, bigger power station that is to be built next door to make up for energy lost to the consumer.
It isn’t viable because it massively reduces the energy returned on energy invested (EROEI), which increases the cost per kw of the electricity generated. By which time plain old renewables are significantly cheaper.
Technically viable? Yes. Economically viable? Not for a long time (if ever), in which it is used as a stalling tactic by the coal industry to advocate for more export, more dirty plants and more expansion, in the promise of “clean coal”.
um, so the CO2 is captured and liquefied and then… what?
If, for every tonne of coal, say, we get about two tonnes of CO2, that’s a LOT of stuff that needs to be transported and buried somewhere. And it’s not like coal that can just sit in the back of a railway car, CO2 tends to be a little more problematic, and so, more expensive.
Does the station’s almost carbon neutral status include the CO2 generated while trying to rid of the CO2 it produced? Hell, does it even include the CO2 generated in mining, processing and transporting the coal in the first place?
George: yes, it reduces the EROI somewhat. But the question is “how much”, and what the resulting cost impost is. I can assert nuclear will be cheaper than either CCS or renewables till I’m blue in the face, but you’d want evidence to back that up. Guess what. So do I.
The second thing to keep in mind is that the efficiency of new coal-fired power stations (and thus the EROI burning the same fuel) has gone up quite a lot. In fact, when you compare Hazelwood to an IGCC plant with CCS, the new plant will almost certainly win on EROI because the much greater thermal efficiency easily outweighs the energy cost of CCS.
Nicki: I did the sums. Essentially, this pilot plant will produce a truckload of liquid CO2 per hour.
In the long run, it’ll almost certainly be piped or shipped to disposal sites. Both are reasonably energy efficient.
Er there is an oxyfuel project in Queensland http://www.asiapacificpartnership.org/JointTFmtg/CallideOxyfuel/CallideOxyfuel.pdf
As well we have a very active generation program that uses coal seam methane for power generation and for injection into the gas supply. Combined cycle gas generation plants can get up to 68% themal efficiency and oxidise the carbon fraction of Methane to Carbon Dioxide. Since the Methane will normally finish up in the atmosphere, oxidising it to CO2 is better than allowing it to leak out. Methane is a 20 times more effective Greenhouse gas than CO2.
Instead of mining coal we should be burning Coal Seam Methane instead. All you have to do is dril lots of holes into the coal seam, drop in pipes and connect them all up to a gas turbine and away you go. No mine, no dredges (and er no miners). Thermal efficiency is more than twice that of coal and as Methane is CH4 you are burning mostly hydrogen – not carbon.
It’s a no brainer really. Can hold the fort while we get the geo-thermal stuff going.
Huggy.
What’s the catch?
1. The cost of doing this, compared to using renewable energy sources. If renewable energy aources are cheaper, then it is the way to go.
2. Time to market. When will this be commercially viable and implemented on production scale? If it is by 2020, then it is 10 years too late
3. Burning more coal to power the CCS processes – increased use of fossil fuel
4. Where will the “sequestered carbon” be stored and will it stay there? What happens if it leaks out?
Looks like a futile and pointless exercise to me. Happy for industry to fund this, but taxpayers should not.