So says Sci-Am. The article is high on pic and low on facts. Only a small percentage of the CO2 is captured - 1.5% - but that is OK, it is only a demo plant. The key question, of course, is how much extra coal is burnt to achieve this? This vital fact is not clearly provided. The 1.5% is clear And now roughly 1.5 percent of the CO2 billowing from its stack is being captured... but the other half is vague: But the primary benefits of the chilled-ammonia process for capturing CO2 are lower electricity and steam consumption, compared with other potential technologies for carbon capture, such as using amines, another ammonia compound, which can consume as much as 30 percent of the plant's power just to run, says Shawn Black, product manager for Alstom. The goal here is to get that number down to under 15 percent. So is that 15% of 1.5%, which seems to good to be true, or 15% of the total, which seems too bad to be true?
Wiki says Capturing and compressing CO2 requires much energy and would increase the fuel needs of a coal-fired plant with CCS by 25%-40%. These and other system costs are estimated to increase the cost of energy from a new power plant with CCS by 21-91%. That is more in line with what I was expecting.  turns out to be a 2005 IPCC report. Their table SPM 3 (yes, its true, I didn't get very far through) says that coal, sans CCS, is 0.04-0.05 $/kWh, and 0.06-0.10 with CCS and geological storage. The Sci Am article is consistent with that, saying Cleaner coal will be more expensive, too, adding at least 4 cents per kilowatt-hour to the power Mountaineer produces at roughly 5 cents per kWh. So I think they do mean 15% or 1.5%, but are probably being optimistic.
Clearly, until carbon acquires a sensible price (hopefully via a carbon tax) these plants will not be commercially viable.
In other news, Mars looks good.
I know it makes me seem a little out there but I only see two real hopes.
1) Air capture using clean energy, or biotech is possible.
[Seems very diffuse; unlikely to be better than CCS. And where do you put it? -W]
2) Some unknown new energy technology comes along that is, without any government intervention, cheaper than fossil fuels.
[Also known as "magic" :-) -W]
On the first point, for non-biotech you would have to use some type of clean fuel like solar. Not sure about storage, but there are probably some options. biotech would use solar naturally. You might merge biotech with my earlier number 2.
On the second point, I know. But I haven't heard any ideas yet other than these two that seem like they will make the slightest difference, other than maybe moving the peak level back a few years.
I read the article (somewhere I don't remember where). The 15% energy penalty is the target (presumably for 90% removal, as that is the claimed removal fraction for the small part of exhaust gases diverted). So the whole reason for using the Amonia based method, rather than the better known Amine based methods, is that the former promises to be more energy efficient. So they are hoping to get a process that consumes 15% rather than the roughly 30% quoted for the Amine based methods.
They also plan to scale it up several fold -but not to cover the entire plant -it is a 1.3GW plant. The claim is the land needed for capturing the entire output stream (presumably captruing 90% of the CO2) is comparable in size to the current plant.
They also discussed plans to geologically monitor the storage underground over several years. The most probable escape mechanism is up abandoned oil wells.
Ouch. They think a process that requires chilling the entire flue gas will have better economics than the conventional amine process? That's surprising. Either way, it's hopeless without a carbon price.
I read it as they're recovering 1.5% of the CO2 in the entire flue gas, but they clearly aren't putting the entire flue gas through the CCS unit. How much of the CO2 that goes into the CCS unit gets recovered is a number you'd think the author would have thought to ask after. As well as the amount of energy required to recover it.
The target of 15% energy cost is neither here nor there in this case; it's just an aspiration.
Now if only we could combine both of the themes and put all of the CO2 on Mars... goodness knows it could use a little :-)
I'm honestly very surprised that there weren't more wells in that area... that is very fortunate because in general this is a non-trivial problem. Out in the gas-producing basins of the western USA, there are dozens of pump jacks in sight from a single vantage point, all of which equal a nice little hole in that impermeable cap rock. I saw a talk last year about addressing those kinds of concerns: experimental and field work showed that if the plug in the well was installed well, there were fewer issues, but if it was installed sloppily, the concrete plug would easily corrode. Their study took a ton of work in very limited area, so it seems clear to me that there needs to be some amount of concerted coordination with oil and gas companies in terms of surveying reservoirs and monitoring well plugs in order to even ready a field for carbon capture and storage. So while the experimental power plant is nice, it's only one step and there needs to be prepared infrastructure for it to work: if the CO2 leaks out, we'll be relegated to a billion-dollar-game of carbon whack-a-mole.
I really shouldn't be so dour though - there is proposed legislation at least in the USA that is starting to address these issues; I'm just cautiously pessimistic because I don't want to get my hopes up about something.
So they hope to have an energy penalty of 15% and a total cost penalty of 80% (from .05 to .09 $/kwh).
Sounds like the main cost is infrastructure, not operation.
[I would imagine that the infrastructure cost would come down as they get used to how to do it. But the energy penalty is presumably thermodynamic and unavoidable. It isn't clear that 15% is achievable -W]
#1 Nicholas: biomass plus carbon sequestration accomplishes the same thing as the fanciful schemes for open air sequestration. Biochar is another possibility, maybe. Neither of these possibilities would eliminate the need to severely reduce emissions, but they could take the edge off of the worst of our problems.
Nice Mars pics. It's unfortunate that lander safety requirements force them to go to the most uninteresting, flat landscapes of Mars.
The use of ammonia or amines to capture carbon dioxide from coal-fired power plants is just plain silly.
Ammonia is made soley from natural gas and the most efficient coal-fired power plants acheive only 25% efficiency when the mercury, pariculates, sulphur dioxide and carbon monoxide are removed.
[I don't understand that. You can make ammonia from lots of sources. And they are essentially recycling the ammonia, not using it up -W]
I don't understand why power companies don't just forget about inefficient coal power plants and focus on 60% efficient gas-fired power plants. Alternatively, coal-fired plants could co-fire with straight natural gas, without converting it to ammonia. It acheives the same effect and it's more economic than using ammonia.
[There is lots of cheap coal. There is less gas, and it is more expensive -W]
Russell: energy efficiency isn't the end-all, be all. Cost efficiency is. Hence, old coal survives, and if you've built a coal plant, you'll want to keep running it.
Russel: The temperatures for efficient natural gas plants and coal fired plants differ, so I think that most of the combustion and turbine stuff would need to be replicated -or else suffer from a design that seriously compromises the efficiency of one or both modes of operation. Supposedly coal plants take a good deal to time to heat up and reach operating efficiencies, so turning then on/off is not considered to be viable. That and the fact that the bulk of the cost of coal plants is in the infrastructure. Anytime you have a plant with high infrastructure costs you want to run it 24/7 to amortize the capital costs. This is the main reason why nuclear is not ramped up/down for load following purposes either.
Ammonia used to be made from lots of sources until several decades ago. Nowadays, more than 90% is made from natural gas and, in Europe, the ammonia is bought from Russia via the Ukraine. Coal costs per kW are only cheaper if the economic externatlities of mercury emissions, particulates, sulphur dioxide and carbon dioxides and other pollutants are allowed by the government and tolerated by the nearby residents. The coal used in UK power plants, for example, comes from Russia and South Africa. The local UK coal contains too much sulphur and is too deep to be mined economically.
Cost efficiency is a direct function of energy efficiency. The less efficient the power plant; the more fuel you have to burn.
If an ammonia or amine process is to be used on an existing coal plant, to keep it running, then you would actually have to demolish much of the extisting plant anyway to fit the ammmonia/amine process. The steam turbine, in particular, needs to be a completely different one with a different expansion process. The higher electrical loads for the chemical processes need new motor control centres. The list goes on and on ... Hence, the 'old' power plant has to be demolished, anyway. The notion of simply 'adding' the ammonia/amine process to an existing plant is naive and is only promoted by the manufacturers of these chemical process plants. There isn't one commercially sized ammonia/amine process 'add-on' installation in existence and there never will be.
For many years, coal mines in China, the Czech Republic, Poland, Russia, and Ukraine have taken advantage of their abundant supply of methane by cofiring it with coal in their boilers to produce heat and electricity with lower carbon dioxide emissions.
In addition to on-site use at the mine, mines can pipe methane to nearby power plants or other industries for cofiring in their boilers.
The gas input to a boiler may vary from less than 10 percent to 100 percent of total fuel input depending on boiler design, gas availability, and the needs of the boiler operator. The required equipment is commercially available, meets all applicable codes, and, in many cases, is already in place.
Because it contains no ash, virtually no sulfur, and is low in nitrogen, the firing of coal mine methane in coal boilers reduces SO2, NOX, particulate emissions and CO2. These benefits are more important than ever before, because of new EPA particulate emissions regulations. The improved combustion achieved with cofiring can also improve carbon burnout and reduce opacity problems.
The ease of boiler conversion and low capital cost of cofiring represents a low-risk approach to improving coal-fired boiler performance and reducing carbon dioxide emissions without the need of huge ammonia/amine absorber/scrubbing facilities. Coal-fired utility boilers in the U.S. consumed more than 70 billion cubic feet of conventional natural gas in 1995. These boilers used this gas for ignition, warm-up, and load carrying.
Many gassy coal mines are in close proximity to industrial boilers, and at least ten gassy coal mines in the U.S. are within 20 miles of utility boilers. EPA's Coal Mine Methane Outreach Program has prepared a report identifying several potential sites in the U.S. that could economically cofire coal mine methane.
Yes, coal is only cheap because externalities are unpriced. But so long as they are unpriced, coal will be continue to be cheap, and that answers your question as to why anybody bothers with it.
"Cost efficiency is a direct function of energy efficiency. The less efficient the power plant; the more fuel you have to burn."
If your energy efficiency is 80%, but the fuel is really expensive, or the costs of building the infrastructure are really high, you can still lose. When comparing across vastly different energy sources, comparing energy efficiency alone is not helpful.
Typically, coal-fired power plants cost between double and treble the cost of a gas-fired power plant. In Europe, an 800 MW coal-fired (42% efficient) power plant costs around 900 million euros, wheras an 800 MW gas-fired (60% efficient) combined cycle power plant costs around 400 million euros. Additionally, if the carbon dioxide emissions are equalled for the coal-fired power plant then the coal-fired power plant infrastructure cost rises from 900 million euros to around 1300 million euros. That's more than treble the cost of a gas-fired power plant. The efficiency of the coal-fired plant also falls to half that of the equivalent gas-fired power plant.
The price of coal, until 3 years ago, was stable at between $25 to $40 per ton. Coal demand from India and China created a dramatic rise in the price of coal to $150 per ton during 2008.
The last coal-fired power plant to be built in the UK was about forty years ago and France has no coal-fired power plants. All of the new fossil fuel power plants in the UK since 1970 have been gas-fired. With coal prices of between $60 to $70 per ton today (11 November 2009), carbon taxes, high infrastructure costs, slow start-up times of 8 hours, large plant surface area needs, 4 year build time, low efficiency, CO2 pipework routing and CO2 sequestration environmental concerns then there is no positive economic or sociological arguement to build any new coal-fired plant in Europe or North America.
The investment into alternative power generating technologies such as nuclear energy may need to be measured against the potential cost when things turn against you as unfortunately happened this year in Japan. Coal prices and coal statistics show developing economies are more likely to increase their investment into & their use of coal mining in coming years because of coal's affordability and ability to quickly meet increasing demands for electricity and steel. www.coalportal.com