Chilled Ammonia Pilot Project Captures 90% of CO2
10 October 2009
|Illustration of the carbon capture plant. Click to enlarge.|
A pilot project by We Energies, Alstom and The Electric Power Research Institute (EPRI) testing an Alstom advanced chilled ammonia process (earlier post) has demonstrated more than 90% capture of carbon dioxide from the flue stream of a coal-fueled power plant in Wisconsin (the Pleasant Prairie Carbon Capture Pilot Plant). Testing at the pilot facility, using a 1.7-megawatt (electric) slipstream from the plant, captures approximately 40 tons of carbon dioxide each day. The project began in early 2008 and will conclude later this year.
The project confirmed the predicted performance of the chilled ammonia carbon capture system at an operating power plant. It achieved key research metrics around hours of operation, ammonia release, CO2 removal levels, and CO2 purity. In doing so, the partners said, the project demonstrated the fundamental viability of the carbon capture technology in real-world conditions such as changes in temperature and humidity, the inevitable starts and stops of a large power plant, and the environmental hurdles that go along with using any chemical process.
Units 1 and 2 at the Pleasant Prairie Power Plant (P4) recently were retrofitted with selective catalytic reduction (SCR) systems to control emissions of nitrous oxides (NOx) and wet flue gas desulfurization (FGD) systems to control sulfur dioxide (SO2) emissions. This retrofit also included the construction of a new chimney.
The chilled ammonia pilot system withdraws about 1% of the flue gas between the outlet of the Unit 1 or Unit 2 FGD and the stack. The gas is first cooled to condense and remove moisture and residual pollutants before it enters the CO2 absorber. There, the CO2 is absorbed by an ammonia-based solution, separating it from the flue gas.
|The three-step carbon capture process at Pleasant Prairie. Click to enlarge.|
The CO2-laden solution is heated, releasing a very pure stream of CO2. In a commercial application, this CO2 stream would be compressed and transported for use in industrial processes, such as enhanced oil recovery, or for injection and storage in a suitable underground geological formation. In this research pilot plant, however, the CO2 is remixed with the treated flue gas after process discharge sampling measurements. The entire extracted gas volume then is reintroduced into the FGD outlet transition duct where it is mixed with the FGD exhaust gas.
At maximum capacity, the pilot system has been designed to capture nearly two tons CO2/hour (equivalent to 15,000 tons/year at full capacity).
As the next step in demonstrations of increasing size, the first of two product validation facilities recently began at the American Electric Power (AEP) Mountaineer Plant in New Haven, West Virginia. A 20-megawatt electric capture system has been installed at AEP’s 1,300-megawatt Mountaineer Plant, where it will remove up to 110,000 tons of CO2 emissions annually from the flue gas stream of the plant.
The captured CO2 will be compressed, pipelined, and injected into two different saline reservoirs located approximately 8,000 feet beneath the plant site. Battelle Memorial Institute will serve as the consultant for AEP on geological storage as an extensive monitoring system will be used to track the extent of the sequestered CO2 over time.
After the Mountaineer project, Alstom plans to develop a third and final phase commercial-scale demonstration project that will be designed to capture between 1.0 – 1.5 million tons of CO2 per year. Alstom currently is working with AEP, TransAlta – a Canadian energy company and other parties to successfully develop this demonstration project.
Alstom has committed to have a commercial offering for a carbon capture technology available by 2015.
This [P4] project has been a success. It proved what we needed to know to stay on schedule to commercialize carbon capture technology for new and existing power plants by 2015, a necessary step to meet ambitious climate change targets being proposed by policy makers in the US and around the world. Alstom believes carbon capture, along with energy efficiency and a full portfolio of low carbon technologies including renewable power, will all be needed to achieve urgent CO2 reduction goals in a timely manner.
—Alstom US President Pierre Gauthier
Alstom, a leader in carbon capture technology, is pursuing 10 demonstration projects in six different countries, including the We Energies project and partnership at Mountaineer with American Electric Power. The Mountaineer project is one of two current or planned post-combustion carbon capture and storage (CCS) demonstrations for which EPRI has formed an industry collaborative to support management of testing and evaluations.
The EPRI collaborative will support the integration process/design of CO2 capture technologies and the monitoring and verification of CO2 storage, and it will assess the large-scale impacts of CO2 controls and storage on post-combustion coal-fueled generation. The data collected and analyzed by the collaborative will support efforts to advance CCS technologies to commercial scale and provide information to the public and industry on future electricity generation options.
EPRI is leading or supporting seven Industry Technology Demonstrations as part of its efforts to help develop a full portfolio of innovative technology approaches needed to make substantial CO2 emissions reductions while minimizing economic impacts.
Pleasant Prairie Carbon Capture Demonstration Project Progress Report 8 October 2009
"Chilled Ammonia Pilot Project Captures 90% of CO2" makes a nice headline.
Too bad no costs are mentioned and 95+% of the plant output was not captured.
Posted by: kelly | 10 October 2009 at 07:20 AM
Kelly - actually the pilot system collected 90% of the C02 from 1% of flue gas generated by the plant....so it sounds like 99.1% of the total CO2 output went into the atmosphere. If the researches are happy & excited, that's the important part I guess...and they can do a major scale-up of the system (either at taxpayer's expense or with costs passed on to consumers).
Posted by: ejj | 10 October 2009 at 07:59 AM
All of the CO2 went into the air.
There is a method of tree farming that provided wood for many uses. It is still practiced on a smaller scale. It is called coppicing. If mechanical methods for coppicing were developed that were low cost it could be a way to capture much CO2 if the wood were used in building products such as oriented strand board.
In coppicing, the roots of suitable trees are kept alive and the multiple replacement stems are harvested every several years. This is a much more effective way of eliminating CO2 from the air than is ethanol and some other biofuels. It must be remembered that ethanol itself is a valuable food, and its use as a fuel when many are not eating as many calories as are considered adequate by studies is questionable. Ethanol from any fermentation process can be made safe enough for human ingestion. Ethanol from other processes can also be purefied sufficiently, but they are illegal for consumption because they do not contain ENOUGH radioactivity under US law.
For most purposes, trees should be considered fossil fuel. When a forest is destroyed its ability to remove CO2 from the air is eliminated in addition to CO2 being released by burning of the wood or its products. The CO2 capture ability of large trees is said to be increased over that of smaller tress of the same kind.
There is one or more pipelines in Europe that move CO2 from some sources to greenhouses where they substantially increase the growth.
With the availability of nuclear reactors that are much much safer than Chernobyl, which itself was safer than many dams, and safer than Three Mile Island which was even much statistically safer than airline travel with less radiation exposure, there is no reason to use biomass for any energy production in a highly industrialized nation.
CO2 can be captured by this or other processes and used to make liquid fuels with hydrogen produced at nuclear reactors. Processes are available that can produce hydrogen with higher efficiency even with present nuclear reactors. New ultra safe pebble bed reactors can make even lower cost hydrogen thermochemically from water.
While nuclear power is fairly cheap in Canada and perhaps France compared to coal power and much cheaper than power from oil at 150, nuclear heat for producing hydrogen directly is much cheaper because there is no expensive electrical equipment involved. Actually, since nuclear heat is so cheap, cheaper electrical equipment could be used.
Electro-thermal methods of producing hydrogen for liquid fuel production with captured CO2 can also be sufficiently cost effective.
CO2 capture directly from the air might even be made economical with nuclear heat by several methods including alkaline metal carbonate regeneration.
Any present or future automobile can be made partially or fully into a plug-in-hybrid. In some cases only additions need to made to the vehicle and no modifications.
New battery technology is not needed to divert much of our automotive fuel use to lower CO2 producing electricity. The existing battery technologies, especially Nickel-sodium-chloride, can be made cheaper to use by several means, and even lead chemistry is still effective and cost competitive.
In any case, the best fuels for many automotive uses remain hydrocarbons, but even more importantly they remain very highly compact, inexpensive and lightweight compared to other means of energy storage. Modern technology now allows for very small and efficient engines to convert this compact fuel into mechanical energy for vehicle propulsion.
Effective engineering for automobiles and trucks require the combination of much use of electrical power from batteries charged whilst the vehicle is parked but also from small liquid fueled generators because of the very low weight of the energy storage of hydrocarbons. If these hydrocarbons are produced exclusively by solar or nuclear energy from captured CO2, there is no net CO2 release from the use of these fuels. Even the comparatively low energy density methanol is light weight enough. There is no need for very large batteries for long distance operation of automobiles, and such automobiles are ineffective and far too costly machines. The extra weight of the larger batteries is better used for storing methanol. Many such equipped vehicles will rarely start the methanol fueled generator, but will almost exclusively use parked charging energy.
Highly used road lanes could actually be economically electrified for continuous charging whilst running.
There is also no economic need for costly quick charging stations for full electric vehicles because such machines and these support facilities are more costly than is practical.
Nuclear heat can also be used to remove minerals from sea water to sell the water and to use the minerals to capture CO2 from the air. Massive mountains of seawater minerals can be built. ..HG..
Posted by: Henry Gibson | 10 October 2009 at 02:45 PM
Well, we've gone from "Chilled Ammonia Pilot Project Captures 90% of CO2" to "All of the CO2 went into the air."
Next thing you know, American politician's will be mocking a US President for being given the Nobel Peace Prize by the rest of humanity.
Posted by: kelly | 10 October 2009 at 03:57 PM
"When a forest is destroyed its ability to remove CO2 from the air is eliminated in addition to CO2 being released by burning of the wood or its products. The CO2 capture ability of large trees is said to be increased over that of smaller tress of the same kind."
As trees age they enter a stage called senescence, like senile. At this point they are no loger increasing in size and eventually the reversal process is emitting more CO2 than is taking in.
Eventually decay consumes the rest. By that time replacements are taking over so that the net emissions average out.
There is much more sequestration to the soil biota than the above ground parts we see, but there are limits there too, as with the ocean it becomes saturated.
The old growth forests (say 100yrs +++++)are known to have sequested about 4~10``20 times? compared to plantation situations. That is the limit is reached and maintained at the higher rates.
Plantations will be taking up a lot more, as they are grow and consume CO2. However the science shows the highest long term benefit comes from those old forests.
This is the soil component 4 to 20 times more than the plantation or disturbed lands. We also lose bio-diversity and hence the resilience of the ecology is compromised.
The acumulated loss of forest lands to agriculture, or any other disturbance creates extra CO2 near order of magnitude greater than we require to sort all our CO2 reduction targets.
This gets to the point you make about coppocing.
"It is concluded that a male tree became established at Lake Johnston at least 10,500 years ago, and has been propagating itself vegetatively ever since, so that the identical genes survive to this day. How it got there originally is an open question, but as carriage by birds or by wind-blow are unlikely, it most probably arrived during the last Interglacial (about 30,000 years ago) and somehow survived through the Last Glacial period. The main method of growth has probably been by layering – A Huon valley pine? Tasmania, are shown to be 4,000 years old and all clones of the one plant arising from the original root system."
also: "At 31,000 ha, the Border Ranges National Park is World Heritage listed, and together with Lamington National Park, the two adjoining parks form the largest sub-tropical rainforest in Australia, with 521 varieties of rainforest tree. You will see the 8,000 year-old Antarctic Beeches, and have a barbeque lunch "
" There are trees all around us, but they are usually under 200 years old. ... cones and wood - found its root system had been growing for 9550 years. ..."
Posted by: arnold | 10 October 2009 at 04:21 PM
Whether we use fossils for energy production or not, we will always have a lot of (toxic and non-toxic) organic waste that needs to be destroyed. so, we can as well capture and burry (or reuse) the CO2. We will need to take out of the air billions of tons of CO2 put in by former and actual generations. Though there are several ways to do it, waste and biomass sequestration may be an interesting method. The only two ways for long-term biomass-carbon sequestration are subsurface sequestration and agrichar. Both can be done while pyrolising biomass for producing biochar, H2 and CO2.
We can simultaneously reduce atmospheric CO2, treat waste-streams, produce H2 (or electricity) and restore the soil.
Consider this (coal)-carbon sequestration the first step.
Posted by: Alain | 11 October 2009 at 05:07 AM
using a 1.7-megawatt (electric) slipstream from the plant
Uhhhm, am I the only one to notice that 1.7 MW is 40.000 kWh per day. With an emission of 1 kg CO2 per kWh for an average coal fired power plant, this process captures as much CO2 as it produces. Net effect: 0.
Please someone point out my error. I must be missing something.
Posted by: Arne | 11 October 2009 at 05:15 AM
We can have unfunded mandates demanding cleaner coal, or we can help them clean it up. It is much better to do IGCC, where we can get the mercury and sulfur out BEFORE it is burned and goes up the smoke stack, but it costs money. Since everyone breaths the air and we would like to be able to eat the fish, it is in the general public interest to help them clean it up.
Posted by: SJC | 11 October 2009 at 09:54 AM
The 1.7 MW electric slipstream refers the amount flue gas from 1.7 MW electricity production. It's a weird metric, I know, but it makes sense to those of us in the power industry who work with carbon capture. It is indicative of the size of the plant.
They are not sequestering any CO2 because this test plant was made for demonstrating that chilled ammonia can remove CO2 from flue gas. The next size (20 MWe) will demonstrate how well this technology scales and give a more accurate prediction of the real energy consumption of this process.
Actually sequestering the captured CO2 would require a massive investment while not making any real difference anyway. The Norwegian government has realized as much in their larger carbon capture demonstration at the Mongstad refinery (not yet built), which was initially intended to include sequestration but that got dropped because of enormous cost for a small total amount of CO2.
As someone who works with carbon capture from coal fired power plants for a living, I have to concede that CC is a questionable concept - why not go directly to renewable is a question that keeps popping up. However, with coal fired power plants responsible for 40% of man-made CO2 emission, it is difficult to do something real about emissions reduction without addressing these sources. It is also the easiest point sources to identify and do something about, although it will increase the cost of electricity production from coal fired power plants by 50-100% (CAPEX and OPEX).
Posted by: Thomas Pedersen | 11 October 2009 at 01:17 PM
Thanks for the explanation Thomas.
Posted by: Arne | 12 October 2009 at 01:05 AM
Yes, Anne, you are right. It takes about 0.5 kg of coal to make one kWh of electricity; burning of 0.5 kg of coal emits about 1 kg of CO2. So this process captures all of the carbon dioxide generated in the process. With CCS, no CO2 will be emitted from such plant.
Posted by: black ice | 12 October 2009 at 02:20 AM
I'm tired of all this bull. Bring on a straight carbon tax. Sometimes you have to make unpopular decisions. It's the right thing to do.
Let coal, oil and gas lobbies bleat their little hearts out. They have enjoyed a good run.
It's all over for fossil fuel. Just die quickly and gracefully.
Posted by: Carlos Fandango | 12 October 2009 at 02:39 AM
Why not inject magnegas into the coal fire stream to cut the co2 and co emissions? You can use city waste water to make the magnegas.
Posted by: aironeous | 12 October 2009 at 07:34 AM