Tamar Hallerman
GHG Monitor
7/3/13
Alstom is vying for additional Department of Energy funding to scale up its chemical looping pilot plant in Connecticut. The French technology company said it recently applied for National Energy Technology Laboratory funding under the second round of the lab’s advanced oxy-combustion R&D program, hoping to win multiple years of grant money to help support the technology Alstom says can “significantly” reduce the levelized cost of electricity generated from such facilities. Alstom’s chemical looping technology “really looks like it has the potential to be somewhere between a 10 and 30 percent—and we think closer to 10 percent—increase in the cost of electricity, which means that we’d come in under DOE’s goal of 30 percent and maybe toward the ultimate prize of 10 percent,” said Bob Hilton, Vice President for Power Technologies for Government Affairs at Alstom Power. “It’s an exciting step forward.”
Hilton said in a recent interview that Alstom has submitted a proposal for additional NETL funding to scale up its 3 MW
pilot unit in Windsor, Conn., to a 15-to-20 MW facility for another multi-year demonstration period. The company received a $1 million grant from NETL last summer under the
first round of its oxy-combustion R&D program to test the unit, which utilizes a calcium sulfate-based system as an oxygen carrier in circulating fluidized bed ash instead of the metals-based systems that others are testing elsewhere. “We see significant advantages to the calcium-based system economically. It’s a very cheap and readily available free agent … when you look at metals like copper, they’re very expensive and much more difficult to handle, so we think this is clearly the best route that will be successful,” he said. To date, the 3 MW pilot has operated for 350 hours, including 45 hours under autothermal operation, the first facility of its kind in the world to do so, according to Alstom. “By demonstrating autothermal operations, we’ve showed that [such a facility] can ignite and maintain itself without external influences,” Hilton said. “That’s a huge step forward.”
DOE Accepts Bids for Second Round Funding
Alstom was one of eight teams working on oxy-combustion capture technologies to receive a slice of $47 million worth of round one funding from NETL last summer, which focused on engineering and economic analyses of the technologies. DOE has said, though, that the second round of the program would center more on moving the technologies toward commercialization. An NETL spokeswoman confirmed that the lab recently received applications from technology developers vying to move into a second phase, but would not provide further details on the procurement’s size or value.
DOE has been pursuing chemical looping technology for the better part of the last decade, frequently listing the technology as one of the most promising of the “second generation” of carbon capture technologies, especially since it does not require an air separation unit. This week, chemical looping was
listed as eligible for a slice of up to $8 billion in new loan guarantee authority under DOE’s new draft solicitation for advanced fossil fuel-based technologies
.
Chemical looping is considered a form of advanced oxy-combustion technology since it aims to combust fuel in a pure oxygen environment, producing a flue gas which largely contains just CO2 and water vapor. But while oxy-combustion typically uses an expensive air separation unit—which carries a large energy penalty of 15 to 20 percent of the power plant in addition to another 6 to 7 percent energy penalty for CO2 compression—chemical looping ditches the separation unit and instead uses two circulating fluidized bed reactors, one for air and one for fuel. The first reactor loop reacts the coal with a solid oxygen carrier—either a metal oxide like iron, nickel or copper, or an alkali such as calcium sulfate—at high temperatures to make CO2 directly. Meanwhile, the second reactor regenerates the solid oxygen carrier, which has been depleted of its oxygen, by a reaction with the air and then transports it back to the fuel reactor so that the process can be run again, leaving pure CO2 that is essentially ready for sequestration or processing. The process gives off heat, which can generate steam that can turn a turbine and generate electric power.
The technology, though, is still in its fairly early stages of R&D and will take years of more thorough testing and scale up before it can be seen as a real option for CO2 capture, experts say. But Hilton said that early pilot testing in Connecticut has made Alstom all the more excited about chemical looping technology. “We’re very enthusiastic and we see this as a really leading second-generation technology. It allows us to burn coal in essentially a zero-emission platform without the post-combustion or IGCC technologies that have become expensive,” Hilton said. “It looks like this has the economics we really need for new plants going forward.”
Competence
A majority of our activities include experimental research work, which takes advantage of our unique test facilities, strong experience and contacts covering the whole research community of Europe.
VTT is developing fluidized bed technology, e.g. based on supercritical steam values, in co-operation with the world’s leading fluidized bed boiler suppliers. The development aims to reach large CFB units up to 800 MWe. Process measurement and modelling methods are being developed in order to strengthen knowledge of the CFB process in all its complexity. The development of zero-emission power generation based on oxyfuel combustion in CFBs has recently risen to be one of the most interesting sectors in R&D.
The technological development of heating and power plants to secure a high level of plant availability and reliability in multifuel operation is one of the VTT’s key areas. VTT’s research activities focus on, for example, ash behaviour, the optimization of multifuel operation at power plants and emission reduction techniques.
In the area of grate combustion technology VTT co-operates with heat and power producers and leading suppliers of grate boilers. The objective of the work is to improve availability and performance of boiler plant utilising grate combustion, and decrease their emissions. This, together with improvements in fuel quality, handling and feeding processes, will strengthen the operational competitiveness of grate combustion.
Challenges
- Increase power plant efficiency and availability
- Reduce the cost of heat and power production
- Reduce all emissions including CO2
To do this with wider fuel selection and poorer fuel quality, e.g. with challenging biomass fuels and wastes
Solutions
- Improve ash behaviour control during combustion by applying a chemical addition −> Improved plant availability and reliability
- Development of new monitoring and calculation methods to optimize multifuel operation at power plants −> Cost reduction
- Development of advanced supercritical CFB technology (OTSC) and scaling up CFBs to 600-800 MWe −> Increasing efficiency
- Zero-emission power generation technology based on oxyfuel and chemical looping combustion −> Emission reduction
