Two years, two million DKK and two parties, each of which provides the best from research and applied technology. These are the elements that make up the commercial research project that Babcock & Wilcox Vølund and DTU Risø entered into on 1 April 2015. The goal is ultimately to extract even more electricity from the waste combustion process. It requires technology that can withstand even higher temperatures – without corroding.
"A very important competitive parameter for us is a high level of electrical efficiency. The greatest obstacle when it comes to increasing electrical efficiency is superheater corrosion, which is brought about by high steam temperatures. That's why we want to develop a special corrosion-resistant coating for the superheater's pipes. The goal is to develop a material solution that makes it possible to increase the temperature from the current maximum of 440°C to 500°C,” says Lars Mikkelsen, R&D engineer at Babcock & Wilcox Vølund, about the joint research project.
The project's key players in front of the testing equipment at DTU Energy. Pictured, from left to right, are: Ming Chen, senior researcher at DTU; Thomas Norman, head of R&D, Babock & Wilcox Vølund; Sebastian Molin, industrial research postdoc candidate, DTU Risø; Peter Henriksen, professor at DTU; and Lars Mikkelsen, R&D engineer, Babcock & Wilcox Vølund
"We're collaborating with DTU on this commercial research project because of the huge benefits, which it offers to both parties. We gain access to the university's expertise and facilities, such as laboratories, and they receive additional resources for their research work," Lars explains.
The two-year project was launched in April and will cost just under 2 million DKK, which will be financed by Babcock & Wilcox Vølund, DTU and Innovation Fund Denmark. Lars Mikkelsen is Babcock & Wilcox Vølund's technical manager for the project. The project's leading research profile is that of Sebastian Molin, a postdoc student and researcher at DTU Risø who possesses a great deal of experience with both heat-resistant coating and corrosion. Needless to say, he holds an ideal combination of skills for the task at hand.
"Sebastian's profile is ideally suited to the development work, and he also works at DTU, which has accumulated a wealth of knowledge about resistant coatings from areas like fuel cell technology. They know a lot about the materials, and they know a lot about how to apply the materials in layers that are dense and highly adhesive. They also have thermodynamic models that can simulate the reactions of various materials in a given environment, which makes it possible to identify promising materials. For example, we will be able to see how much certain materials will corrode in the flue gases found in the boiler at the energy-from-waste plant," Lars explains.
The project will comprise three phases. First, simulations of the thermodynamic models will identify the most promising materials. Next, the selected materials will be tested in the laboratory. And finally, full-scale testing will be carried out at AffaldPlus, an energy-from-waste plant in the Danish city of Næstved. Here, researchers will be able to determine how and the extent to which corrosion occurs over time at different temperatures.
"One of the most promising materials so far is aluminium oxide. It's a ceramic material that is very resistant at high temperatures. One of the things we need to figure out now is how the coating can be applied. It can either be applied as aluminium oxide or as an alloy with aluminium, which then forms aluminium oxide in a sufficiently dense layer when it is heated," Lars expounds.
As applied as can be
Sebastian has several years of research experience with ceramic surface coating for fuel cells, and he is very much looking forward to the professional opportunities created by the close partnership between the university and private enterprise. Over the next couple of years, he will be able to move freely between the lab and the real world. In his own words, "it's as applied as industrial science can ever be."
"We are only at the very beginning of the cooperation, and we might not solve it all in two years, but I have quite a few ideas on how to make the coating work, in order to prolong the lifetime of superheaters and protect the superheaters at higher steam temperatures, thereby increasing electricity production," Sebastian remarks.
Sebastian Molin in brief:
Sebastian Molin is from Poland, where he completed the degree as Master of Science in Applied Physics (2007) and wrote his thesis on "Energy Conversion Technologies and Fluid Dynamics." He completed his PhD in 2011, after which he was offered a postdoc position at DTU Risø, Denmark, in 2012. On 1 April 2015 he became an industrial researcher at the DTU Risø's Department of Energy Conversion and Storage.