Nils Haugen from SINTEF is the project coordinator of the Chinese European Emissions Reducing Solutions (CHEERS) project. Apart from overall management, Nils oversaw the technical and scientific progress of the project. In this interview, he shared some key insights from his experience with the project over the last six years.
Were there any key milestones in this project that you would like to showcase?
“There have been several. One thing was that we got the cold flow unit up and running and got to test the fluidization. That was a very important validation of our design models.
Then of course it was the Front-End Engineering Design (FEED); finalization of the FEED showing that this [carbon capture with chemical looping combustion] could be done. As a follow up on that, a very important milestone was to actually agree on the cost sharing, which led to the final investment decision. That was a big milestone I would say. Of course, the commissioning was also a big step. Now we have finalized commissioning, and the unit is standing there and is currently in the startup phase.”
How long will the demonstration unit be running for?
“We will do the testing of the pet coke design first. This will probably go on through this year. The project formally ended by the end of September but we will continue some months longer than that to be able to finalize the testing. And then, after the pet coke design testing has been finalized, the lignite testing will start, and I guess it will continue for maybe half year.
I also expect, this will not be within the CHEERS project though, that some of the core partners will continue with other feedstock, for example biomass, or other oxygen carriers.”
How did the findings of the project contribute to the development and improvement of carbon capture processes?
“I think the big step that is being made by CHEERS is that we are building the world’s largest CLC unit, up to 4 MW, to bring the technology closer to commercialization. Another very important thing is that the unit is designed and built based on commercial engineering principles; it’s not set up to be used in a lab.
So, when you look at the demonstration unit as it’s standing now, the first commercial unit will probably look pretty similar when it comes to its main design and height. The main differences will be that for a commercial unit the two reactors will have larger diameters and there will be less measurement ports. I think that is the biggest contribution here; that we are showing that CLC can be utilized on a commercial and industrial scale.
Also, what we have shown in the technoeconomic assessment is that when it comes to solid fuels the CLC technology will be beneficial, certainly over any kind of amine-based capture methods. It looks very good for solid fuels; and CLC is the optimal option for (CO2) capture when it comes to solid fuels.”
How does this technical research contribution fit into the broader climate change mitigation picture?
“I think there are some very important places where the CHEERS technology can really contribute.
For example, if you want to do BECCS (Bioenergy with Carbon Capture and Storage); so, you want to burn biomass, which is a solid fuel and it’s really ideal to have a CLC unit for CO2 capture with biomass.
It also seems that for many kind of wastes, like these pretreated wastes that can be fed into in the unit, it will also be a good option for producing heat and power with inherent CO2 capture. Furthermore, we of course have the same benefit if you look at waste such as pet coke. Finally, it also seems that there could be good potential for gasification or reformation, for example for blue hydrogen production.”
The oxygen carrier choice, is it still beneficial for biomass?
“Yes, if we had been using biomass, Ilmenite would still be okay. But we may actually have chosen a different one because there are some synthetic oxygen carriers that show very good performance. But those that we tested did not tolerate the sulphur levels of pet coke, which is rich in sulphur. But for biomass those kind of synthetic oxygen carriers that we studied in the beginning of the project really seemed to have a huge potential. They are significantly more expensive, but the lifetime will be much longer and there will be less waste to handle.”
How can the technical knowledge accrued in this project be used in research and innovation?
“There are two pathways that I think should be pursued. One is to take the technology of CHEERS and scale it up. This means to build the first commercial unit, which could have a size of around 30-50 megawatts. I think that would be the most important next step.
The other thing is to not upscale, but to show that we can do for example the blue hydrogen or BECCS at the same scale. This means that the same CO2 capture process and knowledge accrued in the project can be used for different applications.”
Has your work identified any research gaps that needs to be addressed?
“One thing is the oxygen carriers. We need to identify which one should be used at large scale. Also, what should be done with them afterwards? Can it be utilized somehow or are they just plain waste?
Another thing is that for upscaling purposes we want to be able to do accurate and reliable numerical simulations, which will allow us to do much cheaper parameter studies. But also very importantly, it is a very harsh environments inside these reactors. This means that it’s very difficult to have measurements probes in there. But if you can do good numerical simulations of these units, it will help a lot when it comes to understanding their inner workings. Identifying these numerical models is something we are already working on.
Another issue where there could be a research gap is utilising waste as a sort of fuel. We will have to do some pre-treatment of the waste, but how much pre-treatment do we need? We want to pre-treat as little as possible because pre-treatment is expensive. But at the same time, we want to be able to actually feed the fuel into the system and then it should be converted in the fuel reactor in an efficient way.
Another topic of interest is that, up to now, the vast majority of all testing with CLC has been done with well-defined homogeneous fuels. So, figuring out how to cut costs would be the next ask. One very beneficial aspect about CLC is that all the pollutants are in the fuel reactor while the heat is typically released in the air reactor. This means that you don’t need any heat exchangers in the fuel reactor where you have the troublesome species from the fuel. Instead, the heat production is in the air reactor, which is clean such that you avoid problems related to fouling and corrosion.”