Carbon capture: can it be efficient, cost-effective and commercial scale all at once?
The University of Kentucky Center for Applied Energy Research (UK CAER) has a long record of researching carbon dioxide (CO2) capture technology. The research team at UK CAER partnered with several utilities in their region over the past two decades and recently installed a small pilot-scale CO2 capture facility at the Kentucky Utilities E.W. Brown Generating Station near Harrodsburg, Kentucky. It has been operational since 2015 and has over 4,800 hours of experimentation. The process circulates a liquid, called the solvent, to remove the CO2 from the flue gas and produce a CO2 product with an over 99.9 percent purity.
The Star-Tribune spoke with Kunlei Liu, principal investigator, and Heather Nikolic, co-investigator, about a carbon capture project that they plan to install at Wyoming’s Integrated Test Center with financial support from their utility partners and the U.S. Department of Energy.
The conversation has been edited for clarity.
Casper Star-Tribune: You are planning to execute the third phase of your research into capturing carbon dioxide at Wyoming’s Integrated Test Center. What benefits do you see the ITC providing for your research?
Kunlei Liu: Wyoming shares the same goal as Kentucky in keeping coal a viable source for energy production in an environmentally responsible manner. The Integrated Test Center is one of the few places in the world built to host and facilitate the scale-up of technologies so that commercialization can happen. So, we’re motivated to come to Wyoming because we want to advance our technology to deliver a more cost-effective carbon capture method and make it ready for commercialization. This scale-up step is critical to minimize commercialization problems and maximize the chances of success.
Star-Tribune: What are you going to be doing at the ITC?
Liu: We are going to construct and operate our carbon capture process at the 10 MWe scale. All of our carbon capture technologies have been thoroughly tested at our small-pilot facility in Kentucky. At ITC we will be treating 15 times more flue gas with a process that is about one-half an acre in size.
We are always asking, “How do we reduce the cost of carbon capture?” We will test our modular configuration in Wyoming, continuing to reduce the capital, installation and operating costs with maximize electricity generation output.
Star-Tribune: Can you tell me a bit more about the technologies you plan to introduce and scale up?
Liu: To give you some technical details, we have developed a unique, solvent-independent carbon capture process with heat integration, compact columns, two-stage solvent regeneration, a split-rich primary stripper feed, advanced process controls and an energy loss minimization strategy. Our project is unique because these technologies work synergistically to strike a balance between the capital cost and the energy demand needed for CO2 capture. This may sound complicated, but it’s analogous to replacing the steel used in cars with plastics. It makes the vehicle fuel efficiency better.
Star-Tribune: What makes what you’re researching in the field of carbon capture unique?
Liu: At the beginning of carbon capture research, everyone was working on the solvent composition to reduce the energy demand needed to capture the CO2. They thought the solvent was the dominant factor to impact the carbon capture cost. So, they focused on this one element. Our philosophy is to reduce this energy demand close to what everyone else has done, but with a much lower capital investment. We consider all aspects: equipment sizing, process simplification and integration, heat recovery, the solvent composition and flexible operation. If you look at other technology developers, their process is designed specifically for their own solvent. Our process will work with most solvents. This is like having the freedom to buy a lower cost generic brand.
Heather Nikolic: Like Dr. Liu said, this is a robust process that we’ve developed here, with many focuses. It’s solvent independent, meaning that it works well with most available advanced solvents. It’s also a heat-integrated process, meaning we reuse waste heat that just typically is lost. We also apply several process intensification technologies to make the equipment smaller. Finally, I would just like to say that we’re very excited for the opportunity to be working in Wyoming and we’re looking forward to continuing our great relationship with the Integrated Test Center.
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