December 3, 2011

Ky. power station to implement algae carbon capture project

The staff at East Kentucky Power Cooperative’s Dale Power Station in Winchester, Ky., is excited about a new project led by the University of Kentucky’s Center for Applied Energy Research that will bring algae photobioreactors onsite to the Dale Power Station starting this winter. Rodney Andrews, CAER director, spoke with Biorefining Magazine about the project and how his team hopes to overcome the common hurdles associated with using algae to capture CO2 flue gases from coal-fired power plants.

The project started three years ago in response to UK’s concern regarding the potential for future carbon dioxide regulation, said Andrews. The team at UK built small-scale systems to test the effectiveness of an algae-based carbon capture system. “Along the way,” Andrews said, “we haven’t run into any challenges that have said to us, ‘you can’t do this.’”

Now, through a $1.3 million grant from the Kentucky Energy and Environment Cabinet, Andrew’s team will be able to scale up its 1,000-gallon small stoker boiler lab system to a 4,500-gallon system that runs off of flue gas 24 hours per day, seven days a week. Andrew’s team has expertise in integrating with power plants, he said, and the team has already addressed many of the challenges associated with a large-scale system at the Dale Power Station location. Because the amount of land needed to make a system economical is too large for an open pond system, the system used by the UK team will feature an array of photobioreactors. The team, he said, “is really focused not on fuel production in terms of the amount of oil in the algae,” but rather “we are looking at how to strip the most carbon dioxide out of the flue gas feed as quickly as possible. It is all about how we maximize biomass growth.”

Andrews describes some of the challenges in designing a commercial-scale system that could effectively capture emissions as an issue of understanding how to balance the light differences during the day and night, or how much flue gas can be fed into the system during nonoptimal growing times without creating an imbalance in the pH level of the algae water. But, those issues also come with an opportunity, he said. “We have a source of flue gas that is always there, and always at the same source of concentration.” Because of that, he added, the team can better understand how much CO2 could actually be removed.

The system to be run at the power plant isn’t one unfamiliar to the team. “We’ve actually been running techniques that we are very familiar with because of the work we have done with mineral processing with coal preparation,” Andrews said. The process is flocculation, the method used to harvest the algae and dewater the algae into a thick slurry created by settling over time.

Other teams at the university are currently working to develop more efficient harvesting and dewatering processes, as well as uses for the algae biomass that Andrews said could be used in anaerobic digestion to create methane that could then be reused at the power plant.

The East Kentucky Power Cooperative will provide $75,000 to the early stages of the project, and UK will provide $543,663, all to build the photobioreactor system and staff the project. During a press conference to announce the project, several high ranking Kentucky officials attended, including Governor Steve Beshear, and EKPC’s CEO Tony Campbell. “This research is vital to EKPC and to Kentucky’s economy,” said Campbell at the event.

“We have a long history of working with Kentucky power,” Andrews explained. “When he (Campbell) came in as CEO a few years ago, one of the first things he did is ask, ‘Do you have any projects you want to try at Dale?’”

Andrews said in the spring of 2012 they will significantly expand the project, and eventually the team will have to bring in an outside source to build a larger system.

To learn more about the project, click here.

Original article available here.

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