Reprinted from Herald Times, November 18, 2017
This clear PVC tubing structure filled with algae and water is part of a project at the University of Kentucky’s Center for Applied Energy Research. A similar structure will be used at Indiana University’s Central Heating Plant. (UK CAER | Courtesy photo)
A $50,000 grant from Duke Energy will fund a project at Indiana University to construct a structure of clear plastic tubes filled with algae that will convert emissions from the university’s power plant into fertilizer.
Mark Menefee, assistant director of utility services at IU-Bloomington’s Central Heating Plant, and Stephen “Chip” Glaholt, an adjunct instructor and lab director with IU’s School of Public and Environmental Affairs, came up with the concept. Menefee has done research using algae at the power plant before, in which he documented algae absorbing carbon dioxide.
In this new project, algae will use greenhouse gases, including carbon dioxide, nitrous oxide and water, to grow while on the roof of the campus power plant.
The algae then will be harvested and used as fertilizer in various flower beds across campus.
At IU, natural gas makes up 95 percent of fuel for the power plant, with coal powering only 5 percent. Only emissions from the natural gas portion of the IU plant will be used for the project.
Construction is expected to begin on Dec. 1.
Bruce Calloway, Duke Energy’s community relations manager in the Bloomington area, was positive when talking about the project.
“This is a very significant grant,” Calloway said. “I’ve given very few (grants) of this size in my territory,” which covers an area from Greenwood south to Salem. “I think this has wonderful opportunities.”
Calloway believes the project will have a big impact and be sustainable into the future. He also believes, as do Menefee and Glaholt, that the project will be easily expandable. “This is a living laboratory for students,” Calloway said.
It’s similar to a project currently underway at the University of Kentucky, although the plant there is coal fired and the product isn’t used as fertilizer.
The initial plan
Sequestering carbon dioxide — which basically means storing the gas for a long period of time so it is not released into the atmosphere — is one of the main approaches to trying to slow or stop global warming. The IU project will do that. Horizontal pipes will be cut into the power plant’s stack, leading to the structure with columns of clear PVC pipes on the roof of the power plant. The flue gases will bubble through the columns of pipes, which will be laid out in a serpentine pattern.
The bubbling of the gases is crucial, because that’s how the algae can absorb them. The aeration also keeps the algae suspended in the tubing.
“The flue gases have a high concentration of carbon dioxide,” Menefee said. “And the algae love it.
“Algae are a great biofuel,” Menefee explained. Already, businesses have used algae to make biofuels. One major problem is the time and cost of extracting water from the algae when making the fuel.
“Chip (Glaholt) had the idea to use the algae with the water,” Menefee said of their project.
The concept is to pump emissions and water vapor from the power plant into tubing where algae are growing. The emissions will feed the algae through the process of photosynthesis, converting carbon dioxide and nitrous oxide into algal biomass and oxygen, which will be released into the atmosphere. As the algae grows, it will be harvested and used as an organic fertilizer in more than 200 flower beds on IU’s campus.
Besides being organic, the algae fertilizer will help sequester carbon dioxide and nitrous oxide because the algae’s molecules are large and are more likely to stay in the soil for a long time, Glaholt said. “We’re really putting it back in the ground where we got it from.”
One advantage to the algae fertilizer is that it has both quick-release and slow-release components, Glaholt said. Quick-release fertilizers offer nutrients to plants right after they are applied. For the algae fertilizer, there will be some nitrogen and phosphorus in the liquid portion, which provides nutrients to plants as soon as it’s applied. The solid portion of the fertilizer, which will be the major portion of what’s produced, will be released at a much slower rate, providing more long-term nutrients to plants.
“We’re really excited about this being the best fertilizer,” Glaholt said. The fertilizer will be placed on flower beds at IU, although more applications for the fertilizer could be added in the future.
Glaholt estimates that 200 pounds of carbon dioxide will be taken out of the power plant during the summer months, with less being used in the fall and spring, when there will be less sunshine helping the algae to grow. By using heat waste from the plant in the winter, the project will be able to operate year- round. Glaholt is hopeful there will be enough light in the winter to allow for a 50 percent to 75 percent growth rate of the algae. If that amount is possible, he expects around 1,000 pounds to 1 ton of carbon to be sequestered annually. There are plans to double the capacity of the photobioreactor system in the second year of the project, Glaholt said.
The possibilities
Menefee, Glaholt and staff and students at IU hope to add to the system in the future and expand its reach.
“The biofertilizer is just the low-hanging fruit,” Glaholt said.
He hopes the organic fertilizer will mean less chemical fertilizer is released into the Jordan River that flows across IU’s Bloomington campus. That would not only reduce chemical runoff, but would mean there would be fewer algae blooms downstream. He also wants to eventually reach out to area farms that have community-supported agriculture operations and to explore aquaculture possibilities.
“This is a learning lab for everyone,” Menefee said.
Team members
The team that worked together with the proposal and plan for the project include:
- Mark Menefee, co-leader, assistant director of utility services at IU-Bloomington’s Central Heating Plant.
- Stephen “Chip” Glaholt, co-leader, an adjunct faculty member and researcher in the Indiana University School of Public and Environmental Affairs.
- IU students with the Net Impact team, who are undergraduates in the Kelley School of Business: Maddie Corgiat, Nikhil Prasad and Bailey Kaplon.
Net Impact team leader Megan Yoder died about two months ago after a long fight with cancer. A ceremony to highlight Yoder’s dedication and contribution to the success of the project is being planned for early this summer.
- Students with IU’s School of Public and Environmental Affairs who helped with design and research for the project include: Darah Meister, Tucker Jaroll and Anna Groover.
Other IU faculty:
- Mike Girvin, manager of landscape services at IU-Bloomington, who will manage the application of the organic fertilizer on campus.
- Mia Williams, IU landscape architect, who controls where the fertilizer can be applied on campus.
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