Biomass Magazine webinar highlights on-campus AD systems

By Chris Hanson | September 03, 2013

Roughly 500 participants tuned into Biomass Magazine’s webinar on Aug. 29 to learn how anaerobic digesters are being incorporated into U.S. college campuses. The event was sponsored by SeaHold and Team Biogas.

Clemens Halene, CEO of Quasar Energy Group, showcased its technology at Ohio State University. At the anaerobic digester (AD) site in Wooster, Ohio, Quasar’s technology consumes municipal waste streams and food feedstocks to produce biogas, which is used to generate 600 kilowatts, or roughly 50 percent of the campus’ energy needs. Originally, the site used manure sourced from agriculture operations but evolved to take additional organic waste streams.

“It’s a great marriage between business and academics,” Halene said. “Ohio State really gave us credibility when at a time we probably didn’t deserve it yet, because we were just a startup company putting in the first digester.” He added they now have three to five tours every week and with roughly half of the attendees being from out of state. So far, Quasar has built 10 digesters and will finish six additional units by the end of the year.

In addition to generating electricity and heat, Halene discussed how the project is furthering bioenergy education at the campus. In partnership with the Agriculture Technical Institute, Quasar developed a curriculum, which Halene said benefits students with access to the engineering offices and laboratories to complete the training.

Michigan State University’s AD project was the next featured project in the webinar.  Dana Kirk, assistant professor and manager of the Anaerobic Digestion Research Education Center said the center was founded in 2008 to research, evaluate and educate integrated AD systems for small and medium-sized facilities. “We also offer operator training program that has Michigan certification, but is open to people nationwide interested in operating digesters safely and successfully,” he said.

Kirk demonstrated how AD technology is a good fit for Michigan State’s campus where 23,000 to 25,000 tons of organic waste are generated on campus each year. “Most of that comes from manure,” Kirk explained. “So out of the 51 sources, 92 percent of the total mass is manure based and 7 percent comes from the food side.” The plant gets its feedstocks from a variety of sources. In addition to diverting roughly 500,000 pounds of food waste from the campus, Kirk explained a dairy farm delivers roughly 7,000 tons of manure, a distribution center provides 4,000 tons of food waste and a local grease trapper provides waste fat and oils to the site each year.

Mary O’Leary, project manager of Vermont Technical College’s AD site, explained how the college will be demonstrate biogas technology while meeting the aesthetics of Vermont’s picturesque environment. O’Leary said the project started as a collaboration of two professors and six students in 2006 to 2007 and began construction this July.

O’Leary said the biogas will be run through a genset to generate both heat and power. The campus will be phasing in heating projects over the next few years to include a facilities building, a lecture hall, a dormitory and even the campus pool. 

The AD was designed by Bio-Methatech and built using Lipp technology from Germany. O’Leary said the way the Lipp technology works is that the steel is “spun” onsite with interlocking edges to form the tank. “It’s a ribbon of steel, the roof goes on the concrete pad and then the steel is spun up as you go,” she said. “It’s pretty fascinating technology and us geeky engineers really, really enjoy it.”

Feedstocks for the system will be from 51 percent agricultural and 49 percent residual sources. O’Leary said current permits require the residuals be nonfarm organics and cannot be post-consumer food scraps. “We can only take in food processing waste -- so yogurt whey, brewer’s waste, things like that,” she said. She added that the site is working on other permits to include higher energy feedstocks, including food residuals.

Because of the plant’s location near the historic Randolph Village, O’Leary said some neighbors were concerned how the site might affect the local aesthetics. “Luckily, the tanks actually look very close to silos,” she said. “Also, our building construction is going to look like a barn so that it fits in with the rural scenery.”  The facility is expected to be completed early this winter and operational by January 2014.

The last presenter, Greg Kleinheinz, the associate dean and professor of microbiology from the University of Wisconsin- Oshkosh, spoke about the college’s dry fermentation projects. He explained the campus’ first project, BD1, began construction in 2010 and has been operating for roughly two years. BD2, a wet digester, is scheduled to begin operation in 2014.

BD1, located next to Oshkosh’s waste water treatment plant, primarily utilizes pre-consumer food residues, biological waste and grasses as the feedstocks of choice to avoid issues with manure runoffs and odor, Kleinheinz explained. He added the waste from the campus only provides 500 tons of the total 8,000 tons needed to operate the site; however, its location next to the city’s yard waste collection facility make up the bulk of feedstock collection along with agreements with local farmers and organic haulers.

The facility covers 19,000 square feet and features four fermenter bays that produce biogas for combustion in a combined-heat-and-power (CHP) system to generate roughly 370 kilowatts of electricity, which is sold to the grid through a power purchase agreement. The project also provides heat to the facility and local buildings.