By Scott Pohl, WKAR News
http://stream.publicbroadcasting.net/production/mp3/wkar/local-wkar-938309.mp3
EAST LANSING, MI –
Michigan State University has labeled its environmental initiatives "Be Spartan Green."
Designers of the Brody Hall renovation project, completed earlier this year, took that to heart.
WKAR's Scott Pohl reports on the new food service area at Brody Square, where today's leftovers could be turning into an energy source for tomorrow.
AUDIO:
Thousands of students at Michigan State subscribe to the university's dining hall meal program. That's a lot of banana peels and half-eaten sandwiches, most of it sent through garbage disposals and on into storm sewers.
Is there a better way? Can this stuff be made useful?
Officials at MSU are hoping to answer that question with a yes, and the first step is a food pulper installed at Brody Square.
"The pulper is a machine intended to lessen the use of water and to pulp the material so it's ready to be used for another application."
That's Diane Barker, assistant director of campus living services at MSU. She's showing me how the system here works, starting with the accumulator where diners place their trays when they're done eating. It's essentially a vertical array of racks, stacked five high, that moves from the food service area back to the cleanup area.
As the trays pass, workers dump leftover food into a trough of moving water. The water carries the food into the pulper, and the water is constantly recycling.
"The pulper can take paper, OK, and it can take most food waste," Barker says. "We have to be careful with too many bones or big pieces of grapefruit or whatever, because it could clog it. Obviously, we've put some traps on it to keep the dishes from going into it because initially, we had some issues with that, so we had to put some bars on there to help that out."
Barker says the pulper grinds up the waste and extracts most of the water. What remains is dropped down one floor to a collection bin.
"You know, the good part about it is it's dense," Barker says, "and the liquids are out of it for the most part. It's fairly dry. It's almost like a sawdust, a food sawdust."
The Brody pulper is cranking out about 3,000 pounds of this stuff every week.
TURNING FOOD PULP INTO ELECTRICITY?
That brings us to the research being done with this material. There are thousands of reactors, called digesters, using organic material to produce power all over Europe.
"Food waste from a cafeteria, from processing plants, has a lot of embedded energy in it, and if we can take that food waste and, instead of putting it into a landfill, put it into a reactor and get energy from it, then we're taking it back to a useful purpose."
Steve Safferman is director of MSU's anaerobic digestion research and education center. He and his team are trying to find out if food waste can be used as a reliable, productive component in the production of electricity.
So what we do is, we mix it with different waste that's coming from the university, anything complex, organic waste, like the manure from the dairy farm, material from the bakery, cheese waste, and if we can put it into a reactor and optimize that blend, we could potentially produce energy," Safferman says. "We also reduce greenhouse gases by taking the waste and producing energy from it."
One issue to be dealt with is the variability of the pulp. There might be lots of cheese in it one day, and lots of rice the next, so Safferman needs to find a way to make it consistent.
The questions here go beyond the scientific, to include the economic.
Over the next year and a half or so, Safferman hopes to have enough information to make a recommendation to the university about the suitability of this material for the cost-effective production of electricity. The possibilities include power generation at the MSU dairy farm. It could be sold to other facilities. MSU could then install more pulpers at other food service areas on campus.
If making electricity isn't the end result, the methane gas produced could be burned for heat. There could be an application as a fuel in vehicles that run on natural gas. Safferman also says the food pulp from Brody could go into the production of animal feed.
All of which seem "greener" than sending all of that uneaten food down a disposal.