Franco Milani: Squeezing fuel from cheese whey
[audio:https://news.cals.wisc.edu/wp-content/uploads/2011/05/franco_milani_whey_energy.mp3|titles=Franco Milani: Squeezing fuel from cheese whey]
Now you can squeeze fuel out of cheese whey!
Franco Milani explains in our podCALS this week.
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Franco Milani
Extension Food Scientist
Department of Food Science, Center for Dairy Research
UW-Madison College of Agricultural and Life Sciences
(608) 890-2640
(608) 262-3046
milani@wisc.edu
Energy recovery from cheese plants
Time – 2:46 minutes
0:18 – Squeezing energy from cheese whey
1:15 – How energy extraction works
1:37 – Economic value of recovered energy
2:05 – What remains after fermentation
2:25 – Food science interest in energy
2:38 – Lead out
Transcript:
Capturing energy at the cheese factory. We’re visiting today with Franco Milani, Department of Food Science, University of Wisconsin—Madison, in the College of Agricultural and Life Sciences… and I am Sevie Kenyon.
Sevie: Franco, welcome to our microphone. Franco maybe you can introduce us to the business of recovering energy from the cheese-making process.
Franco: Wisconsin produces over 25% of the cheese in the nation. From 100 pounds of milk you only get 10 pounds of cheese. You get 90 pounds of whey associated with it. And what’s very perplexing about whey is that it’s got a low solids content and it’s highly perishable… so you’ve got to be able to do something with it now, before it spoils on you and also that technology of doing something with it now is fairly expensive. So even here in Wisconsin we have small to medium sized plants that really can’t afford a lot of that equipment. So, what we have is a situation where we’re actually disposing, as best we can, those valuable ingredients.
We asked the question, well, can we derive energy out of it? And so our research is showing that if I’m here with 100 pounds of whey there’s about three cents of natural gas and that converts to about 12 cents of energy in 100 pounds of whey.
Sevie: And so, Franco, how does the energy extraction process work if someone were to look at that route?
Franco: Well the energy extraction process is that you close it down and let it go anaerobic and at that point the bacteria, when they’re looking for oxygen will actually reduce a lot of that carbon in there and they produce methane and other sort of reduced hydro-carbons that are available for energy and very equivalent to natural gas.
Sevie: And Franco, what is the potential value or return to that plant?
Franco: The way I look at it, you’re always guaranteed that energy’s there for as long as your operation is working correctly. Our estimates are showing that we’re talking anywhere between 25-50% of the energy replacement in the typical plant size. And actually, at 25% or lower, you don’t need a lot of special cleaning of the biogas, you can just inject it into your natural gas lines and use it direct with only minimal amount of clean-up.
Sevie: And Franco, after the fermentation process and the methane…what’s left?
Franco: Well, after you ferment off the carbon we would say… the organic compounds within whey, what’s left over is the minerals from milk, so these can be use to help fertilize lands with phosphate otherwise they go into a normal surface water discharge just as we’re doing now with our milk whey.
Sevie: So Franco, why is a food scientist interested in energy?
Franco: The reason why we became interested in energy is because we’re able to take some of our waste byproducts from our food manufacturing and convert those into energy… we actually lower our carbon foot-print, which makes our products even more desirable.
Sevie: We’ve been visiting with Franco Milani, department of Food Science, University of Wisconsin, in the college of Agricultural and Life Sciences, Madison, Wisconsin… and I am Sevie Kenyon.