Recovering Energy: Nothing Wasted, Everything Gained
After earning multiple degrees from MSU, Kirk joined the faculty at his alma mater. Energy is one area of interest. “Energy affects everything that we do in our daily lives.”
July 26, 2016
After earning multiple degrees from MSU, Kirk joined the faculty at his alma mater. Energy is one area of interest. “Energy affects everything that we do in our daily lives. As an engineer in biosystems engineering, we see energy as one of the three key elements for a successful and thriving society. The others being water and food.”
In the Field: Dana Kirk - Transcript
Kraig Ehm: Welcome to In The Field, a podcast originating from the College of Agriculture and Natural Resources at Michigan State University. I'm your host, Kraig Ehm. In this episode of In The Field, I'm joined by Dana Kirk, manager of the anaerobic digester at Michigan State University and Assistant Professor in Biosystems & Agricultural Engineering at MSU. Dana, thanks for joining me.
Dana Kirk: Thanks for having me, Kraig.
Ehm: Dana, where did you grow up and what was it like?
Kirk: I grew up near St. John's, Michigan on a small dairy farm. About 80 milking cows and heifers and some crops. It was just that small farm life, where my parents and grandparents and everyone worked off the farm, they had full-time jobs, and we did all the work related to the farm at nights and weekends, so it was a lot of long days shoveling manure and other stuff. But a good experience, and I'm still involved a little bit in dairy and raise a few pigs at our house once in a while, or did. Still active, I guess, on the small farm side a little bit. But yeah, it was a good experience.
Ehm: Now, the farm life, it taught you a good ethic, though, didn't it?
Kirk: Oh yeah, oh yeah. Like I said, lots of hard work, lots of small square bales and stacking them over your head and sweating it, and like I said, shoveling manure and everything else. It was a good work ethic and a lot of hard work.
Ehm: After high school, you received multiple degrees from MSU?
Kirk: Yes, I actually received all of my degrees from Michigan State. Started in Biosystems Engineering, or in Engineering, added a bachelor's degree in Animal Science, dual-majored in that. Animal Science was always an interest growing up on a dairy farm. But also the thing I liked about Animal Science was there was a lot of scholarship opportunity, and so not only did it fit my interest in combining engineering animal-related activities, but also provided a way to cover some of the academic cost. Once I completed my bachelor's degrees, I was working for Bill [Bickard 00:02:11] at the time, and he offered me the opportunity to do a master's degree in Biosystems, and so I spent another two years working with Bill on phosphorous recovery from dairy manure, separating phosphorous out and creating higher-value fertilizers. After that was over, I continued on to a PhD, again working with Bill, as I ended that PhD also working with Steve Safferman and some others in Biosystems Engineering. And that was focused on anaerobic digestion, converting manure, dairy manure, into energy, but also looking at how our dairy farms are run and how we can incorporate that. So I completed my PhD in 2009, and that's the end of the academic side of it, or at least the degrees.
Ehm: While working on your master's and your doctorate, you consulted?
Kirk: Yeah, in 2001, while I was working on my master's, animal agriculture was starting to see a transition in environmental regulation, and the Michigan Department of Environmental Quality and the EPA were starting to look at animal agriculture a little bit different, a little bit more scrutiny on how they manage manure. So some farms in Michigan were under a little pressure, and I just happened to be ...It was one of those things, right place, right time, where I was working on nutrient-related issues in dairy and we were approached by a dairy farm that was really being looked at, and they needed to apply for a NPDES permit, National Pollution Discharge Elimination permit. So that opened up the door to gaining some experience in permitting livestock farms. Once I finished my master's degree, the consulting really began to expand, and pretty much during my PhD I worked full-time consulting and did the PhD kind of on a part-time basis. But we took a small business that started with one dairy and grew to working with about 80 dairy farms, swine farms, bee farms, turkeys, around the Midwest in a few years. And eventually that grew large enough that we took it into a larger consulting business where we had a team of engineers and animal scientists and other general scientists that could do more or less anything related, from an engineering standpoint, anything related to animal agriculture. We could do permits and compliance, and we could design manure storages, and design facilities, and oversee the construction of those, and also look at other environmental issues related to animal agriculture. So that was a really good practical experience, that really allowed me to utilize both my engineering training but also my animal science background and my farm experience from my younger years.
Ehm: Do a lot of people related engineering and animal agriculture?
Kirk: I would say traditionally engineering and animal agriculture have gone together for a long time. If you think about all of the parts of a dairy farm, for example, the milking system, how the barn and the milking parlor are laid out so that the animals are allowed to flow easily, the waters, the TMR in the distribution of feed and how we store feed. They all have engineering aspects to them. It's always, though, that engineering's kind of in the back or behind the scenes. But in the last decade or so, the last 10-15 years, with this increased emphasis on productivity of our farms and performance, but also then environmental sustainability, I think the role of the engineer has become much more important in certain aspects of that farm. So, while the general citizen may not think of engineering and animal agriculture, we wouldn't be where we are at today as far as our modern farm systems without engineers.
Ehm: For those who don't know, what exactly is an anaerobic digester?
Kirk: Anaerobic digestion is a big part of my research in other operations here at the university. Anaerobic digestion is a mechanical system, but it utilizes natural microbiology, and so to me the easiest way to explain it to somebody that doesn't know is to say it's a cow stomach and intestine, or a person's intestine, taken out of the body and put into either a steel or concrete tank. So what we have is some vessel, like I said, steel or concrete, and it has a holding time, so if we put a gallon of material into a digester, anaerobic digester, it's gonna stay inside of that system, that vessel, for 10 days to maybe upwards of 40 days depending on the type of technology. And during that time, anaerobic microorganisms are allowed to grow, populate, and those microorganisms use organic waste, whether it's cow manure or food waste or distiller's materials from ethanol production, grass clippings, that's the food source for the microorganisms. So their ability to grow and thrive is based on what we feed them and the organic waste that we put in it every day. The important byproducts that we get out of anaerobic digestion, one if biogas, which is predominantly methane, it's the natural gas that we have at our houses. So it's a good renewable fuel source for us. We also get digestate, the undigested material that's leftover, and that's water as well as nutrients and parts of the organic waste that don't degrade in the digester itself. And that makes for a good carbon-based fertilizer. So it's a good opportunity for us to use that fertilizer, it's typically lower in odor, the nutrients are more plant-available than in their raw form. If you just took animal manure versus digestate, a corn crop this year is gonna use more of the nutrients that are available in the digestate. So it's a way for us to really recycle carbon, recycle manures and other organic-based wastes, and put it into a fertilizer form that maybe is a little bit richer or better than just the raw material itself.
Ehm: Why is energy so important?
Kirk: Energy is very important, and the forms in how we use energy of course are important. Energy affects everything that we do in our daily lives. As an engineer, an engineer in biosystems, we see energy as one of the three key elements for a successful and thriving society, the others being water and food. With those three elements, that allows societies to grow, thrive, be productive and prosperous. So, having stable and renewable as well as conventional sources of energy is important, to have the right mix, to have economical and affordable energy. But for us, anaerobic digestion and what we do produces energy, but the real value also to us is the ability to recover and recycle carbon and to really start to create potential fertilizer products that we can then make out of manures and organic wastes. To me, I think that's probably as important in that whole discussion as the energy part itself.
Ehm: Why is reusing waste critical?
Kirk: Well, it's another part of the efficiency/sustainability discussion and debate. At our houses, on an average day we generate about a half a pound to a pound of food waste, just food waste, not considering other waste that we generate. So when you start to look at that across the state of Michigan or the United States, that material really adds up. When you look at a dairy farm, we know that every cow produces about 150 pounds of manure and other waste every day. Again, it's a tremendous quantity of material that we don't wanna view as a waste. We wanna see what the opportunity is to utilize it.
Reusing these materials, keeping that carbon in cycle, keeping the nitrogen and the phosphorous, is really key. From our houses or our cities, they typically go to a municipal wastewater plant, and essentially drive it off to the atmosphere. In landfills, we put storage or disposal site, but the other nutrients, the nitrogen, phosphorous, are really lost forever. From the standpoint of phosphorous, that's a finite resource.
Ehm: Why should people be concerned about anaerobic digestion?
Kirk: Generally people are pretty supportive. We're addressing a lot of environmental and energy-related concerns. A digester uses about 10% of the power it produces in a way that we don't lose the nitrogen and phosphorous values. So we aren't harming the fertilizer value. It excites people and gets them very interested. There are challenges, though, with it. Renewable energy sources are more expensive than our conventional fuels. We're having to pull wet material, so again, the waste that we put into anaerobic digesters, it's normally 80% water or more. It's high in water, it's heavy, it's sloppy, it's smelly, it's garbage that most people don't wanna see or deal with. So it's challenging because we have to pull it from a distance. We're pulling, say the Michigan State Digester, for example, we're pulling material from Grand Rapids to Detroit. We're pulling over a wide swath of southern Michigan, and that's pretty common for anaerobic digesters that, if they're using material other than just the manure on the farm, or the biosolids at the wastewater plant, they're gonna bring material in from a long distance, and that has its challenges that go along with it. With energy prices being low, the technology is expensive to do, and so financially the systems are generally challenged. But the concept is good, I think it's acceptable to most people, the financial pieces of it are still a bit of a challenge, and that's where we spend a lot of time thinking and looking at.
Ehm: Where do you hope this type of waste recovery goes in the future?
Kirk: For me personally, I guess I would like to see us not putting organic waste in landfills anymore. There's too much of an opportunity to reuse that material and find beneficial reuses for it. We need fertilizer in all parts of the United States, our soils need carbon. And so if we can find ways to keep that material out of the landfills, make energy out of it, and then make high-quality fertilizers that crop farms or people can use in their yards, that's really the right use of that material. I think we're very close to being able to figure out how to do it in an economical way. The environmental and sustainability pieces are no-brainers, they already make a lot of sense. We also need to continue to always look at ways to reduce our waste, our organic waste especially, but there's only so much we can do there, so we really need the engineering solutions to find ways to utilize the material and treat it as a resource as opposed to a waste or a disposal.
Ehm: What puts a smile on your face every day when you come to work?
Kirk: I have the fortunate opportunity to work at Michigan State, which is a great place to work. But I have two offices, I have an office on main campus in the academic part, but my main office is on south campus close to the digester. I get to come in to that south campus part of MSU every day, I get to drive by the golf courses, pull up to my building, and park easily, which anybody who's on campus knows the challenges of that ... and look out and I've got the dairy farm across the street, and we've got cows in pastures, and university farms cutting hay around us and straw and wheat this week. I spend my days most of the time on a beautiful part of campus. I spend a lot of time working with undergraduates on the applied aspects of research and engineering, and so that's always a joy to see them actually working on real-life projects that they can talk about in interviews, and they actually get to put things together and build things that will be used in the field. So I like the location that I'm on campus, and I also like the opportunity to work with the undergrads and see them grow from their younger years to when they graduate.
Ehm: So you get a kick out of mentoring.
Kirk: I do, it's a fun part of the job. It's not something that I really had expected to spend as much time on when I took the position at Michigan State, but it's been a real pleasure to do that, to work with students and see them grow and see them succeed, and now that I've been here long enough, see them come back four or five years after they've graduated and hear the things that they're doing and hear how they're actually applied some of the experiences they had at Michigan State to what their careers are.
Ehm: Anything else that you would like to add?
Kirk: Kind of the next chapter in where we're going with anaerobic digestion now is this unique project we have with the Detroit Zoo. This is allowing us to do all the things we do with anaerobic digestion, bring students into the picture, and really use them in a different setting than campus. We've been working with the zoo for a couple years to develop an anaerobic digester for zoo waste. It's under construction now, and it's going online in September of 2016, so this fall. And we have students down there more or less weekly, working with the animal keepers, working with the managers of the zoo, to oversee operations, repair, plans on how to run the digester, but also oversee the safety of the digester and the people that are around it, collect the data, and then work with the zoo to utilize the products that are generated when we're done digesting that zoo waste. Again, they wanna use the material that's leftover for landscaping on the campus of the zoo, and then also work with other neighboring entities around to utilize that material. So it's taking what we do, traditionally we spend most of our time on anaerobic digestion issues with farms or food processors. The zoo puts us in a very unique position to work with exotic animals that we don't normally see, so when the students come in with 33 bags of animal manure that we've never tested or spent any time with, it's kind of a fun little day on campus. But it also allows us to work in an urban setting and really, from an education and outreach standpoint, reach a whole different group of students and people that would not normally know anything about anaerobic digestion and turning animal manures and poop into energy. So that's kind of a fun additional little project we have going on right now, and I think we'll spend a lot of time, we'll see a lot more of that over the next couple years as we get more involved there and that starts to become operational.
Ehm: I would like to thank Dana Kirk, manager of the anaerobic digester at Michigan State University and Assistant Professor in Biosystems & Agricultural Engineering, for being here today. Be sure and listen next time for another episode of In The Field.