Interview with David Thornton, Biodiesel Guru

This is an edited version of a slightly longer interview which I may post later- edited because of size constraints for the Spring 2012 issue of Tigra Scientifica for BioSc 494: Popular Science Journalism.
The Clemson Clean Energy project is pretty neat- check them out here!
 

Danielle- The green energy and the biodiesel and the zymology projects are all interconnected. How many related projects are there?

Thornton- Well, we’re going to have to make a lot more Creative Inquiry sections next year because in Green Energy and Biofuels there’s four different groups. One group- all they care to do is make biodiesel. They just want to master bioprocessing and make biodiesel on the pilot plant, and that’s how the pilot plant program got started. Another group looks at how to produce more oils, and one way was to take cafeteria food waste and process it using black soldier flies that will also produce a protein meal, meanwhile turning the organic food waste into compost that they’ll use at the organic farm. We actually just finished, or we’re in the process of constructing that digester right now.

D- You’ve already done some of the feeding of cafeteria waste to the black soldier flies?

T- We’re building our prototype right now, so we’re doing something that’s a tenth of the scale of the final one, and hopefully we’ll start feeding it next week.

It’s a 12 day loading time, and for every square foot of surface area it can process three pounds a day of food waste. It’s not that much, about two fistfuls. Once it goes through a pulper, and it has a lot of water…  but it’s per square foot, so for each tile on this floor you dump that much food in there and the flies will eat it. They self harvest and they self propagate.

D- Okay. So when you mean self-harvest…?

T- They try to climb up to pupate, and what we do is they train them when they have to pupate so they go through these little channels, and they just jump into our bucket!

D-Well, that’s convenient. What other projects are there?

T- Well, we have one trying to make jet fuel out of sunflower oil, which we have some locally produced sunflower seeds. We pressed them in the press we have over at McAdams, and then we refine that oil and convert it into biodiesel. So basically, we’re trying to make this sample of biodiesel and probably only 25% of it will be these polyunsaturated acids which will be very favorable cold flow. We’ll at least be able to take that fraction and send it off for some testing to see if it’s a good source of blended jet fuel. The remaining 75% will melt down and be good transportation fuel. But it is kind of energy-intensive because we’re using freezing cold temperatures to separate it. Just a start to see how our sunflower will perform.

D- And that started this semester, so it’s kind of a new project?

T- Yep, we have one student who-  I think he’s from mechanical engineering- he’s also a pilot and he’s very interested in how to make jet fuel. The Department of Defense and the military are very interested in jet fuel as well, so it’s a possible source of funding if we get good preliminary results from regional sunflowers. This could be a good way to stimulate that production. And there’s another group…

T- We have another creative inquiry called Coproducts, and they make soap, degreaser, and they kind of overlap feeding yeasts and feeding glycerol to algae. So that’s where the overlap really occurs. I’ve actually got four classes going on right now without me there- they made some degreaser and they’re cleaning our biodiesel processing trailer.

D-Sort of doubles as doing work and cleaning up the lab?

T-Yeah! So they’re taking pictures and documenting, they cleaned it with just warm water, they cleaned it with conventional degreaser, and then they cleaned it with their degreaser, taking pictures of each different form, and comparing their pH and their effectiveness, and how much it costs per volume of cleaning. That’s just kind of a fun one that’s not a really scientific but very practical and applicable. If we could convert all of our glycerol on campus to some of the degreaser to clean the floors in the labs, and the rest of it feed it to algae, it’d be an elimination of our waste stream right now to generate value from the coproduct. Part of biosystems engineering is eliminating the term ‘waste product’. Waste is but a resource misused. That’s why we do all this research on finding uses to support the economics basically of renewable fuel production because they’re not so favorable right now.

D- Yeah. And it sounds like you’re sort of working to self-contain systems, like you mentioned with the ethanol and the algae used to go back into the biodiesel and then take the glycerol waste product from that and use it in these other products and it just cycles.

T-Yeah. And that just ties into what our creative inquiries are going to turn into-we’re trying to do a more integrated research approach on, to create on campus an integrated biorefinery.  It means you’d be producing ethanol and biodiesel, and taking those waste products and then powering the plant with gasification using the waste products- or coproducts from those other things. You’d be producing each of the three mainstream biofuels, which are ethanol, biodiesel, and methane that can come in many forms, either anaerobic digestion, methane gas, or in this case, synthesis gas produced from gasification, which are predominantly methane. They could replace propane or natural gas. Self-contained is the goal. That’s the point of this system.

D- Have you gotten a lot of feedback from campus outside of the biodiesels group, like from Aramark?

T- Yeah, we work closely with Facilities… And Aramark, actually- they were the first company to agree to this because it’s their oil and they’re essentially letting us have it to make biodiesel. We can make probably about 3,000 gallons of biodiesel a year. Last year I think we made somewhere around 2,000 gallons. Some of that oil’s disappeared- I think people were thieving it from the receptacles, so now we have locks on our dumpsters. We’re getting a lot more oil, so we know something was wrong last year. This year we should be getting at least 3,000 gallons from just the oil from Aramark. We’re also picking up from Brioso, the new Sweetgrass restaurant, Crocs… but facilities is supporting us to grow. They want us to get to 10,000 gallons a year, which will be half of the diesel fuel consumed on campus. We’ve been running 20% biodiesel, and this week we’re going to bump that up to 25% biodiesel, and gradually get up to see if we can get some vehicles running on 50% biodiesel during the summer months. We have a few vehicles in our department that we run on 100% biodiesel. The feedback from facilities is positive; we just need a way to make more fuel. Hence, we have this research, right?