Each year at the Annual International Meeting, ASABE recognizes student excellence in the conduct and presentation of research with the Boyd-Scott Graduate Research Award. The competition consists of a written portion and an oral portion. For 2017, UF-ABE’s Joe Sagues, PhD Candidate in Biomass Conversion, placed first in the PhD competition. Fresh off his victory in Spokane, Mr. Sagues agreed to speak with IrriGator about the work he presented in competition and the focus of his current research.
|Joe Sagues, PhD Candidate, UF-ABE|
JS: My research is focused on converting agro-industrial residues – low-value, sustainable sources of biomass – into valued products, particularly valuable chemicals. These biomass sources are composed of cellulose, hemicellulose and lignin - 3 different polymers that are interwoven within each other. We’re selectively targeting the lignin, and we’re depolymerizing it into its different monomers. Those monomers have high-value applications in human nutrition. They can be used as anti-oxidants, used in sunscreens, used as food preservatives and things like that.
You mentioned low-value biomass. Can you give us an example?
JS: Sugarcane bagasse in the state of Florida is the most abundant agro-industrial residue. After the sugar and juice is squeezed from the cane you’re left with this fibrous material which is called bagasse and they just burn it right now. Thousands of tons a year burned for heat and power. We’re trying to take that and make something a bit more valuable.
Flashback to the Boyd-Scott Award competition at ASABE AIM - what research did you present in the competition?
JS: I focused on the first project I completed around the end of year one of my PhD, which looked at sweet sorghum bagasse. It’s almost identical to sugarcane bagasse but instead of sugarcane we’re using sweet sorghum. It’s bigger in Louisiana than Florida, but it’s an emerging crop in Florida. We took that bagasse and used ethanol in the supercritical state along with some catalysts to depolymerize the lignin into these various valuable chemicals.
One noteworthy component of this process is that the hemicellulose and cellulose (2 of the 3 polymers that make up the bagasse), they remain untouched during the process so that they can be used for other valuable applications afterwards. One of the big issues with lignin is that when you try to depolymerize the lignin you end up degrading the other two components. We’ve kind of avoided that. The catalyst was an iron catalyst - low cost, abundant, non-toxic.
Does the value of this research lie in the novelty and real world applications?
JS: As of right now what we’re doing is too costly, but the approach is new to bio-refining. The last 15 years or so everyone has been focusing on the cellulose mainly to make ethanol fuels and the lignin has been discarded because it’s just really hard to work with. But we’ve found a way to work with it more easily and in doing so keep the cellulose in pristine form so it can still be converted to ethanol. We’re creating more value from the feedstock.
What can you tell us about the research you’re working on currently?
JS: The project I presented at ASABE taught me the fundamentals of this new approach which we call selective lignin depolymerization. But there were some drawbacks, which I’ve moved past. I’ve modified the process. I’m using a copper catalyst now for various reasons. But I’m still sticking to using ethanol in the supercritical state because that’s kind of the special ingredient. I’m still building upon it. Eventually, the most important part that needs to be done is a techno-economic analysis to really figure out how expensive this process is. It seems like it will be expensive but then again we’re making these valuable products that would otherwise be burned or land-filled.
The format of the student awards at ASABE AIM didn’t really allow for acknowledgements. Who would you have acknowledged given the chance?
JS: Definitely my advisor Dr. Tong because of the freedom she gives me. Most research with lignin has focused on these lignin residues from current bio-refining processing and the pulp and paper industry. They generate massive quantities of lignin. So lots of scientists have focused on how do we create high-value chemicals from this lignin residue? But obviously it hasn’t succeeded because there’s nothing commercial yet - the yields are low, super harsh processes. I came from a different approach. I want to take the lignin from the whole biomass but keep the cellulose pristine so you can still do what you want with it. At first Dr. Tong was kind of hesitant but then was like just go for it. And it ended up working really well. Aside from my advisor, I’d thank Dr. Haman also, who ultimately gave me the fellowship, which gave me the freedom.
Is there anything I haven’t asked you about that you feel our readers should know?Huge congrats to @UF_ABE's Joe Sagues 1st place PhD contestant 2017 Boyd-Scott Graduate Research Award #ASABEaim17 pic.twitter.com/xZA3ENqk6g— UF/IFAS IrriGator (@IrriGatorUF) July 19, 2017
JS: Something people in the biofuel realm, or in the ag and bio realm more broadly, should think about regarding biofuels in my opinion is airplanes and ships. We need to really focus in on those two forms of transportation because light-duty vehicles, even semi-trucks and larger road vehicles will most likely be electric. The technology costs are coming down and there is a lot of momentum right now. I think we’re wasting time making ethanol. Ethanol can only be used in light-duty vehicles. We should be looking at jet fuel and shipping fuel. They may become electric someday but that’s many decades into the future. There’s really not enough sustainable biomass to power the entire light-duty fleet anyway, but there is to power the planes in the sky and the ships in the ocean.