Integrated BioRefining – Student Spotlight

This semester, through the creative inquiry program at Clemson University, we’ve focused on the use of waste streams as feedstock for production of energy, energy crops, and value added co-products.  Dr. Terry Walker and myself have mentored more than 30 students this semester with hands on applications of key biosystems engineering principles. As we continue research on the optimization of mixotrophic algae production for biomass and biolipid production, we have integrated the use of spent yeast, low-wines, and trubb from the production of ethanol, beer and wine. The goal of the Integrated Biorefinery is co-production of the various biofuels and value added coproducts from regionally available biobased feedstock. For example, production of ethanol and synthesis gas from cellulosic feedstock, with the remnants (yeast/xylose) used for cultivation of algae for biodiesel production. See the attached powerpoint for a schematic.


Environmental Engineering masters student Daniel Carey, of Greenville, SC – has managed a group of undergraduate and graduate researchers in optimizing the rate of vegetative growth of the mixotrophic algael strain Chlorella Protothecoides via the Clemson University Creative Inquiry program.  The attached poster demonstrates our results. Coproducts_Poster_v4

As we continue optimizing growth, we are integrating a combined autotrophic and heterotrophic system including consumption of glycerol from our biodiesel process, and CO2 from combustion emissions to improve the rate of biomass and lipid production in these strains. We will be working dilligently over the summer to scale up this process, with the end goal of consuming 100% of our glycerol stream in the production of additional algae derived bio oils.

Cultured strains are also being assessed for production of synthesis gas to increase energy density of lower density feedstock such as switch grass or sorghum bagasse. Dan graduates next month with his masters in Environmental Engineering from Clemson. He plans to start a Phd program in the fall.


5 Responses to “Integrated BioRefining – Student Spotlight”

  1. Nice work. I’m curious what the numbers are on the synergistic benefits of autotrophic and heterotrophic. In other words, if we get X kg/d of biodiesel under autotrophic conditions and Y kg/d under heterotrophic conditions, we should get Z kg/d under mixotrophic conditions, where Z is greater than X or Y. Then, I guess it would have to be normalized to glycerol input or CO2 input or something. Fun stuff!

    • Absolutely right! So far, rather than nomralizing to Carbon input, we are simply using biomass increase per day comparison between the two methods, with the biomass increasing rapidly during auto – and lipid increasing more rapidly during hetero. Now…how to combine the two to get fastest biomass increase at first – and then force rapid lipid production in a controlled heterotrophic Carbon and Nitrogen environment? Definitely fun stuff, and still plenty to do!

  2. bio ethanol haard…

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  3. Spirulina is a natural health supplement containing far more protein than any other food known to man. The protein content in spirulina powder is a massive 60-70…chlorella for health

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