Whenever Biodiesel is made the amount of Free Fatty Acids (FFA) in the oil sample must first be determined so that the correct amount of catalyst is used in the reaction. Although this may sound complicated it is a relatively simple process! The method that we use is very accurate and can be done in easily in the lab. Soon we hope to move all the testing materials to the new facility at Cherry Crossings, but for now the testing is done in the Biosystems Research Complex, seen below.

We use a method of base titration to determine the amount of acid in the sample.  Here are the steps that we use:

1. Get an oil sample of 100 mL

2. Weigh the oil sample and record in grams

3. Add color indicator, Phenolphthalein and 50 mL of isopropyl alcohol

3. One drop at a time, add KOH solution to the oil solution

4. When the color changes to bright pink stop and record the amount of KOH added


These are all the steps of the titration! Now all that is left to figure out is a little math to be able to know what the amount of KOH used in titration means for us in the reaction!

The formula is simple: ___ Mol KOH * (56.1g/mol KOH) = Amt of Catalyst need to neutralize the FFA

Where the blank is filled in with molarity of the KOH that you are using! This tells you the amount of catalyst needed just to neutralize the FFA, but it is important to remember to add the amount of base catalyst that would be needed if the oil contained no FFA.

Final amount of required catalyst = Amt of Catalyst need to neutralize the FFA + 7g of catalyst / L of oil

It is important when doing this test to run the test 3 times and then take the average of all the similar results. Leaving off any extraneous results, which probably are a result of poor lab techniques.

After determining the amount of catalyst that needs to be used it is a good idea to run a small sample batch to make sure your results are accurate. The steps for that procedure are:

1. Measure out 22 mL of methanol

2.  Measure and then carefully add the calculated amount of catalyst. Screw cap on then stir.


3. Heat up a 100 mL sample of oil to 130 ºF, this can be done in a microwave or on a hot plate.

4. Add the methoxide solution to the oil and quickly add cork.


5. Agitate for 10 minutes and then let in under fume hood.

If this small batch of biodiesel is successful then you know that your calculations were correct and you can apply this to your entire batch.

Below are some of the pictures from the CI’s determination of the amount of catalyst to be used. All of the batches were successful!








The Clemson Biosystems Engineering program just pulled off a harvest from our organic sunflower energy crop. These flowers were produced sustainably without the use of pesticide or herbicide. Nutrients for this plot were supplied from the cover crop of nitrogen fixating field peas which supplied about 70 units of nitrogen per acre. Additional nutrient came from site produced compost from food and animal wastes. Right now the seeds are finishing the drying process, and then we can check our yield!


I’m excited to display some of the first photos of our yeast as we continue the purification process using differential media. Our cleanest samples are coming from the untreated apricots we mashed and fermented. Keeping the alcohol content high has helped us to eliminate some bacteria by lowering the ph and increasing the alcohol content. The round spheres are the Saccharomyces. With some further analyses we hope to confirm the small specs are yeast “buds” and not bacteria.Image

Our nectarine samples showed a bit more bacterial contamination, as well as a hint of we hope to confirm as the beloved species in belgian ales – Brettanomyces – which also produces alcohol in addition to a broad spectrum of additional flavor esters.


Our blueberry specimens were the first to burp CO2, however, as you can notice from this sample, we have a lot going on here in addition to our yeast activity. Using our differential media and increasing alcohol concentrations, we will monitor the presence of these other organism until we have isolated only our desired yeast strains.


Thanks for tuning in and following us! We have so much more to post from our summer research. Stay tuned for a video of our first oil extraction from the BSF composting system and improvements to our BSF Digester!


Thanks to some summer funding from the Clemson Creative Inquiries Program, recent Biosystems Engineering Graduate Jared McKnight and myself spent the early part of our summer winding through the endless rows of peach, nectarine, apricot, and blueberry trees at Musser Fruit Farm. What were we doing there? Other than gorging ourselves on the freshest ripest tastyest fruit in the Upstate, we were sampling fruits for wild strains of yeast of the saccharomyces variety. Image

Our experiments began by segregating samples of unwashed fruits. Each separate sample was mashed in a sterilized stainless steel bowl, then transfered to a sanitized erlynmeyer with airlock to allow the present species to multiply.


We allowed these to ferment for about 1 week, then pitched the liquid phase of each sample into a solution of ~ 12 brix from some light malt extract.


This 2nd generation cultivation sat in a 68 degree mini fridge where we sampled every few days to monitor the rates of fermentation in each sample. Within 5 days all samples were bubbling at a typical rate for saccharomyces, though the blueberry samples were the quickest to burp out some CO2 starting the second day. After about two weeks we pitched samples from each of the second generation into some 1 gallon fermenters and added to it a Saison Wort of 15 Brixx. Since our hop plots in McAdams Hall and the Student Organic Farm were producing well, we decided to pick some fresh Cascade, Nugget, and Centenial Hops to add some flavor and aroma to our experimental brews.


Fresh milled pilsner and wheat malts made up the majority of the grain bill


Boil Saison Wort and pick hops fresh from the vines in McAdams Hall


Organic Cascade hops grown at the clemson student organic farm


Fermentation is off to a good start! I’m possibly most excited about our control however, which is using a purchased Saison yeast from White Labs. We’ll have lots of testing to do under the microscope before any of our wild samples are safe to sample.

 In about a weeks time we will sample each yeast layer, and dillute them for inspection by microscope. We’re hoping to safely identify some saccharomyces, and not detect any clostridium. Hopefully in one years time, we will have some successful grain plots and malting experience to yield a traditional French/Belgian farm style ale, from 100% local feedstock – including our hops, grain, yeast and water!


Scalable Biosystems for Sustainable Energy Production

Introduction: Concerns over rising energy demands and dependence on fossil fuels have led to a great deal of research into renewable energy.  While sources like wind and solar show great potential for electricity generation, there will also be a need for renewable sources of liquid and solid fuels for both transportation and biomass gasification. Current sources of University generated waste can be diverted to displace 35%-50% of diesel fuel demand on campus, as well as contribute to biomass production for biomass gasification to supply steam to the West Campus.  The objective of this project is to construct a scalable biosystem for conversion of food wastes into biodiesel fuel, renewable gasification feedstock, animal protein feed and compost.

Our Creative Inquiry on Value added Co-products Stands by the freshly loaded digester

This multi-faceted project aims to displace an additional 4,000 gallons of petro-diesel through algal and pupae lipid production, as well as divert 209,000 lbs of solid organic waste from Clemson University Facility and Maintenance Organization’s ( CU FMO) disposal. Its scalable design will allow further expansion and replication upon proof of concept.  Mr. Tony Putnam, Director of Utility Services for Clemson University, has indicated his support for this project: “ University Facilities takes seriously our role to create, enhance and maintain a high quality learning environment. In particular, we strive to provide ‘living lab’ opportunities for students and faculty collaboration with our organization. This project is especially appealing to me since it examines multiple processes that can be immediately developed and implemented on our campus to minimize landfill waste as well as exploring alternatives to produce our own clean renewable energy to reduce our campus carbon footprint.“

Why BSF? Similar to the common “vermiculture digesters” utilized across many varying scales of production, this proposal offers an alternative to the use of earth worms and nightcrawlers. Instead, the larvae of black soldier fly, Hermetia illuscens, ubiquitous throughout North America, are voracious consumers of nitrogen-dominant decaying materials, such as kitchen food scraps or manures. Dried pre-pupae contain 42% protein and 35% fat, and as a component of a complete diet they can provide an excellent feed for chicks, swine, rainbow trout and catfish (reviewed in Newton et al. 2011).  Additionally, BSF have been demonstrated to digest over 15 kilograms per day of waste per square meter of feeding surface area per day. According to a current Clemson Recycling Services study ~209,000 lbs of food waste could be collected annually from all dining halls on campus. Based on data from previous studies, this amount of dining hall waste could generate:

▪33,551 lbs of dried BSF pupae to process into oil and protein meal using existing equipment

Mature pupae self harvest

▪45 tons of dry compost for use as a soil amendment at the Student Organic Farm

▪4,473 gallons of oil (based on 35% lipid content of pupae by weight) with a biodiesel value of  $16,774 based on $3.75/gallon cost

▪10.9 tons of protein meal by-product from the oil processing procedure with a value of $5,500 based on value of fish meal

Dan Fleetwood and a group of Civil Engineering students helped with our project and put together this informative video: http://www.youtube.com/watch?v=a6QiE5j0Fpk&list=HL1336049837&feature=mh_lolz

This is our second week operating the system, and so far the critters have consumed over 400 lbs of cafeteria food waste. This number should increase exponentially as our BSF population increases. We started with 9000 young larvae from Pheonix Worms in Tifton, GA. After a spontaneous 38F night, we lost about 1/3 of our population. We made some adjustments to better control temperature, and utilize the adjacent greenhouse for supplemental heat, and since then, their population is soaring. We now have several adults lingering on the shredded paper which provides a nesting area for pupating larvae that don’t migrate into our harvest buckets.

We expect our population to reach 100,000 over the next two weeks, at which time we will begin harvesting larvae to press into oil and feed. We will test lipid for its Fatty Acid profile and conversion into biodiesel. We will test the feed for its nutrient and market value. The compost will not be harvested until the end of summer. This project is a collaboration between the Clemson Biosystems Engineering Program, the Student Organic Farm, and Facilities and Maintenance Organization.


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.


Snow Creek Farms Canola

Canola as far as the eye can see in Statesville, NC

I took a trip to Snow Creek Farms today to check in on how some degumming equipment from Piedmont Biofuels was performing. Last I heard, the system got too gummed up from the “hull-on” sunflower they were processing. Today, however, the Snow Creek subsidiary Agrofuels was steadily degumming expellar pressed soybean oil that is hopefully heading to the fryer fuel market.

Gums extracted from oil entering the soybean meal stream

Gums extracted from oil entering the soybean meal stream

We made some tweaks to the hotwater dosing equipment, cleaned out the sediment columns, and fired up the rotor stator mixer/ disk stacked centrifuge combo, and the system was humming along from the getgo.


Grease appreciation night was a success!

Our conscience was at ease knowing that the fried mozzeralla sticks we were eating were reducing our carbon footprint!

Just wanted to say a quick thank you to managers Christie and Tyler from Brioso. We had about 40 faculty, staff and students come out over the course of the night to dine at Brioso. We loved the food, and we love that you folks have partnered with us. As our program continues to grow, we need to continue to find great partners like Brioso to join our efforts. If you have a restaurant in mind, please leave us a comment so we can follow up.


Hello supporters of Clemson Sustainable Biofuels!   If you live in the Clemson area, we will be having our Grease Appreciation night at Brioso tomorrow night (Wednesday, Nov. 2nd) from 5-8pm.  Please come out and support Brioso who supports Clemson Sustainable Biofuels, by donating their used oils to us.  Each gallon of oil that is recycled into biodiesel saves 20 pounds of carbon going into our ever warming atmosphere.  Hooray!   Hope to see you at Brioso and check back soon for more grease appreciation nights with our other local supporters.


Dex and I made a batch of soap about a month back and it has been curing all this time.  I finally pulled it out this morning, took it to the sink, turned on the water and….voila!  Bubbles!  It lathered up really nicely and rinsed (mostly) cleanly.  It took a bit more rinsing than soap I’m used to, but its a start.  For our first batch, I am very proud.   The ingredients for this soap were recovered glycerin from our biodiesel reactor, chinese tallow oil, sunflower oil, potassium hydroxide and a bit of tea tree oil.  You can’t really smell the tea tree in the final product (maybe we didn’t use enough or maybe it evaporated).  But it does leave your skin feeling clean and not drying at all.  It isn’t the prettiest soap, and looks more like butterscotch brownies or some kind of peanut butter bar, and isn’t super homogenous, but its functional and that is what we were going for!   Next up, we have purchased some new soap making materials, including French Green clay, coconut oil, some citric acid (to experiment with neutralizing the glycerin), lime oil for scent, and buckwheat hulls which we will grind up to use as an abrasive for those really dirty jobs.  The agricultural mechanic lab is right next to ours (read: working on tractor engines) so we can deliver some to them 🙂  I think the issue with the current batch was that we did not mix it thouroughly enough after adding the base to the oils.  We used a wire whisk and may experiment in the future with an emersion blender.   Stay tuned for more soap tales from the biodiesel lab!!