Kean Group Summer Scholars Program: The Role of Biofuels in Sustainable Energy

This summer, I had the wonderful opportunity to do a research project under a professor and other high school students at Kean University. Our project was focused on biofuels, where we aimed to find the optimal conditions for fermentation and distillation to create ethanol fuel starting with food waste.

Our first experiments were focused on the basics of distillation, because none of our group members were very familiar with the process. We created a mixture of methanol and water, and separated them through distillation. We divided into smaller groups, and each group had a different concentration of methanol and water. This was a test run for us, and I learned a lot from this experiment alone.

This was the setup we used for our distillation. Methanol has a boiling point of ~65 degrees celsius, and water has a boiling point of 100 degrees. The goal was to increase the temperature to about 65 degrees, so that the methanol would evaporate and condense into the receiving flask, while the water would remain in the distillation flask. This was essentially the same process for all of the distillation experiments we conducted. At the end of each experiment, we calculated the densities of the receiving flask and distillation flask. This was how we figured out if our separation worked or not.

Our next experiment was similar, but we used ethanol instead of methanol. This was more challenging, as the boiling points of ethanol and water are closer to each other, so it was important to keep track of the temperature and make sure water doesn’t begin to evaporate. However, we found that the ethanol could not be separated completely, due to an azeotrope. To address this, our third experiment was ethanol-water-cyclohexane, where cyclohexane acts as an entrainer, essentially aiding the separation of ethanol and water. We tested different concentrations of water and ethanol and cyclohexane, essentially trying to figure out the minimum amount of cyclohexane we would need for the ethanol and water to be completely separated. We found that we needed more than 50% cyclohexane in order for this to work.

Once we had enough of a background in distillation, we began to move into fermentation. This is where we actually created our biofeedstock solution and fermented it. We created our biofeedstock solution from food waste and added different types of pretreatment. We tested enzyme pretreatment and acid pretreatment. The purpose of the pretreatment was essentially to break down the different layers of sugars so that the yeast would have greater access to use it as food. Then, we added yeast. We then placed these mixtures into different settings, some heated in an oven, and some at room temperature. The next day, we calculated the mass loss of each beaker. The one with the greatest mass loss went through fermentation the most, meaning more ethanol would be found in that beaker. After calculating the mass loss of different conditions and pretreatments we found that the enzyme pretreatment (invertase) and 37 degrees overnight. yielded the greatest mass loss.

The next step was where we tied this back in with distillation. Since there were a lot of solid particles in the beaker, we first had to filter the mixture. We used vacuum filtration, which kept all of the food waste and solid parts out of the final solution. Then, we were finally able to move on to distillation. We were able to separate the ethanol from the rest of the mixture, making our project a success.

We then presented our results in a scientific poster. I really enjoyed presenting our findings to parents/other professors, as well as listening to the other groups’ presentations. Overall, I learned a lot, and met a bunch of great people!