The Search For Additional Value From Food Waste Using Anaerobic Digestion and Pyrolysis
thesisposted on 22.05.2021, 10:02 by Vanessa Bairos
Rethinking food waste could be an effective means to bridge the gap between local liabilities and finding value from this lost resource. While traditionally biomass has been used as a renewable energy source through combustion, there are more clever solutions. Biomass conversion can undergo both biotechnological (anaerobic digestion) and thermal (pyrolysis) conversion processes to produce end products that could sequester carbon from the environment. To date, both processes are being used independently for a number of energy carriers; however, no research at the moment has focused on converting biomass using anaerobic digestion to produce a fertilizer and extract further value by subjecting the digestate to pyrolysis. In the pyrolysis system, this feedstock is burned creating valuable carbon allotropes used to reshape next-generation energy devices, while removing carbon from the atmosphere. The objectives of this thesis are to determine if the digestate can be a suitable fertilizer as is. Based on N:P:K ratio, the digestate may not be as useful as a fertilizer. The second objective is to use the digestate as a suitable feedstock for pyrolysis in the search of high value nanocarbons. Although, the digestate was successful in being a feedstock, it did not provide insight to high value nanocarbons. Lastly, the solid product from pyrolysis (coke) was exfoliated to retrieve the advanced carbons using electrochemical exfoliation and sonication.