Production and Utilization of Biochar from Slow Pyrolysis of UConn Dining Hall Food Waste

As the global human population increases, the amount of waste produced increases as well. There has been a heightened interest in utilizing this waste for a range of purposes. These purposes include the production of useful biochemicals – such as syngas, bio-oil, and biochar – through the slow pyrolysis of organic wastes. Biochar, in particular, has the potential to improve crop yields as a soil additive by adsorbing contaminants. This work specifically focuses on the physical properties of biochar produced under various slow pyrolysis conditions. Food waste from the University of Connecticut dining halls was used as the feedstock. Pyrolysis was carried out at a range of temperatures, from 275 °C to 625 °C, and residence times ranged from 30 minutes to 2 hours. The resulting biochars were studied and compared based on their surface morphology, surface area, pore volume, elemental makeup, bond structure, and oxidation behavior. Pyrolysis at the lowest temperature produced the greatest yield of biochar, but low pore volume suggests that this biochar would be a poor adsorbent. Biochars produced at higher temperatures and greater residence times demonstrated larger pore volumes, despite lower yields. Selected biochars were tested for adsorption of copper and 1-methyl naphthalene, two common soil contaminants, to determine the potential viability of biochar as a soil amendment.