Elucidating the impacts of municipal and industrial organic waste components on the kinetics and potentials of biomethane production via anaerobic digestion

Extensive biomass characterization, biomethane potential reactions, and kinetic modeling was performed on a variety of municipal and industrial organic wastes to elucidate the effects of individual biomass components on the kinetics and total production of biomethane via mesophilic anaerobic digestion. Municipal solid waste with high cellulose, lipid, and starch contents achieved the highest cumulative methane production of 526 mL/g-VS, but had the longest lag phase due to the high lignin content. Vinassse residue from industrial ethanol production exhibited the lowest cumulative methane production of 302 mL/g-VS, likely due to the low cellulose and lipid contents as well as the high percentage of impurities including potassium. Despite having the 3 ^rd highest volatile solids, Vinasse had the lowest total methane production. The two feedstocks with the lowest ash contents had the highest cumulative methane productions, highlighting the potential importance of ash in methane productivity. Kinetic modeling revealed that the Modified Logistic model best fit methane production from the municipal solid waste materials, which exhibited lag phases. The First-order and Modified Gompertz models best fit the industrial waste materials, which exhibited minimal lag phases. Overall, the Modified Gompertz was found to be the most powerful kinetic model for a variety of feedstock compositions.