Empirical Buswell’s Equation for Identifying Anaerobic Digestate

Anaerobic digestion is a promising circular economic technology. Using organic matters as feedstocks, Buswell’s equation can represent anaerobic digestion in accordance with the elemental composition of any organic matter. An organic feedstock is biodegradable to biomethane, biogenetic carbon dioxide, and digestate, but the management of anaerobic digestate encounters some environmental and technological challenges. Currently there is a research gap between Buswell’s concept and the general organic elemental composition of unknown anaerobic digestate. To bridge the gap, this research developed an empirical Buswell’s equation for identifying anaerobic digestate through the integration of theoretical Buswell’s equation and experimental biomethane potential. This model can identify the organic elemental composition and characteristics of any anaerobic digestate, as well as reveal the correlation between an organic matter and its anaerobic digestate. It also discovers a higher heat value of anaerobic digestate which is greater than that of its corresponding organic matter. In addition, the empirical Buswell’s equation can be used for assessing the validity of the empirical formula of organic feedstock.