A review of steady state and dynamic models of the kinetics of anaerobic digestion was carried out. A simplified dynamic model developed by Hill (Auburn University, AL) was determined to have the desired balance between accuracy and complexity. A steady state solution to Hill＇s simplified dynamic model was developed. It predicts the substrate and bacterial concentrations and hence the gas generation rate in a continuously stirred tank reactor. The solution is recommended for general use in optimizing the gas yield from anaerobic digestion processes.