Numerical Optimization of Biogas Production through a 3-Steps Model of Anaerobic Digestion: Sensitivity of Biokinetic Constants Values

Anaerobic digestion (AD) of organic substrates can produce biogas, which consists mainly of methane and carbon dioxide. The objective of this study is to perform, for a given wastewater, useful numerical simulations following model number 1 by integrating an optimization sequence to show biokinetic constants effects on the biogas production rate. Therefore, we obtain via an accurate and simple simulation with less time of calculations a reliable estimation of biokinetic values. Indeed, we evaluate the effect of certain biokinetic constants on the response of 3-steps AD model to select the most significant ones. Thus, the constants in question were varied in specific ranges by setting the others. We conclude that main parameters were saturation constant for acidogenic bacteria (KS1), the solublization rate per unit of acidogenic biomass (ᵝ) and the yield coefficient for the yield of volatile acids from soluble organics (Yb) they have an important effect on the biogas production rate Q max and period to reaches its plateau value.