Comparison Study of Dynamic Models for One-stage and Two-stage Anaerobic Digestion Processes

Abstract

Compared to traditional one-stage anaerobic digestion processes (OSAD) with biomethane production, this paper focuses on the study of biogas yield of the two-stage anaerobic digestion processes (TSAD), which are able to produce simultaneously biohydrogen and biomethane from lignocellusic materials. The one-stage and two-stage systems for anaerobic digestion are obtained based on our previous papers. Additionally, the static characteristics and extremum points of both systems are also investigated. The tracking of maximum points is realized by fuzzy-PID controller. Simulation results suggest that in comparison to OSAD, the increase in biogas production of TSAD can reach to 75.18% by control action, which means TSAD is a better choice considering biogas production.