Modelling anaerobic digestion process for grass silage after beating treatment using design of experiment

Abstract

Anaerobic digestion (AD) is one of the most biomass conversion technologies currently deployed for power and heat. Beating treatment is a mechanical treatment whose technique has recently been introduced. The main goal of beating treatment is to improve degradability of the material which will enhance biogas production and anaerobic digester performance. In this work the effect of beating time (0-10 min) and temperature (35-39 °C) as input factors on the production of biogas as a response were investigated using design of experiment. Face-central composed design and response surface methodology were employed to create design matrix. Mathematical models were developed to determine the effect of temperature and beating time on the response as well as to predict the process performance. The results indicate that the two factors have a positive effect on the response and also show that any increase in the beating time will result in an increase in the biogas production up to beating time of about 3 min. The mathematical models developed are used for any further optimisation analysis.