Effect of Temperature on Co-Anaerobic Digestion of Chicken Manure and Empty Fruit Bunch: A Kinetic Parametric Study

Abstract

The rapid growth of the Malaysian poultry and palm oil industries has led biomass waste generation in abundance specifically chicken manure and empty fruit bunch (EFB). Anaerobic digestion (AD) is a circular economy-based approach which converts chicken manure and EFB into biogas which can be utilized for heating and power generation. Operating temperature is an imperative consideration for AD hence the objective of the study is to evaluate the effect of different temperature profiles namely, psychrophilic (20 °C), mesophilic (35 °C) and thermophilic (50 °C) on AD of chicken manure and EFB. The kinetic parameters are also evaluated using five kinetic models to enable readers to comprehend the kinetic behaviours of the systems. The volume and composition of biogas is measured every five days for a 50-day retention time. The findings observed that mesophilic condition is the most favourable with cumulative methane, CH4 composition of up to 17.07%, almost two folds that of thermophilic (9.12%) and five folds that of psychrophilic (3.49%). The CH4 generation rate, Rb based on the modified Gompertz model which is deemed the best fit further supports these findings as the Rb under mesophilic condition is significantly higher (0.330 mL/gvs day) compared to psychrophilic (0.088 mL/gvs day) and thermophilic (0.120 mL/gvs day) conditions.