Abstract:
Anaerobic co-digestion, ACD, is regarded as a key environmental technology in
industrial, agricultural and domestic sectors for integrated solid and liquid waste
treatment and renewable energy production. The main objective of this thesis is to
optimize the wet co-digestion process of canteen food waste by combined
experimental and mathematical modeling approaches.
Anaerobic co-digestion of canteen food waste with water hyacinth, Gliricidia
and Rice straw was conducted in this study. Two batch experiments were performed
to find out the best co-substrate for co-digestion and subsequently to investigate the
effect of increasing co-substrate fractions. Concurrently, dynamic batch modeling
results from ADM1 is used to validate the results from each experiment. Semicontinuously
fed experiments were conducted to determine hydrolysis rate constants
of best co- substrate mixtures by combining parameter estimation of ADM1. The
highest total Chemical Oxygen Demand (TCOD) removal and the highest average
biogas production were obtained when Gliricidia was used as co-substrate. Total
biogas production increased with increasing co-substrate concentration. Hydrolysis
parameters were estimated using simulated total gas flow rate and experimental gas
flow rate. Estimated hydrolysis rate constant for carbohydrates is higher than for the
protein and lipids. Increase of Gliricidia contents in co digestion feed mixtures did
not influence hydrolysis rate constants.
Keywords: Anaerobic Co-digestion, Optimization, ADM1, Mathematical Modeling,
AQUASIM 2.1f, Canteen Food Waste, Gliricidia,
