title: Assessment and parameter identification of simplified models to describe the kinetics of semi-continuous biomethane production from anaerobic digestion of green and food waste.
abstract: Biochemical reactions occurring during anaerobic digestion have been modelled using reaction kinetic equations such as first-order, Contois and Monod which are then combined to form mechanistic models. This work considers models which include between one and three biochemical reactions to investigate if the choice of the reaction rate equation, complexity of the model structure as well as the inclusion of inhibition plays a key role in the ability of the model to describe the methane production from the semi-continuous anaerobic digestion of green waste (GW) and food waste (FW). A parameter estimation method was used to investigate the most important phenomena influencing the biogas production process. Experimental data were used to numerically estimate the model parameters and the quality of fit was quantified. Results obtained reveal that the model structure (i.e. number of reactions, inhibition) has a much stronger influence on the quality of fit compared with the choice of kinetic rate equations. In the case of GW there was only a marginal improvement when moving from a one to two reaction model, and none with inclusion of inhibition or three reactions. However, the behaviour of FW digestion was more complex and required either a two or three reaction model with inhibition functions for both ammonia and volatile fatty acids. Parameter values for the best fitting models are given for use by other authors.
authors.affiliation: Energy Research Institute, School of Chemical and Process Engineering, University of Leeds, Leeds, LS2 9JT, UK.
authors.forename: Raymond O
authors.initials: RO
authors.lastname: Owhondah
authors.affiliation: Energy Engineering Group, Department of Mechanical Engineering, University of Sheffield, Sheffield, S10 2TN, UK. mark.walker@sheffield.ac.uk.
authors.forename: Mark
authors.initials: M
authors.lastname: Walker
authors.affiliation: Energy Engineering Group, Department of Mechanical Engineering, University of Sheffield, Sheffield, S10 2TN, UK.
authors.forename: Lin
authors.initials: L
authors.lastname: Ma
authors.affiliation: Energy Engineering Group, Department of Mechanical Engineering, University of Sheffield, Sheffield, S10 2TN, UK.
authors.forename: Bill
authors.initials: B
authors.lastname: Nimmo
authors.affiliation: Energy Engineering Group, Department of Mechanical Engineering, University of Sheffield, Sheffield, S10 2TN, UK.
authors.forename: Derek B
authors.initials: DB
authors.lastname: Ingham
authors.affiliation: Energy Research Institute, School of Chemical and Process Engineering, University of Leeds, Leeds, LS2 9JT, UK.
authors.forename: Davide
authors.initials: D
authors.lastname: Poggio
authors.affiliation: Energy Engineering Group, Department of Mechanical Engineering, University of Sheffield, Sheffield, S10 2TN, UK.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Pourkashanian
mesh_terms: D000693:Anaerobiosis; D005502:Food; D007700:Kinetics; D008697:Methane / Q000378:metabolism*; D008962:Models, Theoretical; D035501:Uncertainty; D014866:Waste Products / Q000032:analysis
chemical_list: D014866:Waste Products; D008697:Methane
keywords: Anaerobic digestion (AD); Food waste (FW); Green waste (GW); Modelling; Parameter estimation; Parameter identification