Kinetic modelling and simulation of anaerobic digestion of fibrous waste materials and slaughterhouse waste

Abstract

Background

Anaerobic digestion is a biochemical energy conversion pathway that involves a series of biochemical reactions facilitated by bacteria, leading to the breakdown of organic material into a mixture of gases in the absence of free oxygen. The necessity for modelling the kinetics of the AD of different feedstock, different pretreated feedstock, and comparing them is to establish the most appropriate model that describes a prevailing context. This study as a result, sought to comparatively model and simulate the kinetics of the AD of agricultural residue (slaughterhouse waste, fibrous waste materials and pretreated fibrous wase material mixtures).

Method

To ascertain the practicality of different kinetic models for different feedstock, model selection capabilities, parameter prediction strength of models, and optimisation of AD systems, four distinct kinetic models have been employed. The study also propounded hybrid models from these and applied same. It considers the same selected models for feedstock from two extremes: plant residue and animal residues, however digested with the same technology. Thus, the finding serves as a good benchmark for comparative kinetic modelling.

Results

Throughout both the modelling and validation phases, the estimated correlation coefficient (R²) values consistently exceeded 0.9000, signifying a robust correlation between the experimental data and the model parameters. All models exhibited competence in simulating the anaerobic digestion (AD) of the agricultural residues under investigation.

Conclusion

The utilization of kinetic models for the simulation and modelling of agricultural residues is thus demonstrated to be effective, as the hybrid models as well demonstrate superior performance and offer better kinetic parameter description.