Evaluation and optimisation of biogas production in municipal wastewater treatment plant using computational intelligence approach : potential to generate electricity
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Date
2022-05-13
Authors
Ramrathan, Zesha
Journal Title
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Abstract
Development and optimisation of valued added derivatives from wastewater represent the
future sustainability paradigm. Among the various challenges in the management of
wastewater treatment is the energy consumption for the treatment process that could render
this process inefficient in terms of cost and energy consumption. This study focusses on
the evaluation of egg-shaped digesters treating municipal wastes, and the optimisation of
biogas production using computational intelligence approach (CIA) for sustainable energy
production and policy implementation. The study further estimates the amount of
electricity that could be generated from the optimised biogas produced from the anaerobic
digesters.
Historical 5-year (2010-2015) data of the anaerobic digesters were obtained from the
Darvill Wastewater Treatment Plant in the KwaZulu-Natal Province of South Africa. The
raw data were pre-processed for data cleaning, integration, reduction and data
transformations using a rigorous scientific method to test their accuracy, reliability,
consistency, and localisation gaps with different multivariate statistical tools. Computation
intelligence methods using partial least square (PLS), principal component analysis (PCA)
and Fuzzy Logic algorithms were used in this study for simulating the best operational
condition and predicting the biogas production. The study further created a contextual
framework against the assessment of biogas to energy potential and uses an excel-based
tool to determine the bio-economy of energy recovery from an anaerobic egg-shaped
digester per cubic meter of treated sludge. In average, the actual methane production was
59.60% while, predicted by Fuzzy-Logic was 65.4%. This shows that the model employed
in the improvement of methane production from biogas plants by varying the operational
parameters at; Inflow = 590m3
/day, Temp = 32.3°C, pH = 7.12, TS = 3.47%, VS = 43.4%
and COD = 510 mg O2/L. The obtained total biogas production was 802.80 m3
/day based
on status quo conditions and process configurations. The biogas production translates to
electrical energy of 4580.5 KWh/day with an estimated saving (at R1.90 per kWh
electricity) of approximately R3.1 million per annum.
Description
Submitted in fulfillment of the requirements for the degree of Master of Engineering: Civil Engineering Durban University of Technology, 2022.
Keywords
Biogas production, Municipal wastewater treatment plant, Computational intelligence, Electricity
Citation
DOI
https://doi.org/10.51415/10321/4212