Dr Carol Ngwenya's PhD study has found that confectionery waste has strong potential as a feedstock for bioenergy production while supporting waste reduction and resource efficiency.
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A groundbreaking doctoral study conducted at the University of Cape Town (UCT) has unveiled that confectionery waste, rich in carbohydrates, holds significant potential as a feedstock for bioenergy production. This innovative research, led by Dr Carol Ngwenya, seeks to repurpose what often ends up in landfills, transforming it into a sustainable energy source while promoting waste reduction and resource efficiency.
In her PhD thesis titled The feasibility of renewable bioenergy production from carbohydrate-rich waste streams: confectionery waste as a case study, Dr Ngwenya explored the efficacy of producing bioethanol, biobutanol, and biogas through various microbial systems. The results were promising, revealing that these waste products can be successfully converted into renewable bioenergy. Moreover, the study showed that process optimisation and microbial acclimatisation significantly enhanced substrate utilisation and energy outputs.
“National science and innovation strategies, such as South Africa’s Waste RDI Roadmap and the Integrated Resource Plan, emphasise the crucial role of transforming waste materials into renewable resources instead of simply disposing of them,” Dr Ngwenya explained. “Despite their high energy potential, carbohydrate-rich waste streams produced by the food processing industry, particularly in confectionery, are frequently discarded. My research aims to redirect these waste streams into productive biological processes to generate renewable bioenergy.”
The study not only highlights the transformative potential of confectionery waste but also provides detailed insights into microbial systems, process optimisation, and the comparative viability of various bioenergy pathways. These findings are particularly beneficial for entrepreneurs and innovators within the waste-to-energy sector seeking to establish sustainable bioenergy solutions in South Africa.
Converting confectionery waste into bioenergy stands to substantially decrease environmental pollution, enhance waste management practices, and contribute to the generation of renewable energy. With South Africa striving for a more sustainable and resource-efficient economy, waste-to-energy technologies could also play a pivotal role in diversifying the country’s energy supply.
UCT said a notable aspect of Dr Ngwenya’s research lies in her comparative assessment of diverse bioenergy conversion methods using the same waste substrate. By investigating the production of bioethanol, biobutanol, and biogas from confectionery waste, the research elucidated how various microbial systems and conversion technologies performed based on the waste stream’s composition. This comparative methodology equips industries with the knowledge necessary to make informed decisions regarding the best waste-to-energy technologies suited to their needs.
As Dr Ngwenya celebrates her graduation from UCT’s Faculty of Engineering & the Built Environment, her pioneering work underscores the imperative for sustainable practices in tackling waste, a topic that resonates with growing global concerns regarding resource management and energy sustainability.
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