Lubwama, et al (2024) Characteristics of rice husk biochar briquettes with municipal solid waste cassava, sweet potato and matooke peelings as binders. Materials for Renewable and Sustainable Energy. https://doi.org/10.1007/s40243-024-00262-x

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Rice husks, typically disposed of through environmentally harmful open burning, are difficult to biodegrade. To tackle this issue, a study explored transforming rice husks into biochar briquettes using organic municipal waste peelings as binders. These binders included peelings from bananas, sweet potatoes, and cassava, which are significant components of municipal solid waste.

Rice husk biochar was produced via carbonization in a step-down kiln at temperatures between 400 and 500°C. The biochar was then mixed with different ratios (10% and 15%) of organic peel binders and compacted into briquettes under a pressure of ≤ 7 MPa. Results showed high ash content (44-47%) in the briquettes. The highest particle density (427.1 kg/m³) was observed in briquettes with 15% cassava peel binder. The highest heating value (21.75 MJ/kg) and peak flame temperature (828.7°C) were achieved with 15% banana peel binder.

The findings indicated that increasing the organic binder reduced ash content and enhanced thermal stability, suggesting these briquettes could be an effective alternative to firewood and charcoal. This innovation is crucial for sub-Saharan Africa, where over 80% of domestic energy comes from firewood and charcoal. With a population expected to exceed 3 billion by 2050, sustainable energy solutions like biochar briquettes are vital for reducing waste and mitigating climate change.

This study emphasizes the need for continuous research into sustainable binders for biochar briquettes, aiming to replace traditional fuels and manage municipal waste more effectively, thereby supporting a circular economy.