Botswana environmentalist and urban planner Ludo Ntshiwa developed an interest in smart cities powered by biofuels while working in urban and regional planning. She is providing an affordable renewable energy solution from accessible local materials to street vendors, hospitals, farmers, restaurants, schools, and the textile and ceramic industries.
Most ingredients and materials are sourced from local businesses’ waste products. Ntshiwa collects sawdust, the main igniter in briquetting and a by-product of the timber industry. The sawdust is soaked in water for two days to dissolve all chemical components that may cause the briquette to emit smoke. Dry agricultural waste is then burned in a closed metal drum without oxygen to obtain carbon, the primary ingredient, contributing to the higher calorific value of the briquette and allowing it to burn longer.
Corn starch, obtained from crushed maize from the animal feed production industry, is added to the mixture as a binder and helps to shape the briquettes. Other ingredients include charcoal ash and clay. The ingredients are crushed to a fine powder so that when compressed, they leave little to no airspace. This densifies the briquette and the tightly packed particles mean they burn longer.
Once the raw materials have been collected, they are dried in the sun and manually crushed. They are mixed together, and water is added to make the briquettes easier to compact and mould into the desired shape and size. It takes roughly two minutes to produce a single briquette. They are laid in the sun over a period of three to four days, after which their moisture content is roughly 7.8%.
The Biomass Briquette is three times denser than charcoal at 970 kilograms per cubic metre. A single briquette burns up to 30 minutes longer while producing a consistent supply of energy. They produce more energy per calorie because of their increased calorific value and produce less sparks and smoke. In Botswana, traditional charcoal is sold for US$0.53 per kilogram. Biomass Briquettes are priced at US$0.26 . A 4 kilogram bag of briquettes can burn up to 12 hours in a single day.
Ntshiwa is working to increase her production capacity by obtaining a machine that will mechanise the crushing, mixing, drying, carbonising, and moulding processes, allowing her to make five tonnes of briquettes in an hour. She is working to also produce scented briquettes. To increase production, she aims to employ more employees and is adopting a new marketing strategy.
“Biomass Briquettes is a step towards the circular economy of ‘reduce, reuse, recycle’, where energy can be harnessed from waste, contributing to an environment that is as close to zero waste production as possible.”
Ludo Ntshiwa
