HYDERABAD: For farmers preparing for the next crop, clearing crop residue can mean extra labour, transport and expense. In many villages, burning it remains the quickest way out — and a recurring source of seasonal smoke and air pollution. For B Mohan Venkat Sai Krishna, that practice raised a different question: what if the waste could be put to use instead?
A Design Thinking lecturer at the Centre for Innovation and Social Transformation (CIST), KG Reddy College of Engineering and Technology, and a NITI Aayog Community Innovator Fellowship (CIF) fellow, Krishna developed Eco-Burner, a portable unit that converts agricultural residue into biochar.
The idea emerged from conversations with farmers in Telangana, including Dornal, Chilkur and Nanajipur. Krishna found farmers burning cotton stalks after harvest. When he asked why they did not compost the residue or use it for mulching, farmers told him that processing and transporting the waste was expensive.
Speaking to TNIE, Krishna says the challenge was not simply managing agricultural waste, but finding a solution that farmers could afford and use. This led to the Eco-Burner, which converts agricultural residue into biochar through controlled thermal conversion.
Instead of allowing crop waste to burn completely into ash, the process limits oxygen and controls heat so that part of the biomass is converted into biochar, a carbon-rich material that can be used as a soil amendment.
Getting the technology right, however, took experimentation. Krishna developed three prototypes, with the initial models producing mostly ash instead of biochar. With technical guidance, he modified the design to improve airflow, control the burning process and reduce smoke.
The next challenge was taking the machine to farmers scattered across fields and villages. Krishna developed a community-based model in which the Eco-Burner is mounted on a simple trolley that can be attached to a two-wheeler and transported from one farm to another.
Rather than expecting individual farmers to purchase the equipment, the model envisages community groups and farmer collectives sharing the unit. The Eco-Burner is provided free of cost, while a minimal amount is charged for the trolley.
The prototype was tested in January this year and later deployed in villages including Chilkur. Krishna has since returned to the communities to collect feedback and assess its performance under actual farming conditions.
The idea addresses a problem beyond the farm. Open burning releases smoke and particulate pollution, affecting farmers and nearby communities. Burning or removing crop residue also means losing biomass that could potentially be returned to the soil.
The Eco-Burner attempts to change that equation by turning residue into biochar rather than treating it simply as waste. Its use has also evolved according to local needs. One farmer with around 20 cattle has been using the smoke generated during the process in the evening to help keep mosquitoes away from the animals.
Krishna’s next step is to take the community-based model to more villages, particularly in the Nalgonda region. He is also exploring another mobile solution — a solar dryer that could help lemon farmers process their produce closer to their fields when market prices are low. That project remains at the research and development stage, he says.