Priyadarshini Karwe, an award-winning scientist from Pune has developed an innovative method that creates eco-friendly biochar fuel from agricultural and garden waste. The process reduces the carbon footprint released into the atmosphere by about 30%.
According to a report by ICAR, India generates about 350 million tonnes of agricultural waste every year. This waste is usually burnt, releasing toxic smoke into the air, and contributes to air pollution. Additionally, the increasing urbanisation is leading to excessive consumption. It eventually results in more waste and depletion of natural resources. Pune-based Dr Priyadarshini Karve came up with an innovative solution to manage waste sustainably. Through her enterprise, Samuchit Enviro-Tech (established in 2005), Karve provides feasible and accessible eco-friendly solutions using biochar for sustainable living practices.
The award-winning scientist Karve innovated the technology to convert agricultural waste into biochar briquettes in the late 1990s. It involves biomass gasification of Agri waste with a controlled air supply, also known as pyrolysis. “Making biochar is similar to any other method of decomposition,” comments Karve. The biochar making unit, Trashflasher kiln, is filled with agricultural or garden waste and covered with a lid. Under controlled combustion, volatile gas burns off, leaving behind near pure carbon – biochar. After following an extensive process of hammering, mixing, and compressing, we get the biochar briquettes. These briquettes serve as smokeless fuel and are used to make many products, including soap and deodoriser.
Karve explains the modified design of the kiln for urban waste, “The kiln is essentially double-walled along with strategically placed holes on it.” The first layer consisting of dry organic waste is lit and covered by a lid. The air from the holes enters the chamber, initiating the gasification process. The heat from the first layer permeates the other layer and drives out the volatile gases that burn off. While the product obtained is 30 per cent of the total carbon in the biomass, the remaining releases into the atmosphere without causing pollution. The kiln costs Rs 7,000. The biochar locks 30 per cent of the carbon in the garden waste that would otherwise go into the atmosphere.
Karve has also designed a smokeless cooker stove that runs on high-performing biochar. One can easily prepare a simple meal for 2-5 people, including dal, rice, chapatis using 100 gms of char and a glass of water. Low-temperature cooking results in tasty and nutritious food. When she pitched the product in the rural areas, there were hardly any takers because of the cost and the novel technique. After a series of upgrades, she came up with a compact design made of stainless steel instead of mild steel. Karve shares, “Although the fuel used burns completely within 30 minutes, the food cooks in the steam and heat remaining from the burning.” Currently, the stove costs Rs 3,500 and has been doing good in the market.
Karve was always fascinated by the concept of physics that one form of energy gives way to another. Nothing goes to waste. She recalls, “While walking or cycling back to home from school, I’d come across lush green sugarcane fields.” She remembers how the farmers would burn the agricultural residue producing smoke that would cause discomfort to the villagers and animals. It turned out to be her motivation many years later when she got the opportunity of designing a solution for waste management during her PhD. Karve firmly believes that we need to change our ways early to prevent a disaster in the making. Her current focus remains on cutting down the carbon footprint in urban living.
Karve shares when she started working on sustainability, there were hardly any organisations working in this field. However, with time, more people have begun to explore developing eco-friendly solutions for waste management. It makes her happy, and she would love to continue training budding social entrepreneurs, organisations, and citizens to adopt sustainable practices and propagate them further.