CSIR-Indian Institute of Chemical Technology’s (CSIR-IICT) high rate biomethanation technology based on Anaerobic Gas lift Reactor (AGR) set up and operated at the vegetable market yard in Bowenpally, Secunderabad, received a special mention in Mann Ki Baat in January 2021 from Honourable Prime Minister Shri Narendra Modi.
The Dr B R Ambedkar Vegetable Market Yard in Bowenpally is the biggest in Hyderabad, where approximately 10–12 tons of vegetable waste are generated each day. This waste is treated at the in-house biogas plant facility with a 10 ton/day capacity for generating500–600 cubic meters of biogas, which is converted into 500 units of electricity every day. Part of the biogas thus generated is used to replace about 30 kg of LPG in the market canteen daily.
CSIR-IICT developed the novel Anaerobic Gas Lift Reactor (AGR) to generate biogas and bio manure from biodegradable organic wastes. The AGR technology works on a high rate biomethanation process suitable for operation in Indian conditions. The biogas can be utilized for combined heat and power applications, while the biomanure rich in nutrients can be applied in farms to increase the fertility of the soil for improved crop yield.The AGR technology helps reduce GHGs (greenhouse gases) and avoids the diversion of waste to landfills resulting in a cleaner environment. It is a promising method to treat biodegradable waste in-house in a scientifically safe manner and generate green energy.The salient features of AGR technology:
- Advanced high rate digester design
- Ammonia/ sulfide inhibition control mechanism
- Continuous mixing without mechanical equipment
- Three-phase separation mechanism
- No scum formation
- Smaller digester volume per unit weight of waste
- Lower footprint area
- Scaled up to 10 tons/day (Design capacity available from 150 kg/day to 10 ton/day)
- Higher methane/biogas yield
- Generation of nutrient (NPK) rich fertilizer
First Commercial Plant (Waste to energy from the kitchen-to-kitchen model) The first commercial biogas plant based on AGR technology was installed in The Akshaya Patra Foundation (TAPF), which serves mid-day meals to about one lakh school children. TAPF across India operates about 44 large kitchens. The kitchen generates about 1–1.5 tons of food waste each day. This waste is converted into wealth using the AGR technology. Food waste generated in the kitchen is treated in the in-house biogas plant. The biogas thus generated is supplied back to the kitchen for cooking, thereby replacing LPG consumption. Typically, a one-tonne biogas plant replaces about four domestic LPG cylinders daily. To date, there are about fifteen food waste-based biogas plants currently operational across India.
Rapid industrialization, modernization, and lifestyle changes result in increasing quantities of solid waste. Open landfilling of these wastes is widely practised, as it is an easier and economical approach in the majority of the countries. Still, its negative impact on the environment through emissions of GHGs is greatly neglected. About 45% to 50% of these wastes, including food, market, and yard wastes dumped in the landfills, are composed of biodegradable organic matter, which can be purposefully utilized to recover energy and nutrients. It is said that “Organic Waste is a misplaced RESOURCE and an unrecognized WEALTH”. The AGR technology-based biogas plants aid in converting this biodegradable waste into wealth and are setting a positive example of sustainable, remunerative, and decentralized waste management systems.
Sameena Begum, AmbicaVankamamidi & Gangagni Rao Anupoju
CSIR-Indian Institute of Chemical Technology, Hyderabad