The role of agri waste, press mud waste and Napier grass in fuelling India’s biogas revolution
India generates over 500 million tonnes of agricultural residue per annum, of which it’s estimated that around 120 to 150 million tonnes is surplus and can be used for energy production.
India, an agrarian economy-driven nation, produces a massive amount of agricultural biomass annually. With growing energy demand, environmental concerns and an emphasis on sustainable sources, agricultural waste such as press mud from sugarcane manufacturing and high-yielding crops like Napier grass are proving to be significant agents of India’s biogas revolution. Not only is this reducing carbon emissions, but also promoting rural jobs and circular economy models at scale.
India generates over 500 million tonnes of agricultural residue per annum, of which it’s estimated that around 120 to 150 million tonnes is surplus and can be used for energy production. Realising this resource potential, the government has announced major initiatives like SATAT (Sustainable Alternative Towards Affordable Transportation) and GOBARdhan (Galvanising Organic Bio-Agro Resources Dhan). These schemes are designed to promote the installation of biogas and compressed biogas (CBG) plants throughout the nation. Supported by financial support, policy push, and regulatory shifts, these programmes are promoting a strong bioenergy ecosystem for renewable bioenergy.
CEID is actively playing a part in this shift by establishing cutting-edge CBG plants in the country that turn waste into biogas. They’re not only solving the problem of waste management and rural development but also supporting India’s overall needs of decreasing dependence on fossil fuels by collaborating in the country’s target of net-zero emissions by 2070.
Agricultural waste potential
In states such as Punjab, Haryana, and Uttar Pradesh, the combustion of crop residues, particularly wheat and paddy straw, is a serious environmental issue. It leads to extreme air pollution, especially in North India during winter. Still, the same stubble can be converted into an asset by way of producing biogas. Punjab alone produces 20 million tonnes of crop residue every year, out of which at least 5 million tonnes are available in excess.
Depending on the nature of the residue, one tonne may produce 200–300 m³ of biogas.
New advanced pre-treatment and co-digestion techniques are now making it possible to utilise even lignocellulosic biomass such as cotton stalks, maize husks, and wheat straw as a cost-effective biogas feedstock. Implementation of decentralised biogas units in agricultural clusters not only addresses air pollution problems but also ensures energy security to rural industries and farm households.
Press mud: A precious by-product for green energy
India is the globe’s second-largest sugarcane producer, growing it on more than 5 million hectares in States such as Uttar Pradesh, Maharashtra, and Karnataka. Press mud is produced in large volumes through the process of sugar manufacture, a rich, organic nutrient by-product remaining after juice clarification.
Press mud is very promising as a feedstock for biogas generation and has approximately 30–40 per cent organic content, which is easily digestible in anaerobic conditions. On average, 1 tonne of press mud can generate 80–100 m³ of biogas since India produces more than 12 million tonnes of press mud per year. In contrast to some of the crop residues that must undergo pre-treatment, press mud is half-processed and available for digestion, and hence it is cost-effective and efficient as a CBG plant input. The by-product slurry following digestion can also be utilised as an organic, high-quality fertiliser, completing the circle of nutrients.
Napier grass: The green fuel crop
Napier Grass (Pennisetum purpureum), or Elephant Grass, is rapidly emerging as one of the best feedstocks for bioenergy, particularly as compressed biogas (CBG). Indigenous to tropical regions, it thrives best in Indian agro-climatic conditions and yields just unimaginably high biomass yields of 100 to 250 tonnes per acre annually, based on the type of Napier, soil quality, and weather. This consistent yield ensures a year-round, consistent supply of feedstock for large-scale commercial CBG plants. Napier Grass, as a C4 plant, also efficiently fixes carbon dioxide during growth, which sequesters carbon and generates closed carbon cycles that minimize greenhouse gas emissions, thereby helping reach the targets of clean energy.
Napier Grass has a high biogas potential because it contains high volatile solids content and a balanced carbon-to-nitrogen ratio. For instance, if one tonne of fresh Napier grass contains 22 per cent total solids (TS), i.e., 220 kg solid content. Of this, if 80 per cent is Volatile Solids (VS), the part which can be converted to biogas, then there are 176 kg of VS. As Napier generally produces 0.40 to 0.45 cubic meters of biogas per kg of VS, this amounts to a biogas production of about 70–80 cubic meters per tonne of fresh biomass. Aside from its energy contribution, it also enhances environmental sustainability by preventing soil erosion and, as a good source of nutritious fodder for animals, making it a valuable commodity as a circular, climate-resilient resource.
Integrating biomass streams towards scalable CBG infrastructure
In order to achieve the country’s goal of 5,000 CBG plants by 2025 and produce 15 MMT of CBG per year, it is necessary to integrate various biomass streams like press mud, crop residues, and Napier Grass. By doing so, feedstock will be readily available throughout the year, lower the operational risks, and achieve maximum energy yields.
Challenges such as biomass logistics, seasonality of feedstock supply, and financing infrastructure must be addressed with firm policy support, incentives to farmers, and public-private partnerships. Farmer co-operatives and village-level aggregation centres have been exemplary models in reducing collection and delivery complexity.
The author is the Founder & CEO of CEID Consultant and Engineering Pvt Ltd
Published on July 26, 2025
