Source: MoPNG & PPAC

Biofuel Feedstock producers—such as farmers and agro-processing industries—play a vital role in supplying raw materials for the production of first-generation (1G) ethanol, second-generation (2G) ethanol, Compressed Biogas (CBG), and Sustainable Aviation Fuels (SAF). 

Classification of feedstock

There are four main generations of biofuel feedstocks, each defined by the type of raw material used and the technology applied:

First-generation biofuels are derived mainly from food crops and animal feed sources. Their production uses established processes such as fermentation, distillation, and transesterification, which is why they are commonly referred to as “conventional biofuels.” These methods focus exclusively on fuel generation, with non-fuel by-products typically treated as waste, making membrane technologies unnecessary. Biodiesel is produced through the transesterification of vegetable oils and animal fats, while bioethanol or butanol is obtained by fermenting starches and sugars. Common feedstocks for these biofuels include: 

– Animal fats, 

– Vegetable oils, 

– Oily seeds like soybean, rapeseed, mustard, and sunflower, and 

– Starch-rich crops such as maize, sugarcane, sorghum, and cassava.

Second-generation biofuels are produced from agricultural lignocellulosic biomass through biochemical or thermochemical processes. The feedstocks primarily include-

• Non-food sources such as agricultural residues (e.g., cereal straw, sugarcane bagasse), 
• Forest residues, 
• Organic waste from municipal solid waste, and 
• Dedicated energy crops like fast-growing grasses and short-rotation forests. 

Unlike first-generation biofuels, which rely on food-based feedstocks, second-generation biofuels utilize plant-based residues and waste materials, offering a more sustainable and resource-efficient approach. This method not only enhances fuel recovery but also enables the generation of secondary raw materials, reducing overall energy costs and minimizing waste output. As a result, second-generation biofuel production is considered more economically viable. To improve efficiency and yield, researchers incorporate techniques such as membrane filtration and biorefinery integration. Additionally, various mesophilic and thermophilic microorganisms are employed in both batch and continuous processes to produce biofuels along with valuable by-products like organic acids and amino acids.

Third-generation biofuels utilize non-food-based, environmentally adaptable resources such as microalgae, yeast, and fungi, animal oils, fish oil, waste cooking oil, and animal fats. Microalgae can yield various fuels, including biodiesel, bioethanol, biogas, and jet fuel. This generation of biofuels relies on: 

– Genetic engineering of algae and other aquatic biomass, 

– Chemical extraction of bio-oils, and 

– Pyrolysis of algal cultures. 

These biofuels are primarily obtained through transesterification or hydrotreatment of algal oil, offering significantly higher biofuel yields per year compared to first-generation biofuels derived from conventional crops. Both second- and third-generation biofuels are still under active development and are collectively known as advanced biofuels due to their improved efficiency and sustainability. An additional benefit of these biofuels is their potential to reduce water pollution and lower the burden on waste management systems.

Fourth-generation biofuels are produced using advanced technologies and genetically modified (GM) organisms, particularly GM algae, along with photobiological solar fuels and electro-fuels. GM algae are engineered to enhance photosynthetic efficiency, improve light absorption, and increase biofuel yield. Genetic modification of microalgae also enables improved oil extraction through methods like cell autolysis and enhanced secretion systems. Tools like zinc-finger nucleases (ZFN), transcription activator-like effector nucleases (TALEN), and CRISPR/Cas9, are commonly used for genome editing in this context.

These biofuels rely on abundant, cost-effective, and renewable resources such as solar energy and engineered biomass. The Fourth-generation biofuels incorporate technologies such as hydroprocessing, oxy-fuel combustion, and thermochemical conversion. These processes focus on using genetically optimized feedstocks not only for efficient fuel production but also for carbon capture and storage during both cultivation and processing, positioning them as a carbon-negative energy solution.

Graph: Ethanol contribution share by different feedstocks (percentage)2023-24

Key challenges and the path forward

Although India has abundant biomass resources, creating a reliable, cost-effective supply chain for collecting, storing, and transporting feedstock for waste-based biofuels presents considerable challenges. The key issues include:

Lack of Farmer Incentives: Farmers often have no assured economic returns for supplying agricultural residues. Without clear incentives or purchase guarantees, much of the biomass is either burned or discarded. Many farmers are unaware of its value as biofuel feedstock, leading to low participation even when collection systems exist. Uncertainty around pricing and payments further discourages their involvement.

Inconsistent Biomass Quality: Ethanol production requires biomass with consistent moisture content, particle size, and minimal inert material. However, due to the absence of standardized collection practices, the quality of biomass reaching refineries is highly variable. Farmers generally lack awareness of proper handling methods, and the limited availability of collection machinery worsens the problem. Because biomass must be cleared quickly after harvest, farmers often turn to informal aggregators who also operate without standardized processes.

Infrastructure Gaps: The supply chain suffers from inadequate infrastructure, especially in terms of decentralized storage and sorting facilities. Currently, collected biomass is transported directly to refineries, increasing logistics time and cost. The lack of regional hubs forces farmers to manage collection and transport themselves, despite not having access to the necessary equipment. Developing a hub-and-spoke collection model would help address these issues. Setting up local storage and processing centers near farming regions would streamline feedstock collection, maintain quality standards, and reduce transportation costs.

While these challenges are noted in the context of ethanol production, similar obstacles affect the supply chain for other waste-based biofuels, underlining the need for coordinated policy and infrastructure development.

Scaling up second-generation (2G) biofuels in India requires a focused strategy involving policymakers, farmers, and industry players. To drive India’s ethanol blending ambitions, the initial step should be to set explicit national targets for second-generation (2G) biofuels. Similarly, India should establish binding targets for other advanced fuels—such as compressed biogas (CBG) and sustainable aviation fuel (SAF)—in sync with technological advancements underway.

Equally important is raising farmer awareness about the economic value of agricultural residue as biofuel feedstock. Organisations such as Krishi Vikas Kendras, farmer-focused NGOs, and agricultural universities should be engaged to provide training on proper collection practices and highlight potential income opportunities.

A decentralised biomass collection and storage system is also essential. State governments, in partnership with oil marketing companies, may identify locations for storage depots and facilitate land acquisition. The Crop Residue Management Guidelines issued in 2023, which propose shared investment in collection equipment, must be urgently implemented to support this infrastructure.

In addition, providing more incentives will encourage farmers to participate. States can provide direct financial support, as demonstrated by Haryana’s biomass collection subsidy. Expanding access to carbon credit markets through the Green Credit Programme—by including agricultural feedstock—would provide an additional revenue source and help strengthen India’s biofuel supply chain.

Conclusion

India’s biofuel sector holds strong potential to enhance energy security, reduce carbon emissions, and benefit rural communities. However, realizing this potential requires addressing critical challenges in feedstock supply, farmer participation, and infrastructure. Setting up clear national targets, expanding farmer incentives, building decentralized collection hubs, and raising awareness are essential steps. With coordinated efforts from policymakers, industry, and farmers, India can build a resilient, sustainable, and inclusive biofuel ecosystem for the future.