Praj Industries & CSIR-CRRI Build Highway Using Lignin Bio-Bitumen
Hon’ble Minister Shri Nitin Gadkari inaugurated India’s first national highway constructed with lignin based bio-bitumen blended up to 15%, achieving a 70% reduction in greenhouse gas (GHG) emissions compared to conventional fossil-based bitumen.

India’s first lignin bio-bitumen national highway can save billions in foreign exchange and promote eco-friendly solutions. A joint collaboration between the CSIR-CRRI, and Pune-based biotech firm Praj Industries, the project is a significant step forward in addressing the environmental and supply chain challenges posed by traditional bitumen production, which is derived from lignin - a crop residue.
By blending 15% bio-bitumen into the asphalt, a 1-km stretch was constructed as part of the Nagpur-Mansar National Highway project. The use of lignin as a sustainable binder marks a breakthrough in flexible pavement technology, addressing bitumen scarcity and reducing India’s reliance on imports, which currently account for 50% of the supply. This innovation will support global sustainability goals by generating revenue for bio-refineries, mitigating stubble burning, and cutting greenhouse gas emissions by at least 70% compared to fossil-based bitumen. Leveraging abundant lignocellulosic biomass, it aligns with India’s vision for sustainable industrial growth. What’s more, the road is 40% stronger than traditional asphalt road.

Praj Industries unlocking the full potential of bio-products

Shri Atul Mulay, President, Praj Industries emphasized the importance of sustainable solutions in India’s infrastructure sector, addressing issues like crop residue burning, and the high import cost of petroleum-based bitumen.
He said that India, with around 25 million metric tons of surplus agricultural crop residues, faces challenges in burning the residues, which farmers often resort to as a quick and cost-effective way to clear fields for the next crop planting. However, this practice causes severe environmental and health issues due to the aggravated air pollution, greenhouse gas emissions, and soil degradation, which also pose a major hurdle to sustainable agriculture.
Praj, a leading global player in the biofuels and bioenergy sector, has made significant progress in utilizing crop residues for bioethanol and biogas production. The company operates Asia's largest bioethanol plant, which is powered by EnfinityTM technology, designed to produce 100 KLPD of bioethanol and 60 to 70 tons per day of lignin, a co-product. Praj has also developed crop residue-to-compressed biogas (CBG) production technology, known as RenGasTM. The 12 TPD CBG plant can produce 18-20 tonnes/day of biogas of biogas.

CSIR-CRRI helping road construction industry in developing sustainable infrastructure
Working with CSIR-CRRI, the road construction industry is paving the way for sustainable infrastructure solutions, including flexible pavement construction. Central Road Research Institute, a premier national institute under the Government of India, tested and evaluated lignin bio-bitumen on various dosages of lignin and developed the optimum blending process to achieve desired strength and durability. Following successful lab trials, this lignin bio-bitumen was used to construct a service road on the Vadodara-Halol Highway in Gujarat. After two years and three monsoon cycles, CRRI's evaluation confirmed the material’s reliability, stability, and performance, confirming the potential of bio-bitumen.
After this successful trial, CSIR-CRRI in collaboration with the Ministry of Road Transport and Highways (MoRTH), supported the development of a bio-bitumen road segment on the National Highway at Nagpur-Mansar. In this project, lignin bio-bitumen was blended with conventional CRMB bitumen up to dosage of 15%.. CRRI carefully conducted the asphalt mix design with lignin bio-bitumen, and the mix was prepared under their supervision to be used for road construction. The mix was transported to the construction site, spread uniformly using a mechanical paver, and compacted with a roller to achieve the desired density and quality.
“This research is redefining sustainable green construction materials, and, together with CRRI, we continue to push the boundaries of innovation in paving the way for eco-friendly, climate-resilient infrastructure development,” said Shri Mulay.
Solutions recommended by Shri Nitin Gadkari

Shri Nitin Gadkari, Hon. Minister of Road Transport and Highways, congratulating Praj Industries for developing the innovative technology, said, "The bio-bitumen developed by Praj, in collaboration with CSIR-CRRI, is a significant step toward sustainability. It reduces our dependency on imported bitumen and turns agricultural waste into a valuable resource. This initiative is a revolution that will transform India’s agricultural and rural sectors, and I am confident that this technology will become a model for other regions."
He highlighted the role of farmers in the energy sector, transforming them from "annadata" (food providers) to "urja data" (energy providers) through conversion of biomass into various fuels like Bioethanol, Bio CNG and Bio Hydrogen. He emphasized the potential of this project to reduce India’s import bill and promote energy independence. He also called for policies that would scale up the use of bio-bitumen in road construction, making it a national standard. He pointed to the government's success in promoting ethanol production from maize, which has doubled the price of maize from ₹1200 to ₹2400 per quintal and significantly increased cultivation. This initiative has the potential to raise farmers' incomes by ₹1.5 to ₹2 lakh per acre.
He highlighted the benefits of CNG vehicles, such as Bajaj's two-wheeler model in Pune, which reduces fuel costs by up to 60%, and discussed the use of bamboo and rice straw for producing bio-CNG, which could make areas like Ramtek and Mansar self- sufficient in CNG. He informed that about 400 initiatives to prevent burning rice straw, by using it in projects, are also underway across the country, and a CNG production project in Tumsar Devadi is set to start soon.
Use of biomass materials, along with rubber powder from waste tyres in road construction, can help build roads that are 40% stronger than roads made with traditional bitumen. Such usage will reduce India’s ₹25,000 crore annual expenditure on imported bitumen, promote a cleaner environment, and create over 5 lakh rural jobs. Shri Gadkari Ji assured that his ministry would work closely with stakeholders to fast-track the process and create a robust framework for widespread deployment of this technology.
He is optimistic that farmers will also contribute significantly towards production of hydrogen and other renewable energy resources, further transforming agricultural byproducts into valuable commodities. This would foster new industries in rural areas, particularly in regions like Bhandara, Gondia, Nagpur, and Chandrapur, where agricultural waste is abundant.
The Lignin Bio-Bitumen Technology

Dr. Siddharth Pal, Principal Scientist at Praj Industries, explaining the Lignin Bio-Bitumen Technology process, informed that their proprietary technology refines crude lignin into Lignin Bio-Bitumen and has the potential to replace fossil-based bitumen in the road infrastructure industry. “Our technology is robust and can handle different agricultural feedstocks, such as sugarcane, grass, etc. We have developed the lignin bio-bitumen process at a pilot plant and can now generate higher quantities.”
In 2022, we demonstrated this technology on a service road on the highway in Gujarat, and recently CRRI evaluated the performance of this road. I’m happy to share that after 2.5 years and three monsoon seasons, the performance of the road is very good, and our bio-bitumen road's strength is better compared to conventional bitumen roads. The deflection values of the bio-bitumen road are within the same range as conventional bitumen roads. In a recent trial conducted on the Nagpur-Mansar highway, we used CRMB as the base binder and replaced the bitumen by about 15% with bio-bitumen. This is Asia’s first lignin-based Bio Bitumen Road on the main highway.”
The success of this project will be determined over the next two years after CRRI evaluates the road’s performance under heavy traffic and varying weather conditions. CRRI will submit a detailed report on the results, following which, bitumen manufacturers will be directed to develop a policy for sourcing lignin for blending purposes.

“The availability of biomass in India is approximately 220 million metric tons. We have rice straw, sugarcane bagasse, cotton stalk, and other hard wood and energy crops. Approximately 20-25 million metric tons of lignin bio-bitumen can be blended with fossil bitumen to make lignin bio-bitumen. We have tested blending up to 15% of this lignin bio-bitumen with fossil bitumen. The savings in GHG (Greenhouse Gas) emissions are estimated to be 0.3 million metric tons. This technology helps produce both the main products and the co-products,” said Dr. Pal.
CSIR - CRRI research to support saving of billions

Dr. Ambika Behl, Sr. Principal Scientist at CSIR-CRRI, shared technical insights on the Bio-Bitumen Road Construction trials, and the successful implementation on a 1-kilometer test road. The road’s performance was evaluated over multiple monsoon cycles, showing improved durability compared to conventional bitumen roads.
She explained the rationale behind the development of bio-bitumen, stating that the Hon’ble Minister had once said, "Can’t we empower our farmers to help produce bitumen so that we do not need to import it; which costs 49% of our country’s budget for road construction?"
“I am pleased to inform the Hon’ble Minister that the day has finally arrived. What drove us to undertake the development of bitumen was the widespread stubble burning across the country during the November and December months, which aggravate air pollution. Another major issue was the high cost of bitumen required for road construction, making up 49% of the cost. Our country spends 25,000 to 30,000 crores annually to import bitumen.”
“For the past 2 years, CRRI has been working on this, and have now found solutions for both the issues. We have created a 1-km road using bio-bitumen, and farmers can now help provide bio-bitumen instead of burning stubble. We can replace 15% of imported bitumen with bio-bitumen and save at least Rs 4,000–4,500 crores. India would require about 15 lakh tons of bio-bitumen to achieve 15% blending with conventional bitumen.”
There are several ways to make bitumen from biomass, but under the guidance of the Hon’ble Gadkari Ji and Director-CRRI, we opted for a process that would be economical, durable, and sustainable. CRRI has been working on three different methods: pyrolysis of rice straw, lignin-based bio-bitumen, and using waste materials. A few months ago, we used our patented pyrolysis technology to replace 30% of bitumen with bio-bitumen on a NH in the Northeast.

She added, "CRRI’s collaboration with Praj Industries has accelerated CRRI's progress. The lignin-based bio-bitumen technology has been successfully introduced into the road sector. We have tested the bio-bitumen road under excessive rain, extreme temperatures, and excessive loading to ensure that there would be no potholes, ruts, or cracks. The results have shown that the strength of the lignin-based bio-bitumen is significantly higher compared to conventional roads, and all parameters indicate that this technology is very effective.”
“I am confident that in a few years, bio-bitumen will come from every corner of the country, and agriculture can become the engine of growth for our nation. However, we will need the assistance of MoRTH and have therefore urged the Ministry to create policies/guidelines, allowing at least 10% blending of bio-bitumen, even though our trials have targeted 30%. We need the Ministry’s support in making green roads, not smoky roads!"

Shri Manoranjan Parida, Director, CSIR-CRRI, expressed the Institute’s commitment to advancing the technology further and that development would continue with fine-tuning the process and scaling it up for nationwide adoption. He expressed gratitude to the Honorable Minister, under whose guidance CSIR-CRRI has succeeded in creating the country’s first national highway using lignin bio-bitumen. “About two years ago, when I became Director at CRRI, we had a meeting with the Minister, where we set a target for 30% bitumen replacement. In this particular project, lignin-based bio-bitumen has replaced about 15% of bitumen, and we will continue to develop this technology to increase bio-bitumen substitution and will scale it up for commercial use at the national level.”
“On December 18th, during a conference in Jaipur, the Deputy Chief Minister of Rajasthan had also expressed interest in creating bio-bitumen roads in the state. In addition to national highways, we are exploring how this technology can be applied to rural roads and state highways as well,” he added.

Praj Industries’ Make in India initiative

Dr. Pramod Chaudhari, Founder Chairman, Praj Industries, said, "The inauguration of India’s first sustainable road using a lignin-based bio-bitumen is a proud moment for Praj Industries and a testament to India’s commitment towards a greener and self-reliant future. This innovative lignin-based bio-bitumen, developed under the ‘Make in India’ initiative, not only replaces fossil-based bitumen but also helps save significant foreign exchange, strengthening our nation’s vision of Atmanirbhar Bharat.”
“We thank the Hon. Minister of Road Transport and Highways, Shri Nitin Gadkari, for his visionary leadership and unwavering support in fostering sustainable infrastructure development. As we look toward the goal of Viksit Bharat 2047, we are also advancing our efforts in bio-hydrogen development, which holds immense potential to transform India’s energy landscape and contribute to a sustainable future. At Praj, we remain dedicated to pioneering eco-friendly solutions contributing to nation-building and global climate goals."
CRRI and PRAJ signed a MoU in the presence of Shri Nitin Gadkari Ji to develop different grades of bio-bitumen and deploy the technology across the country.
Prospects & Challenges for widespread adoption
Lignin-based bio-bitumen represents a leap forward in the quest for sustainable infrastructure solutions. By utilizing renewable agricultural waste, this innovative material offers a host of benefits, including reduced carbon emissions, enhanced road durability, and significant cost savings. As the government, businesses, and researchers continue to invest in this technology, lignin-based bio-bitumen could reshape the future of road construction, contributing to cleaner, greener, and more resilient infrastructure for generations to come.
The future of lignin-based bio-bitumen looks promising as both an eco- friendly and cost-effective alternative to petroleum-based bitumen. With continued innovation, increased awareness, and policy support, lignin-based bio-bitumen could soon become the standard for sustainable road construction worldwide.
While lignin-based bio-bitumen holds immense promise, there are challenges to its widespread adoption. One of the key obstacles is scaling up production and ensuring the availability of lignin at an affordable price. As demand for bio- bitumen grows, investing in biomass collection infrastructure and processing facilities will be crucial. Policy support from the government and further research into optimizing the properties of lignin- based bio-bitumen will help make it a mainstream material in road construction.
Understanding Lignin-Based Bio-Bitumen
Derived from renewable biomass, lignin-based bio-bitumen is poised to transform the road construction sector by replacing petroleum-based bitumen with a greener alternative. A complex organic polymer lignin is found in the cell walls of plants, primarily in agricultural residues such as wheat straw, rice husk, and corn stalks.
Traditionally, bitumen used in road construction is derived from petroleum, a non-renewable resource. However, lignin-based bio- bitumen is produced by extracting lignin from these agricultural residues and refining it into a sustainable binder for asphalt.
This bio-bitumen serves as a direct replacement for petroleum- based bitumen, blending well with conventional asphalt to improve its properties while reducing reliance on fossil fuels.
Features & Benefits
- Sustainable and Renewable: Unlike petroleum-based bitumen, which is sourced from fossil fuels, lignin-based bio-bitumen is derived from agricultural by-products, making it a renewable resource. Its production helps reduce waste from farming, addressing environmental concerns like stubble burning.
- Carbon Footprint Reduction: The use of lignin in bio-bitumen results in a significant reduction in carbon emissions. When crop residues like rice straw or wheat husk are converted into bio-bitumen, they help mitigate the environmental impacts associated with agricultural waste burning, which contributes to air pollution and greenhouse gas emissions. Studies suggest that lignin-based bio-bitumen can reduce emissions by at least 70% compared to traditional petroleum-based bitumen.
- Enhanced Road Durability and Strength: Bio-bitumen is known for its superior bonding properties and resistance to cracking, making it ideal for high-traffic roads that require long- term durability. It has also shown resistance to aging, meaning roads constructed with it will require less maintenance over time, reducing long-term upkeep costs. Studies have shown that roads constructed with lignin-based bio-bitumen can be up to 40% stronger than traditional asphalt roads, offering better resistance to wear and tear.
- Cost-Effective: As bio-bitumen reduces dependence on expensive imported petroleum-based bitumen, it offers potential cost savings for road construction. Use of locally available agricultural residues as raw materials can lower the overall production cost, making it a more affordable option for large-scale infrastructure projects. By replacing even a small percentage of conventional bitumen with lignin-based bio-bitumen, India could save substantial amounts on import costs.
- Improved Performance in Extreme Weather Conditions: Lignin-based bio-bitumen has been shown to perform better than conventional bitumen in extreme weather conditions, such as heavy rainfall or intense heat, making it particularly effective for regions that experience harsh climate conditions.
- Waste-to-Wealth: Agricultural residues, which would otherwise be discarded or burned, are transformed into valuable bio- bitumen, promoting a circular economy that supports both sustainable agriculture and infrastructure development.
- Energy Independence: By leveraging locally sourced biomass to produce bio-bitumen, countries can reduce their dependence on petroleum, making their infrastructure development more energy-independent and resilient to fluctuations in global oil prices.
- Job Creation: The adoption of lignin-based bio-bitumen technology can create new jobs in both the agricultural sector and the road construction industry. The processing of agricultural waste into bio-bitumen opens up opportunities for rural employment and supports local economies.