Greener Steel Breakthrough: Rice Husk Pellets Trial Proves Viable Path in India

The World-First Trial at Jindal Steel

In a groundbreaking development for sustainable manufacturing, researchers have successfully demonstrated the use of rice husk pellets as a coal substitute in steel production. Conducted at Jindal Steel's facility in Odisha, India, this trial marks the first commercial-scale integration of agricultural waste into gasifiers for syngas production essential to the direct reduced iron (DRI) process. The experiment blended 5% and 10% rice husk pellets with coal, producing sustained syngas flows without any dip in performance, paving the way for greener steel via rice husk pellets in India.

This initiative highlights how agricultural byproducts can transform waste management challenges into opportunities for decarbonization in heavy industry. Rice husks, typically burned or discarded, were locally sourced, underscoring the trial's practicality for regional steel plants.

Understanding the DRI Process and Syngas Role

Direct Reduced Iron (DRI), also known as sponge iron, involves reducing iron ore in its solid state using syngas—a mixture of hydrogen and carbon monoxide—rather than melting it in a blast furnace. In India, DRI accounts for a significant portion of steel production, primarily through coal-based rotary kilns, which contribute heavily to emissions. Syngas is generated in gasifiers where coal or now biomass is partially combusted with limited oxygen.

The process works step-by-step: First, rice husk pellets are fed into the gasifier alongside coal. High temperatures (around 900-1200°C) pyrolyze the biomass, releasing volatiles and producing syngas. This syngas then reduces iron ore pellets or lumps in the DRI kiln, yielding high-metallization iron suitable for electric arc furnaces (EAF). Traditional coal gasification emits substantial CO2, but biomass like rice husk is carbon-neutral when sustainably sourced, as it recycles recent atmospheric CO2.

Key Collaborators Driving Innovation

The trial's success stems from a strong India-Australia partnership. Australia's CSIRO led the technical execution, funded by the India-Australia Green Steel Research Partnership. The Indian Institute of Science (IISc) Bangalore provided critical expertise through its incubated startup RESCONS Solutions Pvt Ltd, under the Foundation for Science, Innovation and Development (FSID). Jindal Steel & Power Ltd (JSPL) hosted the trial at their Odisha plant, validating real-world applicability.

IISc's involvement exemplifies how premier Indian universities are bridging academia and industry for sustainable solutions. Researchers like Professor Govind S. Gupta emphasized, "We are proud to pioneer biomass in steelmaking, supporting India's greener industrial practices."Explore research positions in materials science and sustainable engineering at institutions like IISc.

India's Steel Sector Emissions Crisis

India, the world's second-largest steel producer, faces acute decarbonization pressures. The sector emits about 2.55 tonnes of CO2 per tonne of steel—higher than the global average of 1.8 tonnes—and accounts for 12% of national emissions. Coal-heavy DRI processes dominate, with 80% of DRI production relying on coal, exacerbating air pollution and contributing to over 30,000 deaths annually from crop residue burning.

With capacity projected to double to 300 million tonnes by 2030 and reach 500 million by 2047, emissions could soar unless alternatives like biomass integration are scaled. The Ministry of Steel's net-zero roadmap by 2070 includes biomass co-firing, green hydrogen, and scrap recycling.

Rice Husk: From Agricultural Waste to Valuable Resource

India, the largest rice producer globally, generates vast rice husk quantities. Processing 100 kg of paddy yields ~20 kg husk, leading to over 100 million tonnes annually. Much is burned openly, worsening air quality, but pelleting densifies it for efficient transport and gasification.

• High silica content (15-20%) and calorific value (~14 MJ/kg) make it ideal for syngas.
• Surplus crop residue: 228 million tonnes/year, mappable to steel plants via interactive tool.
• Circular economy: Reduces waste burning mandates (e.g., 5% biomass in power plants).

This trial positions rice husk as a scalable, low-cost coal alternative, especially in rice belts like Odisha.

Trial Results: Proven Performance and Stability

Over multiple runs, 5-10% blends maintained syngas quality matching pure coal. No blockages, stable temperatures, and consistent reduction efficiency were achieved. CSIRO's Warren Flentje noted, "Biomass can replace coal without compromising performance."

Key metrics:

Validates prior lab studies on rice husk volatiles aiding iron reduction.

Environmental and Economic Implications

Scaling could cut emissions by 1.19 t CO2/t steel, up to 50% sector-wide (357 Mt/year saved). Economically, utilizes waste (valued at zero cost), creates jobs in pelletizing/logistics, and lowers import dependence on coking coal.

• Air quality boost: Less residue burning.
• Rural economies: Agri-steel integration.
• Competitive edge: Greener exports amid EU CBAM.

Challenges in Scaling Greener Steel Production

While promising, hurdles remain: Supply chain logistics for consistent pellets, higher blends (20-30%), ash handling (silica buildup), and policy incentives. Coal economics and infrastructure retrofits pose barriers, but regional co-location eases logistics.

Next: Pilot higher blends, diverse biomass, DRI impact assessment.

Role of Universities in Green Steel Research

IISc's CGPL lab has long researched biomass gasification, now commercialized via RESCONS. Universities drive innovation, from patents to startups, positioning India as green steel leader. Explore India research jobs.

Photo by Ted Balmer on Unsplash

Future Outlook and Global Relevance

This aligns with Mission Green Steel, green hydrogen pilots, and international pacts. Keith Vining (CSIRO) eyes regional expansion. Globally, biomass-DRI could aid net-zero by 2050.

In summary, the rice husk pellets trial proves greener steel is feasible in India, blending research, industry, and waste valorization. For academics, it's a call to innovate in sustainable metallurgy. Check Rate My Professor, Higher Ed Jobs, Career Advice, University Jobs, or post a job.