NIT Rourkela patents green technology for faster, cleaner black terracotta production

In a significant breakthrough for India’s traditional pottery sector, researchers at the National Institute of Technology (NIT) Rourkela have developed a patented green technology that dramatically reduces the time and environmental impact involved in producing black terracotta wares.

The new method, patented under Patent No. 572754 (Application No. 202531008090), cuts the firing duration from nearly 48 hours to less than 7 hours, while eliminating harmful emissions that typically affect artisans’ health. The innovation is expected to revive and modernise generations-old black pottery craft practiced across India and neighbouring regions.

The research team is led by Prof. Swadesh Kumar Pratihar, Professor of Ceramic Engineering, along with Shiv Kumar Verma, Senior Technical Assistant, and Dr. Rupesh Mandal, Research Graduate at NIT Rourkela.

Traditional black terracotta is produced through open-pit firing using organic materials such as cow dung, straw and wood, releasing toxic gases like carbon monoxide, sulfur oxides, and nitrogen oxides. The process is labour-intensive, time-consuming and requires skilled artisans and specialised clay.

The patented technique replaces the old method with indirect heating inside an enclosed, air-depleted chamber, where pyrolysis of carbonaceous oils generates a natural reducing atmosphere essential for the signature black colour. The controlled environment ensures a uniform black finish without the need for open fires or large quantities of organic fuel.

Prof. Pratihar said the innovation blends traditional artisan knowledge with modern technology, offering a cleaner, faster and more scalable solution. 

“This sustainable production process eliminates health hazards and environmental pollution,” he added.

The new process is expected to broaden the availability of black terracotta wares beyond traditional centres such as Nizamabad in Uttar Pradesh and Nixi village in Tibet, where long-established techniques involve complex firing cycles and heavy smoke.

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NIT Rourkela’s technology marks a major step toward preserving traditional crafts while promoting sustainable development, offering artisans across India a viable, modern production method with minimal ecological footprint.