Two species of grass are feeding the world's largest bamboo-based ethanol plant that was inaugurated by Prime Minister Narendra Modi in eastern Assam's Golaghat district on September 14.

Officials of Numaligarh Refinery (NRL) said they are banking on a steady supply of two bamboo types from at least three of the eight northeastern States to run their new ₹5,000-crore bioethanol plant optimally. These species are balco (Bambusa balcooa) and tulda (Bambusa tulda).

The bioethanol plant is near NRL's petroleum refinery, whose capacity is being tripled from 3 million metric tonnes per annum to 9 MMTPA. Oil India Limited (OIL) has almost a 70% stake in the refinery located 260 km east of Guwahati.

Apart from 48,900 metric tonnes of ethanol, the bioethanol plant has been designed to yield 11,000 tonnes of acetic acid per annum, 19,000 tonnes of furfural from raw bamboo stock per annum, and 31,000 metric tonnes of food-grade liquid carbon dioxide.

Also Read | PM Modi inaugurates India's first bamboo-based ethanol plant in Assam

Bamboo supply chain

"Arunachal Pradesh, Assam, and Meghalaya have bamboo cover of more than 10,000 sq. km. We have established a supply chain of farmers and bamboo-chipping units run by local entrepreneurs within 300 km of the bioethanol facility to supply the feedstock," NRL Chairman Ranjit Rath, who is also the Chairman and Managing Director of OIL, said after the refinery's 32nd annual general meeting on Tuesday (September 16, 2025).

Bhaskar Jyoti Phukan, the NRL's Managing Director, explained why two of some 90 species of bamboo grown across the northeast are preferred for the bioethanol plant.

"The balco and tulda varieties have a high cellulose content when they are three-and-a-half years old, which is ideal for the process of producing a high concentration of bioethanol to be used as fuel," he said.

Studies have shown that the balco and tulda bamboos have an alpha-cellulose content in the range of 42.7-60.98%.

The bamboo supply chain was prepared ahead of the establishment of the bioethanol plant, with the NRL authorities distributing saplings to farmers in Assam alone. "Each sapling costs ₹27 in the open market, but we provided the farmers free of cost because we had them grown by start-ups through tissue culture," Mr. Phukan said.

Farmers are being paid ₹65-70 per bamboo pole. They have the option of supplying to the plant directly or through the bamboo-chipping units set up strategically around the plant.

Earlier, Dr. Rath said NRL's net worth reached an unprecedented high of ₹16,069 crore in March 2025, a 25% increase over the March 2024 figure. Revenue from operations increased from ₹23,731 crore to ₹25,147 crore during this period, a growth of 6%.

However, profit after tax dipped from ₹2,160 crore in the 2023-04 financial year to ₹1,608 crore in the last fiscal year. "The moderation in profitability was primarily due to the narrowing spread between product and crude oil prices in the global market, which led to a reduction in the gross refining margin from $13.17 per barrel to $5.14 per barrel," he said.

World's largest bamboo-based ethanol plant getting pick of the north east's grass