BackCSIR, Godavari Sugar to set up India’s first sugar cane biorefinery
CSIR, Godavari Sugar to set up India’s first sugar cane biorefinery
PremiumWaste management: The biorefinery at GSML will be equipped to produce ethanol from bagasse, the fibre left after the juice has been squeezed out of sugar cane, though the technology is still at a prel
New Delhi: The Council of Scientific and Industrial Research, or CSIR, has teamed up with Karnataka-based The Godavari Sugar Mills Ltd, or GSML, to set up the country’s first biorefinery to convert crushed sugar cane into industrial raw materials such as cellulose and lignin.
Cellulose and lignin are extensively used in the pharmaceutical, textile and food preservatives industries.
The biorefinery at GSML, part of the Somaiya Group, will be equipped to produce ethanol from bagasse, the fibre left over after the juice has been squeezed out of sugar cane, though the technology is still at a preliminary stage.
“We believe that once scaled up to commercial levels, there will be international interest in the cellulose we’re able to manufacture because the costs will be extremely competitive," said Samir Somaiya, director, GSML.
Somaiya said he hopes to scale up production of cellulose and other raw materials at the plant in Sameerwadi, 500km from Bangalore, to about 5,000 tonnes in three-four years. Financial terms of the alliance were not disclosed. The technology for the project was developed by scientists at the National Chemical Laboratory, or NCL, a CSIR lab in Pune, who have improved a range of processes that can break down bagasse into high-grade cellulose, lignin and hemicellulose.
These are used in making a range of products, including paper, cardboard, textiles from cotton and fibre, water soluble adhesives, cement, dyes and so on. “Cellulose of the purity we’ve made costs between Rs30 and Rs40 a kg and the bagasse costs Rs1-2 a kg. So you can see the value addition we’ve been able to make," said A.J. Varma, deputy director at NCL.
Cellulose prices are extremely variable and depend on their application and processes employed to refine them.
“Chemical derivatives of cellulose, such as cellulose acetate, sell for nearly Rs200 a kg," added Varma.
Varma heads the Rs15 crore project at NCL, launched in 2002 under CSIR’s New Millennium Indian Technology Leadership Initiative, which funds futuristic high-risk technologies along with the private sector. Due to a decline in sugar prices globally last year and surplus production in India, domestic manufacturers are increasingly looking at deriving as much value as possible from the non-food component of sugar cane.
S. Sivaram, director of NCL, said: “Just being able to derive ethanol from a biorefinery will never make it viable. It’s crucial to be able to extract as many value-added products as possible."
To help sugar cane farmers with excess stocks, the government in 2007 allowed companies to directly make ethanol from sugar cane juice for the first time and fixed the price of ethanol at Rs21.50 a litre. “By diversifying into related segments, sugar firms not only insulate themselves from price volatility, but also earn carbon credits and avail (of) income tax benefits from power generation," said R. Sreesankar, head of research, IL&FS investmart Ltd, a brokerage firm, in an interview to Reuters.
Theory and practice
Getting cellulose from bagasse involves a step-by-step separation of long chains of sugar polymer molecules and its lignin components.
NCL scientists have perfected a steam treatment in which the lignocellulose is steamed in a reactor at a high pressure and at a particular time, the pressure is suddenly eased. “That shock blasts the bagasse into its constituents and thus in a single shot, we get nearly 99% pure cellulose, after which the chemical treatment begins for further purification," said Varma.
According to data from agriculture ministry, the country produces nearly 300 million tonnes of sugar cane, a third of which, according to CSIR estimates, results in bagasse.
Several sugar mills in the country already use bagasse as fuel for their power mills. “It’s an excellent way to use the bagasse. We are doing that too," said Somaiya. “But eventually we hope that is, so to say, the least best use of bagasse."
To further enhance the productivity of the biorefinery, NCL and Godavari want to produce L-lactic acid, the useful form of lactic acid, from sugar cane juice. L-lactic acid is a base organic compound that’s widely used in the pharmaceutical and food preservatives industry. The technology for this has been developed by another group at the NCL.
“We’re helping farmers add value to sugar cane. While sugar cane juice, as of now, has only an edible benefit to it, we’re helping them with an alternative," said Sanjay Nene, an NCL scientist involved with the lactic acid programme.
“Most of our lactic acid is imported," he said.
Part of the sugar cane biorefinery, the lactic acid facility is expected to scale up to an annual 300 tonnes by the end of the year, Nene added.
Across the globe, policy makers as well as scientists have blamed governments and affiliated agencies for encouraging their farmers to grow crops for fuel rather than food and contributing to the recent global food crisis.
“So the real challenge," said Varma, “would be to ensure that the fuel and all value-added products are not at the expense of food. We are the second largest producer of sugar cane in the world, and nearly a third of all sugar cane ends up as bagasse. So with an annual 90 million tonnes of bagasse, we are talking huge potential."
The ethanol rush
It might still prove elusive. But separate teams of scientists at NCL, along with researchers at Delhi University, IIT Bombay and other CSIR labs such as the National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram, and the Institute of Microbial Technology, Chandigarh, are testing strains of some fungi and other organisms, and zeroing on enzymes that will break down bagasse into ethanol.
Though the basic principles of deriving ethanol from cellulose are known, they’re not yet financially viable and research institutions, worldwide are looking at ways to cut production costs.
“That’s still a long time away, but we’ve got some extremely promising strains," said Mala Rao, an NCL scientist who is working on the programme. Ravi Gupta, a member of the Australian Wheat Board and an expert on sugarcane-ethanol issues, said: “The world over cellulosic ethanol is a promising field of research and if India is close to developing technologies around it, it could be immensely beneficial."
India’s ministry of new and renewable energy, the nodal ministry that looks into alternative energy sources, too, is looking at developing bio-refineries. “We’ve asked IIT Bombay to prepare a feasibility report on bio-refineries," said an official, who didn’t want to be identified.
“The fund for research and development in renewables is Rs600 crore, but bio-refineries are an extremely new idea and lots of factors, such as financial viability, crop prices, must come together before these can be scaled up," this official said.
Countries such as Brazil and the US have successfully tapped commercial grade ethanol from sugar cane juice and maize, respectively. But they involve utilizing the starchy, or food component of these crops, to extract ethanol.
The private sector in the country, too, is eyeing opportunities in bio-refineries and cellulosic ethanol (ethanol from agricultural waste) market. Srinivas Kilambi, director at Reliance Industries Ltd, had in a 2006 presentation at a renewable energy conference, outlined plans for a corn-based biorefinery, (modelled on the US approach for using maize waste). He didn’t respond to an emailed questionnaire.
Utpal Bhaskar contributed to this story.
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