NCL scientists have developed a low-cost fuel cell component

Since making fuel cells that use pure hydrogen is prohibitively expensive, scientists make do with so-called diluted hydrogen, which has traces of impurities such as carbon monoxide
Jacob P. Koshy

New Delhi: The National Chemical Laboratory, or NCL, has developed an efficient, low-cost component crucial to build fuel cells which combines hydrogen and oxygen to produce electricity, scientists said.

Though hydrogen as fuel is still not commercially viable when compared with fossil fuels such as petrol and coal, it hasn’t prevented countries including India from making big bets on it, since it is an eco-friendly alternative and does not contribute to climate change.

The Central government last year unveiled a hydrogen economy plan that envisages a million hydrogen-fuelled vehicles on India’s roads by 2020.

Researchers at Pune-based NCL have innovated a variant of polybenzimidazole that can be used as an electrolyte, a part of the electricity-producing mechanism in fuel cells. Polybenzimidazole is a class of polymer used in making spacesuits.

Since making fuel cells that use pure hydrogen is prohibitively expensive, scientists make do with so-called diluted hydrogen, which has traces of impurities such as carbon monoxide.
Though much cheaper, diluted hydrogen has its set of problems such as a higher working temperature and corrosive reactions that reduce performance of the cells.

Researchers, therefore, spend a lot of time in developing electrolytes that can get around these problems, and the polybenzimidazole variant promises to be a suitable one, said K. Vijayamohan, a senior scientist at the NCL, who is closely involved with the fuel cell programme of the Council of Scientific and Industrial Research, or CSIR, the country’s largest publicly funded research and development agency.

Most hydrogen fuel cells currently use nafion, a polymer trademarked by chemical giant E.I. du Pont de Nemours and Co., as electrolyte.

“Nafion is an industry standard. In fact, every major fuel cell application — from cars to stationary power backup — is done with nafion, though most manufacturers wouldn’t advertise it,” said Manoj Neergat, a fuel cell expert at Indian Institute of Technology, Bombay.

“Nobody has yet developed a better substitute to nafion, and being a crucial component, anybody who comes up with a cheaper, more efficient alternative has certainly taken a big step,” he said.

According to Vijayamohan, the polybenzimidazole variant that NCL has developed “will be at least 100 times cheaper to manufacture than nafion”.

He claimed the electrolyte is superior to nafion because it is resistant to carbon monoxide and has efficiently worked at 150 degree Celsius.

Nafion doesn’t tolerate temperatures above 80 degrees Celsius.

However, Vijayamohan said, crucial tests on its viability still remain, such as how many hours it could run without a replacement.

Also, a viable electrolyte is only a part of a series of steps required to develop a successful working fuel cell, said Yogeswara Rao, who heads the technology and business development programmes of CSIR.

“After the membrane (electrolyte), we have to develop fuel cell stacks, (and) that cannot be too heavy. We need to develop reformers (devices that extract hydrogen from fossil fuels such as natural gas and methanol), all of which are being done at various CSIR labs across the country,” Rao said.

With oil prices at nearly $69 (Rs3,367.2) a barrel and the threat of climate change from greenhouse gas emissions on the rise, governments are increasingly looking at alternative sources of fuel, from vegetable oil to bacteria.

CSIR’s Rs23.5 crore fuel cell programme began in 2001, and though it has yielded 11 patents and at least 27 research publications in peer-reviewed journals, even a 1kW indigenous fuel cell is still some time away.

According to Neergat, viable Indian fuel cells are at least a decade away. “Not only in India, but the world over, fundamentally new breakthroughs are yet to be made. Everybody is still working on approaches (membranes, catalysts) that were discovered in the 1990s,” he said.

“So...an indigenous fuel cell is still much more than five years away.”

Source: Livemint