logo
Loading


Novel polymer composite membranes for direct methanol fuel cell

Can you imagine living without electricity? Most of us never give it a thought, but the way we are going we soon might have to. As things stand now, our means of generating the power that we have always taken for granted are slowly but surely being exhausted. While alternate means of power generation do exist, the technologies employed therein are yet to mature to the stage where we can rely solely on renewable energy.

Yet, used as we are to having things work at the flip of a switch, we take it completely for granted. Most of us don't even bother about how much we use or waste, except possibly from the perspective of how big our monthly power bill would be. As long as supply is not interrupted, we don't even spare a thought for how the power that we use is generated or about how much it costs in terms of resources or environmental impact.

Most of us, but not all. There are those who are painfully aware of how bad our situation really is. Wasim Feroze, for instance, even as a schoolboy, used to take it up on himself to switch off unnecessary lights at home and school. His lifelong passion for the efficient use and conservation of energy has led to his current work on creating an efficient and cost-effective material to be used in fuel cells.

Pursuing a PhD at the IITB-Monash Research Academy, Wasim is being guided by Prof. Manoj Neergat of IIT Bombay and Prof. Bradley Ladewig of Monash University. The IITB-Monash Research Academy is a Joint Venture between the IIT Bombay, India and Monash University, Australia. Opened in 2008, the IITB-Monash Research Academy operates a graduate research program located in Mumbai that aims at enhancing research collaborations between Australia and India. Students study for a dually-badged PhD from both institutions, and spend time during their research in both India and Australia.

What excites him about his work is the prospect of "producing power from thin air" to use his own words. "Imagine," he says, "a personal power station in your backyard, silently powering your entire home!" While that dream is still far from realization, Wasim has a clear vision of how to get there. Even more important, the work that he has done so far represents part of the journey to that goal.

Most of the energy that we consume comes from power plants that use what are known as fossil fuels. These include coal, natural gas and petroleum products like diesel, petrol and furnace oil. While these thermal power plants have inherent strengths, they also have a host of weaknesses and disadvantages. These weaknesses and disadvantages have been disregarded for the longest time, since they were considered a more than fair trade-off for the benefits that they provided.

In recent years, however, with the growing awareness and concern about the environmental impact of fossil fuel based power generation, that trade-off has come to be regarded as less than acceptable. Fossil fuels affect the environment adversely even before they are extracted from the earth; searching for deposits of petroleum, gas or coal itself is dependent on intrusive and destructive methods.

Extracting fuel from the earth takes the destruction and disruption to the next level, and transporting fuel worldwide spreads the damage. When the fuel is finally used to generate energy, it creates even more trouble by way of pollution. Added to all of the above is the fact that the process of turning fuel into energy, which has to involve combustion, is not very efficient; the average efficiency of a car engine, for instance, is in the range of 18% to 20%. In plain English, this means that only a maximum of 20% of the fuel burned gets transformed into pure energy that can be used to get work done. The rest is loss as heat, emissions etc.

More than any other factor, what must bother us is that the earth has only a limited supply of fossil fuel that can be extracted and used cost-effectively and efficiently. When that runs out, the lights go out. This makes it imperative that we look to develop alternative sources and technologies for energy generation that are more efficient, less damaging and sustainable.

One of the most promising technologies for efficiently producing clean energy is the fuel cell. Simply put, a fuel cell is an energy conversion device. There are several different types of fuel cells. Of which the one that is regarded as holding the most promise for providing a cheap, accessible and efficient means of generation energy for domestic use, especially in mobile applications, is the Polymer Exchange Membrane Fuel Cell.

A PEM fuel cell has four parts: (1) The Anode, the negative terminal. (2) The cathode, the positive terminal. (3) The Proton Exchange Membrane which works as the electrolyte does in other types of fuel cells. (4) The catalyst which facilitates the splitting of electrons from the Hydrogen molecule.

To begin with, Hydrogen is forced through a porous material containing the catalyst, which results in the molecules being split into positive ions and electrons. The two are then separated by the membrane, which only allows positive charges through and blocks the negatively charged electrons.

The electrons flow out via the anode into the external circuit and provide the electric current that can be used to do whatever work needs to be done, such as run a motor. They then flow back into the cell via the positive terminal. Along with the oxygen that is fed into the cell on the positive or cathode side of the cell, they combine once again with the positively charged Hydrogen ions generating water and heat.

The water thus produced is completely pure and clean and can be used for human consumption. The heat can be recovered and used for doing more work. The fuel cell, therefore, works without producing any harmful emissions; on the contrary, all the byproducts can be put to use.

Although fuel cells were invented more than 150 year ago, they didn't gain traction for a long time because the technology for solving inherent problems hadn't matured. Moreover, there were other means of generating power that were cheaper and besides, back then environmental damage and sustainability were not of the concern that it is today.

Even today, the biggest hurdles in the way of the widespread adoption of fuel cells as an efficient source of clean energy are the catalyst and the membrane. The materials that can perform these two roles efficiently and cost-effectively are yet to be developed.

Material for the membrane is especially challenging as it has to meet several demanding criteria. It has to be able to efficiently transfer protons as well as maintain its integrity in the harsh and hot conditions within the fuel cell. Further, given the dangers involved in storing and handling liquid hydrogen, it is necessary to use safer fuels such as ethanol and methanol. The membrane has to be impervious to these fuels.

About 50 years ago, the Dupont company developed the material for the membrane in the fuel cells that were used during the American space missions. Those fuel cells provided the electricity as well as the drinking water on the space craft. Even after all these years, the Dupont-developed material, which goes under the trade name of Nafion, performs much better than most competing products, but it still has some drawbacks, not the least of which is its high price. Nafion is also hamstrung by relatively low peak operating temp of about 80 degrees C.

Wasim's endeavor is to develop a novel fuel cell membrane that will withstand higher operating temperatures in the region of 180 degrees C for extended periods with minimal maintenance or skilled operator intervention. He has chosen to use polybenzimidazole or PBI membranes, which have displayed exceptional promise in hydrogen fuel cells, displaying the ability to survive sustained high temperature operation.

An alternate form of PBI, known as ABPBI, has been synthesized in the lab. Wasim intends to dope or impregnate this membrane with nanoparticles of a suitable material to enhance proton permeability. The resulting nanocomposite will have excellent thermal stability while retaining proton conductivity.

Wasim is confident that the work he's doing will result in bringing down the cost of fuel cells significantly. He is excited about the prospect of putting a technology that is twice as efficient as conventional internal combustion engines within the reach of the common man. Fuel cells have the potential to change the lives of millions of people, the majority of India's population, who live in villages.

Research scholar: Wasim Feroze G. S., IITB-Monash Research Academy

Project title: Novel polymer composite membranes for direct methanol fuel cell

Supervisors: Prof. Manoj Neergat and Prof. Bradley Ladewig

Contact details: wasimferozegs@gmail.com

For more information and details on this technology, email research@iitbmonash.org The above story was written by Ms. Sandhya Menon based on inputs from the research student and IITB-Monash Research Academy.



^