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Future Perfect: Technologies for low cost hydrogen fuel cells

Fuel Cells

What’s happening right now:

Ever since the former US President George Bush Jr announced the Hydrogen Fuel Initiative in 2003 ,major efforts both in the US and in other countries are being made to bring about what is termed as the hydrogen economy, in order to reduce dependence on fossil fuels and mitigate the effects of global warming.

In a fuel cell hydrogen gas is pumped into the anode compartment of the cell where in the presence of the catalyst , it splits into protons and electrons. The protons pass through the membrane and combine with the oxygen pumped into the cathode compartment to produce water as the harmless by-product while the electrons are conducted away to generate electrical current.

This electricity can then be used with, for example electric motors to drive a vehicle. The idea is not new at all , having been postulated by the German scientist Schonbein as far back as 1838 . Fuel Cells have also been used to power space vehicles . The essential challenge today is to make this technology low enough in cost to get acceptance as the alternative to fossil fuel engines that power our cars and other personal transport vehicles and in other stationary applications. The two major areas that researchers are focusing on are, reducing the cost of the fuel cell itself . This, today is at around $60 per Kilowatt. The second area is to evolve cheaper means of Hydrogen production.

Trends:

The major cost element in the fuel cell is the platinum catalyst , both because it is a precious metal and because it gets easily contaminated. Two new approaches illustrate the importance researchers are giving to reduce Platinum usage.

1. Lung inspired Fuel Cell

Lung shaped H Fuel Cell

Researchers at the Norwegian Academy of Sciences have used the human lung as the inspiration to design a system to deliver the Hydrogen and Oxygen gases through capillary like paths to interact with the platinum catalyst. This increases the surface area of interaction and reduces the usage of Platinum.

2. Plant inspired Fuel Cell

Plant inspired H Fuel Cell

Another such approach by the Department of Energy’s SLAC National Accelerator Labs with researchers from the Stanford University and the Danish Technical University does away with Platinum altogether by using sunlight and water . Slender light absorbers of silicon dotted with newly developed catalysts are arrayed like pillars and these cause the water to split into Hydrogen as efficiently as fuel cells with Platinum catalysts.

The issues with Hydrogen production

The major process now used for Hydrogen production is by the process called “reforming” or steam cracking of natural gas. Making steam in itself, is an energy intensive process dependent on fossil fuels. Given that most fossil burning systems have efficiencies in the 33% to 45% range, the total energy balance in producing Hydrogen is none too attractive. Natural Gas is also a depleting resource and a long term Hydrogen economy cannot be predicated on the continued availability of Natural Gas.

The alternative is electrolysis of water, possibly sea water. This is an energy intensive process . This is viable if say solar or nuclear energy were to be available and we combine the low energy cost from these power generation sources with off-peak utilisation of the power to produce Hydrogen. With the nuclear power industry having had a major setback post Fukushima and with solar energy still in an evolutionary phase, this is still some years away, with some saying, even decades away.

New trends in Hydrogen production:

1. Cheaper Hydrogen from seawater without electrolysis

Purdue University Seawater Cell

Reports of new research however suggest alternatives could emerge for the expensive electrolysis process of producing Hydrogen from seawater. The University of California , Berkeley, have reported using Molybdenum Oxo-catalysts and a Mercury electrode in untreated seawater to produce Hydrogen . This could lead to the deployment of sea-moored buoys or other rigs to produce Hydrogen from seawater that could be transported on-shore by pipelines.

Another team at the University of Purdue has reported success with using shaped components made up 90% of Aluminium and 10% of an alloy of Gallium – Indium – Tin. The alloy that is liquid at ambient temperatures slowly dissolves the aluminum that then reacts with the seawater to generate Hydrogen . In applications like Boats or Ships or Offshore platforms , this could be “Hydrogen-on-demand”. The Aluminum converts into a Hydroxide that can be recycled back into Aluminum.

2. Hydrogen from urine

Urine Derived H fuel cell


Researchers at the University of Ohio , in looking for ways to reduce the energy cost of electrolysis, discovered that in urine, the Hydrogen molecules require only 0.37 volts to split whereas in water it needs 1.23 volts. They have postulated that the sewage treatment process could yield Hydrogen as the valuable by-product. Work is underway to scale up this process and eliminate the problem of bacterial action in sewage that converts urea into ammonia that reduces Hydrogen production.

In summary

The Hydrogen economy , essential for reduction and possible elimination of greenhouse gases ,is visualised based on the low cost production of Hydrogen that is utilized as the energy source in hydrogen fuel cells that can be used both for transportation and stationary applications . These new research approaches need to succeed quickly for this dream to be realized.

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