FuelCellsWorks

Within five years, local researchers could deliver a way to replace conventional batteries with inexpensive, lightweight and environmentally friendly alternatives.

University of Massachusetts Amherst polymer scientist and associate professor Bryan Coughlin is collaborating with scientists from other universities as part of a five-year, $7.5 million study funded by the U.S. Army Research Office to reduce the weight and the environmental impact of battery packs carried by armed forces.

The multi-university research project is expected to culminate with a viable alternative to current battery packs, which can weigh up to 40 pounds, used for powering gadgets soldiers use for communication, night vision, navigation and other tasks. “When soldiers go out on a mission, they carry incredibly heavy and incredibly awkward batteries that have to be charged before they go out,” Coughlin said. “Having a single power source that is lightweight, durable and refillable with something like methanol would be a huge advantage.”

The recycling issue is especially problematic for the armed forces. “The military isn’t fighting wars near recycling facilities,” Coughlin said. “So our military needs a more environmentally friendly battery that can be recharged with renewable energy sources.”

Replacing traditional batteries with fuel cells could be the answer; fuel cells run on renewable energy sources such as methanol or hydrogen, and can be contained in small, lightweight packaging. But today’s fuel cells aren’t widely available or financially practical because they require expensive precious metal catalysts such as palladium and platinum.

Coughlin, who earned his Ph.D. in chemistry at the California Institute of Technology and holds more than 20 U.S. patents, is part of a team working to make fuel cells without using precious metal catalysts. Coughlin’s work on the project is focused on developing novel polymer membranes for use in fuel cells.

The theory behind the research is conceptually similar to that of existing proton exchange membrane fuel cells, but the mode of operation and transport is different, Coughlin said. “The catalysts we are using are more readily available – silver, iron and cobalt – earth abundant materials, which lower costs, and are easier to use than proton exchange membranes,” he said.

The current research will combine computational and theoretical testing. The lead institution for this initiative is the Colorado School of Mines. Other partners include scientists at the University of Chicago who are contributing theory and computational studies and researchers at the University of California-Riverside who will conduct membrane evaluation and testing.

Mobile telecoms coverage in remote rural areas could be set to explode with the launch of field trials of a new hi-tech power plant that utilises the latest in hydrogen fuel-cell technology.

The technology uses ordinary ammonia to extract hydrogen as a fuel source to efficiently power cell phone towers that have no access to main grid electricity. The science could revolutionise the alternative energy solutions market in the telecommunications industry worldwide.

Currently, it is estimated that 130,000 remote area towers are going up each year globally, at a growing rate of more than 6 per cent. This US$9.2-billion market is concentrated in Africa, Asia, the Middle East, Eastern Europe, and South America.

According to auditing and business advisory firm Ernst & Young, the telecoms market in Africa alone is forecast to grow faster than any other region.

In its recent study, ‘Africa Connected, A Telecommunications Growth Story’, Ernst & Young said the telecommunications market in Africa was becoming increasingly competitive and that as competition increased, operational efficiency will take on greater importance for telecommunications operators.

The latest hydrogen-from-ammonia fuel technology currently undergoing field tests is holding out the promise of 25 per cent savings and total equipment cost recovery within two years.

Conducted by UK-based Diverse Energy and leading South African industrial gases company African Oxygen Limited (Afrox), the first field trials are taking place in a remote area of Namibia in 2010.

Robert Carlton-Shields, Afrox Business Manager, special products and chemicals says, “Coverage in remote areas is very patchy and not cost effective at present due to the need to power telecom towers using diesel generators, with all the inherent logistical and environmental emission issues on top.

“What we are trialling with Diverse Energy is their PowerCube® proprietary ammonia cracker integrated system, which produces hydrogen for fuel cells. This compact energy source will replace polluting diesel generators, delivering higher efficiency and lower fuel and maintenance costs, while offering a 25 per cent reduction in total cost of ownership over its five-year life, with a two-year return on investment.”

And with the ammonia readily available from Afrox in most sub-Saharan countries, the “source-to-sink” calculations show an 80 per cent reduction in greenhouse gas emissions compared to diesel generators, together with elimination of noise and local pollution.

“Ammonia is a cheap fuel with high power density,” says Afrox chemicals product manager Jaco Coetzee. “So hydrogen from ammonia dissociation would be the preferred option for small plants like PowerCube®. Millions of tons of ammonia are produced and distributed worldwide every year and the procedures for safe handling have long been since developed and proven, making ammonia as a fuel source for use in rural areas perfect for Africa.”

Recognition of the PowerCube® technology is growing rapidly, testament to which was it being named as the winner the prestigious 2009 UK Government Innovation Award for the “Next Big Thing”. This led directly to the current Afrox / Diverse Energy field trials being part-funded by the UK Government’s Technology Strategy Board.

The provision of cell phone communications is seen as an important enabler for new business development in rural regions and as capable of providing a boost to poverty reduction measures. By lowering the total cost of ownership of rural off-grid cell phone towers, such expansion programmes can be accelerated, says Carlton-Shields.

Having completed tests with Motorola in the UK, a trial in Africa has been initiated with three telecoms operators in three different climatic zones involving 25 PowerCubes® to prove its capabilities in Africa.

“These telecoms operators have the chance to trial the system at a cost no higher than our forward projected sales price, allowing operators to get substantial first mover advantage and experience the benefits of the PowerCube® without having to fund the full cost of a trial,” says Dr. Alastair Livesey, operations director at Diverse Energy.

“Its adoption will bring many benefits when compared with diesel and solar panel power, which have value on the black market. Potential thieves would have difficulty selling the ammonia tanks, and wouldn’t be able to siphon from the tanks as they could with diesel. Between 15 and 22 per cent of diesel in Africa is lost to theft in this way.”

The PowerCube® has by-products of about one litre an hour of highly purified water, which can be used for medical purposes, and 30 kilograms of fertiliser every three months. Livesey says those quantities are too small for operators to sell, so they can be used to help local rural communities instead.

“This is a low cost, environmentally-friendly solution for power in rural areas without access to electricity,” says Afrox’s Carlton-Shields. “It will significantly expand Afrox’s customer base and lower the cost of ammonia in the emerging markets in Africa, where it is traditionally used in fertiliser and refrigeration.

“This project will revolutionise the telecoms industry in Africa and marks the start of Afrox becoming an alternate fuels company as well as a supplier of specialist gases, chemicals and welding equipment.”

In the quest for efficient, cost-effective and commercially viable fuel cells, researchers at Cornell’s Energy Materials Center have discovered a catalyst — platinum nanoparticles — that could make fuel cells more stable, longer lasting, and more resistant to carbon monoxide poisoning.

The research, led by Héctor D. Abruña, the E.M. Chamot Professor of Chemistry and Chemical Biology and director of the Energy Materials Center at Cornell, and Francis J. DiSalvo, the John Newman Professor of Chemistry and Chemical Biology, appeared online recently in the Journal of the American Chemical Society.

Hydrogen fuel cells offer an appealing alternative to gasoline-burning cars: They have the potential to power vehicles for long distances using hydrogen as fuel, they can be rapidly refuled, mitigate carbon dioxide production and emit only water vapor.

But they also require very pure hydrogen to work. That means that conventional fuels must be stripped of their carbon monoxide (CO) — a process that is too expensive and energy intensive to make fuel cells commercially viable.

Fuel cells work by electrochemically decomposing fuel instead of burning it, converting chemical energy directly into electricity. In proton exchange membrane (PEM) fuel cells, an anode and cathode are separated by a membrane that blocks electrons but allows protons to pass through. At the anode, a catalyst oxidizes hydrogen, generating electrons and protons. The protons pass through the membrane while the electrons create an electric current. At the cathode, electrons reunite with protons and oxygen from the air to form water.

Abruna

Platinum and platinum/ruthenium alloys are often used as catalysts in PEM fuel cells, but both elements are rare, expensive and easily rendered ineffective by exposure to even low levels of CO.

To create a catalyst that can tolerate more CO, Abruña, DiSalvo and colleagues deposited platinum nanoparticles on a support material they developed of titanium oxide (with added tungsten to increase its electrical conductivity).

Tests show that the new material works with fuel that contains as much as 2 percent CO, losing only 5 percent efficiency compared with a 30 percent drop in efficiency for conventional platinum catalysts. The material is also more stable and less expensive than pure platinum.

With the new catalyst, “you can use much less-clean hydrogen, and that’s more cost-effective because petroleum has a very high content of carbon monoxide,” Abruña said. Otherwise, to reduce the CO content, “you need to scrape off the carbon monoxide, and it’s very expensive to do that.”

The researchers are now preparing to put the catalyst to the test in real fuel cells. “So far, indications are very good,” Abruña said.

In preliminary experiments comparing the new material’s performance with pure platinum, he added, the platinum cell was readily poisoned by CO and conked out early. “But ours was still running like a champ.”

The research was supported by the U.S. Department of Energy through the Energy Materials Center at Cornell, an Energy Frontier Research Center funded by the Office of Science at the Department of Energy.