Wednesday, October 25, 2006

The Truth About Hydrogen -

Wild promises abound, but can the simplest element in the universe really power our homes, fuel our cars and reduce our contribution to global warming? PM crunches the numbers on the real hydrogen economy.
BY Jeff Wise Published in the November, 2006 issue.
PURE ENERGY: An employee at the Ballard plant in Vancouver, British Columbia, seals the critical component of fuel cells, which convert hydrogen into electric power.
WHEN ASSESSING THE State of the Union in 2003, President Bush declared it was time to take a crucial step toward protecting our environment. He announced a $1.2 billion initiative to begin developing a national hydrogen infrastructure: a coast-to-coast network of facilities that would produce and distribute the hydrogen for powering hundreds of millions of fuel cell vehicles. Backed by a national commitment, he said, "our scientists and engineers will overcome obstacles to taking these cars from laboratory to showroom, so that the first car driven by a child born today could be powered by hydrogen, and pollution-free." With two years to go on the first, $720 million phase of the plan, PM asks that perennial question of every automotive journey: Are we almost there?
And the inevitable answer from the front seat: No. Promises of a thriving hydrogen economy — one that supports not only cars and trucks, but cellphones, computers, homes and whole neighborhoods — date back long before this presidency, and the road to fulfilling them stretches far beyond its horizon.
The Department of Energy projects the nation's consumption of fossil fuels will continue to rise — increasing 34 percent by 2030. When burned, these carbon-based fuels release millions of tons of carbon dioxide into the atmosphere, where the gas traps heat and is believed to contribute to global warming.
At first glance, hydrogen would seem an ideal substitute for these problematic fuels. Pound for pound, hydrogen contains almost three times as much energy as natural gas, and when consumed its only emission is pure, plain water. But unlike oil and gas, hydrogen is not a fuel. It is a way of storing or transporting energy. You have to make it before you can use it — generally by extracting hydrogen from fossil fuels, or by using electricity to split it from water.
And while oil and gas are easy to transport in pipelines and fuel tanks — they pack a lot of energy into a dense, stable form — hydrogen presents a host of technical and economic challenges. The lightest gas in the universe isn't easy to corral. Skeptics say that hydrogen promises to be a needlessly expensive solution for applications for which simpler, cheaper and cleaner alternatives already exist. "You have to step back and ask, 'What is the point?'" says Joseph Romm, executive director of the Center for Energy & Climate Solutions.
Though advocates promote hydrogen as a panacea for energy needs ranging from consumer electronics to home power, its real impact will likely occur on the nation's highways. After all, transportation represents two-thirds of U.S. oil consumption. "We're working on biofuels, ethanol, biodiesel and other technologies," says David Garmin, assistant secretary of energy, "but it's only hydrogen, ultimately, over the long term, that can delink light-duty transportation from petroleum entirely."
The Big Three U.S. automakers, as well as Toyota, Honda, BMW and Nissan, have all been preparing for that day. Fuel cell vehicles can now travel 300 miles on 17.6 pounds of hydrogen and achieve speeds of up to 132 mph. But without critical infrastructure, there will be no hydrogen economy. And the practical employment of hydrogen power involves major hurdles at every step — production, storage, distribution and use. Here's how those challenges stack up.
HURDLE 1: ProductionThe United States already uses some 10 million tons of hydrogen each year for industrial purposes, such as making fertilizer and refining petroleum. If hydrogen-powered vehicles are to become the norm, we'll need at least 10 times more. The challenge will be to produce it in an efficient and environmentally friendly way.
FOSSIL FUELS: At present, 95 percent of America's hydrogen is produced from natural gas. Through a process called steam methane reformation, high temperature and pressure break the hydrocarbon into hydrogen and carbon oxides — including carbon dioxide, which is released into the atmosphere as a greenhouse gas. Over the next 10 or 20 years, fossil fuels most likely will continue to be the main feedstock for the hydrogen economy. And there's the rub: Using dirty energy to make clean energy doesn't solve the pollution problem-it just moves it around. "As a CO2 reducer, hydrogen stinks," Romm says.
Capturing that carbon dioxide and trapping it underground would make the process more environmentally friendly. In July, General Electric and BP Amoco PLC announced plans to develop as many as 15 power plants over the next 10 years that will strip hydrogen from natural gas to generate electricity; the waste carbon dioxide will be pumped into depleted oil and gas fields. And the Department of Energy is largely funding a 10-year, $950 million project to build a coal-fed plant that will produce hydrogen to make electricity, and likewise lock away carbon dioxide to achieve what it bills as "the world's first zero-emissions fossil fuel plant."
Whether carbon dioxide will remain underground in large-scale operations remains to be seen. In addition, natural gas is a limited resource; the cost of hydrogen would be subject to its price fluctuations.
ELECTROLYSIS: Most of the remainder of today's hydrogen is made by electrically splitting water into its constituent parts, hydrogen and oxygen. This year, a PM Breakthrough Award went to GE's Richard Bourgeois for designing an electrolyzer that could drastically reduce the cost of that process. But because fossil fuels generate more than 70 percent of the nation's electrical power, hydrogen produced from the grid would still be a significant source of greenhouse gas. If solar, wind or other renewable resources generate the electricity, hydrogen could be produced without any carbon emissions at all.
NUCLEAR POWER: Next-generation nuclear power plants will reach temperatures high enough to produce hydrogen as well as electricity, either by adding steam and heat to the electrolysis process, or by adding heat to a series of chemical reactions that split the hydrogen from water. Though promising in the lab, this technology won't be proved until the first Generation IV plants come on line — around 2020.
Page 1 2 3 Next »
Industry

The Truth About HydrogenPromises abound, but can the simplest element really power our homes, fuel our cars and reduce global warming? PM crunches the numbers on a real hydrogen economy.


Deal Of The Week




No comments: