Trapping That Elusive Hydrogen Fuel

By James Donahue

Everybody knows that the world is running out of oil at a time when the demand for this important fuel is growing to meet rising population and industrialization demands. We also know that burning oil and coal is polluting the air, which is creating climate change that threatens our planet and all of life on it.

It goes without saying that no one is going to easily give up the luxury life style we have developed through the burning of carbon based fuels. Because of expanding communications, people in underdeveloped nations also are striving for the same kinds of luxuries. They want cars, electric appliances and improved living conditions that demand more consumption of energy. The solution to this dilemma is an alternative fuel source that burns clean and keeps the wheels of cars and industry moving.

After examining all the options, it seems that hydrogen may be a solution. Nuclear fuel is plentiful but extremely dangerous. Electricity depends on alternative power sources to keep the turbines turning and that often takes us right back to the burning of carbon fuels like coal and oil. Solar cells and wind generators provide natural energy, but they are unsightly and the yield per unit is low.

Hydrogen is readily available. It is in the air we breathe. It is found in the rocks under our feet. It is everywhere, but rarely found in its pure state. And this is the catch. There has been a high cost to extracting hydrogen and then storing it, transporting it, and using it as a fuel. Until recently, it took more energy to extract hydrogen than the amount of energy gained. But science has been working on this problem.

Lanny Schmidt, a chemist at University of Minnesota, and three of his colleagues say they have discovered a process that may cut the cost of extracting hydrogen.

Schmidt's process uses a simple fuel injector from an automobile engine, inserted into a glass tube. Next he sprays an ethanol-water mix into a warm chamber to vaporize it. As the vapor passes through a porous ceramic plug embedded with the rhodium and ceria catalyst, hydrogen comes out the other end.

This "autothermal" process bypasses the old steam reforming process that required very high temperatures, large furnaces and a huge expenditure of energy to separate the hydrogen. The word autothermal means it supplies its own heat. Thus the device is much smaller than the steam-reforming systems and requires far less energy.

Schmidt lauds his discovery by also noting that it is clean and will not contribute to global warming. As the hydrogen is extracted from ethanol and then consumed in a fuel cell, its byproducts, including carbon dioxide and water, can be absorbed by the corn crop grown to produce more ethanol.

Schmidt can envision entire cities using this system to provide electric power, and cars running on hydrogen as soon as better fuel cell technology is developed. The problem with hydrogen powered cars today is the lack of the technology to store enough fuel.

The one flaw in the Schmidt process is that it depends on the production of ethanol. The current processes for producing ethanol are environmentally toxic.

--December 27, 2006