But some Department of Energy (DOE) officials doubt that the entire system will be light enough for onboard use. Sunita Satyapal, the hydrogen-storage team leader at DOE, notes that the researchers’ estimates do not include the weight of the water or the other equipment needed to produce the hydrogen. These things could more than double the weight of the system, she says, even if water produced by the fuel cell is recycled. The system will probably be too heavy to give the vehicle a driving range competitive with gasoline engines, suggests Satyapal.
She also notes that the rate of hydrogen production is now orders of magnitude lower than it would need to be for use in vehicles, and it will be very difficult, if not impossible, to sufficiently improve the rate.
But even if the new system is not useful as a way of producing hydrogen in a car, it eventually could prove useful for producing hydrogen at fueling stations. One of the challenges with hydrogen production is the cost of compressing and transporting hydrogen from central locations. On-site production using enzymes at filling stations, or even in people’s homes, could get around these issues. In such applications, the hydrogen production rate can be lower than it is aboard a vehicle, as the hydrogen can be produced around the clock in relatively large tanks.
Still, some are skeptical of the basic concept of using starch to create fuel. “Making food into hydrogen is not such a great idea,” says John Deutch, a chemistry professor at MIT. Indeed, demand for corn to make ethanol is already increasing food prices. Using corn starch to make hydrogen could exacerbate the problem.
But Zhang notes that employing starch to make hydrogen would be a much better use of the available corn than turning it into ethanol: fuel cells can be three times more efficient than ethanol-burning internal combustion engines. Nevertheless, he sees starch as a temporary solution. Zhang is also developing a version of the process that starts with cellulose, found primarily in the nonfood parts of plants.