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How a Hydrogen-Boosted Gasoline Engine Works

What Is a Hydrogen-Boosted Gasoline Engine?
ArvinMeritor This prototype reformer, mounted close to the engine for testing in a V6 SUV, is 18 inches long by 4 inches in diameter.

Hydrogen-boosted gasoline engine technology is new and just now beginning to emerge from the laboratory. It offers the prospect of an economic way to produce a small amount of hydrogen from gasoline with an on-board system designed to do so. Invented by scientists at the Massachusetts Institute of Technology, and being perfected by auto industry supplier ArvinMeritor in cooperation with the German automotive engineering firm IAV, this system may provide a cost-effective alternative to fuel-cell technology and traditional gasoline- and diesel-combustion engines. It's possible that hydrogen-boosted engines could bridge the gap between today's gasoline-powered vehicles and the fuel-cell vehicles of the future.

While fuel-cell vehicles may hold long-term promise, the reality is that they are years away from mass production. Critics cite the high cost of fuel-cell stacks, hydrogen fuel mass-production issues, and general fueling problems as key stumbling blocks. Some believe it may be decades before fuel-cell vehicles become widely available. European automakers have already turned to more expensive diesels but their cost and related complexity is increasing with stiff new emissions requirements for control of particulate matter and NOx emissions.

U.S. carmakers faced with the same concern about diesels are reluctant to commit to the huge expense required by the changeover from gasoline to higher-cost diesel. For example, consumers currently have to pay about a $3000 premium for a diesel-powered light truck vs. a conventional gasoline-powered vehicle. This will increase in the future to compensate for the rising costs associated with making sure diesel vehicles meet forthcoming emissions regulations. The EPA has recently granted diesel vehicles a break by easing near term NOx requirements, but only through 2009 and the high-mileage emissions requirement has been tightened as a trade-off.

What the Experts Are Saying

According to experts at ArvinMeritor, and executive engineers Rudy Smaling and Jens Beister at IAV, the facts about a hydrogen-boosted gasoline engine and its advantages are clear.


A small amount of hydrogen made on-board by the reformer is added to the normal intake air and gasoline mixture. This greatly improves overall combustion quality by allowing nearly twice as much air for a given amount of fuel introduced into the combustion chamber. This is more energy efficient because it saves energy by reducing the amount of engine pumping needed.

Fuel efficiency is also gained through the use of higher engine compression ratios made possible by the hydrogen-rich charge characteristics. A hydrogen-boosted fuel system also saves energy because of the remarkably low amount of electrical energy needed to power the reformer. According to the developers, it needs less than 75 watts, which is less than the electric needs of one standard headlight.

An industry-accepted virtual vehicle analysis based on engine test data indicated the potential for a 20 percent to 30 percent improvement in fuel economy for a turbocharged downsized version of the hydrogen-boosted engine when compared with conventional gasoline engines.

Next, we'll explain what's in store for this technology and where consumers will begin to see it.