Hydrogen Internal Combustion Engine

The volumetric energy density of H2 is less than that of gasoline. Therefore, to provide the same driving range, the hydrogen fuel tank needs to be three times the size of a gasoline tank. Today, a typical passenger car has a range of 575 miles and is provided with an 18-gallon tank, whereas an 18-wheeled semitruck has a 750 miles driving range and requires two 90-gallon tanks.

Actually, the volume of the hydrogen tanks can be somewhat smaller than three times because the efficiencies of hydrogen IC and fuel cell engines are better than the efficiency of gasoline engines (gasoline, 25%; hydrogen IC, 38%; and hydrogen fuel cell, 45–60%).

BMW, DaimlerChrysler, GM, Honda, and Toyota are in the process of placing both IC and fuel cell units into the hands of ordinary drivers to gain experience and to collect data. Their prototype units cost about $1 million each. The manufacturers aim for a “pilot commercialization phase” by 2010–2012 at a unit cost of $250,000. They expect full production by 2013 at a unit cost of $50,000, and this cost will drop as the volume of production increases.

The list of vehicles that can run on H2 is constantly growing. Quantum Fuel Technologies Worldwide converted Toyota Priuses to hydrogen fuel. BMW is marketing its 7 Series, 12-cylinder, 260-horsepower car with an IC engine that can burn liquid hydrogen or run on gasoline, whereas the BMW 750 hL is designed to burn liquid hydrogen. The IC engine of the Ford E-450 shuttle bus burns 5,000 psig hydrogen gas.

In connection with using H2 as a fuel for transportation, there is a lot of activity, but no firm direction or conclusion yet. In Iceland, one can rent a hydrogen-fueled car from Hertz. In Japan, as part of its national hydrogen program, a 200,000 m3 tanker ship has been designed for transporting H2. Also in Japan, an H2-fueled commuter train is in operation, using H2 at 35 mPa (5,000 psig or 350 bar) to fuel a 125 kW ”Forza” proton exchange membrane (PEM) fuel cell by Nuvera (http://www.rtri.or.jp).

Hydrogen buses operate in Montreal and Bavaria, an H2-powered passenger ship sails in Italy, and the 2008 Olympics in Beijing featured hydrogen vehicles. Russia has flown a jet, fueled partly by hydrogen. In the United States, the Defense Advanced Research Project Agency (DARPA), NASA, and the Air Force are jointly developing an Earth-orbit airplane fueled by

H2. Two teams (in Turin and Madrid) are converting two light planes so that they can use hybrid fuel cell–battery electric engines.