Due by midnight on Friday, July 6th, but due to the  holiday you can submit as late as Monday, July 9th by midnight  Send me this as an attachment. THE ASSIGNMENTYou can either go to the WCCC Libr

Doug Komandt

ENG 162—W1

Mr. Hricik

July 7, 2011

Hydrogen Powered Vehicles: Fuel of the Future

In an age where petroleum is becoming more and more expensive and less and less readily available, alternatives are necessary. One promising alternative to fueling passenger cars is the use of Hydrogen Fuel. Pilot programs around the world have already begun, and hydrogen powered cars could be in US markets by 2015. Staff writer Jeff Tollefson of Nature investigates the past, present, and bright future of Hydrogen Fuel in America and throughout the world in his article “Fuel of the Future?” His analysis is divided into the following four main sections which detail the process and challenges of creating a hydrogen fueled global economy:

• The Fuel Cell

• Storing Hydrogen Gas in a Vehicle

• Distribution and Pumping of Hydrogen

• Production of Hydrogen Gas

The Fuel Cell

Using Hydrogen gas to produce energy is a very complex process. It involves a very controlled reaction that involves numerous sophisticated steps. All of the parts necessary for these reactions must be packed into an engine which is light, cheap, and durable yet powerful enough to move an automobile. The engine must provide enough energy not only to accelerate the vehicle, but also to operate the headlights, radio, and other features. The reaction itself is fairly straight forward: stored hydrogen gas reacts with oxygen gas in the air to produce energy and water vapor. It is the process of bringing the elements together in the correct proportions (2 parts hydrogen to 1 part oxygen) and then harnessing the energy for use that is complex. A concern with hydrogen fuel is that the water vapor produced can freeze at cold temperatures, stopping the engine. However, Toyota and General Motors have found that keeping the exhaust system running for a few minutes after the car is shut down will eliminate excess water vapor, allowing hydrogen powered cars to function at up to -37®C. Finally, it is important to make the hydrogen/oxygen reaction as efficient as possible while minimizing costs. To do this, cheaper catalysts are used and the surface area of the catalyst is increased. Catalysts are chemicals which are a part of the engine that serve to speed up the rate of a reaction. Overall, there are many features to the complex hydrogen fuel cell which must be considered.

Storing Hydrogen Gas in a Vehicle

One of the most challenging obstacles in producing Hydrogen Powered vehicles is the safe and efficient storage of hydrogen gas aboard the car. Hydrogen powered cars must be able to travel for long distances on one tank of gas in order to be comparable to a petroleum powered car. This means one tank of hydrogen must provide enough fuel for approximately 693 kilometers of travel. In order to store the necessary amount of hydrogen for these long trips, there are two options. A huge tank containing low-pressure hydrogen is one option, while a small tank which contains the same amount of hydrogen at an extremely high pressure is another. It has been found that a high pressure tank is the best option due to size restraints. As a result, the tank must be very strong to successfully hold pressurized hydrogen gas. In order to achieve the long distance requirement, a tank the size of a normal gasoline tank must withstand hydrogen pressures up to 680 atmospheres. Carbon-fiber tanks have been developed to reach this goal because they are lightweight and can withstand extreme pressures. Finally, there is the comparison of convenience between battery powered cars and hydrogen powered ones. With the long-range driving capability in mind, the hydrogen car is the clear winner since battery cars can only travel about 200 kilometers per charge. Overall, hydrogen storage on board a vehicle must provide enough fuel to travel long distances, and high pressure tanks are the best way to achieve this goal.

Distribution and Pumping of Hydrogen

Which came first: the hydrogen cars or the hydrogen fueling station? The answer: neither. One of the main obstacles for hydrogen fuel today is the reluctance of people to invest in it. Car companies don’t want to produce hydrogen cars until fueling stations are available throughout the nation, and fueling companies don’t want to build stations until the cars are on the roads. Despite this conflict, the process of pumping hydrogen gas into cars has been well developed. It is very similar to pumping typical gasoline, except the hydrogen pump must be firmly attached to the vehicle for fueling to effectively take place. In order to get hydrogen fuel to filling stations, a network of pipelines is needed. In Germany, a small scale trial network is being constructed. By 2020, approximately 1,000 hydrogen fueling stations will be attached to the system across the nation. So far, German car companies and fueling companies are cooperating to make this trial a success. In the long run, constructing a global hydrogen network would be costly, but definitely worthwhile. It is estimated that a small trial network of 50 hydrogen stations could be constructed in the Los Angeles area for just over $200 million. Additionally, a futuristic full scale network covering the United States with over 11,000 hydrogen stations would cost only about $35 billion. While this seems like a lot, the amount of money we spend on oil each year and the environmental improvements that would result would definitely be worth the initial investment.

Production of Hydrogen Gas

Even before the hydrogen gets to the stations to be pumped into cars and be used by the fuel cells, it must be produced. Currently, the most prominent form of hydrogen production is Steam Methane Reforming. This is a process by which steam and natural gas are reacted to produce hydrogen gas and carbon dioxide. While this is the cheapest method, it is not carbon neutral and is nearly as bad for the environment as simply burning gasoline in vehicles. Therefore, an alternate method of hydrogen production must be developed. German engineers have developed a process called Wind Powered Electrolysis, which used excess wind power to split water molecules into hydrogen and oxygen gas. This process is completely green (no carbon dioxide or greenhouse gasses are emitted), but it is not very reliable. Wind speeds vary day to day and month to month, thus this method of hydrogen production is not stable year round. Looking at these two methods of hydrogen production, the cost for the consumer is actually fairly reasonable. The cost of hydrogen produced by steam methane reforming is only about $2.75 per kilogram (one kilogram of hydrogen is about equal to a gallon of gasoline). On the other hand, the eco-friendly wind powered electrolysis produces hydrogen gas for between $4 and $5 per kilogram. Both of these methods provide cost effective sources of hydrogen gas for the everyday consumer. Finally, with cost in mind, “it is not a matter of whether we can afford the hydrogen infrastructure…it is whether we can afford not to have it.” As natural gas is depleted, another energy source is becoming necessary. Hydrogen fuel is that new, renewable energy source.

Conclusion

In conclusion, nobody really knows what the future of hydrogen fuel holds. However, it is necessary to being exploring alternative fuel options. Hydrogen powered vehicles is a sensible, cost effective first step in the right direction.

Doug Komandt

ENG 162—W1

Mr. Hricik

July 7, 2011

Hydrogen Powered Vehicles: Fuel of the Future—Abbreviated Summary

Alternative fuels are necessary, and Hydrogen Fuel is a promising option. Jeff Tollefson of Nature investigates Hydrogen Fuel in his article “Fuel of the Future?” in the following four points:

• The Fuel Cell

• Storing Hydrogen Gas in a Vehicle

• Distribution and Pumping of Hydrogen

• Production of Hydrogen Gas

The Fuel Cell

A hydrogen engine must be light, cheap, and durable yet powerful enough to move an automobile. The reaction itself is fairly straight forward: stored hydrogen gas reacts with oxygen gas in the air to produce energy and water vapor. Cheap catalysts are used to speed up the rate of the reaction.

Storing Hydrogen Gas in a Vehicle

One tank of hydrogen must provide enough fuel for approximately 693 kilometers of travel to be comparable to gas cars. A huge tank containing low-pressure hydrogen or a small tank with extremely high pressure hydrogen are the two options. High pressure tanks are the best option due to size restraints. Hydrogen cars are better than battery powered cars due to their travel range. Hydrogen storage on board a vehicle must provide enough fuel to travel long distances, and high pressure tanks are the best way to achieve this goal.

Distribution and Pumping of Hydrogen

Car companies don’t want to produce hydrogen cars until fueling stations are available throughout the nation, and fueling companies don’t want to build stations until the cars are on the roads. In Germany, a small scale trial network is being constructed. By 2020, approximately 1,000 hydrogen fueling stations will be attached to the system across Germany. A full scale network covering the United States with over 11,000 hydrogen stations would cost only about $35 billion. While this seems like a lot, the amount of money we spend on oil each year and the environmental improvements that would result would definitely be worth the initial investment.

Production of Hydrogen Gas

Currently, the most prominent form of hydrogen production is Steam Methane Reforming. However, this is harmful to the environment, so engineers have developed a process called Wind Powered Electrolysis, which used excess wind power to split water molecules into hydrogen and oxygen gas. The cost of hydrogen produced by steam methane reforming is only about $2.75 per kilogram (one kilogram of hydrogen is about equal to a gallon of gasoline). Wind powered electrolysis produces hydrogen gas for between $4 and $5 per kilogram. “It is not a matter of whether we can afford the hydrogen infrastructure…it is whether we can afford not to have it.” As natural gas is depleted, another energy source is becoming necessary. Hydrogen fuel is that new, renewable energy source.