Need for transportation technologies heads into overdrive
What critical issues face transportation?
We Americans love to drive cars. Cars are part of our culture and will continue to be in the foreseeable future. With more than 200 million cars and trucks registered in the United States and an additional 15 million new automobiles sold each year, the transportation sector is increasingly dependent on imported petroleum as fuel. The U.S. produces only one third of the petroleum we consume. In light of the events of September 11, the growing gap between the petroleum we produce and the petroleum we consume has added significance. While great gains were made in automobile fuel efficiency in the 1980s, over the last 10 years more people are buying less fuel-efficient sport utility vehicles, mini-vans and trucks, including me. We have to balance our love for big vehicles and the increase in foreign oil we consume.
Another critical issue is the release of regulated emissions such as carbon monoxide, oxides of nitrogen and particulate matter. It's amazing that total emissions from all vehicles have decreased over the last 30 years, even though the number of registered cars, trucks and buses has almost doubled. The auto industry has done a great job optimizing engine control, including introducing computer controls, and reducing emissions with three-way catalysts. But this is only the beginning, especially for heavy trucks. Diesel-powered trucks, ships and trains are the backbone of our economy, which depends on efficient and timely movement of freight. Over the last 25 years, the oxides of nitrogen and particulate matter emissions from heavy trucks the 18-wheelers you see on the highway have been reduced by 90 percent. New regulations that take effect in 2010 require another 90 percent reduction in tailpipe emissions. This is a monumental task.
The impact of emissions on human health is another major issue. In recent reports, diesel particulate has been singled out as a carcinogen. There is much debate around these reports, but to me, the important question is how far do we need to reduce emissions before the impact on human health is acceptable? We need a better understanding and correlation between human health and what comes out of the tailpipe. This requires more data on vehicle emissions, how they are transported through the atmosphere and their impact on human health.
The final critical issue is the transportation sector's impact on global warming. Carbon dioxide is a greenhouse gas that contributes to global warming, and the amount released from the transportation sector is growing steadily. Transportation accounts for about a third of the carbon dioxide released, with 473 million metric tons of carbon released in 1997. For cars and trucks, which use carbon-based petroleum fuels, the best way to reduce carbon dioxide is to reduce fuel usage or increase fuel efficiency. If one gallon of fuel can take you farther, less carbon dioxide is emitted.
How did PNNL's research in this area begin?
In the mid-90s, we began materials research and developing lightweight materials as part of the Partnership for New Generation Vehicles, or PNGV, a government program that included Ford, General Motors and Chrysler. The program focused on increasing fuel efficiency in light-duty vehicles such as passenger cars and included a goal to reduce the weight of vehicles by 50 percent.
At the suggestion of PNGV, this Laboratory initiated the Northwest Alliance for Transportation Technologies in 1996. It focuses on engaging the region's producers of aluminum, magnesium, titanium and polymer composites in research and development to support the transportation industry. At that time, Washington and Oregon were responsible for more than 40 percent of domestic aluminum production. PNNL's programs have continued to grow and now include Alcoa and Delphi Corporation, and Northwest-based heavy truck producers, PACCAR and Freightliner. Today we have expanded our program to include emission reduction, solid oxide fuel cells and health effects research.
How do the needs of lightweight vehicles and heavy-duty trucks differ?
Heavy truck purchases are primarily a business decision. Initial cost and operating cost versus the payback period are critical. A new heavy truck costs more than $100,000 and some run 16 hours a day, most days of the year. A fleet owner or independent trucker purchases a truck to make money, so fuel prices and vehicle efficiency are important. They expect trucks to be reliable, durable and cost effective for at least 400,000 miles. Over its life, a heavy truck may end up going more than a million miles.
Personal vehicles are a different story. Most of us buy vehicles based on personal preferences and emotion. The initial cost is very important to us, but operating cost is not usually a major consideration. Surveys show reliability and safety are high priorities for new car buyers. Fuel efficiency is not. Personal vehicles are expected to last about 100,000 miles, which is when typical car owners are ready for something new.
While both heavy trucks and personal vehicles require cost-effective, reliable and durable technologies, there are some major differences in the technologies needed for each. Heavy vehicles are primarily diesel powered while cars are primarily fueled by gasoline. Perhaps the biggest difference, however, is in product volume and cost for new technologies. Each year, the number of heavy trucks manufactured is about a couple hundred thousand, compared to about 15 million personal vehicles. New technologies for trucks can be produced in low volume but must be reliable for several hundred thousand miles. New technologies for cars must be manufactured in very high volumes and last at least 100,000 miles or 10 years.
What are PNNL's areas of expertise?
We have the right fundamental science foundation to contribute in several critical areas. This includes strengths in materials science, chemistry, ceramics, interfacial and surface science and modeling. We also have unique equipment and facilities.
But having the right science isn't enough if it can't be translated into actual applications. We form interdisciplinary teams that work on basic and applied research, building the scientific understanding needed to direct research toward solutions. We have demonstrated that we can develop new concepts, move the technology to pilot-scale demonstrations and address manufacturing issues. Most importantly, our new technologies focus on industry needs.
For example, superplastic forming methods developed at PNNL allow more complicated shapes to be manufactured in less time and with fewer parts. While lightweight materials themselves may be more expensive than traditional materials, the overall cost of raw materials and fabrication is reduced.
What is PNNL's focus?
We're working on lightweight materials, emission reduction technologies and fuel cell technologies, including developing solid oxide fuel cells for auxiliary power units in vehicles.
Fuel cells could provide exactly as much power as long-haul trucks need to sustain their "hotel load." With the help of a fuel cell, a truck's refrigeration unit, lights, heat or air conditioning for the cab, a power source for computers and cell phones, and other power devices could operate during rest stops without the engine running. Today, truckers run a 600-horsepower engine to provide the few kilowatts they need during stops. Due to concerns about truck emissions, there is pending legislation that would prohibit trucks from idling on the side of the road. Fuel cells could be a solution.
Our researchers are working on ways to put fuel reformers onboard vehicles so various kinds of fuel, including diesel, could be converted into the hydrogen gas needed to operate a fuel cell. Through our involvement in the Solid Energy Conversion Alliance, we're working on fuel cell technologies with industry partners, including Delphi, McDermott, Honeywell and Cummins.
We also are excited about our role in understanding and developing advanced catalysts for treating diesel engine exhaust. While diesel engines are more efficient than gasoline engines, they pose different challenges. Diesel engines run lean, meaning there is excess air in the exhaust. In those conditions, different catalysts are needed to reduce oxides of nitrogen, and particulate matter emissions. Almost every technology for reducing emissions decreases fuel efficiency, but the goal is to reduce emissions without a "fuel penalty." Our researchers are working with engine manufacturers and catalyst suppliers to develop new systems that will help industry meet future emission standards.
How does the Laboratory work with industry?
DOE's FreedomCAR and Vehicle Technologies program and the Hydrogen, Fuel Cells, and Infrastructure Technologies program are the primary sponsors of our projects, along with industry partners that help fund our research. By teaming with industry, the answers we provide with scientific research are applicable to industry and actual applications. In addition to the key partnerships already mentioned, we work with Caterpillar, Detroit Diesel and many others. Our industry partners provide direction that focuses our research, including projects that have earned national awards and recognition.
Partnerships with industry have been a common theme throughout our research related to transportation and vehicles. Through these partnerships, we expect our technologies to impact the future.