More aluminum use lowers auto-created greenhouse gases

The world aluminum industry reported July 26 that the application of automotive aluminum in passenger cars manufactured in 2006 will lead to potential global savings of approximately 140 million tons of CO2 equivalent greenhouse gas (GHG) emissions and to energy savings equivalent to about 60 billion liters of crude oil over the life cycle of these vehicles.

"The GHG reductions and fuel savings are the result of weight reduction achieved through the application of aluminum by the world's automakers," according to Robert Chase, secretary general of the International Aluminum Institute (IAI).

These energy savings and emissions reduction numbers were included in a presentation by Marlen Bertram, IAI research associate, at the 2007 China Aluminum & Transportation Conference in Dalian, China, entitled "Improving Sustainability in the Transport Sector Through Weight Reduction and the Application of Aluminum".

As part of her presentation, she reviewed the results of a study by the Institute for Energy and Environmental Research (IFEU) in Heidelberg, Germany, that concluded lightweighting the world's transportation fleet – passenger cars, trucks, rail vehicles, air and sea craft – has the potential of reducing GHG emissions by 660 million tons annually, or close to 9 percent of global, transportation-related GHG emissions.

Bertram presented several case studies demonstrating aluminum's capacity to reduce weight in real-world vehicle applications.

"Our results are based on data from the IFEU study and a life cycle model developed by the aluminum industry,” she said. “This model accounts for all greenhouse gases emitted during aluminum production, vehicle use and end-of-life processing. It has also been tailored for component-specific applications on passenger vehicles. All our analyses are based on publicly available information concerning weight reduction achieved through the application of aluminum. Our model adheres to the principles of lifecycle assessment per ISO standard 14044."

The actual IAI study is available on the IAI website: www.world-aluminum.org.

The study also compared aluminum vs. high-strength steels in two applications: a bumper beam on two similar European-made cars (one using high strength steel the other aluminum) and a hood on a U.S.-made family sedan. In both applications, aluminum achieved significant energy and emissions savings.

The aluminum bumper beam saved 2.6 kilograms (kg) over the high-strength steel beam. Over a 200,000 kilometer (km) driving cycle of these compact vehicles, the aluminum bumper beam will reduce GHG emissions by 15 kg per kilogram of aluminum, or 48 kg for the bumper.

The aluminum hood on the US-manufactured family sedan registered a 42 percent direct weight reduction over high-strength steel. Over the 200,000 km driving cycle of this vehicle, this hood will reduce CO2 equivalent emissions by 131 kg.

The introduction of a single aluminum bumper beam or a hood offers little or no potential for indirect, or secondary, weight savings, whereas a combination of replacements or an all-aluminum body structure enable secondary weight savings of the order of 50 percent or more. For instance, when the secondary weight savings of the bumper and hood are included in the model, the CO2 equivalent emissions reductions increase to 61 and 161 kg, respectively.

The aluminum industry's study also revealed that each ton of the light metal replacing iron in engine blocks has the potential to save the energy equivalent of 8,000 liters of crude oil over its life cycle. According to a 2006 study by Ducker Worldwide, 45 kg of aluminum were put into each car and light truck in form of engine blocks in 2006, resulting in the energy savings equivalent to 375 liters of crude oil per vehicle for this application alone.

"This data underpins the key role that aluminum can play in reducing GHG emissions form transport. It also furthers the 15 objectives of the industry's global sustainability program, Aluminum for Future Generations," the IAI's Chase concluded.

The full report also addresses the issue of vehicle size and weight as important elements of sustainable transportation. It presents the results of a previous study done by Dynamic Research Institute (DRI) where size and weight were key variables in 500 "virtual" collisions.

The study concluded that both vehicle weight and size were key elements in producing passenger vehicles that reduce crash energy to save lives. The study demonstrated that maintaining vehicle size while reducing its weight reduces the energy it has to absorb in a crash and making it less damaging to other vehicles in a collision.

The study also shows that if lightweight structural materials, such as aluminum, are used to increase a vehicle's crush zones, even by several centimeters, significant improvements in safety can be achieved without increasing vehicle weight.

Aluminum is all around us. It is light and strong, corrosion resistant and durable, formable and highly conductive, it has natural shine and is recyclable. Aluminum provides intelligent solutions for present and future generations.

The European Aluminum Association, founded in 1981, represents the European aluminum industry from alumina and primary production to semi-finished and end-use products, through to recycling. The European aluminum industry directly employs about 236,000 people.

The IAI is the global forum of aluminum producers dedicated to the development and wider use of aluminum as a competitive and uniquely valuable material. The IAI in all its activities supports the concept that aluminum is a material that lends itself to improving world living standards and developing a better and sustainable world environment.

The IAI reflects the aluminum industry's wish to promote wider understanding of its activities and its responsibility of approach on questions of environmental protection, public health and safety in the workplace.

The Aluminum Association, based in Arlington, Va., with offices in Detroit, represents U.S.- and foreign-based primary producers of aluminum, aluminum recyclers and producers of semi-fabricated products as well as suppliers to the industry. Member companies operate almost 200 plants in North America and many conduct business worldwide.