Sustainability is an easy concept for a business or industry to put its verbal support behind. Who wouldn’t want to be viewed as a good corporate citizen?
It’s a different matter to actually put weight behind one’s words. The aluminum industry has made, and continues to make, a concerted effort to do just that.
What’s the evidence? Consider that over two-thirds of all the aluminum ever produced is still in use today. Certainly aluminum is a durable metal. But it is not merely its durability that has permitted this remarkable record of sustainability.
Rather, it is due to its recyclability—a property inherent to the metal, but one which nevertheless required the aluminum industry to construct a large infrastructure by which this property could be harnessed to its fullest societal and industrial purposes.
Aluminum Can Recycling
Since that time, the aluminum can recycling rate has increased from 15 percent to over 58.1 percent in 2010; gross tonnage of aluminum cans collected has increased 35-fold, and the number of cans collected has increased by a factor of over 50.
The payoff has been extraordinary—environmentally and economically—and fairly defines the term “sustainable.” As to the environment, the benefits include energy and natural resource conservation, as well as landfill savings. Recycling aluminum consumes 95 percent less energy than does producing aluminum from ore—and that means lower emissions associated with production of the metal.
The economic benefits cannot be overstated. Recycled aluminum—alone among materials in the consumer waste stream that are commonly recycled—pays for its own cost of collection. And then some. Depending on current market prices, recycling one ton of aluminum cans typically yields well over $1,000 of revenue, while recycling a ton of steel, glass, plastics, or paper comes nowhere close to covering the average collection cost of $200 per ton.
Were it not for the recycling of aluminum beverage cans, most consumer recycling would not be remotely feasible and would probably cease—unless it were to be underwritten by government. Recycling aluminum thus benefits not only our industry and its consumers, but also the producers and consumers of many competing industries whose recycling efforts ours effectively underwrites.
Despite the success of aluminum can recycling, the industry continues to work to raise the consumer recycling rate, as each reclaimed can helps further reduce costs—to its own operations and to consumers and the general public alike.
According to the International Aluminium Institute (IAI), the average energy consumption per ton of aluminum production has fallen worldwide by up to 70 percent over the past century. A century ago, primary smelters took roughly 28,000 kilowatt hours (kWh) to produce a metric ton of aluminum from alumina. Today’s state-of-the-art smelters use 13,000 kWh to produce the same amount of aluminum.
Since 1995, U.S. primary aluminum producers have reduced perfluorocarbon emissions over 70 percent under the Voluntary Aluminum Industry Partnership (VAIP)—a joint effort between the Environmental Protection Agency and a group of primary aluminum producers that includes many Aluminum Association member companies, including Alcoa, Century Aluminum, Kaiser Aluminum, Noranda, and Rio Tinto Alcan. Partners achieve reductions by reducing the frequency and duration of anode effects via a mix of management and technological changes, employing the best options on a smelter-by-smelter basis.
Studies recently undertaken by the International Aluminium Institute show just how dramatic those savings can be. Among their findings:
•The use of one pound of aluminum in place of 1.5 lbs. of steel in a typical bus or truck application reduces greenhouse gas emissions by almost 90 lbs. over the lifetime of the bus or truck.
•The use of one pound of aluminum in place of 1.6 lbs. of steel in a typical railway car reduces greenhouse gas emissions by almost 450 lbs. over the railcar’s lifetime.
•Global use of aluminum in the automotive sector increased from 5.5 billion lbs. in 1991 (source: IAI) to 12 billion pounds by 2006 (source: Ducker Worldwide). Assuming that 12 billion lbs. of aluminum is used to replace denser materials, the potential savings in greenhouse gas emissions over the lifetimes of those vehicles would be approximately 240 billion lbs.
So great is the potential for emissions savings from aluminum’s use in the automotive and transportation industries that Alcoa, among others, has forecast that the aluminum industry is well on pace to become “greenhouse gas neutral” in the next decade. That is, the global warming impacts of aluminum production will be fully offset by the amount of carbon-dioxide saved by its use in the transportation industry.
The Association’s Sustainability Initiative, launched in 2008, involves the assessment and communication of aluminum’s performance throughout its life-cycle, with the goal of developing a complete understanding of the positive contributions that aluminum makes to society’s environmental and economic well-being; any negative economic or environmental impacts associated with its production and fabrication; and the balance between these positives and negatives during the life-cycle of the material.
Several studies have been launched as part of this effort, including an aluminum can life-cycle analysis (LCA), a material flow analysis, and an LCA of semi-fabricated aluminum and auto products. Last year, the Association announced the completion of its aluminum can life-cycle analysis.
One of the most comprehensive LCAs ever conducted by an industry group, the “Life Cycle Impact Assessment of Aluminum Beverage Cans” confirmed significant reductions in the aluminum can’s weight as well as the energy used in its manufacture and its carbon footprint. Upon publication, the Association submitted the study’s associated data sets to both Walmart and the Environmental Protection Agency for their respective database revisions.
Promising new technologies recently unveiled include the following:
•Researchers at the DOE’s Argonne National Laboratory and Noranda Falconbridge are developing a way to produce aluminum at significantly reduced temperatures. Specifically, researchers are modifying the cell electrolyte to operate at lower temperatures—which could eventually permit the use of an inert anode.
•The ITP, working with Aleris Inc., among others, has supported the development of a radically new concept for melting aluminum—isothermal melting—that can dramatically improve energy efficiency in melting and other molten metal processes.
•Alcoa has launched a carbon capture technology at its Kwinana alumina refinery in Western Australia. The system mixes bauxite residue with carbon dioxide to lock up large volumes of carbon dioxide that would otherwise be released into the atmosphere.
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