Aluminum Rising

By EV World Editorial Staff

The new Jaguar CX-17 concept car is only the latest in an lengthening line of automobiles being manufactured out of aluminum, to save weight and improve energy efficiency, but it does come at a cost.

This evening in Paris, JaguarLandRover debuted their all-aluminum body CX-17 crossover concept car (pictured above), designed to compete with similar mid-sized SUV/Crossovers offered by its Germany rivals. While it is powered by a conventional ICE-age engine and officially only a concept at this point, the company did announce that it will have an all-aluminum car ready for the U.S. market by 2016, Depending on its reception in Frankfurt, that car could be a production version of the CX-17.

The primary reason cited for introducing an aluminum-bodied car is to meet increasingly tough carbon emissions regulations in Europe and fuel efficiency standards in the United States. A lighter car requires less fuel and thereby produces fewer greenhouse gas emissions, at least during its operational lifecycle. Industry estimates calculate a car made of aluminum components in the form of castings, extrusions and sheet panels can weight 24% less than a comparably-sized steel panel car.

It does, however take a huge amount of energy to make aluminum, which is why key centers for its production are typically located in areas with relatively abundant and cheap hydroelectric power: Washington State in the USA, Quebec in Canada, and Iceland with its vast geothermal fields and glacial melt-fed hydro dams being just a few of the regions where aluminum is produced from the refinement of bauxite, named for the village in France where it was first discovered in 1821.

While the first use of aluminum in auto manufacturing can be traced back to a pair of prototype Bjering two-seaters built between 1918-1920 in Norway, until recently is was used sparingly, in part because of its higher cost compared to cheaper steel and also its malleability: it is a stiff metal that presents challenges for car designers. This is why its use was often restricted to relatively flat applications like car hoods and roof panels.

Within the last twenty years, essentially with Audi's introduction of the all-aluminum A2 and A8, manufacturers have begun to work out ways to sculpt the metal into forms once reserved for steel; the CX-17 being just the latest example. Honda's first Insight hybrid used an all-aluminum body and now, so does the Tesla Model S [see video at end of article]. In the case of the new BMW i3, it combines the best of both worlds of aluminum in the driveModule and carbon fiber reinforced plastic (CFRP) in the passenger lifeModule.

But using aluminum isn't without its environmental costs. In addition to the amounts of electric power its takes to refine it, it also generates a highly toxic waste called 'red mud.' The material has a pH of 13 making it highly corrosive. Disposal of it is a major environmental challenge with it typically being stored in giant settling ponds.

When a holding reservoir ruptured in October 2010 in the Hungarian village Kolontár [see clean up photo above], spilling one million cubic meters of toxic sludge across an estimated 40 sq km (15 sq miles), it killed ten people, injured another 122 others, and reportedly extinguished all life in the Marcal River. Flowing downstream, it then endangered marine life in the Danube. Huge quantities of gypsum had to be dumped into the river to neutralize the hyperalkalinity of the runoff.

While research into alternative uses for red mud has been ongoing [see Possibilities of Exploitation of Bauxite Residue from Alumina Production], the economics have not been attractive enough to encourage its reuse. According to the authors of the paper:

In spite of intensive research of reusing waste mud from Al2O3 production, majority of the mud ends up on terrestrial deposits… One of the major limitations of the successful exploitation of bauxite residue is large transport cost necessary to transfer of waste mud from its disposal sites to the point of application.

Then there is the whole aluminum trading/hoarding scheme that the New York Times exposed in July of this year in which a subsidiary of Goldman Sachs moves pallets of aluminum ingots between two warehouses in Detroit on behalf of commodity traders, churning storage fees, lengthening the order time for the raw material, and driving up costs to producers.

On the plus side, though, aluminum is one of the most widely recycled products of the industrial age. According to the Car Manufacturers Institute, something like 75% of all the aluminum ever produced is still in use today. In 2011, American's recycled 61 billion cans, representing just over 65.1 percent of all aluminum cans produced that year. That is, says the Aluminum Association, equivalent to saving more than 17 million barrels of crude oil.

And the use of aluminum in transportation also finds its way into the two-wheeled variety. Recently overshadowed by carbon fiber, Specialized's new D'Aluisio Smart Weld Technology is making aluminum bicycle frames competitive again with carbon fiber.

Given its advantages in terms of weight reduction and recyclability, expect to see ever greater use of aluminum in the personal mobility vehicles of the future from bicycles to automobiles. But we must also bear in mind that it, like all technologies, comes at a cost, requiring us to carefully consider how we use it and why.

Manufacturing the All-Aluminum Tesla Model S

Times Article Viewed: 7358
Originally published: 09 Sep 2013


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