Low-carbon aluminium leads the way to product sustainability

From the cushy, corporate campuses of Silicon Valley to the design and engineering offices of automakers around the globe, aluminium consumers are retooling their procurement and manufacturing operations in a broad-based campaign to cut carbon emissions.

The mission is not a new one, but it has taken on increasing urgency since the seeds of the low-carbon, circular economy were sowed globally in the form of the Paris Agreement signed in 2016. Since then, the real-world ramifications of failing to embrace greenhouse-gas-emissions mitigation, adaptation and finance - as addressed in the agreement - have become painfully evident.

Rising global average temperatures and catastrophic weather and weather-related events - ranging from unprecedented wildfires in Australia and the western United States, to an Atlantic hurricane season that saw a record-breaking 30 named storms last year - further underscored that urgency. The wildfires, floods, mudslides and meltdown of the Artic ice cap marking 2020 also added momentum to an ongoing shift in the mindset of consumers regarding the steep financial, social and emotional cost of climate change.

Together, those recent events underpinned by a mounting wave of initiatives undertaken by both aluminium producers and major consuming companies in the wake of the Paris Agreement have conveyed low-carbon or “green” aluminium to a key crossroads.

“I’d say that over the course of this year, really the end of last year, we’ve truly reached an inflection point,” Alcoa Corp president and chief executive officer Roy C Harvey told analysts in a third-quarter 2020 conference call when asked to characterize the discussions and interest in green and sustainable products the company was seeing when talking to customers. “I think we’re a bit beyond just general interest and actually starting to see a real beginning of some customers and consumers that are really looking to create deals.”

Deals have already been sealed with major aluminium consumers, including Anheuser-Busch, Apple, Audi Group, and Gränges. The agreements call for the supply and use of low-carbon aluminium to manufacture products ranging from more sustainable beer cans to eco-conscious computer enclosures, smart phones, battery housings serving a line of luxury, electric sports utility vehicles (SUVs) and rolled aluminium products for duty in heat exchangers and other niche products.

“One of the key priorities in our climate strategy is to collaborate along the value chain and increase sourcing and the use of recycled and low-carbon, primary aluminium since such materials significantly reduce our products’ carbon footprint,” Sofia Hedeväg, Gränges senior vice president of sustainability, said in an announcement issued in mid-July 2020. The announcement shared details of an agreement reached between Gränges and Alcoa calling for the supply of the aluminium maker’s Ecolum™ rolling slab to the producer of rolled aluminium for heat-exchanger applications and other targeted markets.

‘Green’ versus ‘black’

Although aluminium might not be the first link manufacturers turn to along their supply chain to reduce their carbon footprint, the recyclability of the material provides consumers a ready route to lighten the carbon burden associated with conventional aluminium production. Current estimates indicate that recycled or “green” aluminium accounts for about one-third of the total market, a figure that is certain to rise as the world shifts from a linear to circular economy.

The remainder of the market is supplied by primary aluminium producers (smelters) at a cost - in terms of carbon intensity - to both consumers and the environment. Figures vary, but on average the electrochemical smelting process per se is estimated to account for about 14% of the overall emissions generated by global aluminium production. Another 70% of that total is tied directly to the electricity used to run smelters, which are power-intensive.

Analysis conducted by the New York-based Columbia Climate Center (CCC) indicates that aluminium smelters consume some 4% of the world’s electricity annually while generating 1% of the world’s greenhouse gases on a yearly basis. More than 50% of that electricity comes from coal or oil-fired power plants located in China, according to the CCC.

The arithmetic is compelling, particularly given that an estimated 74% of global primary aluminium production is produced using non-renewable energy. Shifting to renewable energy sources - hydropower, wind and solar - provides primary aluminium producers as well as consumers another route to reduce their carbon footprint.

Cutting carbon

Low-carbon to the core, Apple, which has committed to total carbon neutrality by 2030, views material selection as key to its pacesetting sustainability drive. “Our strategy is to transition to materials using low-carbon energy and recycled content,” the company said in its 2020 Environmental Report. “We’ve prioritized materials and components that make up a large part of our carbon footprint.”

One of those materials is aluminium, which represented 27% of Apple’s product manufacturing footprint in 2015. Today, as a result of various initiatives, the company has charted a 63% decrease in its aluminium carbon footprint compared with 2015.

“We started by prioritizing the use of aluminium that was smelted using hydroelectricity rather than fossil fuels like coal,” Apple said in the report. The company also re-engineered its manufacturing process to reincorporate aluminium scrap.

“We then went even further to source 100% recycled aluminium, utilizing post-industrial aluminium waste generated during the manufacturing of Apple products,” the consumer electronics giant saidd. As a result, and at last look, the company was selling four products with a 100%, recycled aluminium enclosure.

All aluminium enclosures for new iPad, iPhone, Apple Watch and Mac products released in 2019 were made with either 100% recycled or low-carbon aluminium. Apple recycled 47,000 tonnes of electronic waste in 2019.

As part of the company’s recycling initiatives, Apple has designed its own 100% recycled aluminium alloy that “can accommodate impurities [accumulated as the metal is recycled] while maintaining the finish and durability required for the enclosures. The alloy can be recycled indefinitely while maintaining its properties, the company has claimed.

Apple took a major step beyond recycling in December 2019, when it announced it had purchased the “first-ever commercial batch” of carbon-free aluminium produced using the Elysis process. The aluminium was earmarked for use in the manufacture of the 16in MacBook Pro.

The breakthrough technology, first developed at the Alcoa Technical Center near Pittsburgh, in the US, is said to eliminate all direct greenhouse gases from the aluminium smelting process and instead produce oxygen.

In May 2018, Alcoa and Rio Tinto Aluminium announced Elysis, a joint venture formed to commercialize the patented technology. Apple, which claims to have helped accelerate the development of the technology, said it partnered with both aluminium companies, and the governments of Canada and Quebec, to collectively invest a combined $144 million in future research and development. Elysis is expected by its developers to reach commercial maturity in 2024.

Following in Apple’s footsteps and in a first for the canned beverage industry, Anheuser-Busch announced in early October 2020 that it formed a global partnership with Rio Tinto to deliver “a new standard of sustainable aluminium cans.” The partnership builds on the big brewer’s 2025 US Sustainability Goals, which include a validated, science-based target to reduce carbon emissions across the company’s value chain by 25% by 2025 and invest in more sustainable packaging options across its product portfolio.

The two companies signed a memorandum of understanding committing to work with supply chain partners to bring the brewer’s products to market in cans made of low-carbon aluminium that “meets industry-leading, sustainability standards.” The approach promises to reduce carbon emissions by more than 30% per can compared with similar cans produced today using traditional manufacturing techniques in North America.

To produce what Anheuser-Busch describes as its most sustainable beer can yet, the partners will leverage Rio Tinto’s low-carbon aluminium smelted using hydropower along with recycled content. Currently, around 70% of the aluminium in Anheuser-
Busch’s cans is recycled content. The partners will also leverage outcomes from the development of Elysis, according to a statement announcing the formation of the partnership.

At the time of the announcement, Anheuser-Busch planned to initially focus on North America and pilot the first 1 million cans produced through the partnership on Michelob Ultra, said to be the fastest growing beer in North America.

Charging ahead

From the headquarters cities of BMW and Audi in Germany to Detroit in the US, world automakers are racing to reduce their carbon footprint - and those of their customers - by investing billions of euros, dollars and yuan into the development and debut of electric vehicles (EVs). And for good reason.

In its second annual Impact Report, issued in 2019, Tesla Inc estimated that through its use phase - excluding carbon dioxide (CO2) emitted during the oil refining phase - an average combustion engine vehicle (model year 2019) sold in the US emits 69 tons of CO2. In 2019, Tesla delivered more than 367,000 EVs globally.

Aluminium, of course, is no stranger to the automotive arena. Audi, for one, has been using aluminium in its product offerings since 1994, when the first Audi 8 - featuring the Audi Space Frame and its breakthrough lightweight construction - debuted.

As part of its Mission Zero program, Audi introduced its “Aluminium Closed Loop” initiative at the company’s Neckarsulm site in Germany in 2017 with two suppliers. Aluminium sheet offcuts, or scrap, produced in the press shop are returned directly to the suppliers, where the material is recycled into sheet “of equal quality,” and sent back to Audi for use in production. Secondary aluminium is currently used in various body parts of the Audi A3, A4, A5, A6, A7 and A8 and in parts of the Audi e-tron and e-tron Sport.

Audi credits the rollout of the Aluminium Closed Loop Program at its stamping plants with reducing the company’s carbon footprint by 150,000 tonnes in 2019. The automaker has committed to achieving carbon neutrality at its production sites by 2025.

In early January 2021 and an automotive industry first, Audi AG was awarded the Chain of Custody certificate of the Aluminum Stewardship Initiative (ASI). The award certifies that Audi can comply with the materials flow chain for sustainably produced aluminium in accordance with the ASI standard and can also input correspondingly certified material to the Aluminium Closed Loop with it suppliers.

Essentially, the Chain of Custody certificate attests that the Aluminium Closed Loop process implemented at Audi’s stamping plants correctly sorts and tracks certified material and - due to the seal of quality - is also maintained for the scrap. The common aim of the ASI, which now counts 143 members in the aluminium industry, is to make aluminium production as sustainable as possible and to achieve greater transparency in the aluminium sector. Audi has participated in the ASI since 2013.

Audi is far from alone among automakers in its pursuit of carbon neutrality and the circular economy. Ford Motor Co, which intends to achieve carbon neutrality globally by 2050, is also relying on closed-loop recycling to reduce its carbon footprint.

The automaker is using a closed-loop recycling system to recover up to 20 million lbs of high-strength, military-grade aluminium per month generated during the building of its F-Series trucks. The volume recovered is enough to build 51 commercial jetliners or more than 37,000 F-Series truck bodies per month, Ford said.

A ticking clock

In the race to save the planet, no one can afford to sit on the sidelines. Aluminium consumers and producers alike are responding to the challenge by preserving resources through recycling, plugging into renewable energy, introducing and adopting new, low-carbon aluminium materials - Rusal’s Allow, Alcoa’s Sustana, Hydro’s Reduxa and Circal to name a few - and pioneering innovative, technologies to produce them.

The stakes are high and the sustainability goals and challenges reaching them even higher. So high, in the case of Apple, that the consumer electronics company went so far in its 2020 Environmental Report to say it “envisions a world where we can make products without taking from the earth, using only recycled and renewable materials in our products.”

While the revolutionary technologies now under development at Rusal and the newly constructed Elysis Industrial Research and Development Center in Sagueney-Lac-Saint Jean, Quebec, involve “taking from the earth,” each promises a quantum step forward toward the production of truly “green” aluminium.

In mid-December 2020, Elysis CEO Vincent Christ noted that the development team was seeing strong results on metal purity and electrode durability as the joint venture continued to develop the technology. “And we are extremely encouraged by the interest in the market,” Christ said in a news release detailing the status of the new center.

Thousands of miles to the east, Rusal began testing operations for a pilot industrial, electrolytic cell with inert anodes, which the Russian aluminium giant said features an improved design and a record-low carbon footprint. The new cell, which replaces the inert anode electrolytic cell previously tested by Rusal, incorporates technology geared to improve the purity of the aluminium produced, reduce the carbon footprint to a record-low level of 2 tonnes of CO2 per tonne of aluminium produced and reduce operating costs during the production process. The pilot experimental cell will have a capacity of about 1 tonne of aluminum per day at a 140,000-ampere rate.