By Maria Gallucci

玛丽亚·加卢奇(Maria Gallucci)

When Apple announced new climate goals last week, the tech giant revealed that some of its sleek, silvery laptops will include a novel material: “low-carbon” aluminum. The lightweight metal is chemically the same as the mass-produced version used in products like foil, soda cans, bike frames, and car doors. But it’s made using a different industrial process — one that doesn’t result in the direct release of greenhouse gases.

当苹果公司上周宣布新的气候目标时 ，这家科技巨头透露其一些时尚的银色笔记本电脑将包括一种新颖的材料：“低碳”铝。 这种轻质金属在化学上与用于箔，汽水罐，自行车车架和车门等产品的量产版本相同。 但是它是使用不同的工业过程制造的，不会导致温室气体的直接释放。

Apple is poised to become the first company to include some of this low-carbon aluminum in its products. For experts in the field, this amounts to a breakthrough after decades of development. But while the laptops prove this new approach is viable, researchers are still figuring out how to scale up the material’s production so it can be an option for the entire aluminum sector. If they succeed, the alternative process could eliminate a significant chunk of aluminum’s carbon footprint.

苹果有望成为第一家在其产品中包含这种低碳铝的公司。 对于该领域的专家来说，这是数十年来发展的突破。 但是，尽管笔记本电脑证明了这种新方法是可行的，但研究人员仍在研究如何扩大材料的生产规模，因此可以成为整个铝行业的一种选择。 如果他们成功了，替代Craft.io可以消除铝的大量碳足迹。

“This is a pivotal moment,” Donald Sadoway, a professor of materials chemistry at the Massachusetts Institute of Technology, or MIT.

“这是关键时刻，”麻省理工学院(MIT)材料化学教授唐纳德·萨多威(Donald Sadoway)。

The news arrives as the global aluminum industry grapples with rising greenhouse gas emissions. Even as consumers diligently recycle cans and electronics, repurposed aluminum still only accounts for about one-third of the global market. All told, producing new aluminum results in about 1 percent of global annual emissions. But demand, production, and consumption have climbed in recent years — particularly in China, which still relies heavily on coal-fired power plants.

随着全球铝行业努力解决温室气体排放量上升的消息，这一消息到来了。 即使消费者努力回收罐子和电子产品，但重新用途的铝仍仅占全球市场的三分之一。 总而言之，生产新的铝导致全球每年排放量的约1％ 。 但是，近年来，需求，生产和消费都在增长，特别是在中国，中国仍然严重依赖燃煤发电厂。

Apple said aluminum represented 27 percent of its product manufacturing footprint in 2015. The tech firm now uses more recycled aluminum in its devices and prioritizes suppliers who run their facilities with hydropower, not coal. Such efforts have reduced Apple’s aluminum-related emissions by 63 percent, the company reported in March. To address the rest of its aluminum footprint, Apple is partnering with the firm Elysis to create a supply chain for low-carbon aluminum. In July, Apple announced the first batch of the material would be incorporated into its 16-inch Macbook Pros.

苹果表示，2015年铝占其产品制造足迹的27％。这家科技公司现在在其设备中使用更多的再生铝，并优先考虑使用水力而不是煤炭来运营其设施的供应商。 该公司在三月份报告说 ，这种努力使苹果公司与铝相关的排放减少了63％。 为了解决其余的铝足迹，苹果与Elysis公司合作，建立了低碳铝的供应链。 苹果在7月宣布，第一批材料将被整合到其16英寸Macbook Pro中。

Neither company disclosed how much of the novel aluminum will be mixed into the Macbook Pros. But once laptops hit the shelves, they could potentially spur a larger shift toward cleaner materials in a highly carbon-intensive industry.

两家公司都没有透露将有多少新型铝混入Macbook Pro。 但是，一旦笔记本电脑问世，它们可能会刺激高度碳密集型行业向清洁材料的更大转变。

“That will break open the floodgates for all sorts of other consumers to say, ‘We want green aluminum, too,’’’ Sadoway said.

萨多韦说：“这将为其他各种消费者打开闸门，说'我们也需要绿色铝'。”

Aluminum is the most abundant metal in the Earth’s crust, though it doesn’t naturally occur in an easy-to-scoop form. Mining companies must scrape topsoil to extract bauxite, a reddish clay rock that’s rich in alumina (also called aluminum oxide). Refineries next separate out alumina so it resembles a fine white table salt. Finally, the alumina is heated and melted — or smelted — to make aluminum. This last step contributes the most to climate change, as it results in the direct release of greenhouse gases, and it’s where researchers are searching for innovation.

铝是地壳中含量最高的金属，尽管它不自然地以易铲的形式出现。 矿业公司必须刮下表土才能提取铝土矿，铝土矿是一种微红色的氧化铝，富含氧化铝(也称为氧化铝)。 精炼厂接下来将氧化铝分离出来，使其类似于精细的白色食盐。 最后，将氧化铝加热并熔化(或熔炼)以制造铝。 最后一步对气候变化的贡献最大，因为它可以直接释放温室气体，这也是研究人员寻求创新的地方。

Smelting involves dissolving alumina in a molten salt bath that’s heated to over 1,700 degrees Fahrenheit. Large carbon blocks (or “anodes”) are lowered down into the highly corrosive bath; electrical currents then run through the entire structure. Aluminum deposits at the bottom as oxygen combines with carbon in the blocks, creating carbon dioxide as a byproduct.

熔炼涉及将氧化铝溶解在加热到超过1,700华氏度的熔融盐浴中。 大型碳块(或“阳极”)下降到高度腐蚀的熔池中。 电流然后流过整个结构。 铝随着氧气与块中的碳结合而沉积在底部，从而产生了作为副产物的二氧化碳。

On average, the electrochemical process of smelting contributes about 14 percent of total emissions from global aluminum production. Another 70 percent comes from the electricity used to run the smelters, said Guðrún Arnbjörg Sævarsdóttir, an associate professor at Reykjavik University in Iceland. However, in places where smelters tap into clean power, there is virtually no emissions from electricity use. So the biggest carbon challenge is the smelting process itself, she said.

平均而言，冶炼的电化学过程约占全球铝生产总排放量的14％。 冰岛雷克雅未克大学副教授GuðrúnArnbjörgSævarsdóttir说，另外70％来自冶炼厂的电力。 但是，在冶炼厂使用清洁能源的地方，用电几乎没有排放。 她说，因此最大的碳挑战是冶炼过程本身。

Apple’s low-carbon aluminum supplier uses an alternative electrochemical process that emits only oxygen.

苹果公司的低碳铝供应商使用了一种替代的电化学Craft.io，该Craft.io仅排放氧气。

Elysis, based in Montreal, is a joint venture of the global mining giants Alcoa and Rio Tinto and is supported by the Canadian government. In lieu of carbon blocks, Elysis uses materials that can separate aluminum without causing a chemical reaction. The company made its first commercial batch last year at the Alcoa Technical Center in Pittsburgh, and it sold the supply to Apple in December. The two-year-old firm is currently building a $37 million ($50 million CAD) research facility in Saguenay, Quebec.

总部位于蒙特利尔的Elysis是全球矿业巨头美铝(Alcoa)和力拓(Rio Tinto)的合资企业 ，并得到了加拿大政府的支持。 代替碳块，Elysis使用的材料可以分离铝而不会引起化学React。 去年，该公司在匹兹堡的美国铝业技术中心进行了第一批商业批量生产，并于12月将货源卖给了苹果。 这家成立两年的公司目前正在魁北克的萨格奈(Saguenay)建立价值3,700万美元(5,000万加元)的研究设施。

Elysis hasn’t shared exactly which materials it uses in its system. But scientists around the world have studied a similar concept since the 1980s. The basic idea is to use chemically inactive, or “inert,” metallic alloys in the anodes, through which the electrical currents flow. MIT’s Sadoway previously researched carbon alternatives as a way of reducing electricity use in smelters. Today, programs in China, Norway, Russia, and Iceland are using inert anodes to make aluminum in lower-temperature conditions. Arctus Metal, a small firm in Reykjavik, recently produced its first batch — a one-pound ingot — from its lab.

Elysis尚未完全共享其系统中使用的材料。 但是自1980年代以来，全世界的科学家都研究了类似的概念。 基本思想是在阳极中使用化学惰性或“惰性”的金属合金，电流通过阳极流动。 麻省理工学院的Sadoway以前曾研究过碳替代品，以减少冶炼厂的用电量。 今天，在中国，挪威， 俄罗斯和冰岛的计划正在使用惰性阳极在较低温度条件下制造铝。 雷克雅未克的一家小公司Arctus Metal 最近从其实验室生产出了第一批产品(重1磅)。

“This is like the Holy Grail of aluminum production,” Sævarsdóttir said of the efforts.

“这就像铝生产的圣杯，”萨瓦尔斯多蒂特谈到这一努力时说道。

Sævarsdóttir is involved with Arctus Metal’s research on carbon-free smelting. The company is now scaling its demonstration unit, which uses a 500-amp electric current, to run on up to 10,000 amps, said CEO Jón Hjaltalín Magnússon. (A commercial-scale smelter will run on up to 200,000 amps.) If adopted by Iceland’s three aluminum smelters — which use geothermal and hydropower — the technology would eliminate about one-third of the country’s total emissions, he said.

Sævarsdóttir参与了Arctus Metal的无碳冶炼研究。 该公司首席执行官JónHjaltalínMagnússon表示，该公司现在正在扩展其使用500安培电流的演示装置，以达到10,000安培的电流。 (一个商业规模的冶炼厂将运行高达200,000安培的电流。)他说，如果冰岛的三个使用地热和水力发电的铝冶炼厂采用该技术，它将消除该国约三分之一的总排放量。

Researchers still need to resolve key technical issues before inert anodes can be used at industrial scale. Mainly, the materials require higher voltages of electricity to make aluminum, which drives up smelters’ electricity use and costs. Companies must design more energy-efficient systems so that low-carbon aluminum doesn’t become too expensive or unappealing for construction companies, beverage can makers, and other major buyers of aluminum.

研究人员仍需要解决关键技术问题，然后才能在工业规模上使用惰性阳极。 主要是，这些材料需要较高的电电压才能制成铝，这提高了冶炼厂的用电量和成本。 公司必须设计更加节能的系统，以使低碳铝不会变得太贵或对建筑公司，饮料罐制造商和其他铝的主要买家不有吸引力。

For the wider aluminum industry, the most pressing concern remains reducing carbon pollution from power plants.

对于更广泛的铝工业而言，最紧迫的问题仍然是减少发电厂的碳污染。

Since 2000, smelters have actually grown more reliant on coal and natural gas for electricity, even as solar projects and wind farms proliferate around the world. Many facilities in the Americas and Europe shuttered in recent years, and a significant share of production shifted to China and countries in the Middle East. The result is a market awash in abundant, relatively cheap aluminum — with which low-carbon alternatives will have to contend.

自2000年以来，冶炼厂实际上已经越来越依赖煤炭和天然气来发电，即使太阳能项目和风力发电场在世界范围内激增。 近年来，美洲和欧洲的许多工厂关闭，大量生产转移到了中国和中东国家。 结果是大量的相对便宜的铝市场充斥着低碳替代品。

“The competition on the global scale is really hard,” said Sadoway, who also runs a startup, Boston Metal, that’s developing a carbon-free steelmaking process. Ventures like Elysis, he said, “have a very, very steep hill to climb.”

萨多威(Sadoway)说：“在全球范围内的竞争真的很艰难。”萨多威(Sadoway)也是一家新兴公司，波士顿金属公司(Boston Metal)正在开发无碳炼钢Craft.io。 他说，像Elysis这样的风险投资公司“要爬一个非常非常陡峭的山坡。”

Expanding low-carbon aluminum use will require companies and governments to take deliberate steps, Sævarsdóttir said. For instance, putting a carbon tax on consumer products would make it more expensive to buy conventionally made aluminum. Such a system could pressure manufacturers to adopt low-carbon technologies and encourage contractors to source more sustainable materials for construction projects. Or corporations could simply follow in Apple’s footsteps and commit to buying products with lower supply-chain emissions.

Sævarsdóttir说，扩大低碳铝的使用将需要公司和政府采取有步骤的措施。 例如，对消费产品征收碳税将使购买传统制造的铝的成本更高。 这种系统可能会迫使制造商采用低碳技术，并鼓励承包商为建筑项目采购更多可持续材料。 或者，公司可以简单地跟随苹果公司的脚步，并承诺购买供应链排放量更低的产品。

It’s still unclear how far Apple will go in adopting low-carbon aluminum across its other product lines, or whether producers like Elysis can ultimately scale their technologies beyond the lab (or a single company) and into other industrial facilities. Still, the initiative is an important sign that major companies are willing to invest in greener metals.

目前尚不清楚苹果将在其其他产品线中采用低碳铝走多远，或者像Elysis这样的生产商是否最终可以将他们的技术扩展到实验室(或一家公司)之外，并扩展到其他工业设施。 尽管如此，该计划还是一个重要标志，表明主要公司愿意投资于绿色金属。

“I really approve of what Apple is doing,” Sævarsdóttir said. “This is the way we must go.”

Sævarsdóttir说：“我真的很赞同Apple在做什么。” “这是我们必须走的路。”