Decarbonising industry
工业脱碳
Coke fiends
焦炭恶魔
Steel and cement plants have long lifespans. Change needs to start now
钢厂和水泥厂的寿命很长。变革需要立即开始
On the swedish shore of the Baltic Sea near the Arctic Circle, work has started on a SKr1.4bn ($150m) pilot project aiming to help Sweden become the first country in the world to produce fossil-free steel. Martin Pei, the engineer behind the project, promises that by 2020, passengers flying to the nearby Luleå airport will be able to look down on a 50-metre-high test plant. “We need to hurry up, because ‘Winter is coming’,” quips the Chinese-born engineer. Or should that be global warming?
在瑞典波罗的海沿岸靠近北极圈的地方，一个耗资14 亿瑞典克朗（1.5 亿美元）的试点项目已经启动，目的是帮助瑞典成为世界上第一个不用化石燃料炼钢的国家。该项目的总工程师裴文国承诺，到2020 年，飞往附近吕勒奥机场的乘客将能从空中俯瞰一座50 米高的测试工厂。“我们得赶紧了，因为‘寒冬将至’，”这位中国出生的工程师打趣道。或者应该说全球变暖？
In fact, he says, it was not so much the threat of climate change that led Mr Pei to the idea of making Sweden a pioneer of “green steel”. It is the risk that ssab, the steel company where he is head of technical development, could face public humiliation and a collapse in its business model if it were to stop Sweden from achieving its ambition to become carbon neutral by 2045. ssab’s existing blast furnace and steel plant in Luleå emits 1.6 tonnes of CO2 for every tonne of steel. Though low by global standards, the industry as a whole belches out one-tenth of Sweden’s total emissions.
事实上，他说，他之所以会想到让瑞典成为“绿色钢铁”先驱，并不那么关乎气候变化的威胁，而是因为他担任技术开发主管的瑞典钢铁集团（SSAB）所面临的风险：如果妨碍了瑞典实现2045 年达到碳平衡的雄心壮志，这家公司可能会蒙羞并面临商业模式崩溃。SSAB 现有的位于吕勒奥的高炉和钢铁厂每生产一吨钢就排放1.6 吨二氧化碳。尽管按全球标准来看很低，但整个炼钢业的排放量占到了瑞典总排放量的十分之一。
hybrit Development, the zero-carbon-steel joint venture between ssab, lkab, a state iron-ore producer, and Vattenfall, a state-owned power company, aims to eliminate almost all of these emissions by curbing the use of coking coal. Instead, it will take advantage of Sweden’s abundant renewable energy to generate hydrogen via electrolysis, and use this to produce a product called “direct-reduced iron” (dri). It hopes to complete the experimental phase by 2024, moving on to a full-scale trial in the decade up to 2035.
由SSAB、瑞典国有铁矿石生产商LKAB、国有大瀑布电力公司（Vattenfall）建立的零碳钢合资企业HYBRIT Development 旨在通过抑制焦炭的使用来消除该行业的几乎所有排放。它将利用瑞典丰富的可再生能源，通过电解产生氢气，用氢来生产一种名为“直接还原铁”（DRI）的产品。该公司希望到2024 年完成实验阶段，并在截至2035 年的十年里进入全面试产。
This is not the only example of fossil-fuel-dependent companies trying to reinvent themselves for a post-carbon future. According to McKinsey, almost half of the CO2 emitted by the entire industrial sector comes from four industries; cement, steel, ammonia and ethylene. Unless consumption patterns change, all of them will have to cut emissions while meeting rising demand for cars, buildings, plastics and infrastructure. And because most of their products are commoditised, higher costs imposed by decarbonisation risk “carbon leakage”—the possibility that places with laxer climate policies will produce the commodities more cheaply.
这并不是依赖化石燃料的企业尝试为重塑自我，迎接后碳未来的唯一例子。根据麦肯锡的数据，整个工业部门排放的二氧化碳有近一半来自四个行业：水泥、钢铁、氨和乙烯。除非人类的消费模式发生变化，否则这四个行业都必须在满足汽车、建筑、塑料和基础设施不断增长的需求的同时减少排放。而由于它们的大多数产品都已经成为一般商品，因脱碳造成的成本增加会导致“碳泄漏”，即气候政策更宽松的地方可能会以更低的成本生产这些商品。
In many countries the first priority for reducing industrial emissions will be to encourage recycling. But that will not be nearly enough, and the way the materials are made will also need to change. hybrit’s experience may provide a model. Its technological challenge starts with the fact that 75% of the world’s steel, including ssab’s, is made using a blast furnace into which carbon, in the form of coke, is added to “reduce” the iron ore. In this “basic oxygen furnace” system, the iron oxide and the carbon react to form molten iron, carbon monoxide and CO2 (see chart). In the alternative dri process, natural gas instead of coke is used as the reductant, producing sponge iron that is then converted to steel via an electric arc furnace.
在许多国家，减少工业排放的首要任务将是鼓励回收利用。但这还远远不够，制作材料的方式也需要改变。HYBRIT 的经验可能会提供一个范本。其技术挑战始于这样一个事实：世界上75%的钢，包括SSAB 的，都是在高炉中添加焦炭形式的碳以“还原”铁矿石来炼制的。在这种“碱性氧气转炉”系统中，氧化铁和碳反应生成熔铁、一氧化碳和二氧化碳（见图表）。在替代它的DRI 工艺中，使用天然气代替焦炭作为还原剂，来生成海绵铁，然后通过电弧炉将其转化为钢。
The reduction process generates as much as 90% of the CO2 emissions in steelmaking, so hybrit wants to stop relying on blast furnaces, introduce dri instead and use hydrogen rather than natural gas as the reducing agent. The hydrogen will react with iron oxides to form water rather than CO2. The hydrogen will be produced using fossil-free electricity, which is abundant in Sweden. The arc furnace, into which scrap steel will be added, will also be powered by clean energy.
还原过程产生了占整个炼钢过程高达 90%的碳排放量，因此 HYBRIT 希望停止依赖高炉而改用DRI，并使用氢气而非天然气作为还原剂。氢气将与氧化铁反应生成水而不是二氧化碳。氢气将使用无化石燃料的电力生产，而这种电力在瑞典产量丰富。电弧炉（将向其中投入碎钢）也将由清洁能源提供动力。
hybrit explored the alternative of using ccs to remove the carbon gases from the blast furnace, but found that it would fail to capture about half of the CO2—not good enough for meeting Sweden’s zero-emissions goal. It also rejected the idea, used by some Brazilian steel companies, of using charcoal instead of coke in the reduction process, because of the possible toll on Sweden’s forestry. And it reckoned electricity prices in Sweden will be low enough to make it cheaper to use hydrogen from electrolysis rather than biogas in the dri process.
HYBRIT 曾尝试使用碳捕获和存储（CCS）来去除高炉中产生的碳排放，但发现它只能捕获约一半二氧化碳，不足以满足瑞典的零排放目标。它没有采用巴西一些钢铁企业采用的方法，即在还原过程中使用木炭而非焦炭，因为担心瑞典的林业可能因此受损。并且它认为瑞典的电价会变得足够低，在 DRI 过程中使用电解氢会比沼气更便宜。
That said, the process is likely to add 20-30% to the price of crude steel, assuming electricity prices remain at current levels. The amount of additional electricity needed will be staggering. Mikael Nordlander of Vattenfall says that at full production hybrit would use about 15 terawatt-hours of electricity a year, or 10% of the country’s current power supply.
尽管如此，假设电价保持在当前水平，这项工艺可能会让粗钢的价格上涨20%到30%。所需的额外电量将是惊人的。大瀑布公司的米卡埃尔·努德兰德（MikaelNordlander）表示，如果全面投产，HYBRIT 每年将消耗约 150 亿度电，占瑞典目前供电量的10%。
Production is not expected to reach commercial scale until at least 2035, which seems slow for such an important adjustment. Mr Pei explains that this is because scaling up takes time; all new technologies pass through a “valley of death” when progress appears to stall. Moreover ssab’s blast furnace in Luleå has recently been renovated. He says there would be a stranded-asset problem if the project moved ahead too quickly, because the blast furnace would be suddenly rendered obsolete.
至少在 2035 年之前，生产预计不会达到商业规模。对于如此重要的调整来说，这样的速度似乎太慢。裴文国解释说，这是因为规模化需要时间，而所有新技术都会经历一个进展似乎停滞的“死亡谷”。此外，SSAB 在吕勒奥的高炉最近做了翻新。他说，如果项目进展太快，将会出现资产搁浅的问题，因为这些高炉瞬间就作废了。
Rock-hard
坚如磐石
If steel is a big test, cement is an even tougher challenge. Cement is the world’s most widely used manufactured material, but cement works are typically small, scattered and undercapitalised, which makes them hard to press into service for the good of humanity. Demand for cement, which is mixed with water and aggregates to produce concrete, is set to soar in regions such as India and Africa. That means huge additional volumes of carbon dioxide will be generated. About 60% of the waste gas comes from producing clinker, one of the main ingredients of cement. This process, called calcination, involves heating ground limestone to more than 1,600ºC in a kiln, which produces calcium oxide and CO2.
如果钢是一个重大考验，水泥就更是一个艰难的挑战了。水泥是世界上使用最广泛的制造材料，但水泥厂通常都规模小、分散且资金不足，要敦促它们为人类的福祉服务十分困难。在印度和非洲等地，水泥（与水和骨料混合以生产混凝土）的需求势必飙升。这意味着还将生成巨量二氧化碳。其中约60%来自生产熟料——水泥的主要成分之一。这个过程叫煅烧，要在窑炉中把石灰石粉加热到1600°C 以上，生成氧化钙和二氧化碳。
The clinker is ground and blended with other materials to form what is known as Portland cement; the power used for grinding also normally releases CO2. Nearly all of the remaining emissions come from the fuels used to heat the kilns, often coal or coke. These can be replaced with alternatives, from biomass to waste materials such as tyres and municipal solid waste (but not electricity, which at present cannot generate the high temperatures needed to produce the clinker). Along with efficiency improvements, that would be the quickest way to lower cement’s carbon footprint.
将熟料研磨并与其他材料混合，就制成了人们所知的波特兰水泥。用于研磨的动力通常也会释放二氧化碳。剩余的排放几乎全部来自用于加热窑炉的燃料，通常是煤或焦炭。这里可以使用替代性燃料，从生物质，到轮胎等废料和城市固体废物等（但不能用电，目前电力还不能产生制造熟料所需的高温）。随着效率提高，这将是降低水泥碳足迹最快的方法。
ccs is a possible low-carbon option for capturing the CO2 from calcination and from the heat. McKinsey notes that the combined exhaust gases have low concentrations of CO2, making them more expensive to capture. The consultancy points to an innovative eu-backed project in Belgium called leilac that aims to redesign kilns to make it easier to capture exhaust gases from calcination.
CCS 是一种可能的低碳选项，它将捕获煅烧和加热过程产生的二氧化碳。麦肯锡指出，混合废气中含有的二氧化碳浓度很低，这令捕获二氧化碳的成本上升。该咨询公司指出，比利时一个欧盟支持的创新项目 LEILAC 旨在重新设计窑炉，让捕获煅烧产生的废气变得更容易。
The bigger ambition is to develop clinker substitutes, which would do more to reduce emissions. A recent report by Johanna Lehne and Felix Preston of Chatham House, a think-tank, does not hold much hope for an early breakthrough on clinker. But having analysed 4,500 patents, it found that, surprisingly, “the cement sector is more technically innovative than its reputation suggests” (more than steel, for instance).
一个更大的野心是研发熟料的替代品，这将更大幅度地减排。智库英国皇家国际事务研究所（Chatham House）的约翰娜·莱纳（Johanna Lehne）和费利克斯·普雷斯顿（Felix Preston）最近发表的报告对熟料会较快取得突破并不抱太大希望。但在分析了4500 项专利之后，他们吃惊地发现，“水泥行业在技术上的创新性超过它的名声给人的印象。”（比如超过钢铁行业。）
“Novel cements”, or alternatives to Portland, are being developed by Solidia, an American startup now in partnership with LafargeHolcim, a big cement producer. Solidia claims that its low-clinker concrete slashes CO2 emissions, partly by containing them within the material. But cement and concrete standards usually dictate the Portland clinker content, and builders, architects and customers are understandably wary of new technology, lest their buildings fall down.
美国创业公司 Solidia 正在和大型水泥生产商拉法基豪瑞（LafargeHolcim）合作，研发一种替代波特兰水泥的“新型水泥”。Solidia 声称其含熟料量低的混凝土可以大幅减少二氧化碳排放，部分原因是它将二氧化碳“扣留”在材料中。但水泥和混凝土标准通常都明确规定波特兰水泥的熟料含量，而建筑公司、建筑设计师和客户要避免建筑物坍塌，自然对新技术很警惕。
Other ways of decarbonising industry may be less daunting. One of the companies exploring potentially lucrative opportunities is Elysis, a joint venture between Alcoa and Rio Tinto which could revolutionise aluminium smelting for the first time since it was invented in 1886. At present, aluminium comes from the combination of three ingredients: aluminium oxide (alumina), electricity and carbon. Electricity is run between a negative cathode and a positive anode, both made of carbon. The anode reacts with the oxygen in the aluminium oxide, producing CO2 and liquid aluminium, which is then cast. The quantities of CO2 can be huge. Vincent Christ, the boss of Elysis, says that in China, which uses coal for the smelting process, 16 tonnes of CO2 are produced for each tonne of aluminium. Elysis aims to eliminate emissions by using an undisclosed proprietary, non-carbon material for the anode, producing oxygen rather than CO2.
其他工业脱碳方式的挑战可能不那么令人生畏。美国铝业（Alcoa）和力拓的合资公司Elysis 是积极探索丰厚盈利机会的公司之一。该公司可能会带来炼铝工艺自1886 年发明以来的首次变革。目前，铝来自三种成分的组合：氧化铝（铝矾土）、电和碳。电在均由碳制成的负极和正极之间流动。正极与氧化铝中的氧反应，产生二氧化碳和铝液，然后再进行浇铸。二氧化碳的生成量可以非常大。Elysis 的老板文森特·克里斯特（Vincent Christ）说，在使用煤炭炼铝的中国，每吨铝产生 16 吨二氧化碳。Elysis 的目标是使用一种未公开的专有的非碳材料作正极，生成氧气而非二氧化碳，从而消除碳排放。
The project is backed by Apple, maker of the iPhone, which says it wants to lower the carbon footprint of its products. By 2024, Elysis hopes to sell a technology kit that can be used around the world to retrofit existing smelters or build new ones. The aim is to make zero-carbon aluminium 15% more cheaply and 15% more productively than the existing technology, says Mr Christ, partly because the anode will last 30 times longer. If it works at commercial scale, that will hugely increase the technology’s potential. “It’s taken us ten years to crack the code,” he notes. “If it were merely an environmental initiative, it wouldn’t have as much interest in the market.”
该项目由 iPhone 的制造商苹果公司资助，苹果表示希望降低其产品的碳足迹。到 2024 年，Elysis 希望出售一种技术套件，可在世界各地使用，以改造现有的冶炼厂或建造新的冶炼厂。克里斯特表示，目标是使零碳铝的制造比现有技术便宜15%，生产效率提高 15%，部分原因是正极的使用寿命将延长 30 倍。如果它在商业化的规模上也奏效，那将大大增加这项技术的潜力。“我们用了十年时间来攻克难点，”他指出，“如果它仅仅是一项环保措施，市场不会对它有那么大的兴趣。”
Yet in the end much will depend on China, which produces and uses most of the world’s steel, cement, aluminium and other industrial materials. Mr Pei, who recently explained the hybrit concept in his country of birth, says China has given little thought to producing zero-carbon steel, because its focus is on curbing the use of coal in its power system. It also has relatively new steel plants which it will be unwilling to close.
不过，最终结果在很大程度上将取决于中国。中国生产和使用世界上大部分的钢铁、水泥、铝和其他工业材料。裴文国最近在他的出生国介绍了 HYBRIT 的概念。他说，中国几乎不考虑生产零碳钢，因为它的重点是遏制煤炭在电力系统中的使用。中国的钢铁厂也相对较新，并不愿关闭。
Cement may be a different story. The Chatham House study says China has invested more than any other country in cement r&d. Elsewhere in Asia, Japan’s steel industry is pursuing both the hydrogen and ccs approaches to decarbonising industry.
水泥可能是另一回事。皇家国际事务研究所的研究表明，中国在水泥研发方面的投入超过了其他任何国家。而在亚洲其他地区，日本的钢铁工业正在尝试氢气和CCS 两种方法来寻求实现工业脱碳。
But ultimately it will take pressure from governments to ensure that industry takes the tough, long-term decisions needed for the transformation. They can start by drawing up plans to ensure that enough renewable electricity and sufficient carbon-storage sites are available for a combination of greater electrification and ccs. Then they can offer incentives for hydrogen production and ccs, either by pricing emissions more strictly or providing regulatory and financial support. In time, they can encourage the use of green cement, steel and other zero-carbon materials in public infrastructure projects, creating new markets. That way, industry will be able to move away from old technologies sooner rather than later, without fear that its customers will move elsewhere.
但到头来，需要政府施压来确保工业部门做出转型所需的艰难的长期决策。政府可以从制定计划开始，确保有充足的可再生电力和碳储存设施来实现更大规模的电气化和 CCS。然后它们可以通过更严格地定价碳排放，或提供监管和财务支持来为制氢和 CCS 提供激励。随着时间推移，它们可以鼓励在公共基建项目中使用绿色水泥、钢铁和其他零碳材料，从而创造新的市场。这样，工业部门将能够尽早摆脱旧技术，而不必担心客户流失。
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