One order of steel; hold the greenhouse gases
One order of steel; hold the greenhouse gases
Anyone who has seen pictures of the giant, red-hot cauldrons in which steel is made — fed by vast amounts of carbon, and belching flame and smoke — would not be surprised to learn that steelmaking is one of the world’s leading industrial sources of greenhouse gases. But remarkably, a new process developed by MIT researchers could change all that.
The new process even carries a couple of nice side benefits: The resulting steel should be of higher purity, and eventually, once the process is scaled up, cheaper. Donald Sadoway, the John F. Elliott Professor of Materials Chemistry at MIT and senior author of a new paper describing the process, says this could be a significant “win, win, win” proposition.
The paper, co-authored by Antoine Allanore, the Thomas B. King Assistant Professor of Metallurgy at MIT, and former postdoc Lan Yin (now a postdoc at the University of Illinois at Urbana-Champaign), has just been published in the journal Nature.
Photo: M. Scott Brauer
Worldwide steel production currently totals about 1.5 billion tons per year. The prevailing process makes steel from iron ore — which is mostly iron oxide — by heating it with carbon; the process forms carbon dioxide as a byproduct. Production of a ton of steel generates almost two tons of CO2 emissions, according to steel industry figures, accounting for as much as 5 percent of the world’s total greenhouse-gas emissions.
The industry has met little success in its search for carbon-free methods of manufacturing steel. The idea for the new method, Sadoway says, arose when he received a grant from NASA to look for ways of producing oxygen on the moon — a key step toward future lunar bases.
Sadoway found that a process called molten oxide electrolysis could use iron oxide from the lunar soil to make oxygen in abundance, with no special chemistry. He tested the process using lunar-like soil from Meteor Crater in Arizona — which contains iron oxide from an asteroid impact thousands of years ago — finding that it produced steel as a byproduct.
Sadoway’s method used an iridium anode, but since iridium is expensive and supplies are limited, that’s not a viable approach for bulk steel production on Earth. But after more research and input from Allanore, the MIT team identified an inexpensive metal alloy that can replace the iridium anode in molten oxide electrolysis.
It wasn’t an easy problem to solve, Sadoway explains, because a vat of molten iron oxide, which must be kept at about 1600 degrees Celsius, “is a really challenging environment. The melt is extremely aggressive. Oxygen is quick to attack the metal.”
Many researchers had tried to use ceramics, but these are brittle and can shatter easily. “I had always eschewed that approach,” Sadoway says.
But Allanore adds, “There are only two classes of materials that can sustain these high temperatures — metals or ceramics.” Only a few metals remain solid at these high temperatures, so “that narrows the number of candidates,” he says.
Allanore, who worked in the steel industry before joining MIT, says progress has been slow both because experiments are difficult at these high temperatures, and also because the relevant expertise tends to be scattered across disciplines. “Electrochemistry is a multidisciplinary problem, involving chemical, electrical and materials engineering,” he says.
The problem was solved using an alloy that naturally forms a thin film of metallic oxide on its surface: thick enough to prevent further attack by oxygen, but thin enough for electric current to flow freely through it. The answer turned out to be an alloy of chromium and iron — constituents that are “abundant and cheap,” Sadoway says.
In addition to producing no emissions other than pure oxygen, the process lends itself to smaller-scale factories: Conventional steel plants are only economical if they can produce millions of tons of steel per year, but this new process could be viable for production of a few hundred thousand tons per year, he says.
Apart from eliminating the emissions, the process yields metal of exceptional purity, Sadoway says. What’s more, it could also be adapted to carbon-free production of metals and alloys including nickel, titanium and ferromanganese, with similar advantages.
Ken Mills, a visiting professor of materials at Imperial College, London, says the approach outlined in this paper “seems very sound to me,” but he cautions that unless legislation requires the industry to account for its greenhouse-gas production, it’s unclear whether the new technique would be cost-competitive. Nevertheless, he says, it “should be followed up, as the authors suggest, with experiments using a more industrial configuration.”
Sadoway, Allanore and a former student have formed a company to develop the concept, which is still at the laboratory scale, to a commercially viable prototype electrolysis cell. They expect it could take about three years to design, build and test such a reactor.
The research was supported by the American Iron and Steel Institute and the U.S. Department of Energy.
(本文转载自 ,如有侵权请电话联系13810995524)
* 文章为作者独立观点,不代表MBAChina立场。采编部邮箱:news@mbachina.com,欢迎交流与合作。
备考交流
最新动态
- 哇塞!今年的拟录取通知也太浪漫了吧~ 2024-04-25
- 中国科学技术大学科技商学院院长宋志平、执行院长叶强出席全国MBA教指委成立三十周年座谈会 2024-04-25
- 复旦大学2025年硕博士研究生招生宣讲咨询会报名开始啦!七大城市宣讲会等你来~ 2024-04-25
活动日历
- 01月
- 02月
- 03月
- 04月
- 05月
- 06月
- 07月
- 08月
- 09月
- 10月
- 11月
- 12月
- 04/02 暨南大学MBA名师公开课丨解析AI数字人跳舞视频——制作实操及变现路径
- 04/06 活动报名|投资风险与回报的掌控,港科大MBA大师课助你了解交易的智慧
- 04/06 这所双一流有调剂!云南大学EMBA/MTA调剂政策官方解读来了!
- 04/06 报名 | How your Firm will Shape the Future?“小火车”教授公开课暨复旦大学-BI(挪威)国际合作MBA项目说明会
- 04/08 今晚7点!哈尔滨工业大学商学院调剂说明会直播预约开启
- 04/10 4月10日招生开放日 | 第一批面试前最后一场,交大建筑本科学姐与你分享职业转型经历
- 04/11 【活动报名】4月11日@清华大学|2024科创产业投资峰会:硬科技、智能造、创未来
- 04/11 活动报名 | 中欧思创会洛阳站,聚焦智能制造
- 04/12 活动报名 | 香港中文大学(深圳)金融EMBA校园开放日暨24级课程说明会
- 04/12 长江MBA公开课:AI驱动下的企业变革|活动报名