Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. Space Industry and Business News .




TECH SPACE
One order of steel; hold the greenhouse gases
David L. Chandler, MIT News Office
Boston MA (SPX) May 13, 2013


Antoine Allanore, left, and Donald Sadoway. Photo: M. Scott Brauer.

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.

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 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.

.


Related Links
Massachusetts Institute Of Technology
Space Technology News - Applications and Research






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





TECH SPACE
Engineers fine-tune the sensitivity of nano-chemical sensor
Chicago IL (SPX) May 09, 2013
Researchers have discovered a technique for controlling the sensitivity of graphene chemical sensors. The sensors, made of an insulating base coated with a graphene sheet - a single-atom-thick layer of carbon - are already so sensitive that they can detect an individual molecule of gas. But manipulating the chemical properties of the insulating layer, without altering the graphene layer, may yet ... read more


TECH SPACE
One order of steel; hold the greenhouse gases

Cloud computing is silver lining for Russian firms

Another 'trophy' for the chemistry cabinet

Researcher Construct Invisibility Cloak for Thermal Flow

TECH SPACE
Department of Defense looking to allow Apple, Samsung devices

DARPA Seeks Clean-Slate Ideas For Mobile Ad Hoc Networks

Astrium's secure milsatcoms now cover the world

Gilat to Equip IDF with SatTrooper-1000 Military Manpack

TECH SPACE
NASA Awards Contract to Modify Mobile Launcher

Angara Rocket Launch Delayed to 2014

ESA's Vega launcher scores new success with Proba-V

European Vega rocket launch delayed due to weather

TECH SPACE
Facebook eyes $1bn deal for GPS app Waze

Orbcomm Signs Seven New Customers In Transportation And Logistics Industry

Turn your satnav idea into business

NIST demonstrates transfer of ultraprecise time signals over a wireless optical channel

TECH SPACE
EADS says Pentagon ending helicopter program

Boeing Brings B-52 into Digital Age with Significant Communications Upgrade

Flyers don't turn off phones in planes: survey

Taiwan wavers on F-16 deal

TECH SPACE
Quantum optics with microwaves

Spintronics discovery

New NIST measurement tool is on target for the fast-growing MEMS industry

Use of laser light yields versatile manipulation of a quantum bit

TECH SPACE
ESA's next Earth Explorer satellite Will Map The Tropics

Landsat Thermal Sensor Lights Up from Volcano's Heat

Scaling up gyroscopes: From navigation to measuring the Earth's rotation

NASA Opens New Era in Measuring Western US Snowpack

TECH SPACE
PCBs are everywhere

Nations agree to phase out toxic chemical HBCD

Toxic waste sites cause healthy years of life lost

Progress in introducing cleaner cook stoves for billions of people worldwide




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement