Porosity effects in hydrogen reduction of iron oxides

Fortini, Arthur J.; Perlmutter, David D.

doi:10.1002/aic.690350803

Cited by 18 publications

(6 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The hydrogen-based reduction scenario with the currently highest technology-readiness level is to inject hydrogen into existing blast furnaces, in addition to coke 14,15 . The coke lends the furnace its permeable structure.…”

Section: Approaches To Hydrogen-based Reduction Of Iron Oxide and The...mentioning

confidence: 99%

“…This is a challenging detail as water or, respectively, the oxygen, desorbs and diffuses only slowly compared with the reductant molecules. High partial pressure of water has indeed been shown to act detrimental to the nucleation and growth of iron on wüstite surfaces 13,14 . (3) The availability of green hydrogen (made from sustainable sources) is currently by far too small to mitigate the steel industry's greenhouse gas output.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Influence of Microstructure and Atomic-Scale Chemistry on Iron Ore Reduction with Hydrogen at 700°C

et al. 2020

View full text Add to dashboard Cite

With 1.85 billion tons produced per year, steel is the most important material class in terms of volume and environmental impact. While steel is a sustainability enabler, for instance through lightweight design, magnetic devices, and efficient turbines, its primary production is not. For 3000 years, iron has been reduced from ores using carbon. Today 2.1 tons CO2 are produced per ton of steel, causing 30% of the global CO2 emissions in the manufacturing sector, which translates to 6.5% of the global CO2 emissions. These numbers qualify iron-and steel-making as the largest single industrial greenhouse gas emission source. The envisaged future industrial route to mitigate these CO2 emissions targets green hydrogen as a reductant. Although this reaction has been studied for decades, its kinetics is not well understood, particularly during the wüstite reduction step which is dramatically slower than the hematite reduction. Many rate-limiting factors of this reaction are set by the micro-and nanostructure as well as the local chemistry of the ores. Their quantification allows knowledge-driven ore preparation and process optimization to make the hydrogen-based reduction of iron ores commercially viable, enabling the required massive CO2 mitigation to ease global warming. Here, we report on a multi-scale structure and composition analysis of iron reduced from hematite with pure H2, reaching down to near-atomic scale. The microstructure after reduction is an aggregate of nearly pure iron crystals, containing inherited and acquired pores and cracks. Crucial to the reduction kinetics, we observe the formation of several types of lattice defects that accelerate mass transport inbound (hydrogen) and outbound (oxygen) as well as several chemical impurities within the Fe in the form of oxide islands that were not reduced. With this study, we aim to open the perspective in the field of carbon-neutral iron production from macroscopic processing towards a better understanding of the underlying microscopic reduction mechanisms and kinetics.

show abstract

Section: Approaches To Hydrogen-based Reduction Of Iron Oxide and The...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Influence of Microstructure and Atomic-Scale Chemistry on Iron Ore Reduction with Hydrogen at 700°C

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Reduction of the entrapped iron oxides would then proceeds by solid state diffusion control. 3,24 To explain the behaviour of the third reduction period an investigation of the morphological aspects and phase transformations of the partially reduced Warda iron ore particles, involving the use of electron scanning microscopy, Mo ¨ssbauer spectroscopy and X-ray diffraction, may be needed. 6,25 Conclusions Three stages of the reduction process of Warda iron ore by hydrogen, carried out in the temperature range 400-600uC, were identified.…”

Section: Resultsmentioning

confidence: 99%

A preliminary study on the hydrogen reduction of jordanian iron ore

Hararah¹,

Al-Harahsheh²,

Tobgy³

2009

Mineral Processing and Extractive Metallurgy

View full text Add to dashboard Cite

Jordanian iron ore samples, obtained from Warda area, were reduced using hydrogen gas and preliminary kinetic observations and results were obtained. Samples of iron ore were carefully sized, weighed and reduced using flowing hydrogen in a tubular furnace. Constant temperature experiments were conducted to examine the effect of particle size (180 to 710 mm), temperature (400 to 600uC) and gas flow rate (1 to 3 L min 21 at STP) on the percentage of reduction with time. It was found that the reduction rate increased with decreasing particle size, increasing gas flow rate, and increasing temperature. In general, the course of ore reduction was observed to follow three distinct stages; an initial stage of increasing percentage of reduction at an increasing rate, followed by a stage of decreasing rate, and a final stage with constant percentage of reduction. The initial stage was successfully modelled using the shrinking core model with the chemical reaction step controls, probably combined by gas diffusion. The observed activation energy of reduction for this period was 29 kJ mol 21 .

show abstract

“…The arrangement of the emerging iron phase regions, scattered amidst the FeO, also implies that the classical shrinking core models do not consider the pellet’s real microstructure. This observation suggests to use instead phase-field simulations, − in which pores, cracks, − elasto-plastic deformation and other microstructure features and the associated topo-chemical effects can be explicitely considered, ,,,, Figures and .…”

Section: Feedstock For Sustainable Metal Production: Minerals Metals ...mentioning

confidence: 99%

The Materials Science behind Sustainable Metals and Alloys

Raabe

2023

Chem. Rev.

View full text Add to dashboard Cite

Production of metals stands for 40% of all industrial greenhouse gas emissions, 10% of the global energy consumption, 3.2 billion tonnes of minerals mined, and several billion tonnes of by-products every year. Therefore, metals must become more sustainable. A circular economy model does not work, because market demand exceeds the available scrap currently by about two-thirds. Even under optimal conditions, at least one-third of the metals will also in the future come from primary production, creating huge emissions. Although the influence of metals on global warming has been discussed with respect to mitigation strategies and socio-economic factors, the fundamental materials science to make the metallurgical sector more sustainable has been less addressed. This may be attributed to the fact that the field of sustainable metals describes a global challenge, but not yet a homogeneous research field. However, the sheer magnitude of this challenge and its huge environmental effects, caused by more than 2 billion tonnes of metals produced every year, make its sustainability an essential research topic not only from a technological point of view but also from a basic materials research perspective. Therefore, this paper aims to identify and discuss the most pressing scientific bottleneck questions and key mechanisms, considering metal synthesis from primary (minerals), secondary (scrap), and tertiary (re-mined) sources as well as the energy-intensive downstream processing. Focus is placed on materials science aspects, particularly on those that help reduce CO2 emissions, and less on process engineering or economy. The paper does not describe the devastating influence of metal-related greenhouse gas emissions on climate, but scientific approaches how to solve this problem, through research that can render metallurgy fossil-free. The content is considering only direct measures to metallurgical sustainability (production) and not indirect measures that materials leverage through their properties (strength, weight, longevity, functionality).

show abstract

Porosity effects in hydrogen reduction of iron oxides

Cited by 18 publications

References 15 publications

Influence of Microstructure and Atomic-Scale Chemistry on Iron Ore Reduction with Hydrogen at 700°C

Influence of Microstructure and Atomic-Scale Chemistry on Iron Ore Reduction with Hydrogen at 700°C

A preliminary study on the hydrogen reduction of jordanian iron ore

The Materials Science behind Sustainable Metals and Alloys

Contact Info

Product

Resources

About