Direct reduction of oxidized iron ore pellets using biomass syngas as the reducer

Guo, Dabin; Zhu, Linna; Guo, Shenghui; Cui, Baihui; Luo, Shipeng; Laghari, Muhammad Younis; Chen, Zhihua; Ma, Chunfeng; Zhou, Yan; Chen, Jian; Xiao, Bo; Hu, Mian; Luo, Shiyi

doi:10.1016/j.fuproc.2016.03.009

Cited by 84 publications

(27 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is already the case at Emirates Steel in Abu Dhabi, where 0.8 Mt CO 2 / year is captured for use in enhanced oil recovery (EOR) [8]. Combined with CCS, a biogenic reducing gas [59,60] could theoretically allow for "carbon negative" DRI steel [48•, 50]. Similarly, BECCS in smelt reduction steelmaking routes, such as Corex and the under-development HIsarna process, which are also more fuel-flexible than blast furnace steelmaking, could also allow for carbon-neutral or -negative steel [50, 58•].…”

Section: Retrofitting Beccs Into Carbon-intensive Industriesmentioning

confidence: 99%

Decarbonising Industry via BECCS: Promising Sectors, Challenges, and Techno-economic Limits of Negative Emissions

Tanzer

Blok

Ramírez

2021

Curr Sustainable Renewable Energy Rep

View full text Add to dashboard Cite

Purpose of Review This paper reviews recent literature on the combined use of bioenergy with carbon capture and storage (BECCS) in the industries of steel, cement, paper, ethanol, and chemicals, focusing on estimates of potential costs and the possibility of achieving “negative emissions”. Recent Findings Bioethanol is seen as a potential near-term source of negative emissions, with CO2 transport as the main cost limitation. The paper industry is a current source of biogenic CO2, but complex CO2 capture configurations raise costs and limit BECCS potential. Remuneration for stored biogenic CO2 is needed to incentivise BECCS in these sectors. BECCS could also be used for carbon–neutral production of steel, cement, and chemicals, but these will likely require substantial incentives to become cost-competitive. While negative emissions may be possible from all industries considered, the overall CO2 balance is highly sensitive to biomass supply chains. Furthermore, the resource intensity of biomass cultivation and energy production for CO2 capture risks burden-shifting to other environmental impacts. Summary Research on BECCS-in-industry is limited but growing, and estimates of costs and environmental impacts vary widely. While negative emissions are possible, transparent presentation of assumptions, system boundaries, and results is needed to increase comparability. In particular, the mixing of avoided emissions and physical storage of atmospheric CO2 creates confusion of whether physical negative emissions occur. More attention is needed to the geographic context of BECCS-in-industry outside of Europe, the USA, and Brazil, taking into account local biomass supply chains and CO2 storage siting, and minimise burden-shifting.

show abstract

Section: Retrofitting Beccs Into Carbon-intensive Industriesmentioning

confidence: 99%

Decarbonising Industry via BECCS: Promising Sectors, Challenges, and Techno-economic Limits of Negative Emissions

Tanzer

Blok

Ramírez

2021

Curr Sustainable Renewable Energy Rep

View full text Add to dashboard Cite

show abstract

“…As listed in Table 2.3, the shrinking core model (SCM) is the most widely applied kinetic model used to describe the gas-based reduction of iron ore pellets [79], [86], [100], [122], [127], [128], [130], [131]. Commonly, the SCM is applied by assuming only one rate-limiting reaction interface.…”

Section: Description Of the Modelmentioning

confidence: 99%

Reduction of New Zealand Titanomagnetite Ironsand pellets in H2 Gas at High Temperatures

Zhang¹

2021

Preprint

View full text Add to dashboard Cite

To reduce the emission of carbon dioxide (CO2) from industrial ironmaking in New Zealand (NZ), it is proposed to perform direct reduction (DR) of NZ titanomagnetite ironsand pellets using H2 gas. In this thesis, the H2 reduction behaviour of pellets made from the NZ ironsand are examined. The aim of the thesis is to understand the reduction mechanism, and develop an analytical kinetic model to describe the reduction progress with time. This has been addressed through a series of reduction experiments in H2 gas. The overall reduction kinetics are examined in a Thermogravimetric analysis system (TGA); the phase evolution during reduction is measured by an in-situ neutron diffraction (ND) method; and the evolution of pellet- and particle-scale morphologies are analysed by scanning electron microscopy (SEM) of quenched samples. Based on the analysis of results from these experiments, the mechanism of the reduction is found to be adequately described by a single interface shrinking core model (SCM). Two different types of pellet are considered in this work: Ar-sintered pellets were sintered in an inert atmosphere to produce pellets containing mainly titanomagnetite (TTM). Pre-oxidised pellets were sintered in air to produce pellets containing mainly titanohematite (TTH). The reduction rate of both types of pellets is found to increase with reduction temperature, H2 gas flow rate, and H2 gas concentration. Above 1143 K, it is found that both types of pellets present a similar reduction rate, while below 1143 K, the reduction of pre-oxidised pellets is much faster than that of Ar-sintered pellets. For both pellets, the maximum reduction degree can reach ~97%. After complete reduction, metallic Fe coexists with other unreduced Fe-Ti-O phases (FeTiO3, TiO2 or pseudobrookite (PSB)/ferro-PSB), which is consistent with the observed reduction degree of < 100%. During reduction of both types of pellets, any TTH present is rapidly reduced first. After this step, TTM is then reduced to FeO, with Ti becoming enriched in the remaining unreduced TTM. FeO is further reduced to metallic Fe, which makes up to ~90% reduction degree. Eventually Ti-enrichment of the TTM leads to a change in the reduction pathway and it instead directly converts to metallic Fe and FeTiO3. Above ~90% reduction degree, reduction of the remaining Fe-Ti-O phases occurs (leading to the formation of TiO2 or PSB/ferro-PSB). The enrichment of Ti in TTM which accompanies the generation of FeO is substantially different from conventional non-titaniferous ores. This enrichment is confirmed by EDS-maps of the particles and stoichiometric calculations of the molar fraction Ti within the TTM phase. This enrichment effect changes the morphology of FeO in the particles, leading to the formation of FeO channels surrounded by Ti-enriched TTM. At the pellet-scale, both types of pellets present a single interface shrinking core phenomenon at higher temperatures. Metallic Fe is generated from pellet surface with a reaction interface moving inwards. However, at lower temperatures this pellet-scale interface becomes less defined in the pellets. Instead, particle-scale reaction fronts are observed. A single interface shrinking core model (SCM) is shown to successfully describe the reduction of pellets for reduction degrees < ~90% at all temperatures studied. However, at reduction degrees > ~90% this model fails. This is attributed to the change in reaction mechanism required to reduce the residual Fe-Ti-O phases that remain dispersed throughout the whole pellet at this stage of the reaction. The single interface SCM indicates that the reduction rate of the Ar-sintered pellets is controlled by the interfacial chemical reaction rate. However, two different temperature regimes are identified. Above 1193 K, the activation energy is calculated to be 41 ± 1 kJ/mol, but below 1193 K the calculated activation energy increases to 89 ± 5 kJ/mol. This change in activation energy appears to be associated with the change of the rate-limiting reaction from FeO → metallic Fe to TTM → FeO. By contrast, the pre-oxidised pellets exhibit mixed control at 1043 K, where a role is played by both the interfacial chemical reaction rate and the diffusion rate through the outer product layer. However, at temperatures of 1143 K and above, the pre-oxidised pellets also exhibit interfacial chemical reaction control, with a single activation energy of 31 ± 1 kJ/mol, which again seems to be consistent the rate-limiting reaction being FeO → metallic Fe. In summary, the findings in this thesis contribute to understanding of the reduction of NZ ironsand pellets in H2 gas, and establish a kinetic model to describe this process. In the future, this information will be applied to develop a prototype H2-DRI shaft reactor for NZ ironsand pellets.

show abstract

“…The results show that biochar extracted from waste nut shell could be used as a valuable and renewable carbon resource for sustainable and clean ironmaking production. Guo et al [24] used syngas produced during sawdust cracking as a reductant to produce iron ore pellets. The effects of reduction temperature and time on the reduction rate of iron ore pellets were studied, and the kinetics of the reduction process was analyzed.…”

Section: Introductionmentioning

confidence: 99%

Matte separated behavior from slag during the cleaning process by using waste cooking oil as carbon neutral reductant

Wang

Wei

Zhou

et al. 2021

J min metall B Metall

View full text Add to dashboard Cite

As a waste resource, waste cooking oil (WCO) has not been widely used. Based on the characteristics of WCO cracking, this study proposed to replace fossil-based reductant with WCO for copper slag cleaning, to solve the problem of carbon neutralization in this process. Copper slag cleaning experiments were carried out in a lab-scale electric furnace. The matte separated behavior from slag and the distribution of matte in slag were studied. The results showed that the Fe3O4 content decreases from 12.9 to 3.5 wt.% by injecting 2.2 mL of WCO into 300 g copper slag at 1250?C. The distribution of copper content in slag is gradient along the vertical direction. In the reduction stage, the excessive Fe3O4 is reduced and the fluidity of slag is improved. When the precipitation time above 60 minutes, the copper content in the middle and upper slag is reduced to 0.57 wt.%, which realizes the copper slag cleaning by using WCO.

show abstract

Direct reduction of oxidized iron ore pellets using biomass syngas as the reducer

Cited by 84 publications

References 12 publications

Decarbonising Industry via BECCS: Promising Sectors, Challenges, and Techno-economic Limits of Negative Emissions

Decarbonising Industry via BECCS: Promising Sectors, Challenges, and Techno-economic Limits of Negative Emissions

Reduction of New Zealand Titanomagnetite Ironsand pellets in H2 Gas at High Temperatures

Matte separated behavior from slag during the cleaning process by using waste cooking oil as carbon neutral reductant

Contact Info

Product

Resources

About