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Increasing the share of hydrogen in reduction of iron oxide in the blast furnace iron making will directly reduce the share of blast furnace greenhouse gas emissions. In the present study, injection of H2-rich biomass and plastic materials was studied in terms of its devolatilization, gasification and combustion characteristics. The released gases...
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... FR1, devolatilization of FR2 is a three-step process. During the first step, CO, CO 2 , H 2 , H 2 O and hydrocarbons were released, while, only, H 2 had distinguishable peak during the second and third steps, see Fig. 5. Heating of PUR resulted in loosing up to 70 wt% of its initial mass (Fig. 6). Similar to TSD, the devolatilization curve showed a two-step process. The released gases during the primary devolatilization were CO 2 , CO, Hydrocarbons, H 2 O and H 2 . As the devolatilization approached completion, the CO and H 2 content in the off-gas ...
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In blast furnaces it is desirable for the burden to hold a lumpy packed structure at as high a temperature as possible. The computational thermodynamic software FactSage (version 7.2, Thermfact/CRCT, Montreal, Canada and GTT-Technologies, Aachen, Germany) was used here to study the softening behavior of blast furnace pellets. The effects of the mai...
Citations
... Hydrogen can be employed in ironmaking through three methods: hydrogen injection in blast furnaces, hydrogen direct reduction, and hydrogen plasma reduction (Ahmed et al., 2020;Raabe et al., 2023;Souza Filho et al., 2022, 2021. Among these, hydrogen direct reduction is closest to industrialization, with several companies initiating the construction of their first hydrogen direct reduction plants (Sun et al., 2023). ...
Iron ore pellet reduction in shaft furnaces represents a critical process in the steelmaking industry, with energy consumption being a key factor influencing both economic viability and environmental sustainability. This study employs HSC Chemistry software to model and simulate the energy consumption of hydrogen reduction of iron ore pellets under varying water vapor content within the shaft furnace. Thermodynamic modeling was carried out as the first step to analyze the effect of water vapor on the thermodynamic equilibrium, determining the possible range of water vapor content. Subsequently, energy consumption of the process was modeled based on heat and mass balance. Through comprehensive analysis, we investigate the impact of water vapor on the overall energy efficiency of the process based on the two scenarios of supplying the required heat by preheating the feed materials or injection of oxygen to the furnace. Our findings reveal significant insights into optimizing energy consumption and operational parameters to enhance the sustainability and cost-effectiveness of iron ore pellet reduction. This research contributes to the ongoing efforts towards achieving greater efficiency and reduced environmental footprint in the steelmaking industry.
... On the other hand, the injection of H 2 -rich materials into the blast furnace process had also been proved to reduce the fossil fuel consumption [31][32][33][34][35]. And H 2 greatly affects the formation of cohesive zone and gas flow distribution in blast furnace [36]. ...
... At stage II, given that the reducing agents were introduced from 900 • C, the further shrinkage of the packed bed was obviously controlled by the gaseous reduction, as explained in Fig. 7(b) [31]. The SR of stage II in CO was usually greater than that in H 2 . ...
... Decreasing the reducing agent rate in BF operations by improving the shaft efficiency of the BF without saving energy at the downstream processes can result in enhancing production costs due to increasing purchased energy [23]. Partial replacement of carbonaceous resources like coke and coal, which are the primary energy source in ironmaking, by neutral and renewable carbon-based materials such as waste plastics and biomass offers a viable solution for reducing CO 2 emissions and the dependency on fossil fuels in the integrated steel mills [24,25]. Waste plastics have been proposed as an alternative reducing agent due to their high H 2 content [26,27]. ...
... Although the physical properties of waste plastic, such as porosity, shape and size affect the reaction kinetics [31], the theoretical limit of waste plastic injection is estimated at 70 kg/tHM. Approximately 750 kg of coke can be replaced by one ton of plastics [24]. The use of waste plastics in the BF can decrease CO 2 emissions by up to 30 % due to its higher H 2 content compared to coal and coke [32]. ...
... Biomass utilization in the BF has received much attention due to its renewable nature and significant environmental advantages [24,33,34]. Biomass can be introduced to an integrated steel plant through biosinter, bio-briquettes and/or bio-composites, bio-coke (partial substitution of coal in coke-making), and partial replacement of pulverized coal injection (PCI) or nut coke in the BF [35,36]. ...
... Ironmaking industries created 650 Mt of CO 2 per year, which accounted for 7% of global CO 2 emissions [18]. Additionally, approximately 1.40 tons of coking coal is needed to produce 1 ton of steel and is accompanied by approximately 1.80 tons of CO 2 emissions [19,20]. Hence, substituting coal coke as a source of energy in a cupola furnace with carbon-neutral sources can be one of the strategies for reducing energy consumption and pollutant gas emissions. ...
Growing concern over fossil fuel depletion and the environmental impact of greenhouse gases have driven the demand for solid biofuel energy as an alternative source of coal coke. Therefore, there is increasing attention on Bio-Coke as a new solid biofuel product. The moderate temperature with high loading pressure densification method shows the uniqueness of Bio-Coke, as it has a higher density and mechanical strength when compared to wood pellets and briquettes. These reasons are ideal properties for long-term storage and transportation to ensure the sustainable supply of solid biofuel. Moreover, Bio-Coke also has a stable structure at high temperatures (700 °C), making it suitable for many practical applications such as cupola furnaces. The potential utilization of Bio-Coke and the viability of Bio-Coke feedstock in Southeast Asia are described in this paper. The utilization of agricultural residues from the Southeast Asia region, such as coconut husk and oil palm frond showed a good quality of solid biofuel as it can exhibit a high calorific value of Bio-Coke. The paper also reviews the factors affecting the production process of Bio-Coke and the suggested methods for its mechanical property’s improvement. Moreover, it reviews the economics of Bio-Coke and the impact of its utilization in the Southeast Asia region. Finally, implementing a low-temperature drying system is recommended to lower the production cost of Bio-Coke.
... Consequently, the exothermic reaction at ⁓ 600 ℃ (Fig. 4) can be interpreted as a LiCoO 2 transformation to simpler components. In addition, an H 2 peak is observed in the QMS data that can be interpreted as the product of the secondary devolatilization of organic materials/binder or residual plastics [33]. The diffractogram at 700 ℃ shows the beginning of CoO reduction where a Co phase forms. ...
The increased demand for Li-ion batteries has prompted the scientific community to improve recycling routes in order to reuse the valuable materials in batteries. After their end-of-life, the batteries are collected, discharged, and mechanically disintegrated, generating plastic and metallic streams that are recycled directly; this leaves behind a small particle size fraction known as black mass (BM). BM is composed mainly of graphite and Li-metal complex oxides. Pyrometallurgy is a route known for recycling of BM, in which identifying the BM’s behavior at high temperatures is essential. In this study, two types of BM are characterized in two fractions of 150–700 µm and smaller than 150 µm. The thermal behavior of the BM is studied with thermal analysis techniques. The analyses demonstrate that the mineralogical and morphological properties of the two fractions do not significantly differ, while the amounts of C and organic materials might vary. When the BM was thermally treated, the binders decomposed until a temperature of 500 ℃ was reached, where the volatilization of hydrocarbons was observed, although F mostly persisted in the BM. The Li-metal oxide was partially reduced to lower oxides and Li carbonate at ⁓ 600 ℃, and the main mass loss was caused by carbothermic reduction immediately thereafter. As the products of this process, metallic Co and Ni phases were formed, and part of the graphite remained unreacted. Regarding the Li behavior, it was observed that in the presence of Al, AlLiO 2 is the most likely composition to form, and it changes to LiF by increasing the F concentration in the composition.
Graphical Abstract
... Due to the high H 2 content of biomass compared to coal, replacement of coal by biomass will contribute directly to lowering CO 2 emission from a blast furnace. Increasing H 2 content in the shaft will also improve the reduction kinetics of descending iron oxide [20]. ...
Most modern blast furnaces (BFs) operate with Pulverized Coal Injection (PCI), but renewable and carbon neutral biochar could be applied to reduce the fossil CO2 emission in the short term. In the present study, heat and mass balance-based model (MASMOD) is applied to evaluate the potential of biochar in partial and full replacement of injected pulverized coal (PC) in the ironmaking BF. The impact of biochar injection on the raceway adiabatic flame temperature (RAFT) and top gas temperature (TGT) is evaluated. Three grades of biochar, produced from the pyrolysis of sawdust, were evaluated in this study. The total carbon content was 79.2%, 93.4% and 89.2% in biochar 1, 2 and 3, respectively, while it was 81.6% in the reference PC. For each type of biochar, 6 cases were designed at different injection levels from 30 kg/tHM up to 143 kg/tHM, which represent 100% replacement of PC in the applied case, while the top charged coke is fixed in all cases as reference. The oxygen enrichment, RAFT, and TGT are fixed for certain cases, and have been calculated by MASMOD in other cases to identify the optimum level of biochar injection. The MASMOD calculation showed that as the injection rate of biochar 1 and biochar 2 increased, the RAFT increased by ~190 °C, while TGT decreased by ~45 °C at 100% replacement of PC with biochar. By optimizing the moisture content of biochar and the oxygen enrichment in the blast, it is possible to reach 100% replacement of PC without much affecting the RAFT and TGT. Biochar 3 was able to replace 100% of PC without deteriorating the RAFT or TGT.
... Due to the high H 2 content of biomass compared to coal, replacement of coal by biomass will contribute directly to lowering CO 2 emission from blast furnace. Increasing H 2 content in the shaft will also improve the reduction kinetics of descending iron oxide (Ahmed et al., 2020). ...
The aim of this chapter is to review the link between resources, technology, and changing environmental impacts over time as a basis for informing future research priorities in technology and resource governance models. Given that the iron ore sector has shown boom-bust cycles in the past, it is important to assess in detail the current state of Australia’s iron ore industry, especially in comparison to global trends and issues, with a view to ensuring the maximum long-term benefit for and from Australia’s mining sector. This chapter presents an assessment of Australia’s iron ore mineral resources, production trends, economic aspects, existing and future production challenges, and links these to sustainability aspects, especially environmental issues such as greenhouse gas emissions. The chapter therefore provides a sound basis for ongoing policy development to ensure that Australia can maintain and enhance the benefits that our iron ore resource endowment brings.
... Increasing H2 content in the shaft will also improve the reduction kinetics of descending iron oxide [56]. ...
The iron and steel industrial sector use about 20% of the total annual industrial energy. Coke and coal are the main sources of energy, but they also used as reducing agents for iron ores and consequently contribute to fossil CO2 emission. Partial or full replacement of fossil fuel with neutral biomass products can significantly contribute to lowering the fossil CO2 emission and provide a good opportunity for green steel production. The challenges of biomass usage in iron and steel industry can be generally classified into technical and economic aspects. This chapter will focus on technical issues of biomass implementations and the recent research progresses in iron and steel industry. The discussion will focus on biomass utilization in top charged burden materials into the ironmaking blast furnace but also via tuyere injection at the lower part of the shaft. In addition, the potential of using the biomass in steelmaking will be addressed. Benefits and limitations of biomass applications in each process will be comprehensively discussed and analyzed.
The repurposing of industrial solid wastes for sustainable energy production figures as a convenient alternative to decrease the carbon footprint of industrial processes by increasing circularity and reducing the utilization of fossil-based energy vectors. The furniture industry generates significant amounts of carbon-based waste materials, including high-pressure laminates (HPL) that comprise cellulose-based materials treated with thermosetting phenol-formaldehyde and melamine-formaldehyde resins. There are currently no energy recovery studies for this type of waste, especially concerning thermochemical conversion. In this work, we proposed to evaluate the potential of HPL wastes for the generation of energy relevant gaseous products (syngas) by gasification, using air and steam as gasifying agents in a downdraft gasifier. The influence of temperature (600–900 °C), equivalence ratio (ER, 0.20–0.30) and the presence of the thermosetting formaldehyde-based resins were evaluated in the composition (H2 content, H2/CO ratio) and lower heating value (LHV) of the obtained syngas. The increase in temperature positively influenced the H2 content in the final gas product, contrarily to the increase in ER. High temperature (900 °C) and low ER (0.20) were found to favor H2 production (43.8%vol), increase syngas fraction (58.0%vol) and LHV (7.4 MJ/Nm3) of the gas products. The presence of the thermosetting resins contributed to the production of a larger syngas fraction with high H2 content (62.3%vol, H2/CO = 2.4). Overall, gasification of HPL wastes was shown to be a promising alternative to the production of hydrogen-rich syngas with potential industrial applications.
