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Pulverized coal injection (PCI) into blast furnace tuyeres is widely used by integrated steel mills worldwide to reduce the consumption of coke and costs. High injection rates are desirable. The big challenge is to achieve them with cheaper and lower quality raw materials, without losing the quality of the hot metal and the productivity of the blas...
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Context 1
... for char burning, the thermopositive peak is higher, resulting in a large amount of heat. Figure 3 presents the Tps for the 4 single fuels. MCV has the lowest Tp (508.20 °C) compared to the other sam- ples, and is the sample that shows the best combustibility performance among the fuels, in agreement with literature (Barbieri et al, 2016), followed by CMN (520.81°C), ...
Context 2
... for char burning, the thermopositive peak is higher, resulting in a large amount of heat. Figure 3 presents the Tps for the 4 single fuels. MCV has the lowest Tp (508.20 °C) compared to the other sam- ples, and is the sample that shows the best combustibility performance among the fuels, in agreement with literature (Barbieri et al, 2016), followed by CMN (520.81°C), ...
Citations
... The DTG peak in the 385−585°C range shows that the CH degradation proceeded, along with residual lignin degradation and previously produced char burning. 41 The DTG peak for the CH at 640°C is due to residual char burning and probably inorganic component volatilization. 42 This peak most likely occurred as a result of the previously developed ash's nonporous character for air transfer. ...
In this study, alkali and bifunctional catalysts were synthesized for waste frying oil methyl ester (WFOME) synthesis. Coffee husk (CH) and CH blended with Eragrostis tef straw (TS) (CH–TS) lignocellulosic biomasses (LBs) were utilized during the catalysts’ synthesis. The alkali catalysts were CH and CH–TS ashes, both modified by KNO3 impregnation. They are designated as C-45 and C-Mix, respectively. Zirconia (ZrO2) promoted CH ash catalysts via precipitation followed by impregnation (Bic-PP) and in situ precipitation–impregnation (Bic-Dm) were the bifunctional ones. CH and CH–TS chars were the supporting frameworks during the catalysts’ composite materials (CCMs) preparation. The combustion performance of LBs and CCMs was evaluated and associated with the catalysts’ physicochemical properties. Using XRD, SEM, FTIR, alkalinity, TOF, and BET surface area analysis, catalysts were characterized. The combustion performance of the LBs was in the order of TS > CH–TS > CH. Among CCMs, the highest combustion performance was for CCM-Mix (KNO3/(CH–TS char)) and the lowest was for CCM-45 (KNO3/ CH char). The C-Mix catalyst was a light green powder due to the reaction between inorganic components, whereas C-45 was dark gray due to the presence of unburned char. The CCMs for bifunctional catalysts had moderate combustion performance and yielded light gray powdered catalysts containing tetragonal ZrO2. The optimum WFOME yields were 98.08, 97, 92.69, and 93.05 wt % for C-Mix, C-45, Bic-Dm, and Bic-PP assisted WFO transesterification, respectively. The results were obtained at a reaction temperature of 65 °C, time of 1 h, and methanol to WFO molar ratio of 15:1 using catalyst amounts of 5 and 7 wt % for the alkali and bifunctional catalysts, respectively. The greatest moisture resistance was offered by the C-Mix catalyst. The best reusability was for the C-45 catalyst. Catalysts’ deactivation modes include active site leaching and poisoning.
... These stages are sources for pyrolysis char (γchar) [45]. The fourth sharp DTG peak at 454 • C followed by the broader one which extends up to 597 • C belongs to simultaneous devolatilization of more stable macromolecules and burning (φ-char will be formed at this stage) followed by previously formed chars (γchar) oxidation [49]. The next higher combustion rate was observed at a peak temperature of 640 • C in the temperature range of 598-670 • C due to the combustion char residue and might also possibly be a result of some inorganic components volatilization [45]. ...
... The lignin combustion peak was not visible on the A/C DTA curve (Fig. 2). This result shows the calcination of CH at 600 • C for 2 h was sufficient to convert the majority of the lignocellulosic components in the CH to fixed carbon for KNO 3 impregnation [49]. Combustion of A/C and CCMs dissipated more heat per unit mass than CH because of their higher fixed carbon content than that of CH [45]. ...
... To develop a new injection technology and/or study an existing technology, laboratory-and pilot-scale experiments [14][15][16][17][18][19][20][21] conducted to study the single or blended combustion of hydrogen and carbon-based fuel in BFs for feasibility and optimisation studies. Several purpose-built test rigs found in the literature can simulate many conditions present in the BF raceway, including but not limited to high pressure, high temperature, high radiation, high turbulence, and short residence time [16,[19][20][21]. ...
... To develop a new injection technology and/or study an existing technology, laboratory-and pilot-scale experiments [14][15][16][17][18][19][20][21] conducted to study the single or blended combustion of hydrogen and carbon-based fuel in BFs for feasibility and optimisation studies. Several purpose-built test rigs found in the literature can simulate many conditions present in the BF raceway, including but not limited to high pressure, high temperature, high radiation, high turbulence, and short residence time [16,[19][20][21]. Among these rigs, BlueScope Steel set up a pilot-scale pulverised coal injection (PCI) test rig to study the combustion behaviour of coal or biochar along the tuyere centreline [16,22], and it is regarded as one of the representative replications of in-furnace combustion along the tuyere centreline. ...
... The high level of volatile matter in the torrefied and wood pellets reduce the RAFT and hence more O 2 enrichment in the hot blast is required. The reactive structure of charcoal improves the combustion process in raceway to become comparable to that of coal (Silva and Assis, 2019;. Feliciano-Bruzual and Mathews (2013) found that the maximum injection rate of charcoal was estimated to be in range of 200-220 kg/tHM which able to reduce the net CO 2 emissions by 40%. ...
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.
... The high level of volatile matter in the torrefied and wood pellets reduce the RAFT and hence more O2 enrichment in the hot blast is required. The reactive structure of charcoal improves the combustion process in raceway to become comparable to that of coal [74,75]. Feliciano-Bruzual and Mathews [57] found that the maximum injection rate of charcoal was estimated to be in range of 200-220 kg/tHM which able to reduce the net CO2 emissions by 40%. ...
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.
Biomass is a renewable and potentially carbon-neutral energy source and can be a promising alternative to fossil fuels in the ironmaking industry. Pulverised biomass injection (PBI) is the most promising technology to use biomass-based materials in ironmaking blast furnaces (BFs). This paper reviews key aspects of recent research relating to biomass combustion in the raceway region: experimental studies, numerical studies, and the application of the research findings to optimise BF practice. In the experimental part, the pretreatment of raw biomass to produce pyrolysed biochar products for improving applicability in BFs is reviewed. The properties of raw biomass and biochar are compared with the main requirements for injection into BFs, and the process tests that have been employed at lab- and pilot-scales are reviewed. In the modelling part, a comprehensive overview of mathematical modelling of biomass combustion in BFs is presented, ranging from turbulent flow to heat transfer and mass transfer, as well as key reaction models for simulating the lower part of the BF. With respect to the application of the research, in-furnace phenomena understanding, operation optimisation, and facility design are reviewed, including the co-firing of biomass and coal. In addition, heat and mass balance modelling has been used to demonstrate the operating window of feasible operations using PBI. Life cycle assessment has been reviewed to demonstrate PBI's environmental credentials. Based on the aspects reviewed, conclusions have been drawn on the strengths, limitations, and outlook of PBI studies. This paper offers a comprehensive review of the combustion of biomass in BFs and should prove useful for process understanding, design and optimisation towards green ironmaking technology.
