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The iron and steel industry is a significant contributor to greenhouse gas emissions, responsible for about 7–9 % of the total emissions. This paper examines sustainable production methods in the iron and steel industry, focusing on decarbonization strategies and energy integration. It covers a wide range of alternative reductants to replace the conventional use of coal. Moreover, the paper highlights the challenges and opportunities associated with each approach. Additionally, it discusses the design modifications for coal‐based sponge iron plants, aiming to reduce coal consumption and waste gas generation while ensuring economic viability. This study provides a roadmap for transitioning to environmentally friendly, technically feasible, and economically viable iron and steel manufacturing processes. [ABSTRACT FROM AUTHOR]

In the present work, supercritical fluid extraction (SFE) of hemp (Cannabis sativa) seed oil at various ranges of SFE parameters is performed. These parameters and respective ranges are temperature (40–80) °C, pressure (200–350) bar, solvent (CO2) flow rate (5–15) g/min, particle size (0.43–1.02) mm and amount of co-solvent (ethanol) (0–10) % of solvent flow rate. Central composite design (CCD) suggests 32 experimental runs to perform through SFE. The obtained oil is analysed through gas chromatography to identify its fatty acids concentrations. The ratio of ω-6 linoleic and ω-3 α-linolenic fatty acids (ω-6/ω-3) is optimized through CCD to obtain the desired amount of 3:1 as this ratio is highly preferred for various health benefits. Ratio of ω-6/ω-3 is obtained in the range from 2.11 to 3.06:1 for all experimental runs. The effect of SFE parameters on this ratio is investigated. Further, cross-validation is peformed on the experimental data obtained for the concentrations of both fatty acids by jackknife and bootstrap resampling to authenticate the obtained data. Small value of standard deviation (~1), less standard error of the mean (SEM) (<0.8) and less variance coefficient (<0.11) confirms the validity of the obtained data. All the estimators' values such as standard deviation, variance coefficients and SEM are observed in 95 % of confidence intervals. [ABSTRACT FROM AUTHOR]

Supercritical fluid extraction (SFE) process is the sustainable green process for the extraction. Mathematical modeling of SFE process is carried out using mass transfer resistances, which vary with the types of solute. In this paper, the effect of matrices such as leaves, flower concrete, flower bud, herb plant, shrub seed and vegetable matter is studied on extraction yield through different models. These models are solved using COMSOL Multiphysics 5.2 solver and results are validated with that of literature. Experimental data of each type of solute matrix are fitted in various models and best suited model is predicted. [ABSTRACT FROM PUBLISHER]