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To further unlock the circular economy potential of iron and steel industry and achieve peak carbon and carbon neutrality targets, this study provides a comprehensive analysis of the high value-added use of blast furnace slag (BFS) for the synthesis of X-type zeolite. The thermodynamic and dissolution behaviors during acid leaching are investigated through theoretical analysis, identifying the optimal pH is 0–1.63 and Eh is −1.01–2.00 V. Experiments determine that there are obvious improvement in silica gel leaching ratio at 353 K, 4 mol·L−1HCl and V(HCl):m(slag) ratio of 12:1. Obtained silica gel has 91.56 % whiteness and 86.86 % SiO2. The optimal conditions for X-type zeolite synthesis are crystallization at 363 K for 6 h, with n(SiO2):n(Al2O3), n(Na2O):n(SiO2) and n(H2O):n(Na2O) establishes as 2.8, 2.8 and 45 respectively and resulting material has high crystallinity, purity of crystals and excellent performance. Furthermore, the mechanism is elucidated from the perspective of microstructural and molecular level. Economic evaluation along with carbon tax assessment indicated that it is economically beneficial both in direct profit and potential CO2capture. These findings emphasize the feasibility, efficacy and economy of X-type zeolite synthesis from BFS, which contributes to turning waste into treasure and promoting the concept of “Green steel”.

Climate change posed the greatest threat to human sustainable development, and reducing carbon emissions was a pressing issue for all humanity. Among the most energy-intensive and carbon emissions industries, the iron and steel industry (ISI) represented almost 5 % of energy consumption and 7 % carbon emissions around the world. The ISI faced severe challenges from the “relative constraints” of carbon emissions intensity to the “absolute constrains” of total carbon emissions. Waste heat played an indispensable role in the low-carbon development of ISI. The heat contained in the blast furnace slag (BFS) was considerable, and it was an important position to be occupied. In recent decades, the proposal and development of dry centrifugal granulation (DCG) technology had provided researchers with great encouragement and brought the dawn to overcome the problem of slag waste heat recovery. This technology had been hailed as one of the most suitable technologies to boost sustainable transition of the ISI. This paper provided a detailed review of DCG technology including granulation characteristics of BFS, flight and impingement behavior of slag particles, slag transformation in granulation chamber, waste heat recovery process, etc. Furthermore, the implementation and technical characteristics of semi- and industrialization implementation for DCG technology were explored and elaborated as comprehensively as possible. Ultimately, the problems existing in the development of this technology were analyzed, and suggested the future direction and challenges. This paper aiming to pave the way for the waste heat recovery of BFS while supporting the market penetration and enhancing the role in the fight against climate change for ISI.

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In this paper, molten blast furnace slag was used as a heat carrier to make the coal gasification reaction run smoothly. The characteristics of coal particle motion, heat transfer, and gasification reaction in molten slag were investigated in detail. It could be divided into four forms of coal particles in molten slag, and the coal particle could move across the bubble when the velocity and diameter of coal particle were 4.20 m s–1and 75 μm, respectively. Meanwhile, with the coal particle motion, a large amount of waste heat of molten slag transferred it to ensure the process of the gasification reaction. The slag could enhance the heating rate of the coal particle, promote the gasification reaction, and increase the carbon conversion rate. Molten slag was also beneficial to the syngas production, which improved the fraction of CO and enhanced the combustible gas component in the process of coal/CO2gasification. Moreover, the problem of sulfide emission in the coal gasification process was solved effectively using molten blast furnace slag as the heat carrier. The total sulfide emission decreased dramatically from 0.21 to 0.04 mol kgcoal–1. Overall, not only was waste heat of molten slag recovered by this method, but also the quality of coal gasification and reduced hazardous gas emissions improved.

Chemical-looping technology (CLT) can achieve energy efficiency and reduce the environmental pollution and is usually conducted on a fixed-bed reactor. In this paper, the thermodynamic simulations for flue-gas desulfurization (FGD) systems with CLT are carried out using HSC Chemistry software to choose a suitable desulfurizer, control the type and quantities of reaction products, and collect sulfur-containing byproducts with high economic value. The Ellingham diagrams are developed to relate the Gibbs free energy of the relevant reactions to the temperature. The fixing-sulfur potential; the reaction degree with CO2, H2O, and CO; and the acceleration effect of removing NOxof different metal oxides in 100 to 300 °C are estimated. Compared comprehensively, Mn-based oxides have distinct advantages for flue-gas desulfurization using CLT. Based on calculation results, both low reaction temperatures (T< 400 °C) and sufficient H2(mH2/mMnSO4> 4) can effectively prevent the loss of sulfur element. In the regeneration of Mn3O4, if pure O2is replaced by diluent air or a low level of oxygen, the formation of trace amounts of MnSO4can be inhibited. This paper provides ample theoretical basis for Mn-based oxides as active components of desulfurizer and collecting pure SO2from flue gas through chemical-looping technology.

The steam reforming of four bio-oil model compounds (acetic acid, ethanol, acetone and phenol) was investigated over Ni-based catalysts supported on Al2O3modified by Mg, Ce or Co in this paper. The activation process can improve the catalytic activity with the change of high-valence Ni (Ni2O3, NiO) to low-valence Ni (Ni, NiO). Among these catalysts after activation, the Ce-Ni/Co catalyst showed the best catalytic activity for the steam reforming of all the four model compounds. After long-term experiment at 700 °C and the S/C ratio of 9, the Ce-Ni/Co catalyst still maintained excellent stability for the steam reforming of the simulated bio-oil (mixed by the four compounds with the equal masses). With CaO calcinated from calcium acetate as CO2sorbent, the catalytic steam reforming experiment combined with continuous in situ CO2adsorption was performed. With the comparison of the case without the adding of CO2sorbent, the hydrogen concentration was dramatically improved from 74.8% to 92.3%, with the CO2concentration obviously decreased from 19.90% to 1.88%.

Hepatoprotectant silibinin has anticancer and chemo-preventive effects. In this study, silibinin showed significant inhibitory effect on human fibroblast HT 1080 cell growth cultured in media containing 10% fetal bovine serum or in serum free media, and in the latter case, silibinin exerted a more significant effect. Silibinin induced autophagy at 12 h, confirmed by monodansyl-cadervarine (MDC) staining, up-regulation of Beclin 1 (initiation factor for autophagosome formation), and conversion of LC3 I to LC3 II (autophagosome marker). It also induced apoptosis at 24 h, proved by observation of apoptotic body and activation of caspase-3. 3-Methyladenine (3-MA) inhibited silibinin-induced autophagy and promoted cell survival, suggesting that autophagy enhanced silibinin-induced apoptosis in HT1080 cells. Silibinin generated reactive oxygen species (ROS) in HT1080 cells, and the ROS scavenger N-acetylcysteine (NAC) reversed the cytotoxicity of silibinin, resulting in cell survival by inhibition of autophagic and apoptotic pathways. Application of specific antioxidants demonstrated that H2O2was a major factor in silibinin-induced ROS since the H2O2scavenger catalase reduced both autophagy and cell death. O2•−also contributed to silibinin-induced cell death.