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Due to the complexity of the internal pore structure of petroleum coke loose particle‐packed beds, measuring their thermal conductivity has always been a challenging problem. This work independently developed an experimental apparatus for testing the thermal conductivity of petroleum coke particle‐packed beds and constructed a forward calculation model for the heat transfer process, which was based on one‐dimensional unsteady heat transfer. Using the Sparse Nonlinear OPTimizer (SNOPT) algorithm, a mathematical relationship between the thermal conductivity λ of the coke bed, temperature T, and equivalent particle diameter dp was established through inverse modeling. Concurrently, a digital model of the petroleum coke particle packed bed was derived utilizing three‐dimensional computed tomography (CT) scanning technology, and a pore‐scale gas–solid radiation heat transfer model was formulated based on CFD simulation technology, thereby further elucidating the heat transfer mechanism within the petroleum coke particle packed bed. The research results indicate that the temperature predicted by the established thermal conductivity model aligns well with experimental data. Further CFD simulation studies demonstrate that a smaller particle size leads to a larger temperature difference between the wall and the center of the packed bed, while a higher gas velocity results in a smaller temperature difference, with a linear correlation observed between these two factors. At high temperatures, thermal radiation between particles in the porous petroleum coke‐packed bed plays a dominant role. The research outcomes can offer significant theoretical support for a profound analysis of the heat transfer behavior of petroleum coke‐packed beds within a vertical shaft calciner. [ABSTRACT FROM AUTHOR]

Clarifying the physical properties and contact parameters of petroleum coke was crucial for understanding the descent motion of petroleum coke in the vertical shaft calciner. In this study, the inclined plate collision experiment technique was used to determine the average restitution coefficients of petroleum coke with steel plate, silica brick, and between petroleum coke, which were 0. 400,0. 595, and 0. 608, respectively. The static friction coefficients between petroleum coke and the steel plates, petroleum coke and silica bricks were determined to be 0. 368 and 0. 599, respectively, using the inclined plane lifting method. Based on the fixed funnel experiment method and discrete element simulation technology, using the Box-Behnken experimental design method to calibrate the static friction coefficients between petroleum coke particles were 0.415, as well as the rolling friction coefficients of petroleum coke with steel plate, silica brick, and petroleum coke particles were 0.036, 0.050, and 0.042, respectively. The error in the stacking angle obtained from the funnel physical experiment and simulation calculation was less than 0. 5%. This research can provide theoretical and data support for the particle movement behavior in the vertical shaft calciner. [ABSTRACT FROM AUTHOR]

Because of the increasingly deteriorating quality of petroleum coke raw materials, abnormal furnace conditions, such as "firing and blasting", frequently arise during the calcination of petroleum coke with a high powder/coke ratio in a vertical shaft calciner. This poses an urgent technical challenge that needs to be addressed. In iron and steel metallurgy, the burden distribution system is an important way to regulate blast furnace conditions and improve the permeability of a particle packed bed. In this work, advanced burden distribution concepts were introduced into the calcination process of petroleum coke in a vertical shaft calciner. Experimental devices were established to determine the resistance characteristics of a petroleum coke particle packed bed, along with a cold physical model of a 1/8 scale vertical shaft calciner. The influence of particle size and burden distribution methods on the resistance characteristics and particle motion behavior of the petroleum coke particle packed bed was systematically studied. The research findings indicate that both particle size and burden distribution methods significantly impact the resistance characteristics of petroleum coke particle packed beds. The smaller the particle size, the poorer the permeability of the bed. The layered burden distribution, symmetrical burden distribution, and dual‐particle mixed conventional burden distribution all contribute to improving the permeability of the petroleum coke particle packed bed in the vertical shaft calciner. Furthermore, employing symmetrical burden distribution in Bed‐3, which is packed with petroleum coke particles of diameters −3.2 + 2.5 mm and −1.0 + 0.8 mm, results in the smallest unit pressure drop, at only 1.7% of that of the conventional burden distribution of unscreened raw materials. This is the most effective means of improving the permeability of the bed. During the discharging process, particle size and symmetrical burden distribution have no significant impact on the motion characteristics of petroleum coke particles in the vertical shaft calciner. In general, in the calciner area, particles primarily move in a plug flow pattern and gradually transform into funnel flow in the cooling water jacket area. These research results provide the theoretical basis for addressing the technical challenges associated with powder coke calcination in vertical shaft calciners through reasonable burden distribution methods for fine and coarse particles. [ABSTRACT FROM AUTHOR]

In order to effectively guarantee the smooth supply of emergency materials under public health emergencies, first, we predict the number of daily infected people based on the modified SEIRD infectious disease dynamics model and accordingly construct the dynamic demand prediction model of emergency materials so as to catch the change rule of the demand for emergency materials with greater precision. Subsequently, under the premise of demand satisfaction, we optimize the supply chain network of emergency materials and embed two insurance strategies in the supply system in advance: multi‐source purchase and buffer production capacity, to enhance the stability of supply chain by sacrificing part of the cost. Next, a bi‐objective linear programming model based on minimizing system cost and maximizing demand satisfaction is proposed with the intention of realizing the design of emergency materials supply chain network, which balances the risk and cost. Finally, through the analysis of the example, we find that compared with the traditional supply chain network of emergency materials, the total satisfaction rate of the supply chain network optimized by balancing cost and risk is increased by 11.70%, while the cost is increased by only 2.04%, which fully verifies the validity of the optimized design of supply chain network of emergency materials. [ABSTRACT FROM AUTHOR]

With the increasingly complicated sources of lead smelting materials, it is becoming more difficult to optimize process parameters during the bottom-blowing lead oxidation smelting process. Building a bottom-blowing lead smelting thermodynamic model has significant importance for the green production of the lead smelting process. In this study, we built a multi-phase equilibrium thermodynamic model and simulation system for the oxygen-enriched bottom-blowing lead oxidation smelting process using the MetCal software platform (MetCal v7.81) according to the chemical equilibrium constant method. The equilibrium products composition and important technical indicators were calculated under factory operating conditions. Compared with the industrial data, the calculation results demonstrated that the average relative error of the calculation value of the mass fraction in the crude lead, lead-rich slag, and dust was 3.76%. The average relative error of important technical indicators, including dust rate, crude lead yield, lead-rich slag temperature, slag iron–silica ratio (RFe/SiO2), and slag calcium–silica ratio (RCaO/SiO2), was 6.39%. As a result, the developed modeling and simulation system was able to reflect the current state of the oxygen-enriched bottom-blowing lead smelting. It also demonstrated the potential to enhance the smelting process and optimize the process parameters. Therefore, it is expected to provide a useful tool for thermodynamic analysis. [ABSTRACT FROM AUTHOR]

Sluggish charge kinetics and low CO2 affinity seriously inhibit CO2 photoreduction. Herein, the synchronous promotion of charge separation and CO2 affinity of Bi4Ti3O12 is realized by coupling corona poling and surface I‐grafting. Corona poling enhances ferroelectric polarization of Bi4Ti3O12 by aligning the domains direction, which profoundly promotes charge transfer along opposite directions across bulk. Surface I‐grafting forms a surface local electric field for further separating charge carriers and provides abundant active sites to enhance CO2 adsorption. The two modifications cooperatively further increase the ferroelectric polarization of Bi4Ti3O12, which maximize the separation efficiency of photogenerated charges, resulting in an enhanced CO production rate of 15.1 μmol g−1 h−1 (nearly 9 times) with no sacrificial agents or cocatalysts. This work discloses that ferroelectric polarization and surface ion grafting can promote CO2 photoreduction in a synergistic way. [ABSTRACT FROM AUTHOR]

The effective and highly selective aerobic oxidation of sulfides to sulfoxides under green and mild conditions is still an important but challenging process. Here we present a photocatalytic system for sulfide oxidation to sulfoxides with high yields under blue LED irradiation. The photo-oxidation was carried out in water with oxygen over a bismuth-rich catalyst of Bi4O5Br2. The apparent quantum efficiency of sulfide oxidation reached 57.4%. The developed system provided a simple, robust, green and sustainable promising candidate for the practical application of sulfide oxidation. [ABSTRACT FROM AUTHOR]

Photocatalytic conversion of CO2 to solar fuels is considered an alternative approach for simultaneously mitigating the greenhouse effect and solving energy shortage. The efficient light harvesting and the thermochemical conversion have been demanding quests in photocatalysis due to the relatively low solar energy utilization efficiency. In this work, oxygen vacancies are induced in MoO3 for improving photo-thermal CO2 reduction efficiency by capturing near-infrared (NIR) photons. The localized surface plasmon resonance (LSPR) of MoO3−x triggered by oxygen vacancies enables the efficient capture of NIR photons. Additionally, oxygen vacancies can promote the carrier separation, improve CO2 adsorption on the defective surface and lower the barrier of CO2 hydrogenation during the conversion process. As a result, MoO3−x displayed dramatically enhanced photo-thermal synergistic CO2 reduction under simulated sunlight (UV-Vis-IR) irradiation than MoO3. The amount of CO produced by MoO3−x can reach 10.3 μmol g−1 h−1, which is 20 times higher than that of MoO3 (0.52 μmol g−1 h−1). And the CH4 production of MoO3−x can reach 2.08 μmol g−1 h−1, which is 52 times higher than that of MoO3 (0.04 μmol g−1 h−1). In situ FT-IR and theoretical calculations also proved the enhanced activity of MoO3−x. This work highlights the significance of defect engineering for improving the photo-thermal catalytic conversion of CO2. [ABSTRACT FROM AUTHOR]

The effective and highly selective aerobic oxidation of sulfides to sulfoxides under green and mild conditions is still an important but challenging process. Here we present a photocatalytic system for sulfide oxidation to sulfoxides with high yields under blue LED irradiation. The photo-oxidation was carried out in water with oxygen over a bismuth-rich catalyst of Bi4O5Br2. The apparent quantum efficiency of sulfide oxidation reached 57.4%. The developed system provided a simple, robust, green and sustainable promising candidate for the practical application of sulfide oxidation. [ABSTRACT FROM AUTHOR]

Photocatalytic CO 2 reduction is severely limited by the rapid recombination of photo-generated charges and insufficient reactive sites. Creating electric field and defects are effective strategies to inhibit charge recombination and enrich catalytic sites, respectively. Herein, a coupled strategy of ferroelectric poling and cationic vacancy is developed to achieve high-performance CO 2 photoreduction on ferroelectric Bi 2 MoO 6 , and their interesting synergy-compensation relationship is first disclosed. Corona poling increases the remnant polarization of Bi 2 MoO 6 to enhance the intrinsic electric field for promoting charge separation, while it decreases the CO 2 adsorption. The introduced Mo vacancy (V Mo ) facilitates the adsorption and activation of CO 2 , and surface charge separation by creating local electric field. Unfortunately, V Mo largely reduces the remnant polarization intensity. Coupling poling and V Mo not only integrate their advantages, resulting in an approximately sevenfold increased surface charge transfer efficiency, but also compensate for their shortcomings, for example, V Mo largely alleviates the negative effects of ferroelectric poling on CO 2 adsorption. In the absence of co-catalyst or sacrificial agent, the poled Bi 2 MoO 6 with V Mo exhibits a superior CO 2 -to-CO evolution rate of 19.75 µmol g -1 h -1 , ≈8.4 times higher than the Bi 2 MoO 6 nanosheets. This work provides new ideas for exploring the role of polarization and defects in photocatalysis., (© 2022 Wiley-VCH GmbH.)

Sluggish charge kinetics and low CO 2 affinity seriously inhibit CO 2 photoreduction. Herein, the synchronous promotion of charge separation and CO 2 affinity of Bi 4 Ti 3 O 12 is realized by coupling corona poling and surface I-grafting. Corona poling enhances ferroelectric polarization of Bi 4 Ti 3 O 12 by aligning the domains direction, which profoundly promotes charge transfer along opposite directions across bulk. Surface I-grafting forms a surface local electric field for further separating charge carriers and provides abundant active sites to enhance CO 2 adsorption. The two modifications cooperatively further increase the ferroelectric polarization of Bi 4 Ti 3 O 12 , which maximize the separation efficiency of photogenerated charges, resulting in an enhanced CO production rate of 15.1 μmol g -1  h -1 (nearly 9 times) with no sacrificial agents or cocatalysts. This work discloses that ferroelectric polarization and surface ion grafting can promote CO 2 photoreduction in a synergistic way., (© 2021 Wiley-VCH GmbH.)