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In this work, an existing method of capturing Fe-based fine particles by magnetic fiber is improved, and a weaving method for the fiber filter material is further determined. Different combinations of magnetic fields could form around the magnetic fibers, which change the interaction between orthogonal magnetic fibers when a uniform magnetic field is applied along the X-, Y-, and Z-axes. Therefore, the process of particle capture by the orthogonal magnetic fibers under three configurations was compared using the computational fluid dynamics-discrete phase model (CFD-DPM) and a special user-defined function (UDF) of the magnetic force. The results show that the interaction between orthogonal magnetic fibers could either inhibit or promote the capture of Fe-based fine particles by adjacent magnetic fibers. In industrial production, the magnetic filter material is suitable for the weaving method for the alternate use of magnetic and traditional fibers. When a uniform magnetic field is applied along the X-axis, this weaving method makes the capturing performance of orthogonal magnetic fiber best. Moreover, the magnetic characteristics, flow characteristics, and combination sequence of magnetic fields should be considered. This study provides scientific researchers with new insights for the development of novel high-efficiency fibrous filters to reduce particulate pollutants emissions.

As the solid waste by-product from the delayed coking process, high-sulfur petroleum coke (HSPC), which is hardly used for green utilization, becomes a promising raw material for Hg0 removal from coal-fired flue gas. The effects of the physical–chemical evolution of HSPC on Hg0 removal are discussed. The improved micropores created by pyrolysis and KOH activation could lead to over 50% of Hg0 removal efficiency with the loss of inherent sulfur. Additional S-containing and Br-containing additives are usually introduced to enhance active surface functional groups for Hg0 oxidation, where the main product are HgS, HgBr, and HgBr2. The chemical–mechanical activation method can make additives well loaded on the surface for Hg0 removal. The DFT method is used to sufficiently explain the micro-scale reaction mechanism of Hg0 oxidation on the surface of revised-HSPC. ReaxFF is usually employed for the simulation of the pyrolysis of HSPC. However, the developed mesoporous structure would be a better choice for Hg0 removal in that the coupled influence of pore structure and functional groups plays a comprehensive role in both adsorption and oxidation of Hg0. Thus, the optimal porous structure should be further explored. On the other hand, both internal and surface sulfur in HSPC should be enhanced to be exposed to saving sulfur additives or obtaining higher Hg0 removal capacity. For it, controllable pyrolysis with different pyrolysis parameters and the chemical–mechanical activation method is recommended to both improve pore structure and increase functional groups for Hg0 removal. For simulation methods, ReaxFF and DFT theory are expected to explain the micro-scale mechanisms of controllable pyrolysis, the chemical–mechanical activation of HSPC, and further Hg0 removal. This review work aims to provide both experimental and simulational guidance to promote the development of industrial application of Hg0 adsorbent based on HSPC.

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Fibrous media are widely used in particle filtration. However, few studies have investigated the performance of fibrous media with bimodal and dense-sparse structures. In this study, computational fluid dynamics technology was adopted to simulate the filtration performance of fibrous media. A two-dimensional random multifiber distribution model was proposed based on VC++ and ICEM. Reliability was verified by comparing the model with the empirical formula. The filtration efficiencies and quality factors of submicron particle capture within different fiber arrangements, inlet velocities, and particle diameters were determined. Finally, the mechanism for improving the filtration efficiency of multi-fiber for submicron particles was analyzed. The results showed that, as the particle diameter and inlet velocity increased, the filtration efficiency and quality factor of the different fibrous media decreased, and tended to be similar. The fibrous media combined with bimodal and dense-sparse structures had the highest quality factor owing to the placement of the bimodal structure on the windward side and ratio of coarse to fine fibers.