{"title":"Electric charge neutralization of granular materials using an air-assisted ionizer under different operational conditions","authors":"Khaled Daioui, Thami Zeghloul, Lucian Dascalescu","doi":"10.1016/j.elstat.2025.104168","DOIUrl":"10.1016/j.elstat.2025.104168","url":null,"abstract":"<div><div>An operation of electric charge neutralization is often integrated in complex electrostatic separation processes targeted at the selective sorting of the constituents of granular mixtures in a wide range of industrial applications. The aim of the present work is to prove the possibility of increasing the charge elimination efficiency of a commercial air-assisted neutralizer, under various dynamic conditions simulating realistic industrial scenarios. Three experimental setups were tested. In the first one, particles were charged by triboelectric effect and then transported by a grounded metallic conveyor belt before being subjected to ionic bombardment from the commercial neutralizer. The second configuration employed a custom-designed rotating-roll corona-electrostatic separator. Particles were charged by corona discharge and then transported on the rotating roll electrode before being neutralized by an air-assisted ionizer installed opposite the roll electrode. In the third experimental configuration, the neutralization system was installed downstream from the particle detachment step of the second configuration. After being dislodged from the grounded rotating drum by a mechanical brush, the charged insulating particles fell freely under gravity through the ionization zone. This zone comprised the commercial ionizing neutralizer positioned opposite a grounded rectangular metal plate. The factors investigated were the applied voltage (<em>U</em><sub><em>n</em></sub>) and the distance (<em>d</em><sub><em>n</em></sub>) between the neutralizing electrode and the grounded (belt, roll, the plate) electrode, as well as the air velocity (<em>v</em>). The findings highlight the substantial role of airflow in enhancing ion dispersion and promoting charge neutralization, particularly through its interaction with the electric field geometry and particle dynamics. For instance, residual charge-to-mass ratio dropped to as low as 1–2 nC/g in the first configuration at air velocity of 2 m/s. This study clearly demonstrates the critical importance of finely tuning geometry, electrical field strength, and air dynamics to optimize electrostatic neutralization. These findings provide valuable guidelines for designing more efficient electrostatic separation systems, particularly for industrial recycling processes involving insulating materials.</div></div>","PeriodicalId":54842,"journal":{"name":"Journal of Electrostatics","volume":"138 ","pages":"Article 104168"},"PeriodicalIF":2.1,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145059999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Chains and islands - Particle agglomeration on a three-phase electric curtain","authors":"Sophia Gessman, Jeffrey S. Marshall","doi":"10.1016/j.elstat.2025.104167","DOIUrl":"10.1016/j.elstat.2025.104167","url":null,"abstract":"<div><div>Usefulness of electric curtains for particle mitigation is limited by formation of particle agglomerates, which can remain immobile for long time durations. Agglomerates can form elongated particle chains or more circular particle islands. The paper reports on experimental and computational studies of electric curtain particle agglomerates. The experiments used size-filtered lunar and Martian regolith to examine agglomerate structure and the conditions that result in agglomerate formation, and mapped metrics characterizing agglomerate size, shape, and density. The computations used combined discrete-element method and boundary-element method to explore the mechanism for formation of particle agglomerates.</div></div>","PeriodicalId":54842,"journal":{"name":"Journal of Electrostatics","volume":"138 ","pages":"Article 104167"},"PeriodicalIF":2.1,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Quantitative study on the impact of air humidity on ion flow field and ground Electrical parameters of ±800 kV UHVDC transmission lines","authors":"Zhaobing Han , He Zhu , Tuoxin Fu , Zhuang Tian","doi":"10.1016/j.elstat.2025.104169","DOIUrl":"10.1016/j.elstat.2025.104169","url":null,"abstract":"<div><div>—UHV DC transmission lines have long transmission distance and complex terrain and meteorological conditions along the way. The ion flow field of UHVDC transmission lines is significantly affected by environmental conditions and meteorological factors. Changes in meteorological conditions such as rainfall, wind speed, fog, temperature and humidity will lead to changes in the ion flow field near the UHV DC transmission line corridor. Therefore, it is of great practical value to study the influence of other meteorological conditions on the ion flow field by studying the distribution of synthetic electric field(the resultant electric field generated by multiple electric fields at the same point) and ion current density near the UHV DC transmission line under air humidity conditions. In this paper, a calculation model of ion flow field considering the influence of air humidity is established. Taking Yunguang ±800 kV transmission line as the research object, the ion flow field affected by air humidity is calculated. The distribution law of the surface synthetic electric field and ion flow density affected by air humidity is analyzed, and the validity of the calculation results is verified.</div></div>","PeriodicalId":54842,"journal":{"name":"Journal of Electrostatics","volume":"138 ","pages":"Article 104169"},"PeriodicalIF":2.1,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145018643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the ignition hazards of combustible liquid: the case of S-lactic acid water solution","authors":"B.A. De Liso, G. Pio, E. Salzano","doi":"10.1016/j.elstat.2025.104148","DOIUrl":"10.1016/j.elstat.2025.104148","url":null,"abstract":"<div><div>The simultaneous exceedance of the flash point and the presence of an external source of ignition such as electrostatic sparks or hot spots lead to a flame-related scenario. Nevertheless, anomalous behaviour can be observed if the liquid is subject to thermal degradation, even below the flash point. This work is dedicated to the specific case of the hazard of combustible liquids due to the insurgence of secondary reactions activated by an ignition source and a constant heat flux to the sample within the range 7 kW/m<sup>2</sup> and 50 kW/m<sup>2</sup>. To this aim, an aqueous solution having 90 %w lactic acid has been analysed experimentally by calorimetric analysis. The temperature of the liquid, the mass loss rate, and the heat release rate for the pool fire of lactic acid have been measured by a cone calorimeter. Results were compared with experimental data from the literature and theoretical data. The use of flash point temperature (regardless of the approach adopted for its evaluation) has been found to lead to non-conservative results on the safe side. Based on the collected data, the use of a cone calorimeter is recommended to evaluate the ignitability of liquid substances exposed to heating sources such as fires.</div></div>","PeriodicalId":54842,"journal":{"name":"Journal of Electrostatics","volume":"138 ","pages":"Article 104148"},"PeriodicalIF":2.1,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145010219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Triboelectric charging properties of ABS and PS granules with different concentration of Brominated flame retardants","authors":"Siham Labiod , Thami Zeghloul , Mohamed Sofiane Bendilmi , Arnaud Parenty , Farida Tomasella , Lucian Dascalescu","doi":"10.1016/j.elstat.2025.104158","DOIUrl":"10.1016/j.elstat.2025.104158","url":null,"abstract":"<div><div>— Waste plastics are a significant source of pollution as they contain substances identified as persistent organic pollutants (POPs), such as brominated flame retardants (BFRs). These substances are added to many polymer materials to comply with safety flammability standards, to enhance their fire resistance, delay ignition, slow the spread of fire, or delay the time of flashover. BFRs are released from plastic materials into the environment during use, disposal, and recycling; they require careful management to reduce the risks associated with their dangerous nature for human health. Among the plastics found in WEEE, Acrylonitrile Butadiene Styrene (ABS) and Polystyrene (PS) are the most prevalent, as their excellent insulating and mechanical properties render them essential for the electrical and electronic equipment sector. However, their high flammability makes them particularly targeted for the addition of high levels of BFRs to enhance their fire resistance and comply with safety standards. Moreover, their similar surface properties and close mass density values significantly limit wet separation methods, such as density and flotation methods. In this case, tribo-electrostatic separation might be a low-cost, low-polluting solution that can preserve the original properties of plastic. Tribo-electrostatic separation was chosen over wet methods because it is a dry process that requires no chemical pretreatment, no expensive wetting reagents, and also eliminates wastewater treatment issues. This method exploits the differences in triboelectric properties of ABS and PS, enabling their separation without altering their chemical structure, which is critical for preserving recyclability. The aim of this paper was to investigate the effect of the presence of BFR with different concentrations in ABS and PS materials on their triboelectric charging characteristic and tribo-electrostatic separation process of brominated ABS and PS particles. The tribocharging properties of brominated plastic particles were studied by a fluidized bed tribocharger. The brominated polymers used in the tribocharging experiments were BFR-free ABS, 0.23 % BFR ABS, 4.6 % BFR ABS, BFR-free PS, 0.23 % BFR PS, and 4.6 % BFR PS, produced by CRITT France, using hexabromobenzene as a model of BFR. In the first part of the experiments, this work investigated the influence of the tribocharger wall material, the triboelectric behavior of BFR ABS and PS plastics, their charge density evolution over time, and finally the effect of tribocharging duration. In the second part of the experiments, tribo-electrostatic separation tests were conducted on different mixtures (BFR-free ABS/BFR-free PS, 4.6 % BFR ABS/4.6 % BFR PS, etc.).</div></div>","PeriodicalId":54842,"journal":{"name":"Journal of Electrostatics","volume":"138 ","pages":"Article 104158"},"PeriodicalIF":2.1,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145003937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Contributions of plasma simulations to physical understanding of surface dielectric barrier discharge for flow control (invited paper)","authors":"Hiroyuki Nishida","doi":"10.1016/j.elstat.2025.104115","DOIUrl":"10.1016/j.elstat.2025.104115","url":null,"abstract":"<div><div>Surface dielectric barrier discharge (DBD) has been widely studied as active flow control actuator. DBD plasma actuators have two flow control mechanisms: the electrohydrodynamic (EHD) force and gas heating. Plasma fluid simulations are powerful tool to analyse the plasma physics involved in surface DBD. In this review, an overview is presented focusing on plasma fluid simulations of DBD plasma actuators. For numerical modelling, the three species drift-diffusion model with Local Field Approximation is most generally adopted. The important physical insight obtained from the analysis is that the negative discharge plays a dominant role in the EHD force generation. The electric field shielding by electron accumulation on the surface prevents the streamer formation and this leads to the development of negative ion cloud and strong EHD force generation. For the gas heating, the short-time energy transfer from plasma to the air leads to the formation of micro-shock waves and to the flow modification. Furthermore, structural variations such as the multi-electrode configuration combining AC and DC voltage inputs have significant influence on the discharge. The DC voltage input enhances the ion drift motion and the electric field at the discharge front, which results in the elongation of streamer and EHD force enhancement.</div></div>","PeriodicalId":54842,"journal":{"name":"Journal of Electrostatics","volume":"137 ","pages":"Article 104115"},"PeriodicalIF":2.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hyun-Ha Kim, Ayman A. Abdelaziz, Atsushi Komuro, Yoshiyuki Teramoto
{"title":"Plasma nitrogen chemistry from NOx removal to nitrogen fixation: Personal perspective","authors":"Hyun-Ha Kim, Ayman A. Abdelaziz, Atsushi Komuro, Yoshiyuki Teramoto","doi":"10.1016/j.elstat.2025.104123","DOIUrl":"10.1016/j.elstat.2025.104123","url":null,"abstract":"<div><div><span><span>Plasma is an electricity-driven chemical process which can replace the conventional high-temperature and high-pressure processes, achieving greener production for strengthening renewable energy in the pursuit of carbon neutrality. The adaptability of </span>plasma technology to temporal power variations, along with its rapid startup and shutdown capabilities, can provide a promising solution for renewable energy, which suffers from fluctuations in power output. Various plasma technologies are being investigated in seeking this possibility for various chemical conversion such as CO</span><sub>2</sub> decomposition, CO<sub>2</sub> methanation, dry and steam reforming, NH<sub>3</sub> synthesis and NO<sub><em>x</em></sub> production. Remarkable advancements have been made in plasma NOx production during the last decade, and some startup companies are expanding social implementation of plasma technology for decentralized small- or medium scale power-to-X applications. This short review focuses on the basic but often overlooked aspects in plasma nitrogen chemistry. Fundamentals of N<sub>2</sub> and O<sub>2</sub> molecules related with the plasmas will be first addressed and then removal and formation of NO<sub><em>x</em></sub> will be presented for an important applications of plasma nitrogen chemistry.</div></div>","PeriodicalId":54842,"journal":{"name":"Journal of Electrostatics","volume":"137 ","pages":"Article 104123"},"PeriodicalIF":2.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Recent progress in research on electrostatic precipitation (invited paper)","authors":"Anatol Jaworek , Kazimierz Adamiak","doi":"10.1016/j.elstat.2025.104064","DOIUrl":"10.1016/j.elstat.2025.104064","url":null,"abstract":"<div><div>Electrostatic precipitation is a mature technology for many years successfully used in industrial applications. However, with increasingly stringent environmental protection requirements these devices are expected to work with higher efficiency, especially for small dust particles. In this situation, the research on electrostatic precipitation is still very active with an ever increasing number of publications. The present paper aims on a review of recently published papers in this area. In the first part, new and improved precipitator configurations are reviewed, with a focus on multi-stage precipitation process, particle agglomeration and hybrid filtration. These techniques should be especially beneficial for collecting submicron particles. In the second part of this paper, the numerical techniques for simulating the precipitation process are discussed. The models to predict the particle trajectories and collection efficiency include not only the gas discharge, flow, and the particle dynamics, but also the effect of gas temperature, humidity and chemistry.</div><div>List of contents.</div></div>","PeriodicalId":54842,"journal":{"name":"Journal of Electrostatics","volume":"137 ","pages":"Article 104064"},"PeriodicalIF":2.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the phenomenon of ionic wind induced by corona discharges","authors":"Eric Moreau","doi":"10.1016/j.elstat.2025.104113","DOIUrl":"10.1016/j.elstat.2025.104113","url":null,"abstract":"<div><div>This article reviews the latest knowledge on ionic wind generated by two-electrode volume corona discharges<span><span><span><span> in atmospheric air. We aim to accurately describe the ionic wind topology and explain its properties based on experimental measurements and numerical simulations. The two geometric configurations most commonly discussed in this article are the point-plate and point-ring. After an introduction and brief theoretical overview of the </span>physical phenomenon, we describe the different regimes of DC and AC </span>corona discharges<span><span>, as they play a key role in the properties of the induced ionic wind. Then, in the third part, we discuss the time-averaged characteristics of the ionic wind. We show that positive corona discharges produce a sharp, pointed, and fast ionic wind jet, especially when breakdown streamers are present. On the contrary, the </span>negative corona discharges usually produce a wider and slower air jet. In the fourth part, we describe the </span></span>air movement<span> from the tip when the high voltage is switched on. Moreover, we highlight that the Trichel pulses and the breakdown streamers play a fundamental role in the ionic wind dynamics. Finally, in the last part of this article, we focus on numerical simulations of ionic wind to explain all the experimental results presented earlier. Indeed, the origin of the ionic wind is the electrohydrodynamic force produced by the discharge. To determine this force, we need to know the electric field distribution and the density of electrons and ions everywhere in space at all times, which is achievable only through numerical simulations. To conclude, it can be said that research over the past ten years has led to a much better understanding of the ionic wind phenomenon, particularly regarding the role of unsteady and very fast phenomena such as Trichel pulses and breakdown streamers. However, there is still a lot of experimental and numerical simulation work to be done to optimize all the input parameters of the discharge according to the targeted application. And since the applications of ionic wind will most likely be at small scales, down to the sub-millimeter scale, it will also be necessary to study the behavior of corona discharges and the ionic wind they can generate at this scale.</span></span></div></div>","PeriodicalId":54842,"journal":{"name":"Journal of Electrostatics","volume":"137 ","pages":"Article 104113"},"PeriodicalIF":2.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arianna Parisi , Luigi Piero Di Bonito , Claudia Carotenuto , Francesco Di Natale
{"title":"Wet Electrostatic Scrubbing for gas cleaning applications – a critical review","authors":"Arianna Parisi , Luigi Piero Di Bonito , Claudia Carotenuto , Francesco Di Natale","doi":"10.1016/j.elstat.2025.104133","DOIUrl":"10.1016/j.elstat.2025.104133","url":null,"abstract":"<div><div>Wet electrostatic scrubbing is a gas-cleaning process based on on gas ionization and/or spray electrification. This technique is emerging as a promising solution for fine and ultrafine particle collection, with the additional advantage of simultaneously absorbing soluble gases. This work presents a critical review of its application to particle capture, analysing recent literature to explore: (i) the models developed to describe the underlying physics of the process, (ii) the design of key components, and (iii) the findings from both modelling and experimental studies evaluating the performance of wet electrostatic scrubbers across various gas cleaning applications. The literature survey highlights that wet electrostatic scrubbing is an efficient technology, characterized by low pressure drops, reduced energy consumption, and a wide range of possible designs. Now approaching technological maturity, this technique offers a versatile and scalable solution for air pollution control, suitable for both standalone systems and retrofit applications.</div></div>","PeriodicalId":54842,"journal":{"name":"Journal of Electrostatics","volume":"137 ","pages":"Article 104133"},"PeriodicalIF":2.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145027648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}