{"title":"Influence of Dielectric Barrier Discharge Power on the Removal of CH4 and NO From Exhaust Emissions of LNG Engines","authors":"Zhengtao Zhao, Lin Lyu, Chuang Xiang, Yunkai Cai","doi":"10.1007/s11090-024-10491-7","DOIUrl":"10.1007/s11090-024-10491-7","url":null,"abstract":"<div><p>This study aims to explore the use of Dielectric Barrier Discharge (DBD) technology for the joint treatment of methane (CH<sub>4</sub>) and nitrogen oxide (NO) in the exhaust of Liquid Natural Gas (LNG) engines during cold starts and at mid to low loads when the exhaust temperature is below 500 °C. Through experiment and numerical simulation, the effect of discharge power on the removal efficiency of CH<sub>4</sub> and NO in the exhaust of LNG engines was investigated under the condition of simulated flue gas temperature at 438 °C. A plasma chemical model suitable for analyzing the mixture of N<sub>2</sub>/O<sub>2</sub>/H<sub>2</sub>O/CH<sub>4</sub>/NO in the exhaust gases of LNG engines was constructed and validated. The study found that the conversion efficiency of CH<sub>4</sub> and NO exhibits different trends with the increase of discharge power, and CH<sub>4</sub> tends to be oxidized to CO under plasma conditions. Key reaction pathways for the DBD treatment of CH<sub>4</sub>, NO, CO, and NO<sub>2</sub> were identified, and an important chemical reaction pathway with the potential for the joint treatment of CH<sub>4</sub> and NO was found: CH<sub>3</sub>O<sub>2</sub> + NO → CH<sub>3</sub>O + NO<sub>2</sub>. Additionally, the crucial pathways for the stable conversion of NO to NO<sub>2</sub> were identified: O + NO + N<sub>2</sub> → NO<sub>2</sub> + N<sub>2</sub> and NO + O<sub>3</sub> → NO<sub>2</sub> + O<sub>2</sub>, providing forward-looking theoretical guidance for subsequent research on plasma-facilitated selective catalytic reduction of NOx by CH<sub>4</sub>.</p></div>","PeriodicalId":734,"journal":{"name":"Plasma Chemistry and Plasma Processing","volume":"44 5","pages":"1925 - 1949"},"PeriodicalIF":2.6,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141648868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Low-Temperature Oxidation of Diesel Particulate Matter Using Dielectric Barrier Discharge Plasma","authors":"Baoyong Ren, Tiantian Zhang, Zuliang Wu, Jing Li, Erhao Gao, Wei Wang, Jiali Zhu, Shuiliang Yao","doi":"10.1007/s11090-024-10492-6","DOIUrl":"10.1007/s11090-024-10492-6","url":null,"abstract":"<div><p>The oxidation behavior of actual diesel particulate matter (DPM) prepared from diesel combustion was studied using a dielectric barrier discharge (DBD) reactor. The primary oxidation temperature (<i>T</i><sub>30</sub> at which 30% of DPM was oxidized) was reduced from 524 °C (with non-discharge, NDC) to 409 °C with discharge (DC). It was found that the dry soot (DS) from DPM after dichloromethane extraction was more difficult to be oxidized than DPM due to the loss of soluble organic fraction (SOF) from DPM. The order of activation energies of DPM and DS under conditions of DC and NDC is: DPM–DC < DPM–NDC < DS–DC < DS–NDC. The intermediates of DPM oxidation at different temperatures, pulse peak voltages and reaction gas atmospheres were investigated via <i>operando</i> DRIFTS–MS. It is found that under DC, SOF can be oxidized to oxygen containing compounds (OCC) at low temperatures, and a higher pulse peak voltage is beneficial to DPM oxidation. The main product of 10 vol% O<sub>2</sub>/N<sub>2</sub> discharge gas is high valence nitrogen oxides like NO<sub>2</sub>, which participates in DPM oxidation. DBD plasma enhances DPM oxidation primarily through two mechanisms: first, by ionizing O<sub>2</sub> to produce strong oxidizing substances, and second, by inhibiting the increasing content of graphitized components. This study provides a comprehensive understanding of DPM oxidation kinetics and intermediates under DBD plasma.</p></div>","PeriodicalId":734,"journal":{"name":"Plasma Chemistry and Plasma Processing","volume":"44 5","pages":"1905 - 1923"},"PeriodicalIF":2.6,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141587286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Degradation of Methylene Blue by Using an Argon Microwave Plasma Jet in Humid Environment","authors":"Nadir Aloui, Ibtissem Belgacem, Ahmad Hamdan","doi":"10.1007/s11090-024-10494-4","DOIUrl":"10.1007/s11090-024-10494-4","url":null,"abstract":"<div><p>Plasma-liquid interactions yield numerous physicochemical phenomena, rendering them promising for various applications. Plasma-based technology is proposed for water treatment due to its high efficiency in removing contaminants unattainable by conventional techniques. In this study, we employ an argon microwave plasma jet (MWPJ) to investigate methylene blue (MB) degradation. We observe a significant enhancement in the MB degradation rate in a covered system, attributed to increased air humidity promoting hydroxyl radicals (OH) production, which degrade approximately 95% of MB. Furthermore, the injection of O<sub>2</sub> gas into the solution under the plasma generates more hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), around 30 mg/L compared to approximately 20 mg/L without injection, although the MB degradation efficiency is reduced. We evaluate MB degradation under various solution properties, revealing that increasing electrical conductivity decreases the MB degradation rate until it becomes independent for conductivities > 10,000 µS/cm. In these latter conditions, a non-conventional temporal evolution of solution conductivity was observed: a decrease during the first tens of minutes followed by a continuous increase for longer treatment time. Conversely, solution acidity minimally affects the MB degradation rate. The MWPJ is characterized by optical emission spectroscopy, showing stability over time and under various solution properties. The energy yield (Y<sub>50%</sub>) consistently demonstrates superior performance of the MWPJ in a closed environment compared to an open-to-air environment. Although its efficiency is relatively low compared to other systems, we anticipate improvements through parameter adjustments.</p></div>","PeriodicalId":734,"journal":{"name":"Plasma Chemistry and Plasma Processing","volume":"44 5","pages":"1971 - 1989"},"PeriodicalIF":2.6,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141576558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ali Nawaz, Alessandro Cian, Lorenza Ferrario, Antonino Picciotto
{"title":"Multi-cycle Chamber Conditioning for Plasma Etching of SiO2: From Optimization to Stability in Lot Processing","authors":"Ali Nawaz, Alessandro Cian, Lorenza Ferrario, Antonino Picciotto","doi":"10.1007/s11090-024-10493-5","DOIUrl":"10.1007/s11090-024-10493-5","url":null,"abstract":"<div><p>Hydrofluorocarbon gas chemistries have long been favored for SiO<sub>2</sub> etching. However, the fluorocarbon polymer generated during the process not only assists in obtaining a high selectivity, but also leads to chamber wall contamination. The adhesion efficiency of the polymer depends on the chamber wall temperature, which needs to be well-controlled to ensure controllable polymer deposition rate and etch characteristics. Similarly, the increasing gas temperature during the process is also expected to increase the production rate of polymer precursors. Hence, it is important to properly condition the chamber so that a sufficiently high and stable chamber temperature is reached before starting the actual process. This work utilizes an Inductively Coupled Plasma Reactive Ion Etcher to optimize a multi-cycle chamber conditioning process for two C<sub>4</sub>F<sub>8</sub>/H<sub>2</sub>-based chemistries. We use the integrated optical emission spectroscopy (OES) tool to show that the dependence of etch characteristics on conditioning time is much stronger for the highly polymerizing chemistry. For a low conditioning time (< 15 min), the instability of plasma species indicate that the chamber temperature has not yet plateaued, resulting in a ⁓60% decrease of recess in the underlying silicon layer during the lot processing time. By conducting systematic etch tests, we analyze the behavior of key OES peaks to identify the optimal conditioning time (≥ 30 min) for this recipe, which results in only a 13% decrease in silicon recess depth during the processing time. Subsequently, a method to assess the stability of plasma species during the conditioning process is devised, assisting in advance to identify the optimal moment to initiate the lot process. By comparing the experimental results of the two etch recipes, we also highlight the important correlation between conditioning time and polymerizing degree of the chemistry.</p></div>","PeriodicalId":734,"journal":{"name":"Plasma Chemistry and Plasma Processing","volume":"44 5","pages":"1991 - 2009"},"PeriodicalIF":2.6,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141576559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Particle Condensation in Two-Temperature (2T) Arc Plasmas of Various SF6 Replacements","authors":"Linlin Zhong, Bayitake Baheti, Qi Wu","doi":"10.1007/s11090-024-10490-8","DOIUrl":"10.1007/s11090-024-10490-8","url":null,"abstract":"<div><p>Fluorinated gases, e.g., CF<sub>3</sub>I, C<sub>3</sub>F<sub>8</sub>, C<sub>4</sub>F<sub>8</sub>, C<sub>4</sub>F<sub>7</sub>N, and C<sub>5</sub>F<sub>10</sub>O, show potential to replace SF<sub>6</sub> in power industry due to their high dielectric strength and low global warming potential . However, particle condensation from arc plasmas of these compounds may reduce dielectric performance. We perform a systematic investigation of particle condensation in two-temperature (2T) arc plasmas of various SF<sub>6</sub> replacements mixed with CO<sub>2</sub>, N<sub>2</sub>, and O<sub>2</sub>, by the Gibbs free energy minimization and entropy maximization methods. The influences of buffer gases, non-equilibrium degree, and gas pressure on particle condensation are discussed in various cases. The results indicate that O<sub>2</sub> is necessary to prevent graphite formation in carbon–fluorine gaseous arcs, and specific mixing ratios of CO<sub>2</sub> and N<sub>2</sub> are required to avoid graphite and iodine crystals in CF<sub>3</sub>I arc plasmas. The relationship between condensation temperature and non-equilibrium degree is complex, with peaks and valleys observed for graphite and iodine crystal condensation temperatures. Moreover, different calculation methods (Gibbs free energy minimization versus entropy maximization) show varying sensitivity of condensation temperatures to pressure changes. All the above findings highlight the importance of considering non-equilibrium effects and multiple condensed species in evaluating arc plasma compositions of SF<sub>6</sub> replacements.</p></div>","PeriodicalId":734,"journal":{"name":"Plasma Chemistry and Plasma Processing","volume":"44 5","pages":"1867 - 1882"},"PeriodicalIF":2.6,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141506305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Calculation of the decomposition products of C5F10O-Air mixtures from 500 K to 3500 K with a chemical kinetic model","authors":"Qingqing Gao, Xiaohua Wang, Haofei Sun, Aijun Yang, Chunping Niu","doi":"10.1007/s11090-024-10485-5","DOIUrl":"10.1007/s11090-024-10485-5","url":null,"abstract":"<div><p>C<sub>5</sub>F<sub>10</sub>O-Air mixtures have a great potential to replace SF<sub>6</sub> in medium-voltage power equipment. However, during the partial overheating or arc discharge, C<sub>5</sub>F<sub>10</sub>O-Air mixtures are inevitably to decompose to form various byproducts. The local chemical non-equilibrium and local thermal non-equilibrium appears due to the finite reaction rates and insufficient energy change between species. This paper establishes a chemical kinetic model to calculate the decomposition byproducts of C<sub>5</sub>F<sub>10</sub>O-Air mixtures from 500 K to 3500 K by taking into account the local thermal non-equilibrium and local chemical non-equilibrium simultaneously. The chemical kinetic model contains 50 species and 249 reactions. All the reactions are assumed to be reversible except the reactions producing photos. The local thermal non-equilibrium is characterized by the difference of the electron temperature (<i>T</i><sub>e</sub>) and the temperature of heavy species (<i>T</i><sub>h</sub>). In this work, the ratio of <i>T</i><sub>e</sub> to <i>T</i><sub>h</sub> is determined to be a function of the electron number density. Therefore, the value varies with electron number density. The temperature dependent decomposition composition of C<sub>5</sub>F<sub>10</sub>O-Air mixtures with C<sub>5</sub>F<sub>10</sub>O content to be 5%, 10% and 15% are obtained. In order to investigate the effects of Air on the decomposition of C<sub>5</sub>F<sub>10</sub>O, the decomposition products of pure C<sub>5</sub>F<sub>10</sub>O from 500 K to 3500 K are also investigated. In addition, the main chemical processes in 0.1C<sub>5</sub>F<sub>10</sub>O-0.9Air mixture are investigated by capturing the main reaction pathways. The main reaction pathways can help interpret the formation mechanism of the decomposition products.</p></div>","PeriodicalId":734,"journal":{"name":"Plasma Chemistry and Plasma Processing","volume":"44 5","pages":"1883 - 1903"},"PeriodicalIF":2.6,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141519124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Combined Plasma Treatment Effects on Growth and Yield: Second-Generation Potato (Solanum tuberosum L.) Seeds","authors":"Mamunur Rashid, M. R. Talukder","doi":"10.1007/s11090-024-10467-7","DOIUrl":"10.1007/s11090-024-10467-7","url":null,"abstract":"<div><p>Applications of plasmas in agriculture are fascinating researchers because of its potentiality. Plasmas are applied either for seed treatment or as foliar application of plasma-activated water (PAW) for studying agricultural yield. No work has been done so far to study the effects on growth parameters, enzymatic activities, nutritional parameters, and yield of potato (<i>Solanum tubersum</i> L.) grown from the second-generation seeds (G2) (seeds collected from the potato plants where foliar spray of PAW was applied). Two-fold plasma treatments were applied in this experiment: (a) potato seeds were treated in water with plasma and (b) foliar spray of PAW was applied to potato plants. Effects of plasma treatments were characterized by enzymatic activities, sugar and protein concentrations, potato plant growth and yield characters. The findings show that the plant length, stem diameter, fresh weight, and the concentrations of total chlorophyll and carotene are increased in the plants where G2 treated seeds along with foliar spray of PAWs were provided. Further, the concentrations of total soluble sugar, protein and minerals were increased. Besides, the yield of potato was enhanced by <span>(23.95%)</span>, and <span>(23.21%)</span>, respectively, in the plants where combined plasma treatments were used compared to controls of first-generation (G1) plasma treated and untreated seeds along with PAW foliar spray.</p></div>","PeriodicalId":734,"journal":{"name":"Plasma Chemistry and Plasma Processing","volume":"44 4","pages":"1669 - 1688"},"PeriodicalIF":2.6,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141519125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Influence of the Bulb Geometry and Electrical Supply Parameters on the UV Emission of DBD Excimer Lamps","authors":"Arnold Wiesner, Rafael Diez, Hubert Piquet","doi":"10.1007/s11090-024-10480-w","DOIUrl":"10.1007/s11090-024-10480-w","url":null,"abstract":"<div><p>The aim of this article is to improve the performance of DBD excimer lamps systems for UV production. Within this framework, our approach considers two distinct directions: the geometric dimensions of the double-barrier lamp bulb and the characteristics of the power supply. To explore these directions, a sampling of 19 bulbs of different geometries is considered, and a specially designed power supply is used, capable of controlling the shape (duration and magnitude) and frequency of current pulses injected into the plasma. A dedicated test bench, including a supervisory program that drives the power supply and collects system performance data, is used to perform parametric sweeps and guarantee measurement repeatability: the set of electrical parameters is fully explored for each lamp, and each experiment is characterized by UV emission performance and electrical generator operating conditions. Multiquadric response surfaces, used to format the results of this multi-variable exploration, reveal the most efficient directions for system optimization: increasing gas volume and, at a given operating frequency, providing the shortest possible current pulses with high amplitude can increase both UV emission and conversion efficiency.</p></div>","PeriodicalId":734,"journal":{"name":"Plasma Chemistry and Plasma Processing","volume":"44 4","pages":"1605 - 1623"},"PeriodicalIF":2.6,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11090-024-10480-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141519116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Experimental Validation on the Ionic Strength and Charge Effect in Plasma-Induced Liquid Mobility","authors":"Dai-En Li, Che-Hsin Lin","doi":"10.1007/s11090-024-10486-4","DOIUrl":"10.1007/s11090-024-10486-4","url":null,"abstract":"<div><p>This study utilized a direct current-needle system for plasma generation and liquid flow inducement. The liquid flow was visualized and analyzed by particle image velocimetry. Electrolyte solutions of potassium chloride, potassium bromide, potassium iodide, calcium chloride and chromium(III) nitrate with concentrations ranging from 0.1 to 1.0 mM were studied. The results indicate that the plasma induces an upward liquid flow with an area mean velocity of up to 3.0 mm/s. The flow speed decreases with increasing electrolyte concentration and shows a strong dependence on the solution’s conductivity. This study proposed a physical model based on these findings. The plasma generates short-lived ions and electrons, which shift the hydrogen bonds among the water molecules through their electrical effect. This process creates an intermolecular force gradient and induces liquid flow on the water surface. The distance that electrostatic effect of a charged particle can persist in an electrolyte solution is defined as Debye length. This physical quantity decreases with increasing ionic strength or electrical conductivity. Thus, the plasma induces slower liquid flow in solutions with higher electrolyte concentration. Based on the regression analysis, the characteristic flow velocity is significantly proportional to the square of the solution’s Debye length, with a coefficient of determination of 0.9365.</p></div>","PeriodicalId":734,"journal":{"name":"Plasma Chemistry and Plasma Processing","volume":"44 4","pages":"1811 - 1822"},"PeriodicalIF":2.6,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141506409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Productions of RONS with Duty Ratio in Atmospheric Pressure Plasma Jets","authors":"Jun Sup Lim, Eun Ha Choi","doi":"10.1007/s11090-024-10487-3","DOIUrl":"10.1007/s11090-024-10487-3","url":null,"abstract":"<div><p>In this work, the productions of reactive oxygen and nitrogen species (RONS) with duty ratio in atmospheric pressure plasma jet was studied. This study uses the duty ratio comprising an on-time duration with a sinusoidal voltage bunch and an off-time duration without any voltage bunch for the plasma jet operation. The reactive species NO, NO<sub>2</sub>, N<sub>2</sub>O, and O<sub>3</sub> were measured in the plasma jet in accordance with the duty ratio by gas-FTIR and ozone meter. The NO<sub>x</sub> are the mainly produced in the plasma jet due to the high temperature, and all reactive species exhibited increased production when increasing the duty ratio. But, under the fixed duty-ratio of 10%, reactive species were different trends by the on-time duration. Although there was no additional dissipated power at a given duty ratio, NO production enhanced by 1.5 times, whereas the production of the other species decreased with increasing on-time duration. These phenomena were explained by measured rotational temperature with on-time in this experiment.</p></div>","PeriodicalId":734,"journal":{"name":"Plasma Chemistry and Plasma Processing","volume":"44 4","pages":"1595 - 1603"},"PeriodicalIF":2.6,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141506410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}