介质阻挡放电微等离子体分解二氧化碳研究

二氧化碳既是主要的温室气体之一,也是包含碳和氧的资源,把相对惰性的CO₂转化为易于利用的CO是其利用的方法之一。采用介质阻挡微等离子体反应器通过单变量和正交实验探究了反应器参数(放电区长度、放电间距、介质厚度)和工艺参数(输入功率、放电频率和停留时间)对CO₂分解为CO的转化率和能量效率的影响规律。研究结果表明,影响CO₂转化率的大小顺序依次为：放电间距>放电长度>输入功率≈停留时间>介质厚度>放电频率;输入功率60.0 W、放电频率9.0 kHz和停留时间1.5 s、放电区长度60 mm、放电间距0.5 m、介质厚度1.6 mm时,CO₂的转化率为10.6%,能量效率为4.1%。     

介质阻挡放电等离子体对PP非织造布的改性

利用常压介质阻挡放电(DBD)设备,研究了工作气体、放电电压、处理时间、试样布置方式等对聚丙烯(PP)熔喷非织造布吸水率和处理效果均匀性的影响。结果表明:PP非织造布试样在90kV下用氩等离子体处理40s,吸水率达672%,在氩气中混入少量氧气(Ar/O2体积比为10/1),吸水率可提高至717%;试样吸水率随处理时间及放电电压的增加均提高,可以通过增大放电电压来有效地降低处理时间;随着DBD等离子体处理强度的增加,PP非织造布整体亲水性和表观均匀性均得到有效提高;试样布满放电区域有利于提高其吸水率和处理效果的均匀性。     

埃洛石吸附-介质阻挡放电等离子体处理亚甲基蓝废水

为进一步提高对亚甲基蓝(MB)的降解效果,提出了介质阻挡放电等离子体协同吸附方法,并利用XRD、FTIR方法对吸附剂进行表征分析。研究结果表明,处理120 min后,协同体系对MB的降解率为96.36%。当MB的初始质量浓度为50 mg/L、HNTs的投加量为70 mg/L、放电功率为150 W、pH为6.7、通气量为200 m L/min时,MB的去除效果较好。     

介质阻挡放电等离子体改性碳基材料研究进展

介质阻挡放电等离子体因其高效、经济和易操作等优点, 使得其在材料表面改性方面得到了广泛的应用, 同时表现出良好的应用前景。碳基材料由于其许多良好的物化性能, 使得其在很多领域都得到了很好的应用。而经DBD改性后的碳基材料表现出更好的物化性能, 应用更加广泛。主要综述了DBD在改性碳基材料方面的研究现状, 包括活性基团的引入, DBD改性对碳基材料界面结合能、吸附性能、物理结构及其对负载组分分散度的影响。指出改性过程中仍然存在的许多不够完善之处, 提出许多需要进一步深入研究的问题, 如DBD改性对碳基材料物化性能影响的机理研究, 并展望了DBD改性碳基材料技术未来的发展前景。     

Enhancement of VOCs removal using a novel double-tube packed bed catalytic dielectric barrier discharge (DPDBD) reactor

We developed a novel double-tube packed bed catalytic dielectric barrier discharge (DPDBD) reactor to degrade toluene. The DPDBD reactor contains four discharge cells with one power supply, namely, A–D. NiO/γ-Al₂O₃ is packed in cell A to effectively destroy the branched chains in toluene. TiO₂/γ-Al₂O₃ is packed in cell B owing to its high catalytic oxidation activity to weaken the benzene rings and mineralize the generated partial aromatic compounds. Cell C is a pure DBD process without any catalyst packed to thoroughly mineralize all the generated aromatic compounds and convert CO into CO₂ and NO into NO₂. γ-Al₂O₃ is packed in cell D to reduce the concentrations of byproducts, including O₃ and NO generated by air through oxidation. The combinations of the four discharge cells are optimized by the treatment of −3000 mg m⁻³ of toluene at 11 kV. In comparison with a double-tube dielectric barrier discharge (DDBD) reactor without catalyst packing and with a total discharge length of 6 cm, the selectivity of CO₂ was significantly improved from 45% to 57% when the discharge lengths of A, B, C, and D are 2, 4, 4, and 2 cm, respectively. Furthermore, the concentrations of O₃ and NO in the outlet can also be effectively reduced from 2.80 and 210 mg m⁻³ to 1.30 and 60 mg m⁻³, respectively. We also investigated the effects of applied voltage and styrene initial concentration.     

介质阻挡放电等离子体反应器降解盐酸四环素

采用介质阻挡放电等离子体反应器降解盐酸四环素（TC）,研究了输入功率、放电间距、气体流量、初始浓度等参数对盐酸四环素降解效果的影响,结果表明当输入功率为1.3 W,放电间距为2.5 mm,气体流量为150 ml·min^-1,初始浓度为100 mg·L^-1时降解效果最好,放电处理30 min盐酸四环素的降解率达到92%。动力学研究表明盐酸四环素的降解过程符合拟二级动力学方程。检测了降解过程中生成的中间产物,提出了盐酸四环素的降解路径与机理。     

介质阻挡放电脱硫脱硝过程特性

氮氧化物和硫氧化物在介质阻挡放电(DBD)反应器中的脱除率与很多因素有关,如氧气含量、相对湿度和烟气中SO_2的初始浓度等。本文通过改变SO_2初始浓度、氧气含量和相对湿度来研究脱除氮氧化物和硫氧化物过程中的反应机理。结果发现,在N_2/SO_2/NO体系中SO_2初始浓度在较大范围内变化对NO和SO_2的脱除率影响很小;而N_2/NO/SO_2/H_2O体系中相对湿度的增加对SO_2的脱除的影响较NO的影响大,增加烟气中相对湿度能明显减少SO_2在烟气中的浓度;N_2/NO/SO_2/O_2体系中氧气的增加对SO_2的脱除效率影响不明显,但能促进NO氧化成NO_2或者其他的氮氧化物,同时,在一定的条件下,也能加速NO的生成。探讨NO和SO_2的反应机理,发现SO_2的反应主要与OH和水合电子有关,而NO的反应与O、N等活性基相关。     

Hydrophobic coating of silicate phosphor powder using atmospheric pressure dielectric barrier discharge plasma

A stable superhydrophobic coating was successfully deposited on commercial silicate‐based orange phosphor by using atmospheric pressure dielectric barrier discharge plasma with hexamethyldisiloxane (HMDSO) and HMDSO/toluene mixture as precursors. Owning to the good optical properties, the deposited film acts not only as a hydrophobic protective layer but also as an antireflection optical thin film capable of improving the phosphor photoluminescence efficiency. The plasma‐polymerized film based on Si?O?Si backbone containing methyl and phenyl nonpolar functional groups exhibited high‐water‐repellent characteristics. It was found that the water contact angle gradually increased with increasing the aging time and remained unchanged at about 140° after 1‐month aging. Besides, the thermal stability of the coated phosphor under high‐temperature condition was substantially enhanced by the aging. The findings of this work can contribute to improving the durability and reliability of the phosphor, eventually the long‐term stability of phosphor‐based light emitting diodes in practical applications. © 2014 American Institute of Chemical Engineers AIChE J, 60: 829–838, 2014     

双介质阻挡放电低温等离子体对模拟堆肥气体中氨气的去除

针对固体废物堆肥设施氨气污染问题,本文首次运用双介质阻挡放电低温等离子体（DDBD）技术去除模拟堆肥气体中的氨气。考察了输入功率、氨气流速、氨气初始浓度、反应器放电间隙、氧气含量等参数对氨气去除率和低温等离子体系统能量效率的影响,并分析了副产物的生成情况及其影响因子。研究结果表明,氨气去除率与输入功率和氧气含量呈正相关,与氨气流速和氨气初始浓度呈负相关。低温等离子体系统的能量效率与氨气流速、氨气初始浓度、氧气含量均正相关,但随输入功率的增加先升高后降低。研究发现,在所设定的反应条件下,4mm放电间隙反应器的能耗最低,能量效率最高。O₃和NO_x是DDBD去除氨气的反应副产物,其浓度均与氧气含量呈正相关,均呈现随输入功率的增加先升高后降低的趋势。     

大气压介质阻挡放电及协同催化剂脱硝研究进展

受绿色生态和可持续发展战略理念的驱动,废气排放对环境造成的危害备受关注。NO _x 作为废气的主要污染物之一,是废气污染物控制的重点与难点。基于此,本文介绍了传统后处理脱硝技术的优缺点及应用现状,回顾了介质阻挡放电（DBD）基础研究,分析了DBD脱硝性能,重点阐述了DBD协同催化剂脱硝及脱硝机理。分析指出：①DBD驱动电源与反应器结构是制约脱硝性能的关键因素;②单独DBD技术脱硝性能较差,而DBD协同催化填充床技术展现出优异的脱硝性能和较高的N₂选择性;③等离子体协同催化脱硝机理研究主要包括等离子体特征参数诊断、流体模型验证、等离子体传播机制分析以及原位表征,而在等离子体催化理论计算方面的研究较为缺乏。因此,未来DBD协同催化脱硝技术应立足如下几个方面发展：研发高功率、低能耗电源,提升废气NO _x 处理量;优化反应器结构,提升脱硝的效率与选择性;设计与构筑适宜于DBD环境的脱硝催化剂;深入全面分析DBD协同催化剂脱硝机理。     

Hydrogen from steam methane reforming by catalytic nonthermal plasma using a dielectric barrier discharge reactor

A scaled-up dielectric barrier discharge (DBD) reactor has been developed and demonstrated for the production of hydrogen from steam methane reforming (SMR) by catalytic nonthermal plasma (CNTP) technology. Compared to SMR, CNTP offers conversion at ambient pressure (101.325 kPa), low temperature with better efficiency, making it suitable for distributed hydrogen production with small footprint. There have been several lab-scale DBD reactors reported in the literature. Dimension of the scaled-up DBD reactor is about six times the lab-scale version and can produce 0.9 kg H₂/day. The scale-up is, however, nonlinear; several technical innovations were required including spray nozzle for homogeneous introduction of steam, perforated tube central electrodes for generation of homogeneous plasma. Conversion efficiency of the scaled-up DBD reactor is 70–80% at 550°C and 500 W. A continuous run of 8 hr was demonstrated with typical product gas composition of 69% H₂, 6% CO₂, 15% CO, 10% CH₄.     

双杆介质阻挡放电降解酸性红73废水

研究一种双杆式介质阻挡放电在不同条件下对酸性红73的降解效果,考察了能量密度、初始电导率、初始pH、初始质量浓度和放置时间等因素对染料降解率的影响,并对反应中生成的活性粒子（H₂O₂和O₃）进行了检测。降解实验前后的紫外-可见吸收光谱图表明介质阻挡放电能够破坏酸性红73分子中的偶氮双键和萘环等。实验结果表明：能量密度的增加可以提高酸性红73降解率,当能量密度为265.8kJ/L时,降解率为70.0%,能量效率最高可达2.84mg/（kW·h）。酸性红73的初始质量浓度的增加可以提高反应的能量效率。放电过程中产生的过氧化氢与处理时间呈正相关增长,并可持续存在一段时间进一步引起染料褪色,臭氧则随着时间的增长先增大后减小。     

用活性炭吸附强化超滤过程脱除废水中染料的研究(英文)

In this study, orange G dye was efficiently removed from aqueous solution by ultrafiltration (UF) mem-brane separation enhanced with activated carbon adsorption. The powdered activated carbon (PAC) was deposited onto the UF membrane surface, forming an intact filter cake. The enhanced UF process simultaneously exploited the high water permeation flux of porous membrane and the high adsorption ability of PAC toward dye molecules. The influencing factors on the dye removal were investigated. The results indicated that with sufficient PAC incor-poration, the formation of intact PAC filtration cake led to nearly complete rejection for dye solution under opti-mized dye concentration and operation pressure, without large sacrificing the permeation flux of the filtration process. Typically, the dye rejection ratio increased from 43.6% for single UF without adsorption to nearly 100% for the en-hanced UF process, achieving long time continuous treatment with water permeation flux of 47 L·m 2·h 1. The pre-sent study demonstrated that adsorption enhanced UF may be a feasible method for the dye wastewater treatment.     

Catalysis assisted plasma decomposition of benzene using dielectric barrier discharge

Atmospheric non‐thermal plasma generated by dielectric barrier discharge was applied to decompose benzene with a sheet type catalyst of platinum supported by alumina. The experimental results indicated that an enhancement of the decomposition by the catalyst was achieved at low concentration of benzene. Ozone produced in the plasma seemed not to contribute to the decomposition. The deactivation of the catalyst was also observed due to decomposition products such as CO and a solid deposit. However a heating treatment could regenerate the catalyst. The results suggested the plasma‐catalyst hybrid reactor was the effective method to solve volatile organic compound (VOCs) problem.     

活性炭吸附在炼油化工废水回用中的应用

在炼油化工废水回用于循环冷却水的过程中，采用活性炭吸附对炼油污水进行深度处理。可以有效地降低污水的COD，去除效率随停留时间的增加而增加。利用臭氧对水中有机物的分解氧化作用，将臭氧和活性炭吸附结合起来，不仅可以进一步提高COD的去除效率，还对总固体含量的去除和腐蚀速率的控制有一定的作用。采用连续通水实验测定的活性炭饱和吸附量随不同参数的水质而不同。在活性炭吸附前加上混凝过滤对污水进行预处理可以有效的提高吸附效率。     

介质阻挡放电等离子体处理芳纶的表面性能研究

采用介质阻挡放电(DBD)装置对芳纶1414表面进行改性处理,探讨低温等离子体处理对纤维表面性能的影响。结果表明:经过DBD等离子体处理后,芳纶1414纤维表面粗糙程度加剧,粘结性能和浸润性能有了明显的改善;当DBD等离子体处理功率为200～300 W,时间为60 s,氩气流量为2～3 L/min时,芳纶1414的界面剪切强度从处理前的11.9 MPa上升到14.2 MPa,接触角由处理前的85.0°下降到了60.6°。     

介质阻挡放电协同复合碳材料去除VOCs

挥发性有机物（VOCs）是常见的空气污染物,实验研究低温等离子体催化技术去除以甲苯为代表的VOCs。采用炭粉末、酚醛树脂和致孔有机高分子聚合物的有机溶剂混合物作为前驱物,经过炭化、水汽活化和负载锰催化剂,制备一种基于发泡金属的复合碳材料。采用扫描电子显微镜、XRD、全自动比表面积及微孔孔隙分析仪对材料进行表征。两段式介质阻挡放电反应器结合复合碳材料降解甲苯,前段介质阻挡放电初步降解甲苯,后段复合碳材料利用介质阻挡放电产生的长寿命活性物种和臭氧进一步去除甲苯。输入电压为10 kV时,甲苯去除率约99.4％,CO₂选择性达72.2%,并且有效控制了副产物臭氧。实验结果表明,复合碳材料有望应用于如臭氧和VOCs等的污染控制。     

乙醇胺对介质阻挡耦合电晕放电同时脱除NO、SO2的影响

采用自行设计的介质阻挡耦合电晕放电等离子体反应装置进行了模拟烟气同时脱硫脱硝的研究,分别考察乙醇胺（HOCH₂CH₂NH₂,MEA）在不同模拟烟气体系中对NO、SO₂脱除的影响,深入探讨了MEA在放电过程中与NO的作用机理。结果表明：在N₂/O₂/SO₂/NO体系中,0.56% MEA的加入可以显著消除O₂对NO脱除的抑制作用;在N₂/CO₂/SO₂/NO体系中,MEA会吸收进入体系中的部分CO₂,以减弱CO₂对NO脱除的抑制;在N₂/O₂/CO₂/H₂O/NO/SO₂体系中,0.56% MEA的加入既可以有效减弱H₂O的影响,也可以使NO的脱除率达到71.28%,继续将MEA的体积分数增大至1.20%时,可将该体系下NO脱除率提高到81.25%;同时,MEA可以在短时间内高效吸收体系内的SO₂,且几乎不受其他气体成分的影响,SO₂脱除率保持在95%左右。     

介质阻挡放电在芳纶表面改性中的应用

综述了介质阻挡放电应用于芳纶表面改性研究的最新进展;介绍了介质阻挡放电的机理、特点以及国内主要的介质阻挡放电等离子体的设备;阐述了介质阻挡放电对芳纶亲水性能和粘结性能等表面性能的改善。指出芳纶等离子体表面改性的时间效应限制了其广泛应用,应进一步加强纤维表面等离子体改性的机理研究。