脉冲放电脱硫脱硝技术研究

本文介绍了脉冲电晕放电等离子体法烟气脱硫脱硝技术的研究过程和进展，该脱硫脱硝技术是８０年代后期发展起来的一种很有前途的技术。文中给出了一些有关的研究结果，可为该技术的深入研究提供参考。     

烟气脱硝技术综述及发展趋势预测

烟气脱硝是指从烟气中去除氮氧化物,是世界各国控制氮氧化物污染、防治酸雨危害的主要措施。目前,一些联合脱硫脱硝工艺亦在兴起,如活性炭吸附法,等离子体法,电子束法、脉冲电晕放电等离子体法、CuO法、NOxSO工艺、SNAP法等。     

脉冲放电烟气脱硫脱硝与除尘相结合工艺研究

提出了一种脉冲放电烟气脱硫脱硝与除尘相结合工艺,除尘和脱硫脱硝过程在采用脉冲+直流供电的同一装置内完成,脱硫脱硝产物用直流电除尘回收。与现有脉冲放电烟气净化工艺相比,省去了专门的除尘装置,可降低投资,减少占地面积,且能保证回收产物的经济价值。     

电晕放电同时脱硫脱硝机理研究

电晕放电同时脱硫脱硝技术是最有应用价值的烟气综合治理技术之一。从自由基的产生、SO2和NOx的脱除以及它们之间相互影响方面着手,对电晕放电烟气同时脱硫脱硝过程进行了深入的分析。从结果可知,电晕放电过程中自由基的产生主要依靠电子碰撞和电荷转移激发。在NOx的脱除过程中氧化作用起着决定性作用,而单独的放电过程对SO2脱除的作用不大,其脱除还得依靠碱性物质的加入。烟气中的小颗粒或气溶胶表面发生的异相反应能够促进SO2和NOx的脱除。     

水界面电晕放电脱硫脱氮的等离子化学反应研究

以控制大气污染为目的,对锅炉排烟进行脱硫、脱氮和除尘。依据气水界面电晕放电机理,提出了一种气-水协同电晕放电净化法。为了实现除尘与脱硫脱硝一体化,设计了烟气净化模型和它的实验系统,并进行了脱硫实验模拟和等离子化学分析。     

电晕放电耦合湿式吸收同时脱硫脱硝的实验研究EI北大核心CSCD

为了解决传统组合式燃煤烟气治理技术存在的系统复杂、投资费用高等问题,提出了电晕放电耦合湿式吸收同时脱硫脱硝的新方法。重点分析了电晕放电耦合湿式吸收同时脱硫脱硝的反应过程和协同效应,并考察了影响同时脱硫脱硝效果的关键因素。研究结果表明:SO2的脱除主要依靠中和反应,但电晕放电能进一步强化其吸收;电晕放电耦合湿式吸收能发挥协同效应,大大提高NOx脱除率;单独电晕放电过程和单独吸收过程的NOx脱除率分别为14.3%和7.7%,而电晕放电耦合湿式吸收过程的NOx脱除率则达到了58.2%,协同效应明显;随着液气体积比的增加,SO2和NOx的脱除都有所改善,但0.015的液气体积比已能满足当前脱硫脱硝的要求;吸收剂质量浓度对SO2的脱除影响不大,但随着吸收剂质量浓度的提高,NOx脱除率却显著上升;在20 k V放电电压下,质量浓度为0.3 g/L的Na OH加入后,NOx脱除率提高近30%。研究结论可以为进一步开展电晕放电耦合湿式吸收同时脱硫脱硝的应用基础研究提供理论依据。     

电晕放电耦合湿式吸收同时脱硫脱硝的实验研究

为了解决传统组合式燃煤烟气治理技术存在的系统复杂、投资费用高等问题,提出了电晕放电耦合湿式吸收同时脱硫脱硝的新方法。重点分析了电晕放电耦合湿式吸收同时脱硫脱硝的反应过程和协同效应,并考察了影响同时脱硫脱硝效果的关键因素。研究结果表明:SO2的脱除主要依靠中和反应,但电晕放电能进一步强化其吸收;电晕放电耦合湿式吸收能发挥协同效应,大大提高NOx脱除率;单独电晕放电过程和单独吸收过程的NOx脱除率分别为14.3%和7.7%,而电晕放电耦合湿式吸收过程的NOx脱除率则达到了58.2%,协同效应明显;随着液气体积比的增加,SO2和NOx的脱除都有所改善,但0.015的液气体积比已能满足当前脱硫脱硝的要求;吸收剂质量浓度对SO2的脱除影响不大,但随着吸收剂质量浓度的提高,NOx脱除率却显著上升;在20 k V放电电压下,质量浓度为0.3 g/L的Na OH加入后,NOx脱除率提高近30%。研究结论可以为进一步开展电晕放电耦合湿式吸收同时脱硫脱硝的应用基础研究提供理论依据。     

电晕放电烟气脱硝机理探讨

探讨了电晕放电烟气脱硝之机理,分析了电晕放电烟气脱硝的影响因素,同时提出了一些有待继续研究和探讨的课题。     

高压电晕放电与液相化学氧化协同脱除烟气中NO的影响因素与机理

为了解高压电晕放电与液相化学氧化协同脱硝的影响因素与机理,研究了在高压电晕放电与液相化学氧化的协同作用下,供电电压、水体积流量、吸收剂种类以及NO初始质量浓度、烟气体积流量等因素对脱硝效率的影响,探讨了高压电晕放电与液相化学氧化协同脱硝的机理。NO气体经流量计与空气混合形成模拟气体,输送至反应器内进行反应后排放。测定NO质量浓度,计算烟气脱硝效率。结果表明:脱硝效率随着供电电压、水体积流量、吸收剂浓度的增加而增加,但随着NO初始质量浓度、烟气体积流量的增加而下降。在3 k V高压电晕放电和质量分数为5%的H_2O_2协同作用下,烟气脱硝效率高达60.2%。高压电晕放电和液相化学氧化烟气脱硝具有明显的协同效应。脱硝机理主要包括气相电晕放电等离子体氧化反应和液相氧化吸收反应。     

一种用于脱硫硝的毫微滗脉冲电源的研制

电晕法烟气脱硫脱硝要求快速窄脉冲供电方式，介绍了一种新颖毫微秒波头脉冲电源，其输出电压波形，前沿上升时间小于２０ｎｓ，脉宽小于１００ｎｓ，基压和脉冲幅值分别可调并且脉冲能量转移率和电源自射的能量效率也分别达到９５％和７０％以上。     

Fabrication and Electromechanical Properties of Piezoelectric Micro-Transducers for Smart Device

We have fabricated piezoelectrically driven micro-transducer for the application to smart device. Two types of micro-transducers, i.e., micro-cantilever and micro-bridge, have been designed and fabricated. Finite element method (FEM) simulation was performed on the micro-transducer with various length and shapes. Lead zirconate titanate thin film as a piezoelectric layer was incorporated into the micro-transducer. The transducer structure consists of PZT thin layer capacitor, low temperature oxide (LTO) and low stress SiN_x layer. Pb(Zr_0.52Ti_0.48)O₃ (PZT) films were prepared by diol-based sol-gel process. The PZT films were not damaged by fabrication process and thus maintained their electrical properties in the transducer structure after all the fabrication steps. The dielectric constant and loss of the PZT film in the transducer structure were 870 and 2% respectively. The remanent polarization was 20 μC/cm². The micro-cantilever had a fundamental resonant frequency in the range of 16 to 25 kHz when its length was in the range of 320 μm to 380 μm. Meanwhile, the resonant frequency of the micro-bridge was higher by a factor of 7 than that of the micro-cantilever with a similar dimension.     

Fabrication and Characterization of Ba(Ti,Zr)O3 Thin Films Through the Chemical Solution Deposition Process

Lead- and bismuth-free Ba(Ti_{1 ? x} Zr _x )O₃ (BTZ) thin films were fabricated on Pt(111)/Ti/SiO₂/Si(100) substrates by the chemical solution deposition (CSD) process. The single phase BTZ thin films were obtained at 650°C by conventional process and the control of lattice parameter a was possible by Zr substitution. As the D-E hysteresis loops and J-V characteristics depended on the precipitates on film surface, the fabrication process was reexamined by 2-step sintering process. Consequently the decreasing of first sintering time was able to prevent the precipitates, and the larger grain of about 40–50 nm were obtained by additional sintering for 2 hour.     

Synthesis and Characterization of Zn-Doped TiO2 Nanoparticles via Sonochemical Method

Zn-doped TiO₂ nanoparticles were successfully fabricated using sonochemical method accompanying post calcination process. Titanium isopropoxide (Ti[OC₃H₇]₄) and Zinc chloride (ZnCl₂) were used as starting precursors for Ti and Zn sources, respectively. The homogeneous mixing solution of different Zn (0–1 mol%) and Ti ratio were irradiated in high intensity ultrasound sonometer (750 W 20 kHz) for 30 min at room temperature to obtain as-synthesized Zn-doped TiO₂ nanoparticles followed by calcination at 400–700°C. To evaluate the structure and phase identification of prepared powders, the X-ray diffraction (XRD) and Raman spectroscopy were employed. The results reveal that the as-synthesized Zn-doped TiO₂ nanoparticles are in anatase phase and their crystallinity increases with increasing calcined temperature. The morphology of as-synthesized powders was investigated by transmission electron microscope (TEM). The effect of Zn content and calcinations temperature on TiO₂ properties was also discussed.     

电液净化新工艺研究

本文对目前几种电液快速净化工艺作了介绍,提出了一种电液快速净化的新工艺,其特点:1.氯化锌与氯化铵一步溶解配制成所需浓度的电液;2.采用了凝聚剂进行快速凝聚除铁;3.用金属锌粉全悬浮法除去其它有害金属离子;4.使电液配制从氯化锌溶解到净化成合格电液的总时间缩短到5～6小时。     

Structure and dielectric properties of Cu and (K,Na) doped SrBi2Nb2O9 ferroelectric ceramics

Ferroelectric ceramics, SrBi₂Nb₂O₉ (SBN), Sr_0.8Cu_0.2Bi₂Nb₂O₉ (SCBN) and Sr_0.8K_0.1Na_0.1Bi₂Nb₂O₉ (SKNBN) were prepared by a solid state reaction process. X-ray diffraction analysis shows that the alkali and Cu almost diffuse into the SBN lattice to form a solid solution during sintering and some slight secondary phases was detected. The effect of alkali and Cu on dielectric properties of the SBN ceramics was discussed. The dielectric loss factor of (K,Na) doped SBN ceramics degraded considerably to 0.01 and their frequency and temperature stabilities were enhanced. The dielectric constant was enhanced by approximately 60% and the Curie temperature (Tc) was also improved for Cu doped SrBi₂Nb₂O₉ ceramics.     

Nitric oxide decomposition in air by using nonthermal plasmaprocessing with additives and catalyst

Catalyst (copper-coated zeolite catalyst, i.e., Cu-ZSM-5) was used to enhance NO_x removal plasma chemical reactions. Two kinds of hydrocarbons (2-propane-1-ol, 2-propanol) were added to the synthesized flue gas before the nonthermal plasma process, and their effects on NO_x removal characteristics were investigated. Enhancement effects of NO_x removal by the nonthermal plasma process with hydrocarbons as the additives were confirmed. Usually, the catalyst's working temperature is much higher than the room temperature. A catalytic reactor was installed after the plasma reactor. Catalytic effects on NO_x removal characteristics disappeared when the synthesized flue gas temperature was increased (~250°C). When the synthesized flue gas temperature was at room temperature, about 90% NO _x removal efficiency was realized with a combination of hydrocarbons, the catalytic reactor, and the pulsed discharge plasma     

Influence of Temperature on the Microstructure and Electrical Properties of BBT Thin Films

The BBT films were prepared by a spin-coating process from the polymeric precursor method (Pechini process). In order to study the influence of the temperature on the BBT microstructure and electrical properties, the films were deposited on platinum coated silicon substrates and annealed from 700@C to 800°C for 2 hours in oxygen atmosphere. The crystallinity of the films was examined by X-ray diffraction while the surface morphology was analysed by atomic force microscope. The dielectric properties and dissipation factor of BaBi 2 Ta 2 O 9 films at 1 MHz were observed. The polarization-electric field hysteresis loops revealed the ferroelectric characteristics of BaBi 2 Ta 2 O 9 thin films.     

Low temperature growth of sol-gel SrBi2Ta2O9 thin films by low-pressure annealing

A new low-temperature processing method to prepare SrBi₂Ta₂O₉ thin films is proposed. These thin films were prepared on Pt/Ta/SiO₂/Si substrates by a sol-gel method, and their structural and electrical properties were investigated. Films were annealed before and after the top Pt electrode deposition. The first annealing was performed in a 760-Torr oxygen atmosphere at 600 °C for 30 min, and the second annealing was performed in a 5-Torr oxygen atmosphere at 600 °C for 30 min. The films were well crystallized and fine-grained after the second annealing. The electrical characteristics of the 200-nm-thick film obtained by this new process were as follows: remanent polarization, P_r = 8.5 μC/cm²; coercive field, E_c = 36 kV/cm; and leakage current density, I_L = 1 × 10⁻⁷ A/cm² (at 150 kV/cm). This process is very attractive for highly integrated ferroelectric nonvolatile memory applications. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120(2): 27–33, 1997     

纳米FeSn2金属间化合物的制备和电化学性能研究

用化学还原法和溶剂热法成功地制备了纳米FeSn2颗粒,并对各自的电化学性能进行了测试.用化学还原法制备的纳米FeSn2颗粒呈球形但团聚,颗粒的尺寸约为30～70 nm.用溶剂热法制备的纳米FeSn2颗粒呈现单分散的球状结构,其中颗粒的尺寸为80 nm,且颗粒的尺寸分布均匀.两种不同方法制备的纳米FeSn2颗粒都具有50...     

Improvement of Dielectric and Interface Properties of CeO2 Buffer Layer by Using the Metal Seed Layer and N2 Plasma Treatment

In this paper, we investigated the feasibility of cerium oxide (CeO₂) films as buffers layer of MFIS (metal ferroelectric insulator semiconductor) type capacitors. CeO₂ layer were prepared by a two-step process of a low temperature film growth and subsequent RTA (rapid thermal annealing) treatment. By applying a cerium (Ce) metal seed layer of 4 nm, unwanted SiO₂ layer generation was successfully suppressed at the interface between the buffer layer and the Si substrate. After N₂ plasma treatment, the leakage current was reduced by about 2-orders. By employing a N₂ plasma treatment, we were able to successfully obtain good properties at the interface between the buffer layer and the Si substrate.