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钙基CO2吸收剂的种类和粒径对循环煅烧/碳酸化的影响 总被引:4,自引:0,他引:4
在流化床反应器内研究了吸收剂种类(石灰石、白云石)和颗粒粒径(90~200μm和200~450μm)对钙基吸收剂碳酸化特性、煅烧特性以及循环稳定性的影响,并对新型CaO/Ca12Al14O33吸收剂的循环稳定性进行研究.结果表明:钙基吸收剂在流化床内均能有效吸收CO2.在碳酸化阶段,吸收剂种类对吸收剂的吸收特性影响较大,而颗粒粒径对其影响较小;在煅烧阶段,CaCO3分解速率随颗粒粒径的减小而增大.随着循环反应次数的增加,钙基吸收剂反应活性下降,相对于白云石和石灰石,CaO/Ca12Al14O33具有更高的循环稳定性,并在七次循环后活性不再发生变化.对于石灰石吸收剂,循环稳定性随循环次数的变化受粒径影响较小.白云石吸收剂由于在循环中容易破碎,因此粒径对其循环稳定性有一定的影响. 相似文献
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蒸汽活化钙基吸收剂用于干法烟气脱硫的实验研究 总被引:14,自引:2,他引:12
本文简化模拟实验了燃煤锅炉省煤器后的干法烟气脱硫方案.在沉降炉上实验研究了蒸汽活化对钙基吸收剂脱硫(400~800℃)效果的影响.结果表明,蒸汽活化能显著改善钙基吸收剂的微孔结构,提高其转化率.在400到600℃下反应产物以亚硫酸钙为主,700到800℃反应产物以硫酸钙为主。 相似文献
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唐强宋赞杨仲卿刘川川 《工程热物理学报》2014,(6):1232-1235
采用实验的方法,在鼓泡流化床燃烧装置中研究了低浓度煤层气在床内的流动和燃烧特性,考察了床层温度、气体浓度、流化风速及床料颗粒特性等操作条件变化对甲烷转化率和燃烧产物的影响。研究表明:床层温度升高,甲烷转化率显著增加;增加流化风速及进气甲烷浓度,甲烷转化率减小;颗粒粒径增加,甲烷转化率增加;CO排放浓度随床层温度的升高先增加后降低,并在床层温度约850℃时达到其最大峰值,沿流化床轴向高度CO的排放浓度先增加后降低,呈钟型分布。 相似文献
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本文采用变升温速率煅烧和改变煅烧温度探索孔隙形成的特点,同时利用热重分析进行硫化反应,分析煅烧产物的钙转化率,结果表明升温速率和煅烧温度对孔隙特性有重要影响,此外硫化反应对孔径分布有特定要求。 相似文献
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NO2对中温干法脱硫反应影响的实验研究 总被引:1,自引:0,他引:1
利用鼓泡床反应器对NO2对中温干法脱硫反应的影响开展了实验研究.分别采用分析纯CaO和工业级石灰两种物质作为吸收剂,在250℃和350℃两个反应温度下研究NO2对吸收剂转化率的影响.结果表明,NO2的存在可以提高吸收剂转化率;250℃下NO2的作用显著高于350℃;250℃下NO2浓度的增加对吸收剂转化率基本没有影响;在350℃时,对于分析纯CaO,NO2浓度的增加降低了吸收剂转化率,这主要是由于SO2与NO2的竞争反应引起的;工业级石灰内含杂质较多,对一些反应有催化作用,因而其反应现象与分析纯CaO略有不同. 相似文献
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应用统计物理的方法重点研究量子理想气体,得到其物态方程为pV=NkBT(1 △),并对量子近独立粒子之间的统计关联作了讨论,从而证明pV=NkBT对理想气体不一定成立. 相似文献
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部分回热回注蒸汽燃气轮机循环的研究 总被引:3,自引:0,他引:3
1前言自从美国国际动力技术公司的程大献先生于1976—1981年间提出“双工质平行一复合循环热机”发明专利后,这种回注蒸汽燃气轮机(STIG)循环已在数个国家的多种型号的燃气轮机装置上得到应用,并取得实效。众所周知,回热燃气轮机具有较高热效率,而STIG循环具有高比?.. 相似文献
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从量纲分析的观点出发讨论气体物态方程的形式.指出理想气体的物态方程由量纲特征确定到只差一常数;玻意耳气体族的物态方程族由量纲特征完全确定;还给出了非理想气体物态方程的一般形式. 相似文献
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Navinder Singh 《Pramana》2005,64(1):111-118
A model calculation is given for the energy relaxation of a non-equilibrium distribution of hot electrons (holes) prepared
in the conduction (valence) band of a polar indirect band-gap semiconductor, which has been subjected to homogeneous photoexcitation
by a femtosecond laser pulse. The model assumes that the pulsed photoexcitation creates two distinct but spatially interpenetrating
electron and hole non-equilibrium subsystems that initially relax non-radiatively through the electron (hole)-phonon processes
towards the conduction (valence) band minimum (maximum), and finally radiatively through the phonon-assisted electron-hole
recombination across the band-gap, which is a relatively slow process. This leads to an accumulation of electrons (holes)
at the conduction (valence) band minimum (maximum). The resulting peaking of the carrier density and the entire evolution
of the hot electron (hole) distribution has been calculated. The latter may be time resolved by a pump-probe study. The model
is particularly applicable to a divided (nanometric) polar indirect band-gap semiconductor with a low carrier concentration
and strong electron-phonon coupling, where the usual two-temperature model [1-4] may not be appropriate. 相似文献
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Abstract Chemiluminescence is frequently used as a powerful analytical tool for gas analysis. In this mini-review with 102 references, we summarize the recent advances in chemiluminescence-based analytical methodologies and their application in gas/volatile species analysis, mainly including applications of ozone-induced chemiluminescence, cataluminescence-based gas sensors and arrays, and dielectric barrier discharge–induced chemiluminescence for gas analysis. Efforts in the innovation of the methodologies, the exploration of new sensing materials, and the mechanism studies are discussed in detail. 相似文献
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In the recent past a great deal of research efforts were directed toward the development of miniaturized gas-sensing devices, particularly for toxic gas detection and for pollution monitoring. Though various techniques are available for gas detection, solid state metal oxides offer a wide spectrum of materials and their sensitivities for different gaseous species, making it a better choice over other options. In this article a critical parameter analysis of different metal oxides that are known to be sensitive to various gaseous species are thoroughly examined. This includes phase of the oxide, sensing gaseous species, operating temperature range, and physical form of the material for the development of integrated gas sensors. The oxides that are covered in this study include oxides of aluminum, bismuth, cadmium, cerium, chromium, cobalt, copper, gallium, indium, iron, manganese, molybdenum, nickel, niobium, ruthenium, tantalum, tin, titanium, tungsten, vanadium, zinc, zirconium, and the mixed or multi-component metal oxides. They cover gases such as CO, CO2, CH4, C2H5OH, C3H8, H2, H2S, NH3, NO, NO2, O2, O3, SO2, acetone, dimethylamine (DMA), humidity, liquid petroleum gas (LPG), petrol, trimethylamine (TMA), smoke, and many others. Both doped and undoped oxides are analyzed for the compatibility with silicon processing conditions and hybrid microcircuit fabrication techniques. In silicon processing conditions, they are further analyzed for the suitability for simple silicon surfaces, silicon-on-insulator (SOI) surfaces, and micromachined silicon geometries for different operating temperatures. Discussion on gas-sensing properties of each material and its applications are described in the text in alphabetical order of the elemental oxides. Further, the gas-sensing properties like sensitivity, detection limits, operating temperature, and so on are summarized in tables al ong with relevant references. The figures incorporated in the present review are primarily based on discussions and data in tables. However, these figures provide a qualitative comparison and present a pictorial view to examine suitability of a material for a particular application. From the known parameters, the present study clearly indicates the suitability of certain materials and the gases that they cover for the development of integrated micro gas sensors. A clear picture has been brought out for the development of silicon-based processing technology. Various parameters are discussed for the selection of these materials, to examine their suitability and practical problems that are being associated. Etching of these metal oxides and the reliability of devices are also discussed. 相似文献