Ce/Zr系列催化剂上碳颗粒物燃烧行为

分别在TG和TPO上考察了CeO₂,ZrO₂及不同Ce/Zr比的CexZr1-xO₂固溶体催化剂上soot的燃烧性能,同时考察了反应气氛对活性的影响.结果表明:Ce基催化剂能明显降低soot的起燃温度,Ce/Zr比的不同导致Ce_xZr_1-xO₂催化剂性能的差异.反应的速度控制步骤随O₂浓度的不同而改变;H₂O对Ce_0.5Zr_0.5O₂上soot的氧化活性基本没有影响;由于NO氧化产生的NO₂具有更强的的氧化能力,因此NO对soot的燃烧具有促进作用,起燃温度降低了30℃.催化剂上的β氧种参与了soot燃烧过程.     

昆钢滇中铁合金厂6000KVA电炉烟尘治理

昆钢滇中铁合金厂6000KVA电炉采用干法袋式除尘工艺处理烟气，通过改变滤袋材质、控制在线过滤风速、延长清灰静止沉降时间等措施，使整套装置除尘效率达到99．5％。     

Limestone surfaces in built-up environment as indicators of atmospheric pollution

The concentration of sulphate on limestone surfaces of the external walls of churches in Malta is shown to be related to their position and distance from a power station, the main local point source of sulphur dioxide pollution. Limestone powder collected from these surfaces was examined for the presence of particles which, under low-power optical microscopy, appear as shiny black amorphous bodies which were interpreted as soot particles; the abundance of these bodies was expressed as a black particle count (BPC). The degree of sulphation and BPC were shown to be correlated with each other and both appeared to be strongly dependent on the prevailing wind. The BPC contour map indicated an important contribution to the parameter from vehicular traffic. It is suggested that the degree of sulphation and BPC of limestone surfaces from the built environment should function as environmental indicators of the relative air quality with respect to SO₂ and soot pollution. This data is possibly more accurately representative of the relative long-term air-quality status of different areas of habitation than that deduced from single or episodic measurements of atmospheric pollutant levels.     

手动加煤燃煤机在倒焰窑烟尘治理中的应用

燃煤型倒焰窑排放的烟法浓度高，处理难度大，已成为大气治理中的新热点。采用实用新型燃煤机，改变煤的燃烧方式使其完全燃烧，从而使燃煤烟气污染得到有效的控制达标排放并节约能源。     

水蒸气对层流甲烷/空气扩散火焰中烟黑生成的影响

空气中水的存在会严重影响烷烃类扩散火焰中烟黑的生成,研究氧化剂流中水对烷烃类火焰的影响,对污染物控制及火灾扑救具有重要意义。模拟采用24步简化机理的有限速率化学反应模型、Moss-Brookes烟黑模型及Discrete Ordinates(DO)辐射模型,研究在空气中加入水对甲烷/空气层流伴流扩散火焰的影响,其中烟黑模型包括烟黑的成核、表面增长和氧化。结果表明,伴流空气中的水蒸气会降低火焰的温度、抑制烟黑的生成。这是因为:一方面,水蒸气降低了甲烷燃烧的温度,火焰温度的降低导致化学反应速率减慢,烟黑成核和表面生长速率随之降低,火焰中烟黑质量分数便减少;另一方面,由于水蒸气的加入使化学反应OH+H_2 H+H_2O(R(15))逆向反应加速,继而导致OH生成量增加。但由于氧气浓度降低使火焰体积增大,OH的浓度降低。从而导致烟黑的氧化速率降低,烟黑生成量增加。由于水蒸气的化学效应小于其温度效应,总体上烟黑质量分数降低。最后对比了模拟结果和试验结果。     

浅谈油烟的危害以及相关标准的修订

伴随着经济的繁荣和人民物质生活质量的提高,餐饮业日益繁荣起来,再结合中国素来"民以食为天",传统饮食文化的特殊性及复杂性,导致烹饪过程复杂,同时也带来了各种各样的油烟污染问题。油烟已经成为继噪声、尾气、沙尘之后的又一大污染问题,并且成为百姓环保投诉的热点问题之一。《饮食业油烟排放标准》(GB18483-2001)是目前我国环保行业监测饮食业油烟的唯一标准方法,在实际工作中存在一定的局限性和不完备性,对现行标准进行修订势在必行。     

Catalytic combustion of soot over ceria-zinc mixed oxides catalysts supported onto cordierite

Modified substrates as outer heterogeneous catalysts was employed to reduce the soot generated from incomplete combustion of diesel or diesel/biodiesel blends, a process that harms the environment and public health. The unique storage properties of ceria(CeO2) makes it one of the most efficient catalysts available to date. Here, we proposed that ceria-based catalysts can lower the temperature at which soot combustion occurs; more specifically, from 610℃ to values included in the diesel exhausts operation range(300–450℃). The sol-gel method was used to synthesize mixed oxide-based catalysts(CeO2:ZnO); the resulting catalysts were deposited onto cordierite substrates. In addition, the morphological and structural properties of the material were evaluated by XRD, BET, TPR-H2, and SEM. Thermogravimetric(TG/DTA) analysis revealed that the presence of the catalyst decreased the soot combustion temperature by 200℃ on average, indicating that the oxygen species arise at low temperatures in this situation, promoting highly reactive oxidation reactions. Comparative analysis of soot emission by diffuse reflectance spectroscopy(DRS) showed that catalyst-impregnated cordierite samples efficiently oxidized soot in a diesel/biodiesel stationary motor: soot emission decreased by more than 70%.     

The Adsorption of Formaldehyde on Suspended Particles investigated on model systems

Our laboratory investigation aimed at assessing to what extent suspended particles could adsorb formaldehyde, allowing it, when inhaled, to penetrate deeper into the lung. We used two types of pure soot, N-220 and N-660 (the former being a highly active oil furnace soot with smaller particles and a larger surface area than the latter), because of their chemical inactivity and the adsorptive properties. The results obtained in experimental conditions showed that soot particles could bind 2.3 to 50.2% of formaldehyde, depending on the particle size, relative humidity, amount of particles and the duration of the contact. The recovery of formaldehyde from the particles was also tested. Further investigation is planned under realistic conditions.     

La1-x Cex Cuy Mn1-yO3／HZSM-5催化剂低温去除柴油机碳烟和NOx

为实现对柴油机碳烟和NOx的低温同步去除，采用柠檬酸络合法制备分子筛负载钙钛矿型金属复合氧化物催化剂，应用x衍射分析仪（XRD）和电镜扫描仪（SEM）对催化剂性能进行表征，并在微型固定床反应器中对催化剂低温去除碳烟和NOx进行活性评价。利用程序升温反应（TPR）技术，进行催化剂活性评价、柴油机负荷和排放等特性实验。结果表明，A位用适量Ce部分取代La，B位用适量cu部分取代Mn，可使碳颗粒燃烧温度降低，CO2选择性好，NOx转化率升高。La0.4 Ce0.6 Cu0.2 Mn0.8O3／HZSM-5催化剂的最大NOx转化率为81．0％，Ti、Tm和Tf分别为250、350和475℃，表明该催化剂具有较好的催化活性，能在低温条件下去除碳烟和NOx。     

柴油车烟度计维修二例

环境监测仪器由于受环境条件等因素的影响 ,经常会出现各种故障 ,文章对柴油车烟度计检测时表头指针无指示故障进行了系统分析 ,并介绍了维修方法和步骤