建立了基于索氏提取-固相萃取净化,气相色谱-质谱联用仪测定固定污染源飞灰中多环芳烃类有机污染物的方法,检验了滤筒和溶剂中杂质对测定的影响并提出了解决方案;优化了索氏提取的溶剂体系和提取条件,提高了提取效率;优化了净化程序;建立了基于内标法和选择离子检测的气相色谱-质谱联用仪测定方法,验证了方法的准确性.该方法解决了溶剂和滤筒带入的杂质以及样品基体对测定结果的干扰,组分提取完全,结果准确,是测试固定污染源飞灰中多环芳烃类有机污染物的有效方法.

Flue Gas simultaneous Desulfurization and Denitrification (FGDD) is expected to become a new generation of low-cost technology to achieve ultra-low emissions especially in smelting kilns and industrial boilers. The fixed bed system and in-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) were used to clarify the reaction mechanism of NO and SO2 co-removal by calcium hydroxide absorbent. The hydroxyl radical on the surface of calcium hydroxide was identified by Protium Nuclear Magnetic Resonance (H-1 NMR) and radical scavenger 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO). With synergistic effect of hydroxyl radical and oxygen, NO and SO2 are oxidized to NO2 and SO3 respectively, and then absorbed as nitrate and sulfate, according to the three-step chain reactions: SO2 +HO* -> HOSO2 *, HOSO2 * +O-2 -> SO3 +HO2 * and HO2 * +NO -> HO star +NO2. The key point is the recycling of hydroxyl radical.

Simultaneous DSC-TGA (SDT) and Fourier transform infrared spectrometer (FTIR) and diffuse reflectance in situ Fourier transform spectroscopy (DRIFTs) were used to study the thermogravimetric behavior and the reaction path of hemihydrate calcium sulfite in nitrogen atmosphere. The gas phase products and solid phase products were detected by FTIR. The main conclusions are as follows: in the thermal decomposition process, disproportionation reaction starts at 853 K: 4CaSO3 → CaS + 3CaSO4, and decomposition reaction and desulfurization reaction start simultaneously at 963 K: CaSO3 → CaO + SO2, CaS + 2SO2 → CaSO4 + S2(g), and disproportionation reverse reaction starts at about 1053 K: CaS + 3CaSO4 → 4CaO + 4SO2, calcium sulfate decomposition reaction begins at 1393 K: CaSO4 → CaO + SO2 + 1/2O2. The oxidation temperature and reaction products were obtained through oxidation experiments, which proved that the calcium sulfite has sufficient thermal stability at ambient temperature.

在煤的发热量测定教学实验中,越来越多地使用自动氧弹量热仪进行测定,实验内容简单空洞.尝试从煤在氧化性气氛下燃烧以后,硫氧化物和氮氧化物的生成机理以及它们最终生成硫酸和硝酸带来的热效应的计算作为切入点设计实验教学内容,使学生更深入地理解氧弹量热仪的工作原理,推导出仪器测定的弹筒发热量与高位发热量的关系,弹筒发热量与酸校正的关系,酸校正经验公式与燃烧过程之间的关系以及为什么需要进行冷却校正.这种尝试丰富了实验课内容,可以更好地解释实验数据,进而更好地理解课程内容,具有很好的教学效果.

作为一种提升理工类实验室本质安全的措施,对比了集中供气和气瓶分散供气的优缺点,论述了集中供气解决方案中面临的各种技术问题,包括气体站的建设,管材和附件的选择与安装,以及终端控制面板的设置,提出了集中供气系统安全运行所需的管理措施.

详细分析了各种常见科研排风设备的特点和控制方式,提出了连续风量和临时风量的概念,以此核算每个设备的排风量,进而得到房间的排风量,以连续风量和考虑了同时利用系数的临时风量之和作为总风量进行排风机选型,并考虑风机噪声控制和尾气净化.以房间为单位根据其用途和内部设备进行补风方案设计,优先选择余风量控制方式补风,并根据资金情况选择建设新风管道并进行热回收,或采用分布式空气源热泵.控制分为设备、房间、楼宇3个层级.即:以设备为单位考虑排风,以房间为单位考虑补风,从整栋楼宇进行分级控制.还需要优良的设备安装和系统联调作为保证.

Gas-washing and water injection are two commonly used methods in generating certain moisture content in gas flow stream, but the control accuracy of these methods remains uncertain. The purpose of the study is to investigate the characteristic of water vapor generation of the two methods. The temperature and humidity recorder and FTIR gas analyzer have been adopted to monitor the moisture content in tests. It has been revealed that, in gas-washing process, the moisture content in gas stream is well below saturation, and long time is required before moisture content stabilized after water bath temperature or carrier gas flow rate changed. Water injection pump could directly control the amount of water injected into gas stream. However, the moisture content generated in this way is not stable but oscillates in cycles, whose frequency and magnitude are closely related to water injection amount.

提出了从组织措施和技术措施作为切入点进行高校实验室气瓶管理的新思路。校级职能部门重点在组织措施建设,包括供应商资质审核、采购平台建设、培训和准入体系建设;二级机构实验室在落实组织措施的基础上,在气瓶的储存和使用环节根据不同种类的气体采取技术措施,形成一种建立在组织措施基础上,以技术措施为保障的具有可操作性的综合管理体系,促进高校实验室气瓶管理,杜绝气瓶事故发生。

论述了几种便携式烟气分析仪的工作原理和性能,根据不同仪器的技术特点和局限性,指出了其最佳使用方向,定电位电解法仪器的应用将逐渐减少,非分散红外仪器成为主流,非分散紫外和紫外差分仪器在超低排放改造后的污染源湿基测量中发挥重要作用,傅里叶红外仪器在VOCs治理和应急环境监测中拥有较大技术优势.以上分析可以作为仪表选型时的参考.

对比了火电厂中几种不同原理的CEMS污染物测量仪表,分析了它们各自的性能特点,以及在超低排放条件下的适用性,提出了NDIR仪表的局限性,以及DOAS仪表和化学发光法/紫外荧光法(配合稀释抽取)仪表的技术优势,给出了选型建议.

The specific heat capacities of chars during primary pyrolysis of biomass with different conversion and the heat capacities of virgin biomass were determined.The ratio method was employed to measure the specific heat capacities of two biomass samples and their pyrolyzed chars through thermogravimetry and differential scanning calorimetry ( TG-DSC).A mathematical model was developed to calculate values of specific heat of chars.The results show that the specific heat capacitei s of the two biomass samples and their derived chars increase linearly within 60~200℃.The values oft he specific heat capacity fo the chars are lower than those fo the virgin biomass samples.The specific heat of chars decreases as the extent of pyrolysis increases.The calculated specific heat capacities from the developed mathematical model are quite close to those me asured by TG-DSC analyses eb twe n 150~200℃.

•TG–DSC technique was re-examined to determine the heat of biomass pyrolysis.•Temperature-dependent specific heat was measured for biomass and char samples.•The primary pyrolysis was found to consist of endothermic and exothermic stages.•Linear relations were found between the biomass pyrolysis heat and conversion ratios.•The heat of secondary reactions could be up to 2500–4000J/g for the biomass samples.

Carbon,hydrogen and nitrogen in organic samples were determined with CE-440 elemental analyzer.Under optimized experimental conditions recommended by the manufacture,the regularities of slope variations of carbon,hydrogen and nitrogen were investigated.After 6~10 samples were analyzed,standard samples were added for calibration to improve the accuracy.Carbon,hydrogen and nitrogen in 4 standard samples(acelanilide,cystine,hexane diacid and benzylithiuronium chloride) were tested,the results were in agreement with the theoretical values.Parallel experiments were performed for standard sample acelanilide,the RSDs(n=13) of C,H and N were 0.09%,0.33% and 0.22%,respectively.

The influence of the atmosphere on the transformation of alkali and alkaline earth metallic (AAEM) species during rice straw thermal conversion was investigated by a fixed-bed reactor at 1073, 1173, and 1273 K. Two types of atmospheres were considered: 100% (v/v) N-2 to simulate pyrolysis and 1% (v/v) O-2 in N-2 balance to simulate combustion. The release of the AAEM species during pyrolysis and combustion of the rice straw was quantified by a mass balance based on the weight measurements and inductively coupled plasma (ICP) analysis of the rice straw and the solid residue. Solid residues and released and condensed particles obtained in experiments were processed by water leaching and 1% HNO3 washing and analyzed by ion chromatography (IC) to determine the possible chemical form of the AAEM species contained in them. The experimental results showed that the oxidizing atmosphere facilitated the release of K at 1073, 1173, and 1273 K by enhancing the decomposition of K2CO3 and char K in the char during the char combustion stage of the rice straw combustion experiment. However, the oxidizing atmosphere suppressed the release of Na, Ca, and Mg at 1073, 1173, and 1273 K. For Na, the release suppression was caused by its promoted interaction with silicate in the oxidizing atmosphere. For Ca and Mg, such suppression was supposed to be caused by the suppressing effect of the oxidizing atmosphere on the release of Ca and Mg from char Ca and char Mg in the char of the rice straw.

In research of alkaline soil improvement by flue gas desulphurization byproducts,a large amount of soil should be collected and analyzed.It is necessary to find a quick method to provide the main elements content.This paper describes a new method of soil analysis,the sample is pretreated with microwave-aided acid digestion and tested by ICP-AES,the instrument condition and acid applied are also discussed and experimentally optimized.It is a full digestion method and can provide the determination of several elements simultaneously.It uses less acid,less handling time and has a satisfied recovery.

Microwave digestion was applied in the pre-treatment of limestone sample, and the contents of nine mineral elements (Si, Ca, Al, Mg, Fe, K, Ti, Sr and Mn) in limestone were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). GBW 07120 and GBW 07214a were used as limestone standard reference materials. The effect of three acids (HNO3, HNO3/HF and HNO3/HF+H3BO3) on element recovery was studied. The results showed that limestone sample was completely decomposed with HNO3/HF+H3BO3. This method achieved good recoveries for all elements in the two limestone standard reference materials. The recoveries of nine elements were from 88.5% to 104.1% and all RSD of tests were below 3%.

Three acids (HNO3, HNO3/HF and HNO3 /HF+ H3BO3) were used to decompose gypsum with microwave digestion system. The contents of 10 mineral elements (Al, Ca, Mg, Fe, K, Na, S, Ti, Si and Sr) in gypsum were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) while 6 heavy metals (V, Cr, Mn, Zn, Se and Ce) were determined by inductively coupled plasma-mass spectrometry (ICP-MS). GBW03109a, GBW03110 and FGD-2 were used as gypsum standard reference materials. The results showed that two-step microwave digestion with HNO3/HF at 210 degrees C and then adding H3BO3 for the removal of HF and fluorides completely decomposed the gypsums, while this method achieved good recoveries for all elements in the three gypsum standard reference materials. The recovery was from 88% to 112% and the RSD of tests was below 3%. The method was applied to the elemental analysis for flue gas desulfurization gypsums from three coal-fired power plants.

Aiming at issues of managing professional laboratory for scientific research and auxiliary teaching in energy field,the humanized and meticulous management is advanced and practiced.Through practices exploiting and optimizing human resource allocation,opening the laboratory facilities,expanding function of the laboratory,supporting experiment teaching and personnel training,emphasizing humanized and meticulous management,etc.,the valuable and significant experience for sustainable development of an engineering professional laboratory is accumulated at the Thermal Engineering Laboratory of Tsinghua University.

结合国标中煤样的化学预处理方法和仪器分析方法,提出了一种新的测定煤中全硫含量的方法.该方法用时间少,准确度高,再现性好,适合批量样品的测试.

结合民用燃烧器具的技术现状和国家的能源及环保政策,叙述了球面辐射型气体燃烧器的研制过程、技术优势,以及市场推广情况.