Development of a PEMFC-based heat and power cogeneration system

Hydrogen-fed proton exchange membrane fuel cell (PEMFC) has to overcome high installation and operation cost before being adopted as a distributed power candidate. Cogeneration of power and heat is a good approach to increase hydrogen energy utilization rate. A PEMFC-based power and heat cogeneration system is proposed and established in the current study to investigate system’s technological and economical feasibility. This cogeneration of heat and power (CHP) system composes of a 2.5-kW fuel cell stack, hydrogen supply system, air supply system, water and heat management system, and heat recovery system. The control strategies to automate the system operation are realized by a programmable automation controller (PAC) system. Detailed measurement of the system is also constructed along with a web-based human–machine interface (HMI) platform to facilitate experiments and demonstration. Preliminary testing of the CHP system shows good performance of heat and power outputs. System’s electrical power conversion efficiency and thermal efficiency of the CHP system are measured at 38% and 35%, respectively. System combined efficiency therefore reached about 73%.     

Pd/Al2O3粒子电极电催化还原BrO3-的研究

针对常规方法难以去除水中Br_3~-的问题,采用浸渍煅烧法制备了负载型纳米Pd/Al_2O_3粒子电极,研究了该电极电催化还原Br O-3的效果.催化剂的结构表征表明该反应实现了Pd纳米晶的均匀负载,纳米Pd/Al_2O_3具有较高的电催化活性和较低的能耗,其最佳反应条件为3%Pd负载量,0.9 m A·cm-2电流密度和1 g·L催化剂投量,酸性条件可促进Br O-3的直接或间接还原.ESR检测证实了Pd的负载增强了反应体系活性物种[H]的生成,进而促进了Br O-3的间接电催化还原.     

翻堆频率对厨余垃圾堆肥过程中H_2S和NH_3排放的影响

为研究厨余垃圾堆肥过程中翻堆频率对H2S和NH3排放的影响,以大类粗分后的厨余垃圾为研究对象,玉米秸秆为调理剂,设置4组翻堆频率不同的处理(每周2次,2周1次,2周1次和不翻堆)进行对比研究。结果表明:翻堆频率的变化对H2S的排放影响不大,对NH3的排放有显著的影响,翻堆频率过高会增加NH3的累积排放量,翻堆频率过低虽然能降低NH3的累积排放量,但会影响到堆肥产物的腐熟。综合厨余垃圾堆肥的无害化指标、H2S和NH3的排放以及最终堆肥产品的毒性检验,在实验条件下,翻堆频率设为每周1次在堆料腐熟的基础上对H2S和NH3减排效果最好。     

板式生物滴滤塔高效净化硫化氢废气的研究

采用营养液分层喷淋、pH分别在线控制(pH 2.5、 4.5、 6.5)的板式生物滴滤塔(plate type-biotrickling filter, PTBTF)净化H₂S废气,考察PTBTF于挂膜启动及稳定运行阶段对H₂S的降解性能.结果表明,PTBTF系统在14 d内即完成挂膜,对浓度为188.6mg·m^-3的H₂S去除率达到100%;在进口浓度100～1000mg·m^-3、空床停留时间(EBRT)28～4 s的条件下,H₂S的去除率可达到99%以上;当H₂S去除率≥90%时, PTBTF系统的最大去除负荷随EBRT(3.3～6 s)的增加而增大,EBRT 6 s的最大去除负荷达到1019.0g·(m³·h)^-1;上、中、下3层填料对H₂S的去除负荷随进口H₂S负荷的波动呈显著变化;通过荧光染色观察填料上的细胞数,发现在挂膜阶段微生物数量增长明显,第125 d上层、中层和下层填料上的菌落数(以干填料计)分别达到了1.29×10⁷、 5.47×10⁸和1.07×10⁹个·g^-1;采用扫描电镜观察填料表面的生物膜,可见上填料层和下填料层的优势菌分别为杆菌和丝状菌;利用变性梯度凝胶电泳初步揭示了系统运行过程中生物群落的演替规律;通过对产物的分析,确定该PTBTF系统降解H₂S后主要产生SO^2-₄和单质硫.     

SW型脱硫剂脱硫性能的研究

以硫酸烧渣为主要原料制备ＳＷ型脱硫剂,并对其脱硫性能进行了研究,对半水煤气、葡萄酒厂污水处理产生的沼气和焦炉煤气、水煤气中的Ｈ２Ｓ进行了工业脱硫试验,经半年以上运行证明,可使其Ｈ２Ｓ含量从３０００－５０００ｍｇ／ｍ＾３降为２０ｍｇ／ｍ＾３以下（符合国家标准）,当脱硫剂工作硫容达３０％时可返回硫酸生产中,再生周期一般为３个月,其主要性能达到国内外同类产品水平。     

光助MIL-101(Fe)活化过氧化氢氧化洛克沙胂及同步吸附生成的砷酸根

采用铁基金属有机框架(MIL-101(Fe))在模拟太阳光下活化过氧化氢氧化降解ROX—吸附去除生成的砷酸根.结果表明,光助MIL-101(Fe)(250mg/L)活化氧化剂H2O2(1.0mmol/L)体系可在120min内实现95.27％的ROX去除率,反应过程中形成的无机砷酸盐(As(Ⅴ))会吸附在MIL-101...     

卤素类阻燃剂的阻燃基础理论

本文从阻燃化学反应,化学键能,热传递和反应动力学角度分析勖类阻燃剂的阻燃机理。     

SO2在Co—Mo／AC催化剂上的还原

本文研究了活性焦（ＡＣ）担载Ｃｏ－Ｍｏ催化剂对ＳＯ２还原的催化性能。考查了催化剂不同的预处理方法,Ｈ２／ＳＯ２摩尔比和还原温度对还原过程硫产率的影响,并就硫化后的Ｃｏ－Ｍｏ和活性焦在催化床不同的构成对硫产率的影响进行了研究。结果表明,经硫化后的催化剂在ＳＯ２＋２Ｈ２→Ｓ＋２Ｈ２Ｏ反应有较高的催化活性,在最佳反应温度３００℃,Ｈ／ＳＯ摩尔比为３,空速６０００Ｌ;ｋｇ＾－１．ｈ＾－１条件下,生成硫的产     

Biological removal of air loaded with a hydrogen sulfide and ammonia mixture

The nuisance impact of air pollutant emissions from wastewater pumping stations is a major issue of concern to China. Hydrogen sulfide and ammonia are commonly the primary odor and are important targets for removal. An alternative control technology, biofiltration, was studied. The aim of this study is to investigate the potential of unit systems packed with compost in terms of ammonia and hydrogen sulfide emissions treatment, and to establish optimal operating conditions for a full-scale conceptual design. The laboratory scale biofilter packed with compost was continuously supplied with hydrogen sulfide and ammonia gas mixtures. A volumetric load of less than 150 gH2S/(m^3.d) and 230 gNH3/(m^3.d) was applied for about fifteen weeks. Hydrogen sulfide and ammonia elimination occurred in the biofilter simultaneously. The removal efficiency, removal capacity and removal kinetics in the biofilter were studied. The hydrogen sulfide removal efficiency reached was very high above 99%, and ammonia removal efficiency was about 80%. Hydrogen sulfide was oxidized into sulphate. The ammonia oxidation products were nitrite and nitrate. Ammonia in the biofilter was mainly removed by adsorption onto the carrier material and by absorption into the water fraction of the carrier material. High percentages of hydrogen sulfide or ammonia were oxidized in the first section of the column. Through kinetics analysis, the presence of ammonia did not hinder the hydrogen sulfide removal. According to the relationship between pressure drop and gas velocity for the biofilter and Reynolds number, non-Darcy flow can be assumed to represent the flow in the medium.     

川东北三高气田钻完井风险因素分析

分析了三高（高压、高产、高含硫）气田存在的主要有害因素,以及三高气田钻完井作业过程中存在的主要危险及其发生的潜在原因,并提出了相应的控制措施。针对我国三高气田区域地质环境的特殊性,分析了我国三高气田钻完井过程中可能诱发事故的特殊因素,并对应对措施进行了探讨。