Inhibition of hydrogen production reactions in the wet dust removal system using CeCl3 solutions

For treatment of aluminum dust, a wet dust removal system has been used worldwide. During treatment, aluminum dust is inhaled into a water tank of the dust collector. As hydrogen production reactions are likely to take place in the water tank, there exists a great risk of fire or explosion accidents associated with the wet dust removal system. Based on field research and laboratory experiments, Hydrogen Inhibition Method (HIM) by using CeCl₃ solutions was proved capable of inhibiting reactions between aluminum dust and water. When the concentration of CeCl₃ solutions reached 6.02 g/L, there was basically no hydrogen gas produced. SEM, EDS and XPS characterizations were used to assess the aluminum particles before and after being reacted with water or CeCl₃ solutions, respectively. Shrinking core model was utilized to identify the corresponding chemical reaction kinetics. Additionally, a physicochemical mechanism was established to explain these phenomena.     

Selection of metal hydrides-based thermal energy storage: Energy storage efficiency and density targets

Thermo-chemical energy storage based on metal hydrides has gained tremendous interest in solar heat storage applications such as concentrated solar power systems (CSP) and parabolic troughs. In such systems, two metal hydride beds are connected and operating in an alternative way as energy storage or hydrogen storage. However, the selection of metal hydrides is essential for a smooth operation of these CSP systems in terms of energy storage efficiency and density. In this study, thermal energy storage systems using metal hydrides are modeled and analyzed in detail using first law of thermodynamics. For these purpose, four conventional metal hydrides are selected namely LaNi₅, Mg, Mg₂Ni and Mg₂FeH₆. The comparison of performance is made in terms of volumetric energy storage and energy storage efficiency. The effects of operating conditions (temperature, hydrogen pressure and heat transfer fluid mass flow rates) and reactor design on the aforementioned performance metrics are studied and discussed in detail. The preliminary results showed that Mg-based hydrides store energy ranging from 1.3 to 2.4 GJ m^?3 while the energy storage can be as low as 30% due to their slow intrinsic kinetics. On the other hand, coupling Mg-based hydrides with LaNi₅ allow us to recover heat at a useful temperature above 330 K with low energy density ca.500 MJ m^?3 provided suitable operating conditions are selected. The results of this study will be helpful to screen out all potentially viable hydrides materials for heat storage applications.     

Analysis of the Relation between Coupled Sink and Purification Based on Hydrogen Network Integration

In a hydrogen network, sinks and sources are generally connected to reactors or purifiers, which affect their compositions and flow rates. The relationship between these streams is studied based on the integration of the hydrogen network to identify the feasible and optimal operating conditions of reactors and purifiers. Equations are deduced to describe the quantitative relationship between hydrogen consumption, hydrogen concentration, flow rates of coupled sink and source, purification feed, and purified product. The purification and hydrogen‐consuming reactor parameters can be optimized in the design and operation stage of a hydrogen network. The case study proves that the proposed method is simple, easy to understand, and can be applied to identify the variation trend line and feasible region accurately without tedious calculation.     

食用百合高效生态栽培技术

文章从食用百合的经济意义入手,分析了现阶段百合生产存在的问题,总结了食用百合高效生态栽培技术,期望为食用百合的栽培提供理论基础与实践经验。     

Effect of interfacial friction force on material removal in full aperture continuous polishing process

Full aperture continuous polishing using pitch lap is a key process of finishing large flat optical workpiece. The friction force of the workpiece and pitch lap interface significantly affects material removal. In this work, the friction force was determined by a measurement system that uses force transducers to support the workpiece. Experimental and theoretical analyses have been carried out to investigate the evolution of friction force with polishing time and its effect on material removal. Our results show that the friction coefficient of the workpiece/lap interface decreases during polishing, which is due to surface smoothing of the viscoelastic pitch lap by loading conditioner. In addition, the spatial average and uniformity of material removal rate (removal coefficient) increases with the increase of friction coefficient, which is due to rough lap surface, provides more sharp asperities to charge the polishing particles.     

氮含量对HPD-1双相不锈钢组织及力学性能的影响

通过显微组织观察与力学性能测试研究了氮含量(0.08%~0.22％,质量分数)对HPD-1双相不锈钢硬度、拉伸性能、低温冲击性能及疲劳性能的影响。结果表明,氮含量变化可显著影响试验钢γ/α相比例,当氮含量由0.08％升高到0.22％,γ相含量由38.1％提高至56.5％。α相的硬度由273 HV10提高到343 HV10,γ相的硬度由238 HV10提高到299 HV10,试验钢强度明显提升。氮元素对两相比例和奥氏体相韧性的双重影响导致试验钢低温冲击性能呈先上升后下降的趋势;更高的氮含量抑制疲劳裂纹萌生与拓展,是影响HPD-1双相不锈钢室温疲劳性能的主要因素。撕裂棱是疲劳断口的显著特征。     

不同有机物对硝酸盐氮测试的影响

研究了红糖、葡萄糖、乙酸钠、甲醇、乙醇、乙酸、丙酸、丁酸、正戊酸、混合有机溶剂等10种不同有机物对麝香草酚光谱法和离子色谱法测试硝酸盐氮的影响。结果表明,溶液中含有红糖或葡萄糖时,均会对麝香草酚法测试硝酸盐氮造成影响,使得测试结果偏大;在无硝酸根离子存在时,红糖和葡萄糖的质量浓度与硝酸盐氮的测试浓度非线性相关;而乙酸钠、甲醇、乙醇、乙酸、丙酸、丁酸、正戊酸和混合有机溶剂则对麝香草酚法测试硝酸盐氮没有影响。实验发现,红糖和葡萄糖在浓硫酸的作用下与麝香草酚发生Molisch反应,形成有色复合物和红棕色不溶性沉淀。实验采用离子色谱法测试硝酸盐氮时,红糖和葡萄糖等糖类有机物对测试结果均无影响。     

含铜废水预处理设施脱氮升级改造工程

为了减轻太湖保护区范围内企业处理废水的负担,苏州白荡污水处理厂利用其含铜废水预处理设施的富余处理能力处理某公司产生的含氮废水。针对含氮废水高NO3^--N和低碳氮比等特点,在充分利用原处理设施的基础上,采用"A/O+固定床生物膜工艺+高效脱氮填料+乙酸钠碳源+内回流"组合工艺对含铜废水预处理设施进行脱氮升级改造。改造后实际运行结果表明,设施运行稳定,出水水质达到出水水质达到设计出水要求,TN和NH4^+-N的去除率分别达到85.4%和82.3%,Cu的去除率提高了17.6%。     

烟气多污染物协同处理催化陶瓷过滤管的研究进展

燃烧烟气中各污染物的排放是大气污染的最主要来源，针对烟气多污染物的治理意义重大。本文综述了国内外目前关于烟气多污染物脱除的两种技术，即传统串联脱除技术和一体化协同脱除技术。相比于传统串联脱除工艺，多污染物一体化协同脱除技术具有占地面积小、运行费用低、应用领域广的优点，是烟气多污染物治理的发展趋势。而陶瓷过滤管催化剂技术以其独有的非对称、孔径梯度变化的结构特性，成为一种极具应用前景的一体化协同脱除新技术。国内外关于陶瓷过滤管催化剂的研究主要从过滤管元件的选材和负载脱硝催化剂的工艺方法这两方面，围绕过滤管催化剂的催化活性、过滤压降及性能稳定性的进行研究，取得了一定的成果。结合当前陶瓷过滤管催化剂的研究现状，对今后烟气多污染物陶瓷过滤管催化剂技术的发展提出了建议。     

Primary energy demand and energy costs of fixed-bed drying using the example of chamomile flowers

Abstract

Energy use efficiency in the drying of medicinal and aromatic plants is largely determined by weather conditions and process parameters. While the former are beyond control, the latter can be optimized. In order to achieve such optimization, different energy supply variants, based on typical operating conditions of batch-type grate drying in Thuringia, Germany, were analyzed. It was found that partial air recirculation and integration of heat pumps allow substantial savings in primary energy. However, under the constraint of German energy prices, significant savings in energy costs can only be achieved if combined heat and power generation systems are applied at the same time.