NID半干法脱硫系统脱除烟气中SO2的试验研究

研究NID半干法脱硫系统脱除烟气中SO2,用氮气(N2)等温吸附(77K)测量了生石灰消化后消化产物消石灰与生石灰脱硫剂的比表面积、孔径、孔比表面积、孔容积和孔分布,分析了其物理性质上的差别所造成的脱硫性能的差异,还分析了消化度、消化水初始温度、烟气中水蒸汽份额和水钙摩尔比等参数对脱硫性能的影响.研究结果表明,生石灰经...     

新式整体脱硫工艺的硫汞联合脱除特性及影响因素

选取1台100MW燃煤锅炉的一体化新式整体脱硫(NID)系统为研究对象,对其入炉煤样、底渣、预除尘器灰、新鲜脱硫剂、循环脱硫混合灰和烟气等进行取样分析,获得了汞、SQ2排放浓度和不同运行工况下NID系统的硫、汞联合脱除特性及其影响因素.结果表明:消化度的提高使得消化产物的比表面积增大,孔隙结构更发达,从而更有利于消化产物对SOx和Hg的吸附脱除;随着水钙比、消化水温度及生石灰品质的提高,系统的脱硫效率以及脱硫灰中汞的富集系数均有增大的趋势;NID系统的脱硫效率为84.86%～97.28%,脱汞效率可达86.6%～92.2%.     

消化过程参数对脱硫剂颗粒特性影响的试验研究

用正交试验方法研究了消化水初始温度、消化时间、消化水／生石灰比例以及搅拌强度4个消化过程参数对脱硫剂颗粒特性(比表面积和孔隙率等)的影响，得到了相应试验条件下参数的最佳值，即消化水初始温度为85℃、消化时间为1h、消化杉生石灰比例为4：1以及搅拌强度为0．98m／s，得到了一种相对最佳的脱硫剂制备条件．     

钙基脱硫剂掺加粉煤灰在450_850_下的脱硫研究

在沉降炉上进行了掺加粉煤灰提高生石灰烟气脱硫率的实验。实验表明：生石灰掺加粉煤灰可以提高烟气脱硫率和脱硫剂的钙利用率。这种作用与反应温度有关,反应温度为５５０℃～７００℃时,效果最好。同时也研究了粉煤灰与生石灰掺混方式对气体脱硫率和脱硫剂的钙利用率的影响。     

钙基脱硫剂掺加粉煤类在450℃—850℃下的脱硫研究

在沉降炉上进行了掺加粉煤灰提高生石灰烟气脱硫率的实验。实验表明：生石灰掺加粉煤灰可以提高烟气脱硫率和脱硫剂的钙利用率。这种作用与反应温度有关,反应温度为５５０℃￣７００℃时,效果最好。同时也研究了粉煤灰与生石灰掺混方式对气体脱硫率和脱硫剂的钙利用率的影响。     

生石灰掺加粉煤灰脱硫性能研究

在沉降炉和热分析仪上进行的脱硫实验表明 :生石灰掺加粉煤灰可以提高烟气脱硫率和脱硫剂的钙利用率。这种作用与反应温度有关 ,反应温度为 550～ 70 0℃时 ,效果最好。同时也研究了粉煤灰与生石灰掺混方式对烟气脱硫率和脱硫剂的钙利用率的影响。     

生石灰掺加粉灶灰脱硫性能研究

在沉降炉和热分析仪上进行的脱硫实验表明，生石灰掺加粉煤灰可以提高烟气脱硫率和脱硫剂的钙利用率，这种作用与反应温度有关，反应温度为５５０～７００℃时，效果最好，同时也研究了粉煤灰与生石灰掺混方式对烟气脱硫率和脱硫剂的钙利用率的影响。     

中温烟气生石灰脱硫模型

在晶粒模型的基础上建立了用于描述中温烟气(400℃-800℃）生石灰脱硫过程的数学模型，并进行了求解及模型的验证。通过该模型的计算可以更好地了解中温区域内生石灰脱硫反应的进程和反应机理。采用该模型初步探讨了几种物理参数的变化对钙转化率的影响。该模型的建立为开发中温区域内脱硫技术提供了理论基础。     

水合反应器内浆滴脱硫的研究

在烟气增湿脱硫实验台上 ,分别进行了蒸汽水合和喷水水合生石灰的脱硫实验研究。研究了钙硫比Ca/S、饱和温距 (烟气温度与水蒸汽露点的温差 )ΔT 和烟气流速等因素对脱硫效率的影响 ,结果发现浆滴的脱硫效率对水合反应器的整体脱硫效率有着非常重要的作用     

蒸汽水合生石灰的脱硫实验研究

在烟气增湿脱硫实验台上,进行了蒸汽水合生石灰的脱硫实验研究,结果表明,钙硫比,饱和温距（烟气温度与水蒸气露点的温差）ΔT和烟气流速（停留时间）是影响脱硫效率的主要因素,合理地配置这些因素能够有效地提高脱硫效率。     

Particle size and hydration medium effects on hydration properties and sugar release of wheat straw fibers

Wheat straw is gaining importance as a feedstock for the production of biofuels and high value-added bioproducts. Several pretreatments recover the fermentable fraction involving the use of water or aqueous solutions. Therefore, hydration properties of wheat straw fibers play an important role in improving pretreatment performance. In this study, the water retention capacity (WRC) and swelling of wheat straw fibers were studied using water, propylene glycol (PPG) and an effluent from a H₂-producing reactor as the hydration media with three particle sizes (3.35, 2.00 and 0.212 mm). The effects of swelling were analyzed by optical and confocal laser scanning microscopy (CLSM). The highest WRC was reached with the effluent medium (9.84 ± 0.87 g g⁻¹ in 4 h), followed by PPG (8.52 ± 0.18 g g⁻¹ in 1 h) and water (8.74 ± 0.76 g g⁻¹ in 10 h). The effluent hydration treatment had a synergic effect between the enzymes present and the water. The particle size had a significant effect on the WRC (P < 0.01), the highest values were reached with 3.35 mm fibers. The CLSM images showed that finer fibers were subjected to a shaving effect due to the grinding affecting its capacity to absorb the hydration medium. The microscopic analysis showed the increase in the width of the epidermal cells after the hydration and a more undulating cell wall likely due to the hydration of the amorphous regions in the cellulose microfibrils. The sugar release was determined, achieving the highest glucose content with the effluent hydration treatment.     

Heat pump characteristics of sodium carbonate dehydration/hydration system

A chemical heat pump using dehydration of sodium carbonate decahydrate for generating cold heat is proposed as a method contributing to the load leveling of electricity. Experiments on the dehydration of decahydrate in a packed bed reactor showed the generation of cold heat with sufficiently low temperature. The heat pump characteristics measured were simulated by use of dehydration kinetics of a single particle. Improvement of the heat-transfer rate in the bed is a key factor for creating an efficient system.     

钙基固硫剂水合活性分析

基于ＣａＯ水合放热,设计专用试验装置对生石灰水合活性进行测试比较,其结果对炉内喷钙增湿水合烟气脱硫和以生石灰为吸着剂的简易湿法脱硫技术吸着剂选择有指导意义。     

Dehydration and hydration behavior of metal-salt-modified materials for chemical heat pumps

Lithium chloride (LiCl) modified magnesium hydroxide (Mg(OH)₂) is a potential new material for chemical heat pumps. However, there is insufficient information concerning its dehydration and hydration behavior. In this study, the dehydration and hydration reactions, corresponding to the heat storage and the heat output operations, respectively, of authentic Mg(OH)₂ and LiCl-modified Mg(OH)₂ were investigated by thermogravimetric methods and near infrared spectroscopy. The dehydration of authentic Mg(OH)₂ proceeded as a one-step reaction. In contrast, the dehydration of LiCl-modified Mg(OH)₂ occurred in two steps. The dehydration reaction rates were increased by LiCl modification of the Mg(OH)₂ surface, while the activation energy for the first-order dehydration reaction was lowered. The mechanism for the hydration reaction of magnesium oxide (MgO) was different to that for the hydration of LiCl-modified MgO. This difference was explained by the effect of the LiCl on the MgO particle surface.     

Proton-exchange membrane fuel cell ionomer hydration model using finite volume method

In this paper a dynamic membrane electrode assembly water transport model, based on the Finite Volume Method, is presented. The purpose of this paper is to provide an accessible and reproductible model capable of real time simulation. To this aim, a detailed explanation is provided regarding the equations and methods used to compute the physical-based fuel cell model. Additionally, the model is purposely developed using basic code (on Matlab?), to not be limited to a single programming language. Two phase water transport through multi-gaseous porous media (electrodes), interfacial transport, as well as diffusion, convection, and electro-osmosis within the polymer are considered. The main novelty relies in the restructuring of all equations into a single implicit system, which can iteratively be resolved through LU decomposition. This computationally efficient method allows the model to be capable of real-time simulation, by displaying the membrane water content profile evolution on a 3D figure. For nominal PEMFC operating conditions, a dry membrane reaches 35% of its final water concentration value after 2 s, and fully converges after 20 s. The final water content profile displays an 18% gradient (9 and 11 molecules per sulfonic acid sites on the anode and cathode sides, respectively). To calibrate and validate this model, mass transfer (flowmeter) and electrical (ohmmeter) methods have been applied.     

循环流化床锅炉脱硫飞灰的水活化实验研究

以310 t/h循环流化床锅炉脱硫飞灰为原料,在不同的水活化条件下进行活化机理的实验研究,探讨了水活化温度、活化时间、活化水量对灰中游离氧化钙水合反应转化率的影响规律,并研究了水活化对孔隙结构的影响。结果表明:水活化过程中,水合反应与消耗氢氧化钙的胶凝反应同时进行;水活化过程中氢氧化钙含量呈现快速上升、慢速上升、缓慢下降的规律;随活化温度提高,水合反应与胶凝反应速率均提高,中期持续时间缩短,活化时间一定时,活化温度存在最佳值;活化水量的增加,可以加快水合反应与胶凝反应速率,活化时间处于后期时,活化水量存在最佳值。     

Kinetic study of the hydration of magnesium oxide for a chemical heat pump

A kinetic study of the hydration of magnesium oxide was performed to test the possibility of developing a magnesium oxide/water chemical heat pump. The hydration rate of magnesium oxide was measured by a gravimetric analysis with a sample of average particle size 10 μm for the reaction temperature 373–423 K and the reaction vapor pressure 12.3–47.4 kPa. It was a reasonable hypothesis that the reactant magnesium oxide had four reaction regimes. An empirical rate equation based on this hypothesis was proposed with parameters determined from experimentally measured values. The performance of the heat pump was estimated numerically using the rate equation. The heat output rate was large enough in comparison with other common heat pumps. It was shown that the reaction system would be applicable to a chemical heat pump system.     

Supported ionic liquid-copper catalyst for synergistically catalytic and highly efficient hydration of acetylene

At present, heterogeneous mercury-free catalysts are suffering from rapid deactivation caused by reduction or aggregation/growth of copper particle during preparation and reaction. Here, a high-performance and long-lived catalysts with activated carbon supported copper-ionic liquid system (Cu-xIL/AC, x is the molar ratio of IL and Cu) was prepared by wet impregnation method for the hydration of acetylene to acetaldehyde. Over the optimal Cu-1.5IL/AC catalyst, the acetylene conversion of 96.8% and acetaldehyde selectivity of 87.1% could still be obtained at 20 h (T = 240 °C, GHSV_C2H2 = 90 h^?1 and V_H2O/V_C2H2 = 1.15). The experimental results indicated that Cu species were embedded in ionic liquid (IL) and the interaction and synergistic effect between metal ions and IL guaranteed high and stable dispersion of active species on the host and suppress the reduction of active Cu specie, which are mainly responsible for the excellent catalytic property. The findings highlight the contribution of ILs in heterogeneous catalytic reaction and supply a promising industrial application of Cu-1.5IL/AC catalyst in acetylene hydration.     

A chemical heat pump using hydration of mgo particles in a three-phase reactor

A chemical heat pump using hydration of magnesium oxide in a three-phase reactor is proposed. Magnesium oxide particles suspended in the triethylene glycol are hydrated exothermally by introducing water vapour. The hydration rate was measured under the temperatures ranging from 383 K to 523 K. It was found that the reaction rate was proportional to the amount of adsorbed water molecules, and correlated in an equation.