基于钙基和钠基喷雾半干法烟气脱硫技术的经济性研究

为研究喷雾半干法烟气脱硫特性,搭建了试验平台,分别选用Ca(OH)_2溶液、Na_2CO_3溶液和NaHCO_3溶液进行了脱硫特性试验研究,分析了进口烟气温度、进口SO_2质量浓度、化学计量比和绝热饱和温差对脱硫效率的影响,并以某垃圾电厂为例进行了经济性分析。结果表明:保持出口烟气温度不变,随着进口烟气温度的提高,3种吸收剂的脱硫效率均有一定的提高;随着进口SO_2质量浓度的增大,脱硫效率降低;在相同条件下,使用NaHCO_3溶液作为吸收剂时脱硫效率最高,Na_2CO_3溶液次之;使用Ca(OH)_2溶液作为吸收剂,综合脱硫效率可达84%,工程上将其作为吸收剂更合适。     

TS-35型氨法脱硫影响因素及其经济性分析

在对TS-35型氨法脱硫工艺进行了系统的工业性试验研究的基础上，分析了烟气量、炉膛出口SO2浓度、煤种、氨水量、氨水浓度等因素对脱硫效率的影响，同时还分析了脱硫设备对锅炉运行参数的影响。结果表明：该脱硫工艺结构简单，系统阻力小，能耗低，对原有锅炉参数影响很小；脱硫用氨水量小，脱硫效率可达80％；几乎无废水排放，二次污染程度小，特别适用于中小型锅炉的脱硫，但有可能会加剧锅炉尾部设备的腐蚀。通过经济性分析得出：对于大中型锅炉，必须考虑副产品硫酸铵的销路和价格问题；目前实施的排污收费制度存在一定的弊病．有必要完善以总量控制为目标的排放许可权交易制度。     

富氧型高活性吸收剂同时脱硫脱硝脱汞的实验研究

以粉煤灰和消石灰为主要成分,分别添加了少量添加剂制备了2种富氧型高活性吸收剂M和N.在固定床实验台上,研究了富氧型高活性吸收剂同时脱硫脱硝脱汞的性能.结果表明:当温度升高时,2种富氧型高活性吸收剂脱汞效率均提高;SO2抑制了2种富氧型高活性吸收剂对汞的脱除效率,但延长了穿透时间;当NO浓度增加时,吸收剂M对单质汞的脱除率降低,而对吸收剂N的汞脱除效率影响很小;模拟烟气中汞浓度的变化对脱硫和脱硝效率几乎没有影响.     

喷淋式湿法脱硫装置的试验研究

提出了一种采用高效离心式喷嘴的湿法脱硫装置，对该装置的吸收段阻力特性和石灰石作为吸收剂的脱硫特性进行了试验研究，对试验结果进行了分析。同时对几种添加剂对该装置脱硫特性的影响也进行了试验研究和分析。并得出了一个较好的工况点。图8参6     

水分对钙基吸收剂脱硫性能影响的研究

本文利用实验系统和理论模型，分析和研究了水分含量对吸收剂脱硫反应速率的影响，及湿度、粒度和转化率等因素对于有水分存在的含湿吸收剂颗粒脱硫反应速率的影响。实验和理论模型的计算结果为半干法脱硫装置的设计提供了帮助。     

循环流化床烟气脱硫效率的研究

基于对气固传质、气固反应模型、浆滴蒸发等理论,从物料循环对热力学参数、传质过程和化学参数的影响几个方面对物料循环的作用过程进行研究。通过对循环流化床烟气脱硫物料循环过程的研究与分析,提出物料循环对脱硫效率的贡献由新鲜吸收剂脱硫效率的提高和循环物料中未完全反应的吸收剂参与脱硫反应产生的脱硫效率两个部分组成,还提出了物料循环对热力学、传质以及化学等参数影响的模拟计算方法。实验验证了方法的可行性与有效性。图3参12     

烟气主要成分对基于高活性吸收剂的烟气脱硫脱硝过程影响

采用自行制备的"富氧型"高活性吸收荆.在最佳工艺条件下,通过固定床实验研究了烟气中CO2、O2对高活性吸收荆脱硫脱硝效率的影响和SO2、NOx共存时对彼此脱除效率的影响.研究结果表明:O2的存在对脱硫脱硝有一定的促进作用;CO2的存在时脱硫有抑制作用,但对脱硝有促进作用;SO2在浓度小于2 500 mg/m3时对NO的脱除起促进作用,大于2 500 mg/m3时则阻碍NO的脱除;NO的存在对脱硫起促进作用,使脱硫产物中硫酸钙比例增加.该研究结果对基于高活性吸收剂脱硫脱硝工艺深入研究和应用提供了理论依据.     

基于吸收剂分区的同时脱硫脱硝反应特性研究

在鼓泡反应装置中进行了MgO为吸收区吸收剂、NaClO_2为氧化区吸收剂的脱硫脱硝实验,研究了NaClO_2浓度、NaClO_2溶液的pH、温度和烟气体积流量等参数对脱硫脱硝效率的影响,并在液相产物分析的基础上推测了反应历程。结果表明:在最佳条件下,SO_2和NO的脱除效率均达到100%,NO_x的脱除效率可达65%。     

基于石灰石的CO2吸收循环特性多参数线性回归分析

基于热重分析法（TGA）测试2种钙基吸收剂的CO2循环特性，引入多参数线性回归统计分析方法，确定了反应参数（循环次数、碳酸化反应时间、煅烧温度及煅烧气氛）与循环反应速率和转化率之间的关系，引入评价函数F推导了各参数对吸收剂循环吸收特性的影响程度．结果表明：通过对不同反应机理阶段分别建立回归方程，准确描述了不同参数条件下钙基吸收剂的CO2吸收循环过程；在化学反应控制阶段，反应时间对吸收效率的影响最为显著，而进入扩散反应控制阶段后循环反应次数成为决定因素．     

影响固定床烟气脱硫因素的实验研究

以CaO粉末做吸收剂,通过固定床干法脱硫实验,分别研究了温度、进口浓度、Ca/S摩尔比、吸收剂粒径和停留时间等各因素对脱硫效率的影响,结果表明：当T= 825℃、Ca/S=2.82、粒径为75μm、进口浓度Cin=1783 mg/m3、tR=0.4 s时,脱硫效率可达89.6%,出口SO2浓度为185 mg/m3,低于国家标准规定的260 mg/m3.     

基于钙基吸收剂煅烧/碳酸化循环吸收CO2研究进展

对钙基吸收剂煅烧/碳酸化循环吸收CO2的最新研究进展进行了阐述,包括反应条件对钙基吸收剂吸收CO2的影响,如压力、颗粒粒度、反应时间及SO2存在等因素,和提高钙基吸收剂吸收CO2的各种方法,如采用添加剂、进行水合反应等.提出了一种提高钙基吸收剂吸收CO2能力的可能方法:对钙基吸收剂进行闪蒸改性,以优化吸收剂的孔隙结构.     

钙基脱硫剂煅烧过程中产物CaO孔径分布的模拟

以孔径分布密度函数和孔长度分布函数为基础,结合氧化钙比表面积和孔隙率等参数的测量,建立了钙基脱硫剂煅烧过程中产物CaO孔隙分布模型及孔隙分布变化模型,并对其分布特性及其演化过程进行了研究.结果表明:该模型可以较完整地描述钙基脱硫剂的孔径及其分布.     

Experimental study on pore distribution characters and convert rate of CaO

During the reaction between calcium sorbents and SO2, calcium sorbents are first calcined and converted into CaO. CaO can be obtained by calcining Ca(OH)2or CaCO3. The porosity of the sorbent is increased because of calcination and is decreased because of sulfurization. In the calcination process H2O or CO2 is escaped from the particles and pores are formed in particles. The reaction or convert rate of CaO is influenced strongly by the pore structure characters. From Ca(OH)2 to CaO the escape velocity of H2O or its mass transfer is one of the key factors influencing the pore forming. During calcination process different healing velocity, different heating time and temperature were suggested. The temperature rising rate and calcining temperature play important role to the pore structure. The convert rates of CaO obtained through different calcining conditions were investigated experimentally. Some interesting results were showed that the calcium utilization of CaO particles is determined not only by the special surface area and total pore volume, but also by pore-size distribution. The main factor influencing the sulfation is the pore diameter distribution at lower sulfation temperature. For higher reaction temperature specific volume is the important reason. But pore-size distribution is strongly influenced by heat flux and temperature in the calcining process.     

Modeling of carbonation reaction for CaO-based limestone with CO2 in multitudinous calcination-carbonation cycles

In the cyclic carbonation-calcination reaction processes, CaO-based solid sorbents have been substantiated to be the effective sorbents for CO₂ capture at high temperature. The carbonation reaction has been depicted the carbonation reaction by several kinetic models. Some kinetic models are capable to calculate the intrinsic carbonation rate in the cyclic carbonation-calcination reaction, but the mathematic equation of those models is basically complicated. In this work, a modified model was proposed to delineate the carbonation reaction in multitudinous carbonation-calcination cycles, and was qualified to characterize the whole progression of carbonation reaction in highly cycled particles. The sharp corner is inexistent simultaneously. Additionally, the mathematic equation of this model is apparent simplified. The disconnected pore size distribution is expressed by the log-normal function, and the time evolution of pore structure was also discussed.     

多孔脱硫剂孔结构的特性

多孔脱硫剂孔结构的特性对脱硫效果有着重要的影响.借助压汞分析微观手段对脱硫剂孔结构的特性进行了大量的实验,表明脱硫剂的孔径分布满足高斯函数分布形式,建立了SO2和多孔CaO反应的孔分布数学模型.通过计算表明,脱硫剂颗粒中不同的孔径大小具有不同的CaO转化率,孔径范围在100～600nm之间的孔具有较高的CaO转化率.研究结果可为脱硫反应过程的实际应用提供理论指导.     

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...     

钙基脱硫剂孔隙分形特性的实验研究

分形维数是描述分形结构特性的一个重要参数,其反映了结构的规划程度。通过实验的方法,研究钙基脱硫剂在不同温度,气氛及烧结时间等煅烧条件下,对孔结构分形维数的影响,以及分形特性对脱硫剂的硫化能力的影响。结果表明煅烧温度对CaO孔结构的分形维数影响较小;CaO孔隙的分形维数随着煅烧气氛中的CO2浓度的增加而减小,随着烧结时间的延长而减小,脱硫剂硫化过程中形成的不可进行孔隙量随着分形维数的增大而增大。     

钙基吸收剂脱硫反应特性的研究

本文对两种钙基吸收剂－ＣａＯ和Ｃａ（ＯＨ）２的脱硫反应机理进行了试验研究。对两者的反应活性进行了比较，并就一些因素对脱硫活性和影响作了研究，所得结论对脱硫反应的优化，脱硫剂的选择及干法ＦＧＤ装置的开发和研制有参考意义。     

Post-combustion carbon dioxide capture: Evolution towards utilization of nanomaterials

Carbon dioxide (CO₂) is not the gas that gives the most severe global warming impact among the greenhouse gases (GHGs). However, its highest annual emission into the atmosphere makes it the most imperative anthropogenic GHG. This elevated emission is primarily coming from fossil fuel power plants. Hence, post-combustion CO₂ removal from power plants becomes crucial in global warming mitigation as it can be retrofitted directly into an existing plant. CO₂ removal technology nowadays is utilizing solvent-based sorbents, such as amine solutions and ionic liquids. Many extensive research works have been carrying out to improve the constraints of existing technology. In this paper, a general review on existing CO₂ removal technologies, existing research works on CO₂ removal sorbents was done. In conjunction with that, we will look into the potential and development of nanomaterials as CO₂ removal sorbents in the future. Nanomaterials have shown their potentials in CO₂ capture with its high surface area and adjustable properties and characteristics. Many limitations in existing technology were found improvable by nanomaterials.     

Study on the performance of a proton exchange membrane fuel cell related to the structure design of a gas diffusion layer substrate

Although characteristics of the gas diffusion layer (GDL) affect the performance of a proton exchange membrane fuel cell (PEMFC), mass transfer mechanisms inside the GDL and the performance of the PEMFC have not been directly correlated. To determine the design parameters of the GDL, the effects of substrate design of the GDL on performance of a PEMFC are investigated. By adding an active carbon fiber (ACF), which has a high surface area, the substrate is designed to have a different pore size structure. The results show that steady-state and transient responses are determined by capillary pressure gradient characteristics of the GDL made by pore size distribution of the substrate. The small macro-pore functions as water-retaining passage and the large macro-pore functions as water-removal passage. It is concluded that both small and large macro-pore must be present on the substrate to facilitate its function in a wide range of operating conditions.