软测量在检测碳酸化塔中CO_2浓度的应用

利用自适应滤波辨识的方法,构造了联碱碳酸化塔中CO_2浓度的估计器,解决了在碳酸化过程中不能在线检测碳酸化塔中CO_2浓度的难题,对碳酸化过程的有效控制和节约检测成本有着积极的意义.     

石灰石和白云石高温循环脱除CO2过程分析

在N2气氛和高浓度CO2气氛两种典型锻烧气氛下,对石灰石和白云石在循环煅烧/碳酸化捕集CO2过程中的主要系统参数包括长周期循环碳酸化转化率、平均碳酸化转化率、CO2捕集效率和煅烧炉能量需求进行了实验研究和计算分析.结果表明,吸收剂补充流率和吸收剂循环流率对平均碳酸化转化率、CO2捕集效率和煅烧炉所需能量具有直接影响.在...     

高浓度铝酸钠溶液碳酸化分解产品中Na2O含量的控制

依据铝酸钠溶液碳酸化分解遵循晶种分解的机理,在自制碳分槽中采用间断碳分的方法,在不添加Al(OH)3晶种的条件下,研究了不同分解工艺条件[分解温度70~95℃,CO2气体浓度25%~60%(j),CO2通气速度0.055~0.167 m3/(h×L)]对高浓度铝酸钠溶液碳酸化分解产品Al(OH)3中Na2O含量的影响规律. 结果表明,通过提高碳酸化分解温度、降低CO2通气量来调控铝酸钠溶液的过饱和度,控制碳酸化分解速率,能显著降低分解产品中Na2O的含量. 当碳酸化分解原液Al2O3浓度在170~180 g/L、溶液苛性分子比ak=1.40~1.50时,控制碳酸化分解温度为95℃左右,采用低浓度、慢速通气制度,分解6 h左右分解率达到90%~93%,所得碳酸化分解产品中Na2O含量可控制在0.25%(w)以下.     

氧化铬清洁生产新工艺中钾碱的再生

研究了蔗糖水热还原Cr(Ⅵ）制备氧化铬的绿色工艺过程，对过程中滤液处理与钾碱再生进行了研究，探讨了碳酸化工艺条件CO2分压PCO2、碳酸化时间tc、碳酸化温度Tc及搅拌速率Sc对CO2吸收过程的影响规律，确定了滤波碳酸化处理的最适宜工艺条件为PCO2＝0．2MPa,Tc=50℃，Sc=1200r/min；tc视处理液量而定。     

不同条件对钢渣碳酸化反应的影响及动力学分析

钢渣碳酸化捕集固定CO2既可实现CO2的减排,又能改善钢渣的安定性,具有很好的发展前景.以转炉钢渣为原料,系统研究了不同气氛、温度、升温速率下钢渣的碳酸化反应.通过热重实验,分析了不同升温速率下钢渣碳酸化反应的速率和温度区间,计算了CO2和水蒸气气氛下钢渣碳酸化反应的活化能;利用XRD分析了不同条件下钢渣碳酸化试样中碳酸钙和游离氧化钙含量的变化规律.结果表明,不同气氛下钢渣碳酸化反应受温度的影响不同.单一CO2气氛下,钢渣碳酸化反应速率随着温度的升高而加快,在600～700℃范围内,碳酸化率达到最高;CO2和水蒸气同时通入时,钢渣碳酸化反应更易进行,在400℃已有明显碳酸化反应,随温度升高在600℃左右碳酸化率达到最大温度升高到700℃后,碳酸钙的分解反应明显加快,游离氧化钙增多.同时通入CO2和水蒸气的气氛下,在400～500℃时,钢渣碳酸化反应的活化能为2.35 kJ·mol-1.     

温室气体CO2矿物碳酸化固定研究进展

将温室气体CO2以碳酸盐（如CaCO3、MgCO3）的固体形式永久储存起来,即CO2矿物碳酸化固定,是减少大气中CO2含量,解除温室效应的一种全新方法。从温室气体CO2矿物碳酸化固定所需的原料、化学及热力学、反应动力学机理等方面,分析了此种方法的特点,同时评述了CO2矿物碳酸化固定的6种典型工艺路线,以及国外有关温室气体CO2矿物碳酸化固定的研究热点。最后指出以工业固体废弃物为原料的间接工艺路线是温室气体CO2矿物碳酸化固定的具有较好应用前景的技术途径。     

基于钙基吸收剂吸收CO2的研究进展

综述了钙基吸收剂煅烧/碳酸化循环吸收CO2的国内外研究状况.从反应条件对碳酸化反应的影响、改善钙基吸收剂吸收CO2的性能、钙基吸收剂循环热稳定性的方法以及碳酸化反应动力学特性这4个方面进行分析,认为碳酸化反应主要分为化学反应控制和产物层扩散2个阶段,指出CO2分压和吸收剂的颗粒粒径决定着碳酸化反应温度和CO2的脱除效率...     

二氧化碳矿物碳酸化固定的技术进展

CO2矿物碳酸化固定可实现CO2的永久封存,环境风险性小,但苛刻的反应条件、过低的反应速率是困扰该技术发展的瓶颈.对CO2矿物碳酸化固定的工艺路线、所用原料及其强化措施的研究现状做了详细评述;指出以工业固体废弃物为原料,结合运用超重力强化传递反应技术与碳酸酐酶高效催化性能,实现烟气CO2分离、碳酸化固定、固体废弃物资源化利用多过程集成耦合的原位CO2固定技术是适合我国现阶段国情的CO2重要控制措施.     

磷石膏加压碳酸化转化过程中平衡转化率分析

围绕磷石膏加压碳酸化转化过程,首先通过实验研究了原料种类对加压碳酸化转化过程的影响,进一步采用Aspen plus流程模拟软件深入分析了各工艺参数对磷石膏加压碳酸化过程平衡转化率的影响规律。结果表明,在加压条件下碳酸化反应均可在5 min时达到平衡,其中分析纯无水硫酸钙更容易完全转化,而二水硫酸钙及磷石膏因含有结晶水或其他杂质,使得其难以完全转化。增大初始氨水浓度、N/S(氨和原料中SO3的摩尔比)以及适量提高反应温度与体系压力,均能有效提高磷石膏加压碳酸化反应平衡转化率。特别是在高温和加压条件下,氨与CO2反应生成的碳酸铵盐可以通过降压闪蒸操作实现其自分解,经吸收返回用于加压碳酸化转化过程,可有效提高氨的利用率,降低硫酸铵生产成本。     

钾基CO2吸收剂的碳酸化反应特性

对钾基CO2吸收剂的碳酸化反应机理进行研究.利用热重分析、XRD、扫描电镜和氮吸附仪进行试验.结果表明:分析纯碳酸钾的组分为K2CO3·1.5H2O,碳酸化反应速率缓慢;先将分析纯碳酸钾样品脱除结晶水后再进行碳酸化反应时,K2CO3与气氛中的水蒸气迅速生成K2CO3·1.5H2O,不利于碳酸化反应的进行;由KHCO3分解产生的K2CO3却表现出优越的碳酸化反应性能,20 min内转化率高达85%以上,经过多次循环试验后吸收剂仍保持很高的活性.从微观角度分析了两种改性钾基CO2吸收剂碳酸化反应机理差异的原因,通过拟合计算得到了这3种钾基吸收剂的碳酸化反应速率常数,为干法K2CO3/KHCO3循环脱除CO2的研究提供了一定的基础数据.     

超重力法脱除变换气中的CO2

用N2和CO2的混合气体模拟变换气,采用苯菲尔溶液为吸收液进行了超重力法脱除CO2的实验研究,考察了反应温度、系统压力、超重力水平、气液比对反应器出口CO2含量的影响。实验结果表明:随着温度的升高和超重力水平的增强,反应器出口CO2含量先降后升;随着压力的升高,反应器出口CO2含量逐渐降低;液体流量一定时,随着气液比的增大,反应器出口CO2含量逐渐升高。     

Simulation analysis of gas–solid flow characteristics and water evaporation in flue gas semi-dry desulphurization process based on CPFD method

The gas–solids flow in an industrial-scale semi-dry method desulphurization tower is simulated by the computational particle fluid dynamics (CPFD) approach. Compared with previous studies on desulphurization towers, this study focuses on analyzing particle distribution characteristics such as particle volume fraction, temperature distribution, and residence time. The simulation fully considered the particle–fluid, particle–particle, and particle–wall interactions in the desulphurization tower. Based on these considerations, the effects of flue gas inlet velocity and temperature on the gas–solid distribution characteristics of the desulphurization tower are simulated. An optimization scheme for adjusting the gas–solid flow in the desulphurization tower is proposed. The research results show that the error between the CPFD simulation data and experimental data is small and the changing trend is consistent. The particles in the bed of the desulphurization tower show a typical core–annulus flow. The distribution of gas and particles in the bed has a serious deviation with the increase of the flue gas inlet velocity and temperature. As the axial height of the desulphurization tower increases, the flue gas velocity, temperature, particle concentration, and water vapour distribution in the bed become more uniform. The relatively stable operating conditions for the gas–solid flow in the desulphurization tower is that the flue gas inlet velocity and temperature are 15 m/s and 393 K, respectively. Under these operating conditions, the pressure loss caused by the venturi accounted for 73.6% of the total pressure loss of the desulphurization tower. When the particle radius is between 0–150 μm, the particle size and the flue gas inlet velocity have the greatest influence on the particle residence time. Finally, the distribution of gas and particles before and after the adjustment of the desulphurization tower is compared, which showed that adjusting the bottom structure of the desulphurization tower could optimize the gas–solid flow.     

Mass transfer investigation and operational sensitivity analysis of amine-based industrial CO2 capture plant

In this article, the industrial process of CO₂ capture using monoethanolamine as an aqueous solvent was probed carefully from the mass transfer viewpoint. The simulation of this process was done using Rate-Base model, based on two-film theory. The results were validated against real plant data. Compared to the operational unit, the error of calculating absorption percentage and CO₂ loading was estimated around 2%. The liquid temperature profiles calculated by the model agree well with the real temperature along the absorption tower, emphasizing the accuracy of this model. Operational sensitivity analysis of absorption tower was also done with the aim of determining sensitive parameters for the optimized design of absorption tower and optimized operational conditions. Hence, the sensitivity analysis was done for the flow rate of gas, the flow rate of solvent, flue gas temperature, inlet solvent temperature, CO₂ concentration in the flue gas, loading of inlet solvent, and MEA concentration in the solvent. CO₂ absorption percentage, the profile of loading, liquid temperature profile and finally profile of CO₂ mole fraction in gas phase along the absorption tower were studied. To elaborate mass transfer phenomena, enhancement factor, interfacial area, molar flux and liquid hold up were probed. The results show that regarding the CO₂ absorption, the most important parameter was the gas flow rate. Comparing liquid temperature profiles showed that the most important parameter affecting the temperature of the rich solvent was MEA concentration.     

不同开车工况对天然气脱碳装置响应特性影响

由于气田及输送环境影响，现场运行长期处于波动状态，而装置能否稳定运行与其在不同工况下的响应动作是否及时有效息息相关。为分析装置在不同开车工况下的响应特性，本文基于实验室建有的天然气脱碳循环实验装置实际运行情况进行优化研究，分析其中关键影响因素。研究结果表明，在单因素实验研究中，开车工况下不同进气流量、塔内压力以及贫液进塔温度对于吸收塔内温度场及闪蒸罐液位响应特性的影响差别不大。而对于开车工况处于较大的进气流量、较高的塔内压力、较低或较高的贫液进塔温度，其控制器响应会出现一定延迟或塔釜液位波动幅度较剧烈的情况。因此以吸收塔塔釜液位响应时间为评价指标，利用BBD设计法对各因素交互作用进行响应面分析，得到吸收压力对塔釜液位响应时间的影响极显著，并且在三种因素交互作用中，吸收压力与贫液进塔温度的交互作用对目标值的影响更为显著。     

填料塔中哌嗪二胺吸收低浓度SO_2的传质性能

为满足有机胺法脱硫设计开发的需要,采用动态吸收法测定了填料塔中哌嗪二胺(PA-A)水溶液吸收低浓度SO2的体积总传质系数KGa,考察了吸收工艺参数如吸收液中的PA-A浓度和初始pH值、液相流率、吸收温度、进气SO2浓度及流速等对KGa的影响。结果表明:KGa随着吸收液中的PA-A浓度和初始pH值、液相喷淋密度的增加而增大;随着吸收温度、气相流率及进气SO2浓度的增加而减小。通过实验结果分析得到体积总传质系数KGa与气液相流率比(qG/qL)之间符合指数关系式,该经验关系可用于工程设计计算。     

中压变换系统的优化运行

为使中压变换系统在不增加较大投资的前提下由中串低工艺稳定地过渡到中低低工艺,对饱和塔、热交换器、调温水加热器等设备进行了改造,对工艺流程、热水循环量和中变催化剂的配置进行了优化,对改造前后变换系统运行数据进行了对比,结果表明,改造后蒸汽消耗由每班98.7t下降到56.2t,变换气中CO体积分数达到1.2%~1.5%的净化要求。     

低温甲醇净化合成油尾气重整气的模拟分析

根据低温甲醇净化工艺流程,利用Aspen Plus软件建立了费托合成油尾气重整气的低温甲醇净化过程的数学模型,获得了净化气流量、各组分体积分数等关键参数,并与实际数据对比,二者相互吻合. 采用灵敏度分析方法进行了分析优化,结果表明吸收塔装置处理负荷可提高8.84%. 当吸收塔负荷不变、且净化气出口CO2的体积分数低于0.5%时,贫甲醇液的温度控制范围为-44~-41℃,吸收塔贫甲醇液量和热再生塔的蒸馏速率分别降低了11.96%和9.55%,净化过程总能耗下降9.43%.     

Experimental investigation of an industrial scale black liquor gasifier. 1. The effect of reactor operation parameters on product gas composition

A novel technology to mitigate the climate changes and improve energy security is Pressurized Entrained flow High Temperature Black Liquor Gasification (PEHT-BLG) in combination with an efficient fuel synthesis using the resulting syngas. In order to optimise the technology for use in a pulp and paper mill based biorefinery, it is of great importance to understand how the operational parameters of the gasifier affect the product gas composition. The present paper is based on experiments where gas samples were withdrawn from the hot part of a 3 MW entrained flow pressurized black liquor gasifier of semi industrial scale using a high temperature gas sampling system. Specifically, the influence of process conditions on product gas composition (CO₂, CO, H₂, CH₄, H₂S, and COS) were examined by systematically varying the operational parameters: system pressure, oxygen to black liquor equivalence ratio, black liquor flow rate to pressure ratio and black liquor pre-heat temperature. Due to the harsh environment inside the gasification reactor, gas sampling is a challenging task. However, for the purpose of the current study, a specially designed high temperature gas sampling system was successfully developed and used. The results, obtained from two separate experimental campaigns, show that all of the investigated operational parameters have a significant influence on the product gas composition and present valuable information about to the process characteristics.     

净化黄磷尾气部分变换制甲醇合成气中试研究

在40 m3/h部分变换中试装置上,采用铁铬系中温变换催化剂,以净化黄磷尾气为原料,经部分变换工艺直接制取甲醇合成气。研究结果表明:以净化黄磷尾气燃烧气为升温介质,负压和循环升温相结合是可行的升温与还原方法;催化剂宜采用二段填装;在汽/气体积流量比1.35—1.40、催化剂床层入口温度310—320℃、原料气流量30—32 m3/h的条件下可获得H2/CO体积流量比合格的甲醇合成气;催化剂床层平均温度随入口温度、蒸汽量和原料气量的增加而升高;中试装置连续运行130 h,合成气中H2/CO摩尔比1.87—3.40。