供氢体应用于碳捕集与资源化领域的前景分析

二氧化碳（CO₂）的大量排放已显著加剧温室效应和生态环境恶化。催化转移氢化法在CO₂资源化利用领域研究广泛且技术成熟。从以气态氢为主要还原剂催化氢化CO₂工艺的研究现状、供氢体还原特性及其目前应用进展等角度展开综述,并就上述研究中存在的优势和不足提出见解,建议未来供氢体应用于碳捕集与资源化领域可能的研究方向,旨在为推动CO₂资源化利用研究的长足发展提供借鉴。     

CO2催化氢化催化剂及其反应机理综述

研究二氧化碳资源化利用技术将对电厂CO₂减排工作具有重要意义。综述了基于催化氢化思想的CO₂转化催化剂及其反应机理,其主要涉及铜、镍、锌等过渡金属和钌、铱、钯等贵金属。现有催化氢化CO₂转化技术研究主要集中于研究与开发高活性催化剂,分析与推测反应机理,提高产物产率及选择性,优化反应体系结构与条件等方面。高活性催化剂如双金属合金,过渡金属催化体系将是未来CO₂催化氢化领域主要的研究方向之一。各催化剂催化氢化CO₂反应机理较为复杂,值得深入研究。随着经济、环保、节能等新型CO₂催化氢化技术的开发及研究的深入,电厂CO₂减排及资源化工业应用也将成为可能。     

浸渍法制备的固态胺CO2吸附剂吸附性能

控制和减缓化石燃料电厂的CO₂排放对于缓解大气中CO₂浓度的持续上升具有重要意义。作为一种燃烧后CO₂ 捕集技术,固体CO₂吸附剂具有低能耗、弱腐蚀性、易再生等优点,在CO₂减排领域有着广泛的应用前景。介绍浸渍法制备的固态有机胺吸附剂对CO₂的吸附性能,着重介绍载体性质、有机胺负载量、温度和烟气含水量等因素对固态胺吸附剂吸附性能的影响,并对其机理进行了分析。此外,对比了不同固态胺吸附剂在75 ℃下对CO₂的吸附能力。分析认为,相对于其他类型的CO₂固体吸附剂,固态胺吸附剂较适用于从高温湿烟气中捕集CO₂。     

分段电极介质阻挡放电CO2重整CH4过程放电特性与反应性能研究

大气压低温等离子体可在温和条件下进行CO₂重整CH₄反应，对环境保护和能源供应具有双重意义。介质阻挡放电(DBD)是进行该反应最常用的放电等离子体形式之一，但其工艺过程和反应性能受到反应器结构的显著影响。前期研究发现，分段电极DBD可以调节CO₂重整CH₄反应过程的反应物转化率、产物分布及能量效率，但是分段电极数量和相邻电极间距对上述性能参数的影响机理尚不清晰。因此，该文设计了具有不同电极数量和不同相邻电极间距的分段电极DBD反应器，并用于CO₂重整CH₄反应，从电学特性和温度特性的角度研究了不同实验条件下的放电特性，比较分析了对应条件下的CO₂重整CH₄反应性能。结果表明，分段电极的引入可以增加放电边缘数量以增强边缘效应，且增加分段电极数量和增加相邻电极间距均可延长反应物的有效停留时间，上述因素均有助于提高等离子体CO₂重整CH₄的反应性能。在施加电压11.0 kV条...     

硅酸锂吸附CO2的特性研究

硅酸锂比锆酸锂吸附容量大、吸附速度快、成本低,是将来高温CO₂吸附的首选材料。用双壳机理解释了硅酸锂吸附CO₂的过程;分析了合成工艺、合成温度、金属掺杂、粒径等合成条件和吸附温度、脱附温度、CO₂浓度、气体流量、再循环等运行条件对硅酸锂吸附CO₂性能的影响;指出硅酸锂在甲烷制氢和整体煤气化联合循环工程的CO蒸汽重整工艺分离CO₂方面具有良好的应用前景。     

亚临界压力下二氧化碳传热特性及临界热流密度预测模型研究

二氧化碳(CO₂)布雷顿循环系统有着紧凑、高效、灵活的特点在第三代光热系统和第四代核电系统中具有良好的应用前景，而CO₂传热恶化现象影响着机组的安全运行。为研究竖直上升管内CO₂的传热恶化现象，在实验室建立了CO₂传热特性系统，对比了亚临界与超临界状态下CO₂传热特性，获得了热工参数对CO₂传热恶化的影响规律，并建立了CO₂临界热流密度预测关联，预测值与实验值吻合良好，误差在±30%以内。研究结果表明：亚临界压力下，CO₂发生传热恶化时壁温峰值更高；远离临界压力，增加质量流量均有利于抑制传热恶化的发生。     

CO2地质利用与封存环境下钢材腐蚀行为与腐蚀控制措施研究进展

CO₂地质利用与封存(CO₂ geological utilization and storage,CGUS)是实现“碳中和”目标的重要技术手段,解决CGUS过程中的钢材腐蚀问题对于降低CGUS技术风险、实现CGUS技术规模化推广应用至关重要。综述了目前已经提出的CO₂腐蚀钢材反应机制,总结了CO₂腐蚀钢材的主要影响因素,阐明了CO₂分压、温度、矿化度及p H值、CO₂封存环境中含有杂质、流体流动等因素对钢材腐蚀行为的影响,归纳了适用于CO₂腐蚀钢材防护的主要措施。基于此,提出了CGUS环境下钢材遭受CO₂腐蚀问题的重点研究方向。主要包括：CO₂腐蚀钢材反应机制的进一步探究;各项环境因素耦合作用影响CO₂腐蚀规律和腐蚀程度的量化研究;高浓度CO₂条件下腐蚀防护技术的开发与应用。     

膜法二氧化碳分离技术研究进展及展望

二氧化碳的排放导致了严重的环境和生态问题,而碳捕集、利用和封存技术(carbon capture,utilization and storage,CCUS)是减缓CO₂排放的有效途径。在众多的CCUS方法中,膜分离因其能效高、成本低、投资少、维护运行简单等优点引起了广泛关注。综述了燃烧前捕集、燃烧后捕集和天然气脱碳中的膜材料及其膜分离性能,分析影响CO₂捕集效率的关键膜结构因素和调控规律,膜组件开发关键问题及产业化情况,膜分离系统集成及经济性规律。结合研究现状和CO₂捕集需求,提出未来膜法CO₂捕集的研究方向。     

焦载体下CH4及CO2气氛对低阶煤流化床热解特性的影响

以新疆润北煤为研究对象,在小型鼓泡流化床上开展了热解实验,结合气相色谱、SEM等表征手段对热解产物及其特性进行了分析,考察了以半焦为热载体不同热解温度条件下CH₄和CO₂气氛对煤炭流化床热解特性的影响。结果表明:由于煤半焦促进了CH₄和CO₂的重整反应,CH₄/CO₂混合气氛下热解产气率与单一气氛相比有所减少,减少幅度随温度和CO₂体积分数提高而增加;同时,热解温度为600 ℃以上时,CO和H₂产率随着CO₂体积分数的提高和温度的升高而明显增加,相应的热解水产率也明显增加;随着温度升高,受CH₄裂解、CH₄与CO₂重整及CO₂与碳的气化等反应的影响,CH₄/CO₂混合气氛下焦油产率有所增加,在热解温度600 ℃左右时焦油产率最高的同时增加幅度也较大;受CH₄裂解反应积碳以及CO₂和半焦的气化反应等过程的影响,CH₄气氛下半焦产率增加,CO₂气氛下半焦产率降低;CH₄/CO₂混合气氛下半焦产率及特性同样有明显的变化,且随热解温度升高变化更大;较低体积分数CO₂（6%）时,CO₂促进CH₄裂解积碳,其影响大于CO₂与碳的气化反应,半焦产率提高且半焦孔隙变小,表面变粗糙;而随着CO₂体积分数提高时（增加到15%）,CO₂与碳的气化作用增强,使得半焦产率反而明显减少且孔隙变大。     

基于GA-BP神经网络的超临界二氧化碳折射率及密度预测

基本光学性质折射率是研究物质物理性质的重要参数。本文以超临界二氧化碳（S-CO₂）为对象，整合各文献在不同温度、压力下对S-CO₂折射率的测量数据，使用遗传算法（GA）优化后的BP神经网络建立了预测S-CO₂折射率的模型，并基于S-CO₂密度与波长、折射率内在联系的洛伦兹-洛伦兹关系式，对S-CO₂的密度进行反演。结果表明:该模型预测 S-CO₂折射率的最大相对误差仅为0.844%；反演的S-CO₂密度值同REFPROP软件结果相比，平均误差不超过3.65％；在亚临界和超临界区，通过实验测量折射率来研究CO₂物性是可行的；在近临界区，由于CO₂物性变化剧烈，对折射率变化规律的测量及折射率与CO₂物性的关系尚需进一步研究。     

特高压配套外送电源碳排放水平研究

随着国家清洁低碳、安全高效的现代电力工业体系的构建,远距离、大容量配套新能源电力外送已成为转变能源资源配置的一项重要途径.如何评估此类项目CO2排放水平及节能减排效益,已受到各界关注.以陕北某特高压直流输电工程为例,对其配套外送电源的CO2排放水平进行研究.结果表明:该工程实施火电与新能源打捆外送,不仅扩大送端省份的新...     

Decomposition of benzene using alumina-hybrid and catalyst-hybridplasma reactors

In order to investigate the effects of alumina and metal ions in plasma discharge, plasma reactors packed with a mixture of BaTiO₃ pellets and porous Al₂O₃ pellets (alumina-hybrid reactor), and with a-mixture of BaTiO₃ pellets and metal-supported Al₂O₃ pellets (catalyst-hybrid reactor) were examined for oxidation of dilute benzene in air. It was found that the oxidative decomposition of benzene was enhanced by concentrating benzene on the Al₂O₃ pellets and the catalyst pellets. Furthermore, the selectivities to CO ₂ in the alumina-hybrid reactor and the catalyst-hybrid reactors were higher than those in the plasma reactor packed with BaTiO ₃ pellets alone. In particular, the selectivities to CO₂ in the catalyst-hybrid reactors using Ag, Co, Cu and Ni/Al₂ O₃ were higher than those from the alumina-hybrid reactor. In addition, the presence of the alumina and catalysts suppressed the formation of N₂O     

The effect of residence time on the CO2 reduction fromcombustion flue gases by an AC ferroelectric packed bed reactor

An experimental investigation was conducted to reduce CO₂ from combustion gases using an AC ferroelectric packed bed reactor. This ferroelectric packed bed reactor consists of two mesh electrodes packed with ferroelectric particles between them. An AC voltage is applied to the reactor to generate partial or spark discharges. The results show the following: the CO₂ gas reduction rate increases with increasing flue gas residence time and primary applied power; the CO₂ gas reduction rate increases with decreasing gas flow rate and dielectric constant of packed ferroelectric particles; and the CO₂ concentration is reduced by up to 18000 ppm, and 108 g of CO₂ are removed by 1 kWh of primary applied energy used in the packed-bed reactor     

Effects of Temperature, Voltage Properties, and Initial Gas Composition on the Plasma Reforming of Aliphatic Hydrocarbons With $hbox{CO}_{{bf 2}}$

CO₂ reforming of methane, propane, and neopentane was investigated with a ferroelectric packed-bed and silent discharge plasma reactors in N₂ at temperature from 303 to 433 K. The conversions of the substrate hydrocarbons and CO₂, and the yields of H₂ and CO were expressed as functions of reactor energy density irrespective of voltage waveform. The positive temperature effect on the hydrocarbon conversions and the product yields can be ascribed to the promotion of secondary decomposition of the hydrocarbons induced by radicals formed in situ because reactor power consumption was not affected by reaction temperature at the same frequencies and peak-to-peak voltages. At 303 K, the reactivity of the hydrocarbon decreased in the following order: neopentane > propane > methane. At 433 K, propane and neopentane showed the same reactivities. The molar ratio of H₂ to CO was affected by hydrocarbon structure and the initial concentration ratio of CO₂ to the carbon atom in hydrocarbon, but not by reaction temperature. Better carbon balances were obtained for all the hydrocarbons at 433 K than at 303 K, suggesting higher reaction efficiencies at 433 K. Carbon balance was also affected by initial gas composition, and the carbon atoms in reacted neopentane were quantitatively recovered as CO, CO₂ and lighter hydrocarbons at 10 of [CO₂]/[neopentane].     

Reduction of CO2 from combustion gases by DC coronatorches

An experimental investigation has been conducted to reduce CO₂ from combustion gases by using DC corona torches. This plasma device, the corona torch, consists of two small-diameter hollow electrodes. The gas flow enters the upstream cylindrical hollow electrode and exits at a downstream cylindrical hollow electrode. Therefore, all the reactive gas passes through the active corona-induced plasma zone. High-speed gas flow near the exit of the electrode cools the electrodes; hence, the chemical reactions and the stability of discharge are enhanced. Various amounts of argon gas were added to the model combustion gas (N₂:O₂:CO₂=0.745:0.15:0.105). The results show that the CO₂ gas reduction rate increases with increasing corona current when the model gas is seeded with argon. The CO₂ gas reduction rate increases when the percentage of argon gas in the mixture increases up to 20%, and decreases when the percentage of argon gas in the mixture increases above 20%     

基于区间规划的多区域行业间碳排放权交易模型研究

碳排放权交易是为促进全球温室气体减排所采用的市场机制。在区域及行业层次的CO₂减排目标基础上,考虑交易过程不确定性特性及交易参数浮动特征,运用区间线性规划方法,建立了多区域行业间碳排放权交易模型,并应用于仿真案例研究,以期为区域及行业层次碳排放权交易管理决策提供有效的技术支持。     

Comparison of SF6/N2 and SF6/CO2 gas mixtures as alternatives to SF6 gas

The interest in SF₆ gas mixtures has been re-ignited in recent years by the issue of the greenhouse effect of the SF₆ gas, and most research work is now focused on a SF₆/N₂ gas mixture, which is suitable for application in electrical apparatus with slightly non-uniform fields. This paper presents a comparison of SF₆/N₂ and SF₆/CO₂ gas mixtures with a viewpoint of their possible applications to gas-insulated transformers, where both highly non-uniform field problems and partial discharges in gas/film insulation are inevitable. It is shown that in this case the dielectric strength of SF₆/CO₂ is superior to that of SF₆/N ₂ with a minor disadvantage related to the gas decomposition in SF₆/CO₂. However, this may not be a problem for the SF₆/CO₂ gas mixture to be used in gas-insulated transformers, where internal breakdown is not allowed     

富氧燃烧气氛石灰石溶解特性研究

在实验室小型试验台上研究富氧燃烧气氛下湿法脱硫用石灰石溶解特性,研究结果表明：较高的CO₂浓度对石灰石的溶解有促进作用,CO₂体积分数在80%时,石灰石的溶解速率明显增大;在相同的pH值情况下,CO₂浓度越高,石灰石的溶解速率越快。在pH=4.5时,低浓度CO₂气氛比高浓度CO₂气氛下溶解时间增加70 min,CO₂浓度对溶解速率的影响比较明显。