燃煤电厂烟气二氧化碳胺法捕集工艺改进研究进展

有机胺化学吸收法是当前最具大规模工业化应用前景的燃煤电厂烟气二氧化碳捕集技术,但目前仍存在能耗较高的缺点,而通过工艺改进将是降低碳捕集系统能耗的有效方法之一。本文从吸收端和解吸端分别对十余类工艺改进方法的原理和研究进展进行了阐述,其中吸收端涉及吸收塔内部冷却、富液循环、贫液分配流和旋转塔4类工艺;解吸端则包括解吸塔塔级再热、富液分流、闪蒸再生、闪蒸压缩、多压力解吸、多效解吸塔和直接蒸汽解吸共7类工艺。分析表明,富液分流、闪蒸压缩、多效解吸塔和直接蒸汽解吸工艺展示了较好的改进效果。并进一步介绍了多种工艺联合改进的碳捕集系统综合优化方法,特别对综合优化过程中需要重点关注的各工艺间相互作用以及吸收剂与优化工艺匹配性进行了讨论说明,由此指出联合采用新型胺吸收剂和复合工艺改进是未来开发先进胺法碳捕集系统的重要研究方向。     

电厂烟气CO_2胺法捕集工艺模拟优化

本文根据胜利电厂烟气实际数据,设计了胺法捕集二氧化碳工艺流程,基于ProⅡ软件对烟气二氧化碳吸收和解吸过程进行了数值模拟,分析了不同种类吸收液、MEA浓度和循环量,吸收温度和解吸温度对二氧化碳捕集效果的影响,对不同种类吸收剂进行了优化筛选以及工艺参数的优化.     

二氧化碳的捕集分离技术的研究进展

减少CO2排放是缓解全球变暖的有效途径,如何将CO2从混合气体中捕集并分离是减少CO2排放的前提和基础。文章对国内外的CO2分离技术进行了综合阐述,并分析了各种分离技术的存在的问题,为以后的研究提供方向。     

烟气中二氧化碳捕集技术研究进展

二氧化碳是一种主要的温室气体,而化石燃料燃烧产生和排放出大量的CO2气体是造成全球气候变暖的最主要原因,CO2减排控制技术在碳资源循环利用和环境保护方面均具有重要的意义,CO2的排放控制以及封存利用已经成为一个举世关注的重大科学研究课题.本文综述了近年来CO2捕集技术的研究进展.     

温室气体CO2的捕集和分离--分离技术面临的挑战与机遇

介绍了采用溶剂吸收、膜分离和变压吸附等方法捕集和分离温室气体CO2的最新进展,并对技术发展动向进行了讨论。     

二氧化碳捕集技术研究进展

结合目前二氧化碳捕集技术的发展现状,对二氧化碳捕集方法进行深入研究,在此基础上,对二氧化碳捕集机理进行深入分析,为推动二氧化碳捕集技术的进一步发展奠定基础。     

二氧化碳捕集技术研究进展

在“碳达峰、碳中和”的双重任务下,CO₂捕集已经成为今后工业发展的必然趋势。分别介绍了燃烧前捕集、燃烧后捕集以及富氧燃烧技术,并总结了相关技术还存在的问题。同时,系统地总结了国内外主要的CO₂捕集方法,分析了不同捕集方法的优缺点,并针对不同行业提出了合理的捕集方法。其中,重点介绍了溶液吸收法,通过对现有吸收液存在的能耗高、易挥发、毒性大的问题,提出了今后溶液吸收法的主要发展方向,并针对现有吸附法存在的问题提出开发新型低温、低压、低成本的固体吸附材料及相关工艺的研究思路。     

中国将实施首个燃煤电厂二氧化碳捕集研究项目

来自华能集团的最新消息显示，华能集团公司与澳大利亚联邦科学工业研究组织已正式签署《关于洁净煤发电及二氧化碳捕集与处理等技术研究的合作框架》协议。     

二氧化碳捕集技术研究进展

随着全球工业的快速发展,二氧化碳的大量排放被认为是造成气候变暖最主要原因,二氧化碳的捕集和封存已经成为研究的热点,本文综述了近年来CO2捕集技术的研究进展,主要有燃烧后捕集、燃烧前捕集和富氧燃烧三条技术路线,最后提出了可以提高二氧化碳捕集能力的策略与展望。     

CO2捕集技术的研究现状

针对目前主要的CO2捕集技术进行了综述,总结了各种技术的优缺点,并阐述了各种方法目前存在的问题,指出了可能的改进方法,并提出未来CO2捕集技术研究的重点以及方向.     

空气中直接捕集CO2技术研究进展

减少碳排放并推动碳中和是应对气候变化、促进经济社会绿色转型的重要途径之一,碳中和技术已成为工业界和学术界的关注焦点。目前碳捕集与封存主要对工业固定源排放的CO₂进行处置捕集,而对占CO₂总排放近50%的分布源CO₂关注度不高。直接空气捕集(direct air capture,DAC)技术不仅可对数以百万计的小型化石燃料燃烧装置以及数以亿计的交通工具等分布源排放的CO₂进行捕集处理,还可有效降低大气中CO₂浓度。介绍了DAC的发展历史、研究现状以及发展趋势,综述了已有DAC技术的工艺流程以及反应装置,对DAC现行工艺中涉及的空气捕捉模块、吸收剂或吸附剂再生模块、CO₂储存模块进行了叙述,对比了几种工艺的优缺点以及吸附剂类型和再生方式,指出DAC技术发展的关键在于研发高效低成本的吸收/吸附材料和设备。分析了DAC吸收/吸附材料的作用原理以及吸附效果,碱性溶液原料成本相对低廉,但再生过程中能耗较高。分子筛及金属有机框架吸附剂虽然再生能耗较低,但对空气中CO₂的吸附容量和吸附选择性表现一般。胺类吸附剂具有较好的吸附能力,由于其再生温度较低,可使用工业废热或少量热能为系统供能;使用胺类吸附剂时吸附和解吸在一个单元中逐步发生,具有更高的效率和操作时间,有望降低DAC系统成本。对比了DAC与其他碳捕集技术的成本并进行了技术经济性分析,DAC成本主要包含运营和维护成本(N_Q&M)、吸附剂材料成本(N_S)和工厂设备的净成本(N_bop);指出目前限制DAC工业化应用的主要因素之一在于吸收/吸附材料和相关工艺成本过高,随着阴离子交换树脂等新型吸附剂的出现和工艺的发展,DAC成本逐年下降。全面探究吸收/吸附材料稳定性、动力学、吸附容量、选择性、再生能量损失等综合性能,研发利于快速装载和卸载吸附剂的相关装置,开发成本低廉的工艺系统是目前DAC领域的发展方向和迫切需求。DAC技术将为减少全球碳排放、实现碳中和提供重要技术支撑。     

Integrated adsorption and absorption process for post-combustion CO2 capture

This study explored the feasibility of integrating an adsorption and solvent scrubbing process for post-combustion CO₂ capture from a coal-fired power plant. This integrated process has two stages: the first is a vacuum swing adsorption (VSA) process using activated carbon as the adsorbent, and the second stage is a solvent scrubber/stripper system using monoethanolamine (30 wt-%) as the solvent. The results showed that the adsorption process could enrich CO₂ in the flue gas from 12 to 50 mol-% with a CO₂ recovery of >90%, and the concentrated CO₂ stream fed to the solvent scrubber had a significantly lower volumetric flowrate. The increased CO₂ concentration and reduced feed flow to the absorption section resulted in significant reduction in the diameter of the solvent absorber, bringing the size of the absorber from uneconomically large to readily achievable domain. In addition, the VSA process could also remove most of the oxygen initially existed in the feed gas, alleviating the downstream corrosion and degradation problems in the absorption section. The findings in this work will reduce the technical risks associated with the state-of-the art solvent absorption technology for CO₂ capture and thus accelerate the deployment of such technologies to reduce carbon emissions.     

碳酸钾-乙醇胺复合溶液吸收烟气中CO2的实验研究

分别以不同浓度的碳酸钾溶液及不同配比的碳酸钾—乙醇胺复合溶液作为吸收剂,以吸收速率和吸收量为指标,研究了吸收剂对烟气中CO2的吸收效果.结果表明,纯碳酸钾溶液吸收效果不佳,而掺入乙醇胺后的吸收效果显著改善,部分复合溶液的吸收效果甚至好于同浓度纯碳酸钾溶液与纯乙醇胺溶液的吸收效果之和,碳酸钾与乙醇胺在吸收过程中存在正交互作用.确定0.6 mol·L-1碳酸钾-0.4mol· L-1乙醇胺复合溶液为最佳的吸收剂,其饱和吸收量最大(0.185 mol)、再生温度最低(105℃)、再生率最高(98.8％).     

13X-APG沸石真空变压变温耦合工艺吸附捕集烟道气中CO2

采用13X-APG沸石吸附捕集烟道气中CO2,并研发了五步循环真空变压变温(VTSA)耦合吸附捕集工艺. 实验测定了循环吸附/解吸过程中吸附剂再生率、烟道气中CO2回收率、产品气量及产品气中CO2纯度,并与传统的真空变压吸附工艺(VSA)和变温吸附工艺(TSA)比较. 由于VTSA在真空解吸的同时加热吸附剂,减少了真空泵的电耗,可在较温和的真空下(约3′103 Pa)操作,附加的吸附剂再生温度也不高,90~150℃下吸附剂再生率达97%以上,CO2回收率达98%以上. 吸附剂捕集CO2的量可提高到1.8 mol/kg,是VSA工艺产品气量的2倍,且产品气中CO2纯度提高到90%以上.     

Alkali and alkaline-earth cation exchanged chabazite zeolites for adsorption based CO2 capture

In this study chabazite zeolites were prepared and exchanged with alkali cations – Li, Na, K and alkaline-earth cations – Mg, Ca, Ba and were studied to assess their potential for CO₂ capture from flue gas by vacuum swing adsorption for temperatures below 120 °C. Isotherm measurements (CO₂ and N₂) were made for all samples at 273 K, 303 K and 333 K using a volumetric apparatus and represented with the Dual-site Langmuir model for CO₂ and N₂. Henry’s constants and isosteric heats of adsorption were calculated and qualitative analyses performed for all samples. Adiabatic separation factor (ASF) and capture figure of merit (CFM) were proposed and used as indices for assessing adsorbent performance and compared with a commercial NaX-zeolite sample. It was found that NaCHA and CaCHA hold comparative advantages for high temperature CO₂ separation whilst NaX shows superior performance at relatively low temperatures.     

混合醇胺溶液吸收烟气中CO2

研究了温度、CO2含量与吸收液浓度对醇胺溶液吸收CO2性能的影响,并比较了不同复配体系对二异丙醇胺(MDEA)的活化效果。结果表明,醇胺溶液对CO2的吸收速率随反应时间的增加而降低,随吸收温度的升高而增强,以40℃为宜;吸收反应速率均随气、液相反应物含量增大而增强;混合体系对MDEA的活化效果为二乙烯二胺最好,乙醇胺最差。     

The maximum capture efficiency of CO2 using a carbonation/calcination cycle of CaO/CaCO3

The use of natural calcium carbonates as regenerable CO₂ sorbents in industrial processes is limited by the rapid decay of the carbonation conversion with the number of cycles carbonation/calcination. However, new processes are emerging to capture CO₂ using these cycles, that can take advantage of the intrinsic benefits of high temperature separations in energy systems. This work presents an analysis of a general carbonation/calcination cycle to capture CO₂, incorporating a fresh feed of sorbent to compensate for the decay in activity during sorbent re-cycling. A general design equation for the maximum CO₂ capture efficiency is obtained by incorporating to the cycle mass balances a simple but realistic equation to estimate the decay in sorbent activity with the number of cycles.     

Separation of CO2 from flue gas using electrochemical cells

Past research with high temperature molten carbonate electrochemical cells has shown that carbon dioxide can be separated from flue gas streams produced by pulverized coal combustion for power generation. However, the presence of trace contaminants, i.e., sulfur dioxide and nitric oxides, will impact the electrolyte within the cell. If a lower temperature cell could be devised that would utilize the benefits of commercially-available, upstream desulfurization and denitrification in the power plant, then this CO₂ separation technique can approach more viability in the carbon sequestration area. Recent work has led to the assembly and successful operation of a low temperature electrochemical cell. In the proof-of-concept testing with this cell, an anion exchange membrane was sandwiched between gas-diffusion electrodes consisting of nickel-based anode electrocatalysts on carbon paper. When a potential was applied across the cell and a mixture of oxygen and carbon dioxide was flowed over the wetted electrolyte on the cathode side, a stream of CO₂ to O₂ was produced on the anode side, suggesting that carbonate/bicarbonate ions are the CO₂ carrier in the membrane. Since a mixture of CO₂ and O₂ is produced, the possibility exists to use this stream in oxy-firing of additional fuel.From this research, a novel concept for efficiently producing a carbon dioxide rich effluent from combustion of a fossil fuel was proposed. Carbon dioxide and oxygen are captured from the flue gas of a fossil-fuel combustor by one or more electrochemical cells or cell stacks. The separated stream is then transferred to an oxy-fired combustor which uses the gas stream for ancillary combustion, ultimately resulting in an effluent rich in carbon dioxide. A portion of the resulting flow produced by the oxy-fired combustor may be continuously recycled back into the oxy-fired combustor for temperature control and an optimal carbon dioxide rich effluent.     

变压吸附气体分离技术应用及展望窥探

为了深入探究变压吸附气体分离技术,分析了技术工作原理,依据此原理,研究此项技术在H_2、CO_2、C0、氯乙烯精馏尾气的回收与提取中的应用方法,并探究参数指标变化下气体回收与提取纯度的影响。基于变压吸附技术应用现状,气体吸附提取纯度仍有上升空间,具有较高的研发应用前景。     

烟道气CO2回收改造方案

对烟道气CO2回收改造项目的背景、技术方案的比较与选定、改造工艺路线及特点进行了总体介绍。改造的总体方案是用改良MEA脱碳法从燃气快装锅炉的烟道气中回收3 000 m3/h(标态)CO2作为尿素、甲醇和碳酸二甲酯生产装置的补充原料气。