燃煤电厂烟气中二氧化碳的减排技术

由于CO2等温室气体引发的温室效应对全球生态环境和社会经济发展造成了显著影响,使得CO2减排受到了国际社会的密切关注。文章针对CO2的集中排放源,介绍燃煤电厂烟气中CO2减排技术路线和目前国际上常用的CO2捕集分离技术,最后分析和展望CO2捕集分离技术的发展前景。     

燃煤电厂C02捕集技术与经济分析

随着全球CO2排放量的逐年递增,气候变化和CO2减排问题已经引起了世界性的关注。电厂CO2捕集技术研究也成了热点。主要对国内外燃煤电厂CO2捕集技术与经济分析作了综述,并对我国现运行的燃煤电厂碳捕集示范装置进行简要的技术与经济分析。     

燃烧后碳捕获新的膜法技术已进行中型规模试验

<正>美国能源部支持的新的碳捕获技术已用于从燃煤发电厂经济地捕获所排放的90%的CO2,并于2015年1月27日开始半工业规模测试。该Polaris膜法系统由膜技术和研究公司(MTR)开发,使用一种特殊设计的CO2选择性微孔膜作为半透屏障,用于从燃煤电厂烟气(包括其他气体,如氮气)中分离CO2。     

负载型钾基CO2吸收剂的结构表征和碳酸化反应特性

CO2减排已成为21世纪人类面临的焦点问题.而在我国燃煤电厂作为CO2排放量最大、排放最集中的化石燃料燃烧场所,对其进行CO2减排技术的研究和开发势在必行.     

负载型K2CO3/Al2O3二氧化碳吸收剂的碳酸化反应特性

引言 全球变暖已经成为一个备受关注的环境问题.据预测,如不采取积极的温室气体减排措施,从现在起到2100年,全球近地面平均气温将继续升高1.4～5.8℃[1].CO2是主要的温室气体,而我国燃煤电厂是CO2排放量最大、最集中的化石燃料燃烧场所.因此研究和开发适用于燃煤电厂的CO2减排技术至关重要.     

聚丙烯中空纤维膜组件分离烟气中的CO2

膜吸收法在大型工业燃煤电厂二氧化碳（CO2）捕集方面具有很好的应用前景,但烟气组分对该技术效果影响还有待进一步研究。本文以单乙醇胺（MEA）为吸收剂,开展了疏水性聚丙烯（PP）中空纤维膜组件分离模拟烟气中的CO2的实验研究,考察了吸收操作条件以及燃煤烟气中水汽和SO2对膜组件吸收效率的影响。结果表明,试验的最佳液气比为24 L/m3;MEA的浓度为0.6 mol/L;膜组件进口的温度变化对吸收效率基本没有影响;CO2的浓度在10%～20%内变动对吸收效率影响不大。与CO2相比,SO2会优先发生吸收作用,而水汽则会吸附在聚丙烯中空纤维膜组件的孔壁上,产生毛细管凝聚现象,阻塞CO2的渗透吸收。     

用于油田注气的燃煤电站锅炉烟气处理工艺分析

将燃煤电厂锅炉产生的烟气经处理后注入油井既能提高原油采收率,同时还可以实现CO2温室气体的减排,因而具有经济和社会的双重效益。利用电厂燃煤锅炉烟气的关键在于烟气的净化处理工艺,本文针对注入烟道气和CO2气两种情况,对烟气处理技术路线进行了分析。对注入烟道气的情况,推荐采用非选择性催化烟气脱硝除氧 石灰石湿法脱硫 静电或袋式除尘 冷冻或吸附干燥处理工艺流程,同时,烟道气的输送采用高压管道输送方式。对注入CO2气的情况,推荐采用非选择性催化烟气脱硝除氧 石灰石湿法脱硫 静电或袋式除尘 化学溶剂吸收法CO2分离 冷冻或吸附法CO2干燥 氨制冷法CO2液化处理工艺流程,同时,CO2的输送可以采用管道输送或罐车运送方式。     

限碳背景下燃煤电厂对策分析与电化学催化还原技术进展

分析了目前CO₂减排的压力和趋势,以电化学催化还原为技术核心,结合燃煤排放特点,对电化学体系进行了优选,提出限碳背景下燃煤电厂的减排策略。在缓解日益严峻的CO₂减排和温室效应问题的同时,将大体量废弃的CO₂转化为具有利用价值的产品是碳捕集与利用的必由之路。对CO₂电化学催化还原技术的过程原理进行简要阐述,围绕电极、电解质、CO₂溶解性、反应器形式进行讨论,结合电化学催化还原技术特点和燃煤电厂结构特征,对大体量、低浓度CO₂电化学催化还原条件进行筛选,确定了以Cu基气体扩散电极-离子液体-连续式反应器为核心的基本电化学体系,进而提出燃煤电厂烟气中CO₂电化学催化还原对策,但在向实际应用转化过程中该技术仍面临非理想气源中杂质的影响、还原电流密度低引发的产物生成速率慢、电极寿命短、产物多样性伴随的分离及提纯难度大等障碍,为面向应用的技术发展指明了研究方向。     

火电厂和IGCC及煤气化SOFC混合循环减排CO2的分析

二氧化碳减排已经成为缓解全球气候变化的一个重要议题 .目前 ,火电厂排放的 CO2约占中国 CO2 排放量的 1 /3左右 ,减少其 CO2 排放可以通过提高能量转化效率和回收封存 CO2 两种主要方式 .常规锅炉汽机电厂、IGCC以及煤气化 -固体氧化物燃料电池 ( SOFC)混合循环分别代表了现在、近期及未来燃煤电厂的典型配置 ,超临界及超超临界电厂效率可以达到 40 %以上 ,采用GEH型等先进燃气轮机的 IGCC可提高到 5 0 %以上 ,而混合循环电厂的效率则有望达到 60 %以上 .利用 Aspen Plus TM对这三种电厂进行了模拟 ,考察了三者在回收 CO2 前后性能的变化 .在此基础上 ,分析了减排 CO2 及征收排放税等措施对各电厂发电成本的影响 ,进而就未来如何促进电厂减排 CO2 进行了探讨 .     

离子液体二氧化碳分离膜研究进展

离子液体支撑液膜在较大跨膜压差（0.25～0.3MPa）下的稳定性较差,具有较好稳定性的聚离子液体膜和离子液体-聚合物共混膜等逐渐被关注。本文综述了离子液体支撑液膜、聚离子液体膜、离子液体?聚合物共混膜等离子液体膜CO2分离性能、分离机理及稳定性的最新研究进展,介绍了无机颗粒-离子液体-聚合物共混膜的研究现状。指出离子液体膜的高CO2渗透通量与高稳定性之间的矛盾、共混膜结构调控难等问题是其工业化应用的主要障碍,提出开发新的膜材料、改进制膜工艺以减小膜厚、优化膜结构是提高膜的CO2渗透和分离性能,并保持膜稳定性的有效途径。无机颗粒-离子液体-聚合物共混膜兼有较高的CO2分离性能和较好稳定性,具有良好的应用前景,对其制备方法、结构、性能及CO2分离机理的研究将成为这一领域的热点。     

Carbon dioxide sequestration in petrochemical industries with the aim of reduction in greenhouse gas emissions

The mitigation of greenhouse gas emissions to acceptable levels is arguably the greatest environmental challenge these days. Vast utilization of fossil fuels and forest destruction are main causes of CO₂ increase in the atmosphere. Carbon dioxide sequestration that consists of separation, transportation and utilization or storage of CO₂, is one way for reduction of its emission, in which the most costly section is separation. Different methods can be used for carbon dioxide separation such as absorption, membrane separation, adsorption and cryogenic distillation. Economic, technical and environmental issues should be considered in selection of the technology for particular application. Carbon dioxide concentration, temperature, pressure and flow rate are influential operating parameters in the selection of the appropriate separation method. Nowadays, absorption is the worldwide industrial separation method. New researches are focused on developing new stable solvents and efficient column configuration with suitable internals to minimize pressure drop. Membrane separation and adsorption (PSA type) are other long-term alternatives that can increase separation efficiency and decrease separation cost. The level of energy consumption in various separation methods are in the order: chemical absorption>physical absorption>membrane separation. Because of high investment costs, current separation technologies are suitable for large concentrated sources. In the present paper, different processes for carbon dioxide separation are investigated and compared. Available technologies and commercial plants for CO₂ sequestration are provided.     

燃煤烟气杂质影响膜法捕集CO_2的研究进展

膜法捕集CO₂系统运行的稳定性直接制约其大规模运用,本文总结分析了其稳定性一方面受到膜自身特点,如孔径分布、孔隙率等的影响;另一方面燃煤烟气杂质对膜系统的作用也是限制其发展的要素所在,如细颗粒物会吸附沉积在膜表面或膜孔内部、水蒸气易冷凝于膜表面或在孔径内形成毛细管冷凝现象、SO₂会与CO₂形成竞争吸附,这些因素都会引起气体通量的变化,从而改变膜捕集系统的性能。     

三种气体分离技术应用于电厂烟气二氧化碳捕集经济性的比较(英文)

Three gas separation technologies,chemical absorption,membrane separation and pressure swing adsorption,are usually applied for CO2 capture from flue gas in coal-fired power plants.In this work,the costs of the three technologies are analyzed and compared.The cost for chemical absorption is mainly from $30 to $60 per ton(based on CO2 avoided),while the minimum value is $10 per ton(based on CO2 avoided).As for membrane separation and pressure swing adsorption,the costs are $50 to $78 and $40 to $63 per ton(based on CO2 avoided),respectively.Measures are proposed to reduce the cost of the three technologies.For CO2 capture and storage process,the CO2 recovery and purity should be greater than 90%.Based on the cost,recovery,and purity,it seems that chemical absorption is currently the most cost-effective technology for CO2 capture from flue gas from power plants.However,membrane gas separation is the most promising alternative approach in the future,provided that membrane performance is further improved.     

Comparative assessment of sub-critical versus advanced super-critical oxyfuel fired PF boilers with CO2 sequestration facilities

This work focuses on the techno-economic assessment of bituminous coal fired sub- and super-critical pulverised fuel boilers from an oxyfuel based CO₂ capture point of view. At the initial stage, two conventional power plants with a nominal power output of above 600 MWe based on the above steam cycles are designed, simulated and optimised. Built upon these technologies, CO₂ capture facilities are incorporated within the base plants resulting in a nominal power output of 500 MWe. In this manner, some sensible heat generated in the air separation unit and the CO₂ capture train can be redirected to the steam cycle resulting in a higher plant efficiency. The simulation results of conventional sub- and super-critical plants are compared with their CO₂ capture counterparts to disclose the effect of sequestration on the overall system performance attributes. This systematic approach allows the investigation of the effects of the CO₂ capture on both cycles. In the literature, super-critical plants are often considered for a CO₂ capture option. These, however, are not based on a systematic evaluation of these technologies and concentrate mainly on one or two key features. In this work several techno-economic plant attributes such as the fuel consumptions, the utility usages, the plant performance parameters as well as the specific CO₂ generation and capture rates are calculated and weighed against each other. Finally, an economic evaluation of the system is conducted along with sensitivity analyses in connection with some key features such as discounted cash flow rates, capital investments and plant efficiencies as well as fuel and operating costs.     

Progress in carbon dioxide capture and separation research for gasification-based power generation point sources

The purpose of the present work is to investigate novel approaches, materials, and molecules for the abatement of carbon dioxide (CO₂) at the pre-combustion stage of gasification-based power generation point sources. The capture/separation step for CO₂ from large point sources is a critical one with respect to the technical feasibility and cost of the overall carbon sequestration scenario. For large point sources, such as those found in power generation, the carbon dioxide capture techniques being investigated by the Office of Research and Development of the National Energy Technology Laboratory possess the potential for improved efficiency and reduced costs as compared to more conventional technologies. The investigated techniques can have wide applications, but the present research is focused on the capture/separation of carbon dioxide from fuel gas (pre-combustion gas) from processes such as the Integrated Gasification Combined Cycle (IGCC) process. For such applications, novel concepts are being developed in wet scrubbing with physical sorption, chemical sorption with solid sorbents, and separation by membranes. In one concept, a wet scrubbing technique is being investigated that uses a physical solvent process to remove CO₂ from fuel gas of an IGCC system at elevated temperature and pressure. The need to define an “ideal” solvent has led to the study of the solubility and mass transfer properties of various solvents. Pertaining to another separation technology, fabrication techniques and mechanistic studies for membranes separating CO₂ from the fuel gas produced by coal gasification are also being performed. Membranes that consist of CO₂-philic ionic liquids encapsulated into a polymeric substrate have been investigated for permeability and selectivity. Finally, processes based on dry, regenerable sorbents are additional techniques for CO₂ capture from fuel gas. An overview of these novel techniques is presented along with a research progress status of technologies related to membranes and physical solvents.     

Clean coal technologies in Japan: A review

Coal is the primary fossil fuel most used in the world for the electricity generation, iron making, and cement/concrete and chemical production. However, utilization of coal also results in emissions of CO2, SOx, NOx and other noxious compounds. The development of clean coal technology (CCT) is a main issue to maintain a clean environment. CCT in Japan is considered the highest level in the world. In this review, the developing CCTs in Japan including high efficiency combustion technologies, advanced gasification technologies, CO2 recovery and utilization technologies, and flue gas cleaning technologies are introduced and discussed. It is expected to provide some new view-of-points for CCT development.     

Combined Decarbonization of Electrical Energy Generation and Production of Synthetic Fuels by Renewable Energies and Fossil Fuels

Power generation from renewable energy sources and fossil fuels are integrated into one system. A combination of technologies in the form of a carbon capture utilization (CCU)-combined power station is proposed. The technology is based on energy generation from fossil fuels by a coal power plant with CO₂ recovery from exhaust gases, and pyrolysis of natural gas to hydrogen and carbon, completed by reverse water-gas shift for the conversion of CO₂ to CO, which will react with hydrogen in a Fischer-Tropsch synthesis for synthetic diesel. The carbon from the pyrolysis can replace other fossil carbon or can be sequestered. This technology offers significant CO₂ savings compared to the current state of technology and makes an environmentally friendly use of fossil fuels for electricity and fuel sectors possible.     

CO2‐Abtrennung für fossil befeuerte Kraftwerke

An overview of technologies for fossil fuel power plants with drastically reduced CO₂ emissions is given. Post combustion capture, Pre combustion capture, and Oxyfuel technology are introduced and compared. Current research results indicate that Post combustion capture may lead to slightly higher losses in power plant efficiency than the two other technologies. However, retrofitting of existing plants with Oxyfuel technology is complex and costly, and retrofitting of Pre combustion capture is not possible. On the other hand, Post combustion capture is suited for retrofitting. Based on the mature technology of reactive absorption, it can be implemented on a large scale in the near future. Therefore, Post combustion capture using reactive absorption is discussed here in some detail.     

CO2 Capture for Fossil Fuel‐Fired Power Plants

An overview of technologies for fossil fuel‐fired power plants with drastically reduced CO₂ emissions is given. Post‐combustion capture, pre‐combustion capture, and oxyfuel technology are introduced and compared. Current research results indicate that post‐combustion capture may lead to slightly higher losses in power plant efficiency than the two other technologies. However, retrofitting of existing plants with oxyfuel technology is complex and costly, and retrofitting of pre‐combustion capture is not possible. On the other hand, post‐combustion capture can be retrofitted to existing power plants with only minimal effort. Based on the mature technology of reactive absorption, it can be implemented on a large scale in the near future. Therefore, post‐combustion capture using reactive absorption is discussed here in some detail.