燃煤发电排放CO2的处置利用途径

CO2是能源与环境生物活动循环的依存产物,工业化后煤炭等化石燃料的使用产生了大量的CO2排放,打破了CO2的自然生态平衡。介绍了CO2的来源,分析了燃煤发电CO2的排放量,我国每年燃煤发电约排放C0230．7×10^8t,指出燃煤发电是减排CO2的重点。提出CO2的利用与处置的方法主要有：CO2和合成氨加工成尿素,并发展大颗粒尿素促进造林绿化;美国正在建的CO2零排放燃煤发电装置,采用了CO2收集与封存（CCS）技术,以及煤制油清洁燃料联产电力。     

O2/CO2混合富氧燃烧技术探讨

分离处置化石燃料燃烧产生CO2的技术被认为是近期内减缓CO2排放的较为可行的措施.在众多CO2分离回收技术中,O2/CO2混合富氧燃烧技术具有明显的优势和较强的应用前景.它不仅可以使CO2的回收和利用容易进行,还可以有效减少NOx和SO2的排放,同时能提高锅炉效率,是一项高效节能的燃烧方式.对O2/CO2混合富氧燃烧技...     

天然气水合物气藏开发技术探讨

天然气水合物是本世纪最具开发前景的替代能源，开发天然气水合物资源，对我国宏观能源战略决策和可持续发展具有重大的现实意义。文章概述了天然气水合物气藏的特点和国外水合物气藏勘探项目的进展．对热激发技术、降压技术和化学试剂技术等3种技术进行了对比分析，并着重研究了微波加热技术和CO2置换技术。微波加热技术的优点是作用速度快、设备简单、灵活性高、不会对储层造成任何污染。CO2置换技术的优点是利用天然气水合物生成和分解的机理，不仅考虑了经济地开采资源，并且还提出了在开采后消除对海底环境产生有害影响的对策。     

美国Wisconsin燃煤电厂试验CO2捕集技术

美国电力的50％和CO2排放的30％来自燃煤。碳捕集技术是未来能源和煤炭相关工业的发展重点。 美国wisconsin公用事业公司于2008年3月初宣布，其燃煤电厂将基于氨溶剂试验CO2捕集技术，以便将CO2于地下封存。如果成功，该技术将会用于所有燃煤和燃烧天然气的电厂，减少燃烧化石燃料的电厂向大气排放温室气体。     

两种物理吸收法在沼气脱碳中的模拟对比研究

运用化工流程模拟软件PRO/II对水洗法和碳酸丙烯酯法沼气脱碳进行了模拟对比,原料气组分按CH4为57%,CO2为40%,N2为2.8%,O2为0.2%模拟计算,结果显示两种方法在2.7,1.3,0.7 MPa的操作压力下,CH4回收率都可达到98%以上,操作压力极大影响系统运行能耗,宜根据生物天然气终端用途和CO2是否具有回收及利用价值来确定。生物天然气中CH4>93%,CO2<1.5%,N2<5%,O2<0.5%,达到《天然气》二类气及《车用压缩天然气》指标;水洗法CH4和CO2回收率略高于碳酸丙烯酯法,但碳酸丙烯酯法投资低、能耗低、操作维护简单,经济上更有优势。经净化脱碳后的沼气利用价值得到提高,经济和社会效益显著。     

我国首套低品位天然气CO2膜分离装置应用成功

日前,由中科院大连化学物理研究所研究员曹义鸣领导的膜技术组完成的年处理量为1360万m^3低品位天然气中CO2膜法分离技术在海南试车成功,并顺利通过验收。这是目前国内第1套膜分离CO2装置,也是目前世界上同类装置中处理CO2含量量高的天然气膜法处理装置。它标志着我国利用膜技术分离天然气中CO2技术工艺步入世界先进行列。     

天然气水合物开采技术——CO_2-CH_4置换法最新研究进展

CO2-CH4置换技术作为一种既可生产CH4又能减少CO2排放的天然气水合物开采方法,近20年来得到了广泛深入的研究。该技术的优势是:当温度低于10℃,CO2水合物较CH4水合物在热力学上更为稳定,两者的置换反应在理论上是自发的,CO2水合物的形成有助于保持气体水合物藏的地质力学稳定性。但该方法也有缺点,CH4水合物周围CO2水合物的形成限制了CH4水合物的分解,孔隙空间中形成的次生水合物会堵塞可用于气体置换的渗透性通道,因此并不是所有的CH4都能被CO2所替换。近年来业界在CO2-CH4置换技术的室内实验、数值模拟和现场试验等方面取得了一些进展。未来主要的研究方向应是全面了解不同生产策略下CO2-CH4-CH4水合物-CO2水合物-水/卤水系统的行为和储层条件;开展更多的现场规模生产项目;数值模拟中需要考虑更多的组分和相态,了解和考虑更多的过程和机理,并结合室内和现场试验结果,考虑地质特性的影响;更深入地了解CO2和N2对CH4的驱替。     

天然气与煤制气的区别

<正>天然气是一种多组合的混合气态化石燃料,主要成分为CH4,也含有乙烷(C2H6)、丙烷(C3H8)、N2和CO2等成分。作为产品天然气,国家标准GB17820-2012天然气对其热值有规定:高位发热值31.4 MJ/m3。天然气被广泛应用于工业生产及居民生活,是一种洁净能源,燃烧后没有H2O和废渣的产生。煤制气是人工煤气     

中国将成为第二个开发页岩气的国家

煤炭占中国一次能源消费量的70％以上。能源资源中单位能源消费量CO2排放量最大的是煤炭,大体相当于天然气的2倍。过去的煤电厂与天然气联合循环发电厂比较,相同发电量前者的CO2排放量达到后者的3倍。     

天然气水合物开采技术——C02-cH4置换法最新研究进展

C02-CH4置换技术作为-种既可生产CH4又能减少CO2排放的天然气水合物开采方法,近20年来得到了广泛深人的研究。该技术的优势是：当温度低于10℃,CO2水合物较CH4水合物在热力学上更为稳定,两者的置换反应在理论上是自发的,CO2水合物的形成有助于保持气体水合物藏的地质力学稳定性。但该方法也有缺点,CH4水合物周围CO2水合物的形成限制了CH4水合物的分解,孔隙空间中形成的次生水合物会堵塞可用于气体置换的渗透性通道．因此并不是所有的CH4都能被CO。所替换。近年来业界在CO2-CH4置换技术的室内实验、数值模拟和现场试验等方面取得了-些进展。未来主要的研究方向应是全面了解不同生产策略下CO2-CH4-CH4水合物-CO2水合物-水／卤水系统的行为和储层条件;开展更多的现场规模生产项目;数值模拟中需要考虑更多的组分和相态,了解和考虑更多的过程和机理,并结合室内和现场试验结果,考虑地质特性的影响;更深入地了解CO2和N2对CH4的驱替。     

浅析二氧化碳捕获技术应用于炼厂的可行性

温室气体减排已成为炼厂面临的严峻挑战。CO2捕获是具有大规模减排潜力的技术方案,炼厂可在继续使用廉价化石燃料的同时降低排放。目前许多炼厂已在评估从烟道气中捕获CO2的技术,探索经济可行的捕获方案,这些方案主要包括燃烧后捕获、燃烧前捕获和富氧燃烧捕获等。其中,燃烧后捕获技术相对成熟,可对大多数现有装置进行改造,仅需增加简单的后处理设备,缺点是能耗大,CO2浓度较低,难捕获,从胺溶液中释放的CO2达不到碳封存所需的压力;燃烧前捕获方案的优点是CO2浓度较高,压力高,易于回收,降低了压缩成本及负荷,缺点是这种方法主要适用于新装置,因为炼厂现有的气化装置较少,建设投资成本高且需要大量的辅助系统;富氧燃烧捕获方案的优点是烟道气中的CO2浓度非常高,分离容易;缺点是空气分离设备投资很高,冷却的循环烟道气必须保持一定温度。对3种方案评价表明,在CO2总量和浓度最高的排放源进行捕获成本最低,例如当气体中CO2浓度从12%下降到4%时,捕获成本将上升25%以上;燃烧前捕获和富氧燃烧捕获比燃烧后捕获可节约35%~40%的成本。     

IGCC系统控制CO_2排放的研究进展

整体煤气化联合循环(IGCC)作为一种被验证的具有发展前景的洁净煤发电技术,如何实现IGCC中CO2的零排放,已经成为国内外学者研究的热点。概述了目前国内外控制IGCC系统中CO2排放的研究进展,归纳总结了IGCC系统中CO2分离和回收的四类途径:燃烧后分离与回收、燃烧前对燃料气进行处理与分离、以IGCC为基础的煤基动力化工多联产系统以及燃烧与CO2分离一体化途径。并引入控制CO2排放科技创新一体化理论,指出未来控制CO2排放的方向。     

CO2的捕集和封存技术的现状、前景与挑战

本文对CO2捕集和封存技术的现状、前景和可能遇到的挑战进行了论述,指出CO2捕集是煤炭现代化利用的一个重要趋势。同时指出,成本、捕集效率和方式都是影响CO2捕集和封存发展的重要因素,目前一些问题仍需要得到进一步证实。     

Linear Models for Optimization of Infrastructure for $hbox{CO}_{2}$ Capture and Storage

This paper presents linear models of the most common components in the value chain for $hbox{CO}_{2}$ capture and storage. The optimal investment planning of new gas power plants traditionally includes the cost of fuel versus sales of electricity and heat from the plant. If a new power plant also causes additional investments in gas infrastructure, these should be included in the optimization. With the increasing focus on global $hbox{CO}_{2}$ emissions, yet another aspect is introduced in the form of technology and infrastructure for capture, transport, and storage of $hbox{CO}_{2}$. To be able to include all these aspects in the planning of new power plants, linear models for $hbox{CO}_{2}$ capture and storage are formulated consistent with current models for gas, electricity, and heat infrastructures. This paper presents models for the following $hbox{CO}_{2}$ infrastructure: source, combined cycle gas turbine producing electricity, heat and exhaust, capture plant, pipeline, liquefaction plant, storage, ship transport, injection pump, and demand/market.      

Parametric study of membrane reactors for hydrogen production via high-temperature water gas shift reaction

This study presents numerical studies of hydrogen production performance via water gas shift reaction in membrane reactor. The pre-exponential factor in describing the hydrogen permeation flux is used as the main parameter to account for the membrane permeance variation. The operating pressure, temperature and H₂O/CO molar ratio are chosen in the 1–20 atm, 400–600 °C and 1–3 ranges, respectively. Based on the numerical simulation results three distinct CO conversion regimes exist based on the pre-exponential factor value. For low pre-exponential factors corresponding to low membrane permeance, the CO conversion approaches to that obtained from a conventional reactor without hydrogen removal. For high pre-exponential factor, high CO conversion and H₂ recovery with constant values can be obtained. For intermediate pre-exponential factor range both CO conversion and H₂ recovery vary linearly with the pre-exponential factor. In the high membrane permeation case CO conversion and H₂ recovery approach limiting values as the operating pressure increases. Increasing the H₂O/CO molar ratio results in an increase in CO conversion but decrease in H₂ recovery due to hydrogen permeation driving force reduction. As the feed rate increases in the reaction side both the CO conversion and hydrogen recovery decrease because of decreased reactant residence time. The sweep gas flow rate has a significant effect on hydrogen recovery. Low sweep gas flow rate results in low CO conversion H₂ recovery while limiting CO conversion and hydrogen recovery can be reached for the high membrane permeance and high sweep gas flow rate cases.     

Gasification characteristics of organic waste by molten salt

Recently, along with the growth in economic development, there has been a dramatic accompanying increase in the amount of sludge and organic waste. The disposal of such is a significant problem. Moreover, there is also an increased in the consumption of electricity along with economic growth. Although new energy development, such as fuel cells, has been promoted to solve the problem of power consumption, there has been little corresponding promotion relating to the disposal of sludge and organic waste. Generally, methane fermentation comprises the primary organic waste fuel used in gasification systems. However, the methane fermentation method takes a long time to obtain the fuel gas, and the quality of the obtained gas is unstable. On the other hand, gasification by molten salt is undesirable because the molten salt in the gasification gas corrodes the piping and turbine blades. Therefore, a gasification system is proposed by which the sludge and organic waste are gasified by molten salt. Moreover, molten carbonate fuel cells (MCFC) are needed to refill the MCFC electrolyte volatilized in the operation. Since the gasification gas is used as an MCFC fuel, MCFC electrolyte can be provided with the fuel gas. This paper elucidates the fundamental characteristics of sludge and organic waste gasification. A crucible filled with the molten salt comprising 62 Li₂CO₃/38 K₂CO₃, is installed in the reaction vessel, and can be set to an arbitrary temperature in a gas atmosphere. In this instance, the gasifying agent gas is CO₂. Sludge or the rice is supplied as organic waste into the molten salt, and is gasified. The chemical composition of the gasification gas is analyzed by a CO/CO₂ meter, a HC meter, and a SO_x meter gas chromatography. As a result, although sludge can generate CO and H₂ near the chemical equilibrium value, all of the sulfur in the sludge is not fixed in the molten salt, because the sludge floats on the surface of the carbonate by the specific gravity of sludge lighter than the carbonate, and is not completely converted into CO and H₂. Moreover, the rice also shows good characteristics as a gasifying agent. Consequently, there is high expectation to using the organic waste as a molten salt gasifying agent. However, this requires lengthening the contact time between the organic waste and the molten salt.     

碳捕集与封存技术的现状与未来

全球气候变暖问题已经越来越严重,碳捕集与封存（CCS）技术被看作是最具发展前景的解决方案之一,随着研究的不断深入,CCS技术成本将进一步降低。碳捕集工艺按操作时间可分为燃烧前捕集、富氧燃烧捕集和燃烧后捕集,其中最有发展前景的是富氧燃烧捕集。CO2-EOR技术虽然不是直接针对性地封存二氧化碳,但其不仅可以解决二氧化碳的封存问题,还能提高油田采收率,近年来得到广泛应用。我国在CCS技术的研究上进行了大量工作,CCS技术已被列入＂973计划＂和＂863计划＂,北京高碑店热电厂二氧化碳捕集示范工程受到国内外的关注。虽然CCS技术取得了长足的进步,但仍面临着很多问题,如二氧化碳泄漏问题、技术难点、建设和运行成本高昂等。CCS技术项目投资较大,如果没有政府在立法和税收机制上的激励与优惠措施,很难真正进入商业化应用阶段。好在种种迹象表明,随着全球气候问题的加剧,各国政府越来越重视CCS技术的研发和利用。     

Transient reaction and exergy analysis of catalytic partial oxidation of methane in a Swiss-roll reactor for hydrogen production

Catalytic partial oxidation of methane (CPOM) is a promising method for hydrogen production with autothermal reaction. To figure out the unsteady reaction characteristics of CPOM in a Swiss-roll reactor along with heat recirculation, a numerical method is employed to simulate the transient reaction dynamics, with emphasis on energy recovery using exergy analysis. Three different gas hourly space velocities (GHSVs) of 5000, 10,000 and 50,000 h⁻¹ with the condition of atomic O/C ratio of 1 are considered. The predictions indicate that increasing GHSV substantially shortens the transient period of chemical reactions; however, it also reduces the methane conversion, as results of more reactants sent into the reactor and shorter residence time of the reactants in the catalyst bed. Within the investigated range of GHSV, the methane conversion with energy recovery at the steady state is larger than 80%, much higher than the reaction without heat recovery. The selectivities of H₂ and CO in the product gas are always larger than 90%. The exergy recovery is in the range of 66–80%, implying that over two-third useful work contained in the product gas can be reused to preheat the reactants in the reactor, thereby enhancing the performance of CPOM.     

钙基吸收剂捕集火电机组烟气中CO_2的热力性能分析

针对燃煤火电机组减排CO2的问题,以某1 000MW超临界机组为例,建立了钙基吸收剂循环煅烧/碳酸化法捕集CO2的系统流程,得到了CO2捕集率与弛放率、钙碳物质的量比和气固分离效率等参数的关系,基于Aspen Plus软件分析了关键参数对系统性能的影响.结果表明:捕集90%CO2和100%SO2使得机组的发电热效率比设计值降低了8.73个百分点;随着弛放率的提高或气固分离效率的降低,固体循环物料质量流量、煅烧能耗和发电热效率均下降;随着CO2捕集率的提高,固体循环物料质量流量和煅烧能耗呈逐渐增大的趋势,但发电热效率则降低.     

Thermodynamic analysis of hydrogen production via glycerol steam reforming with CO2 adsorption

Thermodynamic equilibrium for glycerol steam reforming to hydrogen with carbon dioxide capture was investigated using Gibbs free energy minimization method. Potential advantage of using CaO as CO₂ adsorbent is to generate hydrogen-rich gas without a water gas shift (WGS) reactor for proton exchange membrane fuel cell (PEMFC) application. The optimal operation conditions are at 900 K, the water-to-glycerol molar ratio of 4, the CaO-to-glycerol molar ratio of 10 and atmospheric pressure. Under the optimal conditions, complete glycerol conversion and 96.80% H₂ and 0.73% CO concentration could be achieved with no coke. In addition, reaction conditions for coke-free and coke-formed regions are also discussed in glycerol steam reforming with or without CO₂ separation. Glycerol steam reforming with CO₂ adsorption has the higher energy efficiency than that without adsorption under the same reaction conditions.