Economic analysis of CO2 capture from natural gas combined cycles using Molten Carbonate Fuel Cells
Economic analysis of CO2 capture from natural gas combined cycles using Molten Carbonate Fuel Cells
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DOI：
10.1016/j.apenergy.2014.04.011
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发表时间：
2014-10-01
期刊：
影响因子：
11.2
通讯作者：
Bedogni, S.
中科院分区：
文献类型：
--
作者：
Campanari, S.;Chiesa, P.;Bedogni, S.
在寻求低CO2排放的高效率发电的驱动下，近年来的一些工作研究了燃气涡轮机循环和高温燃料电池的集成，以布置具有CO2捕获的发电厂。从中期角度来看，最有前途的配置之一依赖于使用熔融碳酸盐燃料电池（MCFC）作为天然气联合循环（NGCC）中的"活性CO2浓缩器"。这项工作提出了一个评估的经济前景的两个最有前途的配置，以前进行了详细的模拟分析，在米兰理工大学，讨论其潜力的长期（2025+）的技术组合的电力utility.The燃料电池阴极侧接收气体涡轮机排气，以转移二氧化碳从这个流到阳极侧。在这样做的同时，MCFC需要总燃料输入的约20%，并以类似的比例贡献于工厂的电力输出。MCFC的下游放置了热回收蒸汽发生器（HRSG）;释放到电池流出物中的废热在底蒸汽循环中回收。考虑了两种不同的方法来净化离开燃料电池阳极的富CO2流：（i）将CO2与残余可燃化合物分离的低温过程，所述残余可燃化合物再循环回到燃气轮机，或（ii）残余可燃物质的氧燃烧，随后通过冷凝进行热回收、冷却和水分离。在所有情况下，净化都会产生高纯度的CO2流，然后泵送至液态进行储存。与基准NGCC相比，这两种工厂配置都可以捕获高达70 - 85%的CO2，效率损失很小或可以忽略不计，同时显着增加工厂的功率输出，因此在竞争性CO2捕获技术方面具有相关优势。此外，燃料电池部分的相对有限的功率输出表明，考虑到迄今为止建造的最大的现有MCFC工厂超过50 MWel的规模，所提出的概念具有合理的中期可行性。本文在介绍MCFC技术现状和经济前景之后，分析了拟议工厂的经济性能，以评估其经济可行性。考虑工厂的所有组成部分，并采用详细的自下而上的方法来确定组成部分的成本分布和工厂的总成本。电力成本和二氧化碳捕获成本的最终影响得到解决，允许证据是否以及如何这种解决方案可能在未来的竞争力。表明当前MCFC成本不允许相对于"传统"碳捕获循环的经济优势（即，NGCC与氨洗涤）;而假设中期MCFC成本目标更积极，情况将发生变化。为在经济基础上成功竞争，MCFC应达到的盈亏平衡具体成本接近1500（sic）/kW（el）（根据设备总成本TEC），天然气成本等于6.5（sic）/GJ，假设天然气成本为9（sic）/GJ，则增加到2000（sic）e/kW（el）。(C)2014爱思唯尔有限公司版权所有。
Driven by the search for high efficiency power generation with low CO2 emissions, several works in the last years investigated the integration of gas turbine cycles and high temperature fuel cells to arrange power plants with CO2 capture.One of the most promising configurations in a mid-term perspective relies on the use of Molten Carbonate Fuel Cells (MCFC) as "active CO2 concentrator" in natural gas combined cycles (NGCC). This work presents an assessment of the economic perspectives of the two most promising configurations, previously analyzed through detailed simulations carried out at Politecnico di Milano, discussing their potential for the long-term (2025+) technology portfolio of an electric utility.The fuel cell cathode side receives the gas turbine exhausts, in order to transfer CO2 from this stream to the anode side. While doing this, the MCFC requires about 20% of the total fuel input and contributes to the plant electric power output by a similar fraction. Downstream the MCFC is placed the heat recovery steam generator (HRSG); exhaust heat released to the cell effluents is recovered in the bottoming steam cycle.Two different approaches were considered for purification of the CO2-rich flow exiting the fuel cell anode: (i) a cryogenic process that separates CO2 from the residual combustible compounds, which are recycled back to the gas turbines, or (ii) an oxy-combustion of residual combustible species, followed by heat recovery, cooling and water separation by condensation. In all cases, purification yields a high purity CO2 stream, pumped to liquid form for storage.Both these plant configurations can capture up to 70-85% of CO2 with small or negligible efficiency penalties compared to a baseline NGCC while increasing remarkably the plant power output, thus yielding relevant advantages with respect to competitive CO2 capture technologies. Moreover, the relatively limited power output of the fuel cell section suggests a plausible mid-term feasibility of the proposed concept, by taking into account that largest existing MCFC plants built so far surpassed the 50 MWel size.After an introduction about MCFC technological status and economic outlook, this work analyzes the economic performances of the proposed plants in order to evaluate their economic viability, considering all plant components and adopting a detailed bottom-up approach to determine the component cost distribution and the total plant costs. The final effect on cost of electricity and CO2 capture cost are addressed, allowing to evidence whether and how this solution might be competitive in the future. It is shown that current MCFC costs do not allow an economic advantage with respect to 'traditional' carbon capture cycles (i.e., NGCC with ammines scrubbing); while the situation would change assuming more aggressive mid-term MCFC cost targets. The breakeven specific costs that MCFC should achieve to successfully compete on an economic basis results close to 1500 (sic)/kW(el) (in terms of Total Equipment Cost, TEC) for a cost of natural gas equal to 6.5 (sic)/GJ, increasing to 2000 (sic)e/kW(el) assuming NG cost of 9 (sic)/GJ. (C) 2014 Elsevier Ltd. All rights reserved.