Comparative study of fuel-N and tar evolution in chemical looping combustion of biomass under both iG-CLC and CLOU modes
Comparative study of fuel-N and tar evolution in chemical looping combustion of biomass under both iG-CLC and CLOU modes
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DOI：
10.1016/j.fuel.2018.09.003
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发表时间：
2019-01
期刊：
影响因子：
7.4
通讯作者：
Antón Pérez-Astray;I. Adánez-Rubio;T. Mendiara;M. Izquierdo;A. Abad;P. Gayán;L. F. D. Diego;F. García-Labiano;J. Adánez
中科院分区：
文献类型：
--
作者：
Antón Pérez-Astray;I. Adánez-Rubio;T. Mendiara;M. Izquierdo;A. Abad;P. Gayán;L. F. D. Diego;F. García-Labiano;J. Adánez
化学循环燃烧(CLC)技术与二氧化碳封存和生物质可持续管理相结合，是一种很有前途的具有碳捕获和储存(BECCS)技术的生物能源。在生物质燃烧中需要考虑的一个方面是NOx的形成和气体产品流中可能存在的焦油。与其他二氧化碳捕集技术相比，CLC技术的优势在于，只有燃料氮有助于氮氧化物的形成。此外，关于《中图法》中焦油形成的信息也很少。因此，本文针对这两个方面进行了研究，并比较了两种不同的化学链燃烧方式--气化化学链燃烧(IG-CLC)和氧解偶联化学链燃烧(CLU)的燃烧效果。根据燃烧模式的不同，观察到了重要的差异。在这两种情况下，燃料反应堆中的大部分燃料-N都以N2的形式出现。然而，INIG-CLC在燃料反应堆中测得的氮中有94%以上是氮气，与所使用的生物质无关。在CLU模式下，这些百分比较低。在这种情况下，也检测到少量的N2O，尽管它在850 °C时几乎降至零。在空气反应器中，没有发现NO，其浓度保持在所有类型生物质测试和运行模式下的电力设施中NOx排放的法定限值以下。燃料反应堆出口气流中的焦油种类和浓度在两种燃烧模式下是不同的。在G-CLC模式下，在980 °C燃烧时，总焦油含量约为2.5~3.7 g/Nm~3，其中以萘为主。相反，在Clou中发现了少量的焦油。
Chemical looping combustion (CLC) processes combined with CO2sequestration and sustainable management of biomass represent a promising BioEnergy with Carbon Capture and Storage (BECCS) technology. One of the aspects to be considered in the combustion of biomass is the formation of NOxand the possible existence of tar in the gaseous product stream. The advantage of the CLC technology compared to other CO2capture technologies is that only fuel-N contributes to nitrogen oxides formation. Moreover, scarce information is available about tar formation in CLC. Thus, this work focuses on these two aspects and compares the results obtained when two different chemical looping combustion modes are used, namelyIn SituGasification Chemical Looping Combustion (iG-CLC) and Chemical Looping with Oxygen Uncoupling (CLOU). Important differences were observed depending on the combustion mode. In both cases most of the fuel-N appeared as N2in the fuel reactor. However, iniG-CLC more than 94% of the nitrogen measured in the fuel reactor was N2independently of the biomass used. These percentages under the CLOU mode were lower. In this case, low amounts of N2O were also detected, although it decreased to almost zero at 850 °C. In the air reactor, NO was found and its concentration remained below the legal limit for NOxemissions in power installations with all the types of biomass tested and operating modes. Tar species and concentrations found at the fuel reactor outlet stream were different under the two combustion modes. About 2.5–3.7 g/Nm3total tar could be found at 980 °C burning underiG-CLC mode, mostly naphthalene. On the contrary, insignificant tar amounts were found in CLOU.