Suresh P V, Menon Kavitha G, Prakash K S, Prudhvi S, Anudeep A
Department of Chemical Engineering, National Institute of Technology Warangal, Warangal, 506004, India.
Environ Sci Pollut Res Int. 2016 Oct;23(20):20111-20119. doi: 10.1007/s11356-015-5757-z. Epub 2015 Nov 13.
Chemical looping combustion (CLC) is an inherent CO capture technology. It is gaining much interest in recent years mainly because of its potential in addressing climate change problems associated with CO emissions from power plants. A typical chemical looping combustion unit consists of two reactors-fuel reactor, where oxidation of fuel occurs with the help of oxygen available in the form of metal oxides and, air reactor, where the reduced metal oxides are regenerated by the inflow of air. These oxides are then sent back to the fuel reactor and the cycle continues. The product gas from the fuel reactor contains a concentrated stream of CO which can be readily stored in various forms or used for any other applications. This unique feature of inherent CO capture makes the technology more promising to combat the global climate changes. Various types of CLC units have been discussed in literature depending on the type of fuel burnt. For solid fuel combustion three main varieties of CLC units exist namely: syngas CLC, in situ gasification-CLC (iG-CLC) and chemical looping with oxygen uncoupling (CLOU). In this paper, theoretical studies on the iG-CLC unit burning Indian coal are presented. Gibbs free energy minimization technique is employed to determine the composition of flue gas and oxygen carrier of an iG-CLC unit using FeO, CuO, and mixed carrier-FeO and CuO as oxygen carriers. The effect of temperature, suitability of oxygen carriers, and oxygen carrier circulation rate on the performance of a CLC unit for Indian coal are studied and presented. These results are analyzed in order to foresee the operating conditions at which economic and smooth operation of the unit is expected.
化学链燃烧（CLC）是一种固有的二氧化碳捕集技术。近年来，它备受关注，主要是因为其在解决与发电厂二氧化碳排放相关的气候变化问题方面具有潜力。一个典型的化学链燃烧装置由两个反应器组成——燃料反应器，燃料在以金属氧化物形式存在的氧气的帮助下发生氧化反应；空气反应器，还原后的金属氧化物通过空气流入进行再生。然后这些氧化物被送回燃料反应器，循环继续。燃料反应器产生的产物气包含一股浓缩的二氧化碳流，它可以很容易地以各种形式储存或用于其他任何应用。这种固有的二氧化碳捕集的独特特性使该技术在应对全球气候变化方面更具前景。根据燃烧的燃料类型，文献中讨论了各种类型的化学链燃烧装置。对于固体燃料燃烧，存在三种主要的化学链燃烧装置类型，即：合成气化学链燃烧、原位气化化学链燃烧（iG-CLC）和氧解耦化学链燃烧（CLOU）。本文介绍了对燃烧印度煤的iG-CLC装置的理论研究。采用吉布斯自由能最小化技术，以FeO、CuO以及混合载体FeO和CuO作为氧载体，确定iG-CLC装置的烟气组成和氧载体。研究并展示了温度、氧载体的适用性以及氧载体循环速率对印度煤化学链燃烧装置性能的影响。对这些结果进行分析，以便预测该装置实现经济平稳运行的操作条件。
