He Feng, Linak William P, Deng Shuang, Li Fanxing
Department of Chemical and Biomolecular Engineering, North Carolina State University , 911 Partners Way, Raleigh, North Carolina 27695-7905, United States.
National Risk Management Research Laboratory, U.S. Environmental Protection Agency , 109 T.W. Alexander Drive, Research Triangle Park, North Carolina 27709-0002, United States.
Environ Sci Technol. 2017 Feb 21;51(4):2482-2490. doi: 10.1021/acs.est.6b04043. Epub 2017 Feb 1.
Attrition behavior and particle loss of a copper oxide-based oxygen carrier from a methane chemical looping combustion (CLC) process was investigated in a fluidized bed reactor. The aerodynamic diameters of most elutriated particulates, after passing through a horizontal settling duct, range between 2 and 5 μm. A notable number of submicrometer particulates are also identified. Oxygen carrier attrition was observed to lead to increased CuO loss resulting from the chemical looping reactions, i.e., Cu is enriched in small particles generated primarily from fragmentation in the size range of 10-75 μm. Cyclic reduction and oxidation reactions in CLC have been determined to weaken the oxygen carrier particles, resulting in increased particulate emission rates when compared to those of oxygen carriers without redox reactions. The generation rate for particulates <10 μm was found to decrease with progressive cycles over as-prepared oxygen carrier particles and then reach a steady state. The surface of the oxygen carrier is also found to be coarsened due to a Kirkendall effect, which also explains the enrichment of Cu on particle surfaces and in small particles.
在流化床反应器中研究了基于氧化铜的氧载体在甲烷化学链燃烧（CLC）过程中的磨损行为和颗粒损失。大多数淘析颗粒通过水平沉降管后的空气动力学直径在2至5μm之间。还识别出了大量亚微米颗粒。观察到氧载体磨损会导致化学链反应引起的CuO损失增加，即Cu富集在主要由尺寸范围为10 - 75μm的破碎产生的小颗粒中。已确定CLC中的循环还原和氧化反应会削弱氧载体颗粒，与没有氧化还原反应的氧载体相比，导致颗粒排放率增加。发现<10μm颗粒的生成速率随着制备好的氧载体颗粒的循环次数增加而降低，然后达到稳定状态。还发现由于柯肯达尔效应，氧载体表面变得粗糙，这也解释了Cu在颗粒表面和小颗粒中的富集。
