Received: 6 February 2020 | Revised: 28 June 2020 | Accepted: 9 July 2020 DOI: 10.1002/ese3.792
RESEARCH ARTICLE
Kinetic analysis about the CO 2 capture capacity of lime mud from paper mill in calcium looping process Rongyue Sun 1,2 | Rui Xiao 1 | Jiangming Ye 2
1 Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing, China 2 School of Energy and Power Engineering, Nanjing Institute of Technology, Nanjing, China Correspondence Rongyue Sun and Rui Xiao, Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, No. 2 Sipailou, Nanjing 210096, China. Emails: sunrongyue@163.com; ruixiao@ seu.edu.cn Funding information National Natural Science Foundation of China, Grant/Award Number: 51706094
Abstract Lime mud, a kind of industrial waste that produced in paper mill, was proposed as CO 2 sorbent in calcium looping process. The carbonation performance of the lime mud was investigated in a dual-fixed bed reactor (DFR) and a thermogravimetric an- alyzer (TGA). The carbonation kinetics of the lime mud in the chemical reaction con- trolled stage was analyzed by a surface reaction-controlled kinetic model. The results show that the lime mud presents much poorer carbonation performance during the chemical reaction controlled stage compared with the limestone, mainly due to the high content of chlorine in the lime mud. A prewash treatment process was used to decrease the chlorine content to mitigate the sintering of the lime mud when calcined at high temperature. After prewash treatment, the prewashed lime mud shows much higher CO 2 capture capacity during the chemical reaction controlled stage compared with the lime mud. A prolonged carbonation process successfully further enhances the microstructure and improves the carbonation performance of the prewashed lime mud in the chemical reaction controlled stage. The lime mud can be effectively used as CO 2 sorbent in calcium looping process after prewash treatment and the following prolonged carbonation treatment.
KEYWORDS calcium looping process, CO 2 capture, kinetics, lime mud
1 | INTRODUCTION Large amount of industrial wastes are discharged from com- mercial production every year. 1 Lime mud is a kind of in- dustrial waste that produced during the causticization process in paper mill. China is one of the papermaking and paper consumption powerhouses. In China, about 50 million tons of paper was produced every year, which means dozens of million tons of lime mud were discharged to the environment. The discharge of such a large amount of lime mud leads to
serious environmental aspects including water pollution and land occupation. 2 Therefore, how to recycle the lime mud in environmentally friendly ways is an interesting topic and has drawn lots of researchers’ attentions. Lime mud was firstly recovered as soil amendments and building materials. 3 Qin et al 4 have proved that recycling of lime mud as raw materials of anorthite ceramic was a feasible approach to solve the solid wastes. Madrid et al 5 successfully reused lime mud to produce concrete masonry units that with better thermal properties. In recent years,
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2020 The Authors. Energy Science & Engineering published by Society of Chemical Industry and John Wiley & Sons Ltd
| 1 wileyonlinelibrary.com/journal/ese3
Energy Sci Eng. 2020;00:1–11.
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