PDF《性分析》

第37 卷第

3 期2017 年3月环境科学学报Acta Scientiae Circumstantiae Vol.

37,No.3 Mar.,

2017 基金项目: 国家自然科学基金(No. 51308132);

广东省科技计划(No. 2014A050503063, 2015B020235013);

广州市科技计划项目(No. 201510010033,2016201604030058) Supported by the National Natural Science Foundation of China(No.51308132), the Science and Technology Planning Project of Guangdong Province ( No. 2014A050503063, 2015B020235013 ) and the Scientific and Technological Planning Project of Guangzhou ( No. 201510010033, 2016201604030058) 作者简介: 傅杰文(1990―),男, E?mail:1204177969@ qq.com;

?通讯作者(责任作者), E?mail: liujy@ gdut.edu.cn Biography: FU Jiewen (1990―), male,E?mail:1204177969@ qq.com;

?Corresponding author, E?mail: liujy@ gdut.edu.cn DOI:10.13671 / j.hjkxxb.2016.0168 傅杰文,刘敬勇,孙水裕,等.2017.污泥与煤在 CO2 / O2 及N2 / O2 气氛条件下的混燃特性分析[J].环境科学学报,37(3):1021?1031 Fu J W, Liu J Y, Sun S Y, et al. 2017.Co?combustion characteristic of sewage sludge and coal under CO2 / O2 and N2 / O2 atmosphere[J].Acta Scientiae Circumstantiae,37(3):1021?1031 污泥与煤在 CO2 / O2 及N2 / O2 气氛条件下的混燃特 性分析 傅杰文1 ,刘敬勇1,2,? ,孙水裕1 ,郭家宏1,2 ,黄绍松1 ,张耿1 , 孙健1 , 卓钟旭1 , 梁凯云1 1. 广东工业大学环境科学与工程学院,广州

510006 2. 广东工业大学环境健康与污染控制研究院,广州

510006 收稿日期:2016?03?23 修回日期:2016?04?26 录用日期:2016?04?26 摘要:采集了广州具有代表性的市政污泥,利用热重法对单一污泥、煤及其混合样品在 CO2 / O2 及N2 / O2 气氛条件下进行了 TG(热重)实验,同 时计算了污泥和煤的

4 个燃烧特性指数,获得了燃烧的动力学参数.实验结果表明,污泥燃烧有

4 个燃烧阶段,包括水分析出、挥发分析出与燃 烧、固定碳的燃烧和无机盐类挥发分解,其中,挥发分析出与燃烧是污泥燃烧的主要阶段;

煤掺烧污泥可以提高煤的着火性能.在CO2 / O2 及N2 / O2 燃烧气氛下,增加 O2 浓度,污泥与煤混合样的热重曲线整体向低温区移动,微商热重曲线峰值增大,峰宽变小,燃烧性能增强.在CO2 / O2 气氛下,O2 浓度从 30%增加到 60%时,污泥的挥发分释放特性指数 D、可燃性指数 C、燃尽指数 Cb 、综合燃烧特性指数 S 分别增加了 45%、12%、 18%、6%.相同 O2 浓度条件下,污泥与煤在 CO2 / O2 气氛下的着火性能较 N2 / O2 气氛滞后,最大峰值变小,高浓度的 CO2 抑制其混合样的燃烧.采用Coats-Redfern 方程计算得到

3 个燃烧阶段反应的动力学参数,其中,增加 O2 浓度,污泥与煤混合样品的质量平均表观反应活化能 Em 减小, 并且 O2 浓度越高越有利于燃烧反应的进行.污泥与煤混合燃烧取 n =

2 可以对挥发分燃烧与固定碳燃尽峰峰前与峰后的反应模型进行描述. 关键词:污泥;

煤;

混合燃烧;

热重分析;

燃烧特性;

动力学模型 文章编号:0253?2468(2017)03?1021?11 中图分类号:X705 文献标识码:A Co?combustion characteristic of sewage sludge and coal under CO2 / O2 and N2 / O2 atmosphere FU Jiewen1 , LIU Jingyong1,2,? , SUN Shuiyu1 , KUO Jiahong1,2 , HUANG Shaosong1 , CHANG Kenlin1 , SUN Jian1 , ZHUO Zhongxu1 , LIANG Kaiyun1 1. School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou

510006 2. Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou

510006 Received

23 March 2016;

received in revised form

26 April 2016;

accepted

26 April

2016 Abstract: Sewage sludge and coal were collected in Guangzhou, both of these materials and their mixtures were estimated by thermogravimetric analysis (TGA) under different CO2 / O2 and N2 / O2 atmosphere conditions in this study. Four combustion characteristic indexes and their kinetic parameters were also calculated. Experimental results obtained from TGA tests showed there were four combustion steps for sludge samples including moisture exhalation, volatile exhalation and combustion, fixed carbon combustion and exhalation of inorganic salt. Results found that the process of volatile exhalation and combustion was the control step of the whole combustion. On the other hand, with the increasing of O2 concentration under CO2 / O2 and N2 / O2 atmosphere, TG curves of the mixture samples were tended to migrate into the low temperature area, and combustion performance enhanced while the maximum value of DTG peak increased and also peak width decreased. Nevertheless, volatile combustion characteristic index D, parameters of the 环境科学学报37 卷flammability index C, burnout index Cb and comprehensive index of combustion characteristics S were all calculated and observed an increasing level of 45%, 12%, 18%, 6%, respectively. With the same concentration of O2 , the combustion performance of mixture samples under CO2 / O2 atmosphere is lower than those in N2 / O2 atmosphere according to maximum DTG peak variation. Higher concentrations of CO2 would inhibit the combustion performance of mixtures. Besides, application of the Coats?Redfern equation in this study achieved the understanding of both reaction equations and the kinetic parameters (E) during various combustion stages. The calculation results found that this model can fit the experimental results of before or after volatile combustion and fixed carbon burnout peaks of the sample combustion when n value is equal to 2. Keywords: sludge;

coal;

mixed combustion;

thermogravimetric analysis;

combustion characteristics;

kinetics model

1 引言(Introduction) 随着污水排放标准日趋严格及污水处理技术 的发展,污泥产量大幅增加,浓缩在其中的重金属、 致病微生物及难降解的有机物等有毒有害物质的 种类和数量也急剧增加( Jones et al., 2014). 据统 计,2015 年中国城市污水污泥的年产量超过

3000 万t,这些污泥的成分复杂、含水率高、不稳定且较易 腐化,急需进行有效的处理处置(Yang et al.,2015). 环境相关法令已经在国外执行,严禁可降解污泥进 行填埋处理(Cieslik et al.,2015),而焚烧处理不仅 可以回收能源,而且符合固废处置的 三化 原则, 因此,鼓励对污泥进行焚烧处理( Kelessidis et al., 2012).我国相关部门颁布了《污水处理厂污泥处理 处置最佳可行技术导则》,将污泥焚烧作为我国污 泥处理处置最佳可行技术之一,但目前各类机械脱 水后的污泥具有高水分、高灰分、高粘度、低热值的 ........