题名 | 城市生活垃圾热解燃烧特性和氯转化机理 |
作者 | 李季 |
学位类别 | 博士 |
答辩日期 | 2003 |
授予单位 | 中国科学院过程工程研究所 |
授予地点 | 中国科学院过程工程研究所 |
导师 | 林伟刚 |
关键词 | 城市生活垃圾 循环流化床 氯化氢 垃圾焚烧 清洁焚烧 |
其他题名 | Characteristics of Pyrolysis and Combustion and Chlorine Release Mechanisms of Municipal Solid Wastes |
学位专业 | 化学工艺 |
中文摘要 | 城市生活垃圾焚烧技术可实现垃圾的减量化、无害化和资源化,近年在中国得到了迅速的推广,但焚烧技术仍存在高温腐蚀,二恶英类污染物排放等运行和污染问题.中科院过程工程研究所提出了双级料腿循环流化床垃圾焚烧工艺,该工艺采用燃前脱氯方法,将垃圾在焚烧装置内分级治理,可望解决垃圾焚烧技术中存在的主要问题.该文以城市生活垃圾典型组分作为研究对象,对其热分析特性、热力学特性、典型含氯组分的氯逸出特性及反应机理等方面进行了研究.目的是掌握中国典型垃圾组分的热解、燃烧特性,寻求双级料腿循环流化床垃圾焚烧装置各部分的最佳运行条件和工艺条件,实现垃圾的高效清洁焚烧.该文在实验部分对垃圾中的典型组分进行了热重天平的热解及不同氧浓度下燃烧的TG-DSC分析,得到中国垃圾可燃组分的热解燃烧特性,分别建立热解和半焦燃烧的反应动力学模型,获得各阶段的反应动力学参数.该文在理论部分进行了垃圾焚烧体系的化学热力学平衡分析,计算PVC及典型成分垃圾在不同温度、过量空气系数、含氯量等条件下焚烧产物的形态及平衡浓度,得到HCl的生成和转化规律,根据计算结果得到垃圾焚烧过程中抑制HCl生成、消除二恶英的反应工艺条件,同时研究了钙基脱氯剂的脱氯效果. |
英文摘要 | Incineration has been widely applied over the past decade for disposal of municipal solid wastes (MSWs) in China due to its advantages of volume reduction, high toxicity elimination and energy recovery. However, high chlorine content in MSW results in two major problems: high temperature corrosion and the emission of dioxins. It is not an easy task to solve these problems by changing operating conditions in conventional incinerators, because the two problems are interrelated. A new type of incinerator, so called double-dipleg circulating fluidized bed (DDCFB) incinerator, was proposed in the Institute of Process Engineering, Chinese Academy of Sciences to solve these problems. The new concept is based on the in situ staged conversion of MSWs, which decouples the interactions between high temperature corrosion and the emission of dioxins, by pre-remo val of chlorine before combustion stage. The knowledge of behaviors of MSWs in thermal conversion process is of essential importance for the design of the new type of incinerator. The main objective of this work is to study pyrolysis and combustion characteristics of typical components in Chinese MSWs and to find out the optimized conditions in a DDCFB incinerator. The typical ingredients in MSWs were investigated by applying thermal analysis, thermodynamics equilibrium calculation, chlorine release experiments and chlorine release mechanisms studies Pyrolysis and different oxygen levels combustion of typical components in MSWs were studied in a TG-DSC apparatus. The kinetics characteristics and parameters in different stage of thermal conversion process were obtained. The chlorine release during pyrolysis and combustion of PVC were studied experimentally in a lab-scale fluidized bed, with online HC1 measurement. The influence of temperature and heating rate oil the pyrolysis, combustion behaviors and the release of HC1 were studied. The results showed that bed temperature only has minor effect on HCl release. However, the heating rate has a significant influence on the HCl release: a higher heating rate will restrain the release of HCl in a fluidized bed. Thermodynamic equilibrium calculations were performed to reveal the trend of formation of chlorine-containing compounds during thermal conversion process of PVC and MSWs under different conditions. The calculations were also applied to the reactions between Ca-based sorbents and chlorine-containing compounds. The release mechanisms of chiorine in PVC's under fluidized bed conditions were analyzed. Pyrolysis of PVC may be divided into two stages: HCl release at low temperature and evolution of aliphatic and aromatic hydrocarbons at high temperature. Due to the high heating rate in a fluidized bed, the competition between the release of aliphatic and aromatic hydrocarbons and HCl may be the main reason for the low release of HCl from PVC. Based on the experimental results and thermodynamic equilibrium analysis, the optimized conditions for a DDCFB incinerator were proposed, which may be useful for further design of the new type of incinerator. |
语种 | 中文 |
公开日期 | 2013-09-16 |
页码 | 132 |
内容类型 | 学位论文 |
源URL | [http://ir.ipe.ac.cn/handle/122111/1379] ![]() |
专题 | 过程工程研究所_研究所(批量导入) |
推荐引用方式 GB/T 7714 | 李季. 城市生活垃圾热解燃烧特性和氯转化机理[D]. 中国科学院过程工程研究所. 中国科学院过程工程研究所. 2003. |
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