生物干化污泥热特性与成型特征研究
文献类型：学位论文
| 作者 | 张瑞宇 |
| 学位类别 | 硕士 |
| 答辩日期 | 2015-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 张付申 |
| 关键词 | 生物干化污泥，混煤燃烧，热重分析，尾气排放，衍生燃料，bio-drying sludge, co-combustion with coal, thermogravimetric analysis, exhaust gas emission, derived fuel |
| 其他题名 | Thermal and Molding Characteristics of Bio-drying Sludge |
| 学位专业 | 环境工程 |
| 中文摘要 | 生物干化法处理污泥是近年来发展起来的一种新型污泥预处理方式，这种方法相对于传统的污泥干化方式具有诸多优势，因而受到了广泛的关注。目前，国内外对于生物干化污泥的研究主要集中在干化过程、工艺参数调控、干化机理和干化产品土地应用的研究，有关干化产品燃烧性能及其能源利用的研究比较少见。本论文主要针对生物干化污泥的热特性、混煤焚烧特性、成型特征和污染物排放规律进行了系统研究。 分析其实际应用价值，以期为燃煤发电厂的实际应用提供支持。研究得到的主要研究成果如下： （1）对生物干化污泥分别进行热解热重和燃烧热重分析，计算相关热重参数，对比分析样品的性质，利用方程模拟计算反应过程中的表观活化能和指前因子。结果表明，生物干化污泥具有其自身的燃烧特性，热重过程可以分为水分挥发、挥发分析出燃烧、难挥发分和固碳燃烧以及最终燃尽四个阶段，在200 ℃即有挥发分析出燃烧，着火点温度为269-272 ℃，综合燃烧特性指数随原料自身组分变动，可达5.25-14.43×10-12 K-3•min-2。与煤样品相比，干化污泥着火点温度较低，燃尽性能较差，综合燃烧特性指数相接近。在实际焚烧应用中，生物干化污泥与煤混合燃烧可以改善燃料的着火特性，使其能在较低温度下着火，同时提高自身燃尽特性，使燃烧更加稳定持久。 （2）针对污泥衍生燃料气化焚烧或直接焚烧过程中产生的尾气，利用现有的研究平台，分析尾气中有害物质的种类与含量，重点研究氮、硫氧化物的产生、扩散特点和污染控制方法，燃烧试验表明，生物干化污泥燃烧过程中二次污染物排放量比煤大，混烧可以降低二次污染物的排放量。混烧中NO的排放基本呈现单峰排放规律，而SO2则呈现双峰排放规律。在实际混烧过程中，适当提高燃烧温度可以减少NO的排放，但是SO2排放会相应增加，可通过缩短燃料燃烧停留时间，抑制无机硫的挥发燃烧，也可以通过添加脱硫剂，减少SO2的产生，从而降低燃烧过程中二次污染物的排放。 （3）以生物干化污泥产物为主要原材料，研究污泥干化产物生产不同类型衍生燃料的方法，明确不同助剂的最佳添加量和添加方式，确立的最佳成型工艺参数为：与煤样混合制备时成型压力12 MPa，煤粉添加量20 %，氢氧化钙添加量为4 %；与聚乙烯混合制备时成型压力15 MPa，PE添加量20 %，氢氧化钙添加量为4 %。 |
| 英文摘要 | Sludge incineration with the advantages of volume reduction, stabilization, harmlessness and energy recovery, is considered to be the most thorough way among different methods of sludge disposal. During the process of sewage sludge incineration, if the emissions secondary pollutants are not effectively controlled, serious environmental pollution will occur. Due to its special fuel properties, incineration and pollutants emission characteristics of sewage sludge are different from those of coal and biomass. Therefore, it is theoretically important to study incineration characteristics and pollutants emission and control of bio-drying sludge, which is also with application value for the disposal of sludge incineration. But the studies on bio-drying sludge focus on the mechanism, process optimization and application on land use. The incineration research of bio-drying sludge is little and needs to be conducted. This work study the pyrolysis and combustion thermogravimetric properties of bio-drying sludge, explore co-combustion properties and typical pollutant emissions of bio-drying sludge with aiding agent in tube furnace and tried to prepare bio-drying sludge derived fuel with different aiding agent for practical manufacture. 1. Typical samples were collected from bio-drying sludge plant and coal-sludge burning power plant. The thermogravimetric properties and combustion parameters of the samples were determined, and thermogravimetry experiments indicated that the bio-drying sludge samples had low kindling points in the range of 257-264℃. The sludge samples could be entirely burned at about 600℃. The overall burning indexes of the sludge were generally the same as the coal, but their ignition points reduced while co-burning with coal and their combustion behaviors could be improved. 2. The burning properties of their blends with different proportions were examined. The emission trends of NO and SO2 during the burning process were also studied. Combustion experiments showed that the emissions of NOX and SO2 were relatively higher when sludge were burnt alone, but the emissions could be reduced while co-combustion with coal. The main nitrogen gas was NO with a single apex during the co-combustion. NO emission could be enhanced when burning at 800-900℃ because of the synergistic effect between bio-drying sludge and coal. The emission of SO2 was typically bimodal. Accordingly, it is suggested that a higher combust temperature and shorter retention time are preferable in actual co-combustion in power plants so as to reduce the secondary pollutants emission. 3. A special bio-fuel derived from sludge. Heat value, density, dropping intensity and heating stability were examined, and the influences of various process parameters were established. It was found that the addition of an aiding agent could increase the caloric value and higher briquetting pressure contributed to the quality and stability of the bio-fuel. The optimal parameters obtained from the study were 12 MPa of briquette pressure, 20 % of coal, 4 % of Ca(OH)2 and 15 MPa of briquette pressure, 20 % of PE, 4 % of Ca(OH)2, respectively. |
| 源URL | [http://localhost/handle//34470]  |
| 专题 | 生态环境研究中心_固体废弃物处理与资源化实验室 |
| 推荐引用方式 GB/T 7714 | 张瑞宇. 生物干化污泥热特性与成型特征研究[D]. 北京. 中国科学院研究生院. 2015. |
入库方式： OAI收割
来源：生态环境研究中心
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。