论文总字数：31631字

摘 要

科技的进步促使着经济的发展和人民生活水平的提高，但同时也带来了诸多的能源与环境问题。其中有关污泥的处理就是比较突出的问题之一。近年来的污泥产量随着各行各业的蓬勃发展而呈激增的态势，并且污泥成分中包含诸多有害物质，例如二噁英，病毒，重金属等，如若处置不当会对社会及生态环境产生重大影响。

现有污泥的处置方法中，热解技术因其安全、资源化程度高而更具优势。单独的市政污泥因其含水率及无机物含量高，热解性能较差，已有研究显示生物质与市政污泥共热解可提高工艺经济性，同时共热解过程中两种物料存在某些协同作用，对热解产物及其品质产生影响。为了具体研究污泥与生物质共热解之间的协同作用相关问题，本课题选用了棉杆与市政污泥开展实验。首先选择在700℃下单独热解纯棉杆与纯污泥，再按1:1的质量配比热解混合原料，对比三组结果探讨协同作用的具体表现。实验结果证实棉杆与污泥在700℃共热解存在协同作用，其会促进固体产物向气液两相产物转化，使气液两相产率上升，热解更加充分。同时发现气体产物中的可燃气产率上升，产物的品质同样有一定程度的提升。

本研究进一步通过改变实验条件探究原料配比、反应温度等影响因素对共热解效果的影响。首先选用了棉杆与市政污泥配比为3:7与5:5与7:3的原料分别在700℃共热解，研究混合比的改变产生的影响。最后得出结论，在700℃下，共热解气相产率随着棉杆在原料中的占比上升而上升。但700℃下棉杆与污泥之间共热解的协同效应表现却随着棉杆添加比例上升而下降。在已知的三个实验点中棉杆占比为30％时，协同作用最显著，对气体产率的促进最明显。混合比改变对气体产率变化分析表明两种物料协同作用效应影响小于原料组成中棉杆占比提升带来的影响。

热解温度变化对共热解效果的影响研究选择了650℃，700℃，750℃三个热解温度，针对1:1配比的原料开展共热解。实验结果显示在650℃-750℃温度区间，温度的提升会对共热解产生促进作用，其中700℃-750℃之间该比例混合原料共热解的协同作用更为明显。

最后本课题针对污泥含水率高的问题提出新的解决方案，即采用连续进料的方式将原料中的水分转变为水蒸气，水蒸气将与前一批物料热解生成的C反应生成水煤气。如果方案可行，将为解决含水率问题提供另一种思路。不同操作方式实验结果显示连续进料的方式要优于一次进料，在排除其它因素后，C与H₂O反应生成水煤气的反应占据主要因素，为方案奠定初步条件，具体的可行性有待深入研究。

关键词：棉杆 市政污泥 共热解 协同作用 含水率

Experimental Study on Municipal Sludge and Biomass Co-pyrolysis

Abstract

The progress of science and technology promotes the development of economy and improves the people's living standard, but it also brings many energy and environment problems. The sludge treatment is one of the noticeable problems. In recent years, with the rapid development of our society, the sludge production has been increasing rapidly. And the sludge components contain many harmful substances, such as dioxins, viruses, heavy metals, etc. if not handled properly, it will have a significant impact on society and ecological environment.

Among the existing disposal methods of sludge, pyrolysis technology has more advantages because of its safety and high degree of resource utilization. Due to its high moisture content and inorganic content, the pyrolysis performance of municipal sludge alone is poor. It has been shown that the co-pyrolysis of biomass and municipal sludge can improve the process economy of its treatment. At the same time, there are some synergistic effects between the two materials in the co-pyrolysis process, which have impacts on the pyrolysis products and their quality. In order to study the synergistic effect during the co-pyrolysis of sludge and biomass, the experiment was carried out with cotton rod and municipal sludge. First, the pure cotton rod and pure sludge were pyrolyzed separately at 700℃, then the mixed raw materials were pyrolyzed with 1:1 mass ratio. Experiment results showed that there was a synergistic effect between cotton rod and sludge co-pyrolysis at 700℃, which could promote the transformation of solid products to gas-liquid two-phase products, making the gas-liquid two-phase yield rise, and pyrolysis was more sufficient. At the same time, it was found that the production rate of combustible gas in the gas product increased, and the quality of the product also improved to a certain extent.

In this study, the effects of raw material ratio and reaction temperature on co-pyrolysis were investigated by changing experimental conditions. Firstly, the raw materials with the ratio of 3:7, 5:5 and 7:3 of cotton stalk and municipal sludge were pyrolyzed at 700 ℃, respectively. Finally, it is concluded that at 700℃, the gas phase yield of co-pyrolysis increases with the increase of cotton rod. But the synergistic effect of co-pyrolysis between cotton rod and sludge at 700℃ decreased with the increase of cotton rod addition ratio. The synergistic effect was most significant when the cotton rod accounted for 30% of the three experimental points, and the promotion of gas yield was most obvious. The gas yield analysis with the change of mixing ratio showed that the synergistic effect of the two materials was less than the influence of the cotton stalk proportion increasing in the raw material composition.

In the study of the influence of pyrolysis temperature on the co-pyrolysis effect, three pyrolysis temperatures of 650 ℃, 700 ℃ and 750 ℃ were selected to carry out co-pyrolysis experiments using 1:1 mixed materials. The experimental results showed that the increase of reaction temperature can promote co-pyrolysis reaction in the range of 650℃-750℃, and the synergistic effect between 700-750℃ was more obvious.

Finally, a new solution to the problem of high water content of sludge is put forward. The water content in the raw material is evaporated to water vapor through the continuous feeding way, and the water vapor will react with the C generated by pyrolysis of the previous batch of materials to produce water gas. If the scheme is feasible, it will provide another way to solve the high water content problem of municipal sludge. The experimental results of different operation modes showed that continuous feeding was better than direct feeding. C reacting with H₂O to produce water gas might be the main factor for the improvement of gas production quality, which gives the preliminary support for the scheme, and the specific feasibility needs to be deeply studied.

Key Words: Cotton stalk; Municipal sludge; Co-pyrolysis; Synergy; Moisture content

目 录

市政污泥与生物质共热解实验研究 I

摘 要 I

第一章 绪论 1

1.1 研究背景 1

1.1.1 突出的环境问题及国际能源形势 1

1.1.2 热处理技术概述 2

1.1.3 共热解技术及协同作用概述 2

1.1.4 影响协同作用的主要因素 3

1.1.5 协同作用的作用机理简述 5

1.2 本课题来源及研究内容 5

1.2.1 课题来源 5

1.2.2 课题内容 6

第二章 市政污泥与棉杆共热解特性分析 7

2.1实验材料与试验方法 7

2.1.1 实验材料 7

2.1.2 实验装置 8

2.1.3 实验过程 8

2.1.4 实验问题及解决方法 10

2.1.5 数据处理方法 11

2.2 市政污泥热解特性分析 12

2.3 棉杆热解特性分析 12

2.4 共热解特性分析 13

2.4.1 共热解产物分析 13

2.4.2 混合试样协同作用 14

2.5 本章小结 15

第三章 协同作用主要影响因素验证与探究 17

3.1 实验材料与试验方法 17

3.1.1 实验材料 17

3.1.2 实验装置 17

3.1.3 实验过程 18

3.1.4数据处理方法 18

3.2 原料混合比对协同作用的影响分析 18

3.3 共热热解温度对协同作用影响分析 22

3.4 本章小结 24

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