污泥与褐煤水热脱水提质及共成浆特性研究

发布时间：2018-01-03 15:23

  本文关键词：污泥与褐煤水热脱水提质及共成浆特性研究　出处：《东南大学》2016年硕士论文　论文类型：学位论文

  更多相关文章： 城市污泥 褐煤 水热提质 煤化作用 污泥煤浆

【摘要】：将污泥与低阶褐煤水热脱水提质制备低黏高浓度浆体燃料,不仅可以将污泥内部的结合水转化为有利于成浆的自由水,还可以实现污泥的减量化、无害化和资源化。但是对于污泥与褐煤水热提质过程中的煤化作用机理以及提质之后的成浆特性有待深入研究。本文考察了水热处理温度和污泥添加量对提质产物理化特性和浆体燃料的成浆性、流变特性、稳定性的影响。采用元素分析、工业分析、FTIR、13C-NMR、GC-MS等仪器设备对提质产物的理化特性进行了分析表征,获得了原料中的碳分布到气液固三相产物中的规律,深入探究了污泥褐煤在水热过程中发生的煤化作用机理。通过元素和工业分析发现,随着水热温度升高,污泥与褐煤提质固产物水分和氧含量显著降低,固定碳含量升高,热值大幅度提高,疏水性增强,重吸水能力减弱,煤化程度加深。随着污泥添加量的增加,提质固产物平衡水含量和重吸水率逐渐降低,O/C原子个数比显著下降。GC-MS分析表明,提质废液中有机组分主要为酚类、酮类、杂环类、胺类、酯类、烷烃类。随着水热温度升高,废液中杂环类和胺类的含量呈增加的趋势,酮类的含量在水热温度为200℃～250℃时相对较高；胺类主要来自污泥中蛋白质的水解,酚类主要来自木质素的部分水解或褐煤大分子侧链中较弱键的断裂。水热处理过程中,由于脱羧、脱甲烷以及分解反应的发生会有一定量的气体产生,其主要组分为CO2、CO、H2和CH4。原料中的氧主要以CO2的形式释放出来。FTIR分析表明,污泥与褐煤在提质过程中发生了显著的脱水和脱羧反应,使得固产物羟基或羧基官能团中-OH和酰胺或羧基官能团中-C=O的相对光谱吸收强度显著降低。通过13C NMR分析发现,城市污泥中脂肪碳和烷氧基碳的含量分别占总有机碳的43.35%和30.53%。随着水热温度升高,烷氧基碳减少的速率最快,其相对含量至少减少40.97%,羧基和羰基的相对含量分别至少减少12.5%和15.63%,说明固产物中氧元素的减少不仅与脱水作用有关,与羰基和羧基的转化以及甲氧基的变化也密切相关。污泥掺混褐煤水热提质之后仍然有90%以上的碳保留在浆体中,对于浆体在气化过程中实现碳的最大转化非常重要。水热脱水提质显著地脱除原料内部的结合水,改变原料的亲水特性,提高浆体的定粘浓度,并且提质废液中含有大量的酚、苯并芘、低环苯系物等具备水煤浆分散剂基本分子结构特征的有机物,在制浆过程起到分散稳定作用,使得浆体在定粘浓度增加的同时,仍然保持较好的假塑性流变特性和较高的稳定性。当污泥掺混量为50%时,内蒙古褐煤和云南褐煤两种废液污泥煤浆的定粘浓度分别达到58.13%和64.78%。
[Abstract]:Low viscosity and high concentration slurry fuel can be prepared by dehydration of sludge and low rank lignite, which can not only transform the binding water of sludge into free water in favor of pulp formation, but also realize the reduction of sludge. However, the mechanism of coalification in the process of sludge and lignite hydrothermal extraction and the characteristics of slurry formation after purification need to be deeply studied. The effects of hydrothermal treatment temperature and sludge addition on the yield of lignite were investigated in this paper. Physical and chemical properties and slurry properties of slurry fuels. The physical and chemical properties of the products were characterized by elemental analysis, FTIR 13C-NMR-GC-MS and so on. The distribution of carbon from raw materials to gas-liquid-solid three-phase products was obtained, and the coalification mechanism of sludge lignite in hydrothermal process was deeply explored. Through element and industrial analysis, it was found that with the increase of hydrothermal temperature. The content of water and oxygen in the solid product of sludge and lignite decreased significantly, the fixed carbon content increased, the calorific value increased significantly, the hydrophobicity increased, the heavy water absorption capacity weakened, and the degree of coalification deepened. The equilibrium water content and the heavy water absorption ratio of the extracted solid products gradually decreased. GC-MS analysis showed that the main components in the waste liquor were phenols ketones heterocycles and amines. Esters, alkanes. With the increase of hydrothermal temperature, the contents of heterocyclic compounds and amines in waste liquid tend to increase, and the contents of ketones are relatively high when the hydrothermal temperature is 200 鈩，

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