城市污泥热解特性及理化性能研究

来源期刊:中南大学学报(自然科学版)2021年第6期

论文作者:樊保国 郭晋荣 贾里 王彦霖 郭婧楠 王晓霏 张永强 乔晓磊

文章页码:2023 - 2032

关键词:污泥;热解;分布活化能模型;微观特性

Key words:sewage sludge; pyrolysis; distributed activation energy model; microscopic characteristics

摘    要:对等温和非等温2种升温方式下污泥的热解过程进行研究,利用热重分析仪、X线衍射仪、傅里叶变换红外光谱仪及扫描电镜对污泥的热解和理化特性进行分析,结合热解特征参数,采用分布活化能模型,揭示其相应热解机理。研究结果表明:在非等温条件下,随着升温速率增加,热解过程在高温区发生,最大质量损失率提升,对应峰值温度偏移,产生热滞后,利于挥发分析出;分布活化能模型适于热解率α≤0.8范围内的动力学分析,活化能随热解率α增长呈先增后减趋势;污泥矿物组分中Si元素结晶性能较好,多以SiO2和SiS2等无机形式赋存,同时检测到AlPO4和属六方晶系且具α-型晶体结构的α-HgS存在;在等温条件下,随着热解时间延长和温度升高,表面官能团种类及含量减少,挥发分析出促进孔隙结构发展,热解过程中碳架结构坍塌和孔道烧熔表现为微观形貌上的无序程度和玻璃化程度加深。

Abstract: The pyrolysis process of sludge was studied under isothermal and non-isothermal heating conditions. The pyrolysis characteristics and physical and chemical characteristics of the sludge were analyzed using TGA, XRD, FTIR and SEM. The reaction mechanism was revealed by using the distributed activation energy model and the apparent dynamic parameters. The results show that under non-isothermal condition, the differential thermogravimetric curves move to the high temperature side, with the increase of heating rate, the maximum mass loss rate increases, and the peak temperature shifts. At the same time, the thermal inertia occurs, which is conducive to the precipitation of volatiles. The distributed activation energy model is suitable for kinetic analysis in the range of conversion α≤0.8. The activation energy increases first and then decreases with the increase of conversion α; SiO2 and SiS2 exist in the mineral composition of sludge, while AlPO4 and α-HgS are detected. Under isothermal conditions, with the increase of pyrolysis time and temperature, the surface functional groups decrease, and the release of the volatiles promotes the development of pore structure. The collapse of the carbon frame and the melting of the channel during pyrolysis show that the disorder degree and vitrification of the micro-morphology increase.

相关论文

  • 暂无!

相关知识点

  • 暂无!

有色金属在线官网  |   会议  |   在线投稿  |   购买纸书  |   科技图书馆

中南大学出版社 技术支持 版权声明   电话:0731-88830515 88830516   传真:0731-88710482   Email:administrator@cnnmol.com

互联网出版许可证:(署)网出证(京)字第342号   京ICP备17050991号-6      京公网安备11010802042557号