烟气氛围下富碳材料中纳米孔隙的形成及演变机制研究

项目名称： 烟气氛围下富碳材料中纳米孔隙的形成及演变机制研究

项目编号： No.51506115

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 能源与动力工程

项目作者： 王涛

作者单位： 山东大学

项目金额： 21万元

中文摘要： 利用O2、H2O和CO2对煤焦烧蚀成孔特性的差异，提出调制烟气活化、煤粉快速热解制备烟气脱硫用粉状半焦的新方法。纳米孔隙是活性焦吸附SO2及赋存氧化产物H2SO4的主要空间，研究烟气（低氧多组分活化气体）氛围下不同碳材料纳米孔隙形成及演变机理十分重要。本项目首先以高定向热解石墨为研究对象，采用原子力显微镜对不同活化气体氛围下得到的多孔石墨碳表面纳米孔隙的源发点、分布及演变进行直观表征，阐释烟气氛围下碳表面纳米孔的形成及演变过程及机理。然后，以四种典型煤为研究对象，考察不同煤种在烟气氛围下的快速热解行为及其对煤焦中纳米孔隙形成和演变过程的影响，探寻产品半焦孔隙结构的调控方法。最后，建立基于原煤反应动力学的孔隙结构演化模型并进行验证与优化，为烟气氛围下快速热解半焦的孔隙参数预测提供方法。本项目研究将为燃煤电厂脱硫活性焦的炉前制备工艺提供基础依据和理论指导。

中文关键词： 孔结构；热解；半焦；烟气氛围

英文摘要： A novel method for powdered semi-coke preparation by fast pyrolysis of pulverized coals under flue gas atmosphere is proposed, which is based on the difference of pore formation characteristics caused by coal char ablation with O2, H2O and CO2. Nano-pore is the main space of SO2 adsorption and occurrence of the oxidation product H2SO4 in active cokes; therefore, it is important to study the mechanisms on formation and evolution of nano-pore structures in carbon-rich materials under flue gas atmosphere. First, the highly oriented pyrolytic graphite (HOPG) is used as the research object, and a visual characterization of the nano-pores’ origin, evolution and distribution on the carbon surface is conducted using atomic force microscope (AFM). Then, the mechanism of formation and evolution of nano-pore structures on the carbon surface under flue gas atmosphere can be concluded. Second, four typical coals are used to prepare the semi-cokes by fast pyrolysis on a drop tube furnace under different atmospheres. The fast pyrolysis behaviors of different coals under flue gas atmosphere are studied and the influence of the behaviors above on the formation and evolution of nano-pore structures is also investigated. Based on the mechanism above, the regulation method of semi coke pore structure can be explored. Finally, a pore structure evolution model based on coal chemical reaction kinetics is established. It could predict the pore structure parameters of product semi-cokes prepared under flue gas atmosphere. This study will provide basic data and theoretical guidance for the in-situ preparation of active cokes in a coal-fired power plant.

英文关键词： pore structure;pyrolysis;semi-coke;flue gas atmosphere