摘要
对气化过程中3种不同变质程度煤的焦炭表面孔隙结构的发展变化规律及其表面分形特征进行研究，发现气化过程不同变质程度煤的焦炭的吸附特性曲线一般均属于典型的I类吸附等温线，表征了煤焦表面主要为微孔的吸附特征；随着气化反应的深入，微孔逐渐生长扩大，焦炭的吸附等温线出现了由I类向II类吸附等温线变化的趋势；同时，煤焦表面的孔径为2—10nm内的中孔随着气化反应的进行变化比较明显，且此范围内的变化与煤的变质程度密切相关，而孔径为10-200nm的中孔和部分大孔则基本保持不变。利用吸附法计算煤焦表面的分形维数，发现煤焦表面存在2个不同的分形维数D1和D2，分别表征了不同的孔径范围的表面分形特征，且D1和D2与煤焦比表面积和微孔比表面积有一定的关联性，但是其变化一般超前于比表面积和微孔比表面积的变化。
The char pore structure and its fractal characteristics of three different rank coals during gasification were studied. It was found that, all the chars＇ absorption isotherms were type I isotherm, which identified micropore dominated surface pore structure; and as the gasification went on, the micropore grew and formed mesopore and macropore, which led the symptom from type I isotherm to type II isotherm The mesopore in the diameter range of 2-10 nm varied apparently and showed a close relation with coal rank, while 10-50 nm mesopore and 50-200 nm macropore were almost unchanged. The fractal characteristics were also studied by absorption method. Two surface fractal dimensions, D1 and D2, were found in the different pore diameter range. D1 and D2 showed a little relevance with BET specific area and micropore specific area and the change of D1 and D2 was generally superior to the change of BET specific area and micropore specific area.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2010年第8期9-14,共6页
Proceedings of the CSEE
基金
国家重点基础研究发展计划项目(973项目)(2010CB227003)
国家自然科学基金项目(50721005)~~
关键词
气化
表面孔隙结构
吸附特征
分形
gasification
surface pore structure
absorption
fractal
