一种生物污泥热解半焦孔隙结构特性

污泥半焦的孔隙结构是影响热解反应的重要因素之一。该文利用固定床反应器在N2气氛下，温度为300~900℃对一种取自香港的生物污泥进行热解。采用ASAP 2010型比表面积及孔径分布分析仪测定生物污泥热解半焦的比表面积及其孔隙结构，研究污泥半焦的孔隙结构在热解过程中的变化规律。利用分形理论和等温吸附理论对半焦进行分析。试验研究与理论分析表明，随着热解终温的提高，孔隙结构变得发达，孔的种类多样化，总孔容积逐渐增加。比表面积总体呈现增加的趋势，从300℃时的0.72 m2/g增加到900℃时的64.88 m2/g，平均孔径为3.7~8.53 nm。不同温度制得的半焦，孔径分布具有相似的特点，在孔径为4 nm左右出现峰值。表面分形维数随热解终温的提高而增高，从2.539增加到了2.824，表面分形维数的增加，有利于污泥的热解。

Pore Structure Properties of Chars During Pyrolysis of Bio-sludge

The pyrolysis of one type of bio-sludge from Hong Kong was carried out in a fixed bed reactor under N2 atmosphere with the operating temperature of 300oC to 900oC. Special surface area and pore structure of chars were analyzed using ASAP 2010. And the surface fractal dimensions were determined using the fractal theory and isothermal adsorption theory. The results indicate that total pore volume and specific surface area increase with the increasing of final pyrolysis temperature. The specific surface area increases from 0.72m2/g (at 300oC) to 64.88m2/g (at 900oC). The average pore diameter ranges from 3.7nm to 8.53nm. There are similar in the spectific surface area and the pore size distribution of different samples with the peaks showing at about 4nm. The fractal dimension is increased from 2.539 to 2.824 with the temperature increasing, which is beneficial to pyrolysis.