污泥热解中残焦表面官能团结构演化特征

Characteristics of Surface Functional Groups Structure of Residues During Sewage Sludge Pyrolysis

针对污泥热解过程生烃能力,研究了不同温度下污泥热解残焦表面官能团结构变化特征.结果表明:温度对污泥热解残焦表面羟基、—CH_3和—CH_2键、羰基、碳碳双键等官能团热裂解演化程度影响较大,但对于其他杂原子团影响较小;550,℃以下低温热解脂肪结构裂解程度较大,芳香结构裂解程度较小;随着温度升高,受芳香结构裂解、芳构化及缩合效应综合影响,残焦富氢程度振荡变化;相比低温热解,高温下污泥有机结构芳构化和缩合程度较高、残焦脂肪链长程度提高、但残焦支链化程度变化不大.

The functional groups of sludge is relatively rich in fatty hydrocarbon with a high capacity of hydrocarbon generation.In this paper,the characteristics of major functional groups during sludge pyrolysis were investigated at different temperatures.The experimental results showed that pyrolysis temperature highly influenced the thermal transformation behavior of some major surface functional groups,such as-OH,-CH3,-CH2,C=C,and C=O,but scarcely affected that of impurity functional groups.During low temperature pyrolysis below 550,℃,fatty hydrocarbon structures were evidently cracked,but aromatic structures were hardly influenced.The hydrogen-enriched degree of pyrolysis residues was changed irregularly due to the integrative influence of cracking,aromatization and condensation reaction.During high temperature pyrolysis,the aromatization and condensation degree of sludge were relatively higher than those during low temperature pyrolysis,the degree of fatty chain length of the residues was also increased,but the branched degree was little changed.