Abstract:

The pyrolysis experiment of waste wood building formwork was carried out in a horizontal fixed bed reactor to explore the influence of pyrolysis temperature (400—800℃) on the pyrolysis products of waste wood building formwork. In addition, two typical biomass, wood chips and rice husks, were selected to compare and analyze the distribution and properties of the pyrolysis products of the three raw materials. The results show that with the increase of pyrolysis temperature, the solid phase yield of waste wood building formwork and two typical biomass shows a decreasing trend, while the gas phase yield shows an increasing trend, and the liquid phase product yield reaches a peak at 500℃ and then gradually decreases. The content of functional groups on the surface of biochar decreases continuously, and the pore structure of biochar tends to be abundant except rice husk. The oxygen-containing heavy organic molecules in the pyrolysis oil are gradually transformed into light aromatic and hydrocarbon molecules. The proportion of combustible components in pyrolysis gas increases. The solid phase yield of wooden building formwork is the highest at 400℃, reaching 40.16%. The pyrolysis liquid phase yield is the highest at 500℃, reaching 53.6%. With further increase in temperature, the gas phase yield reaches 43.3% at 800℃. At the same pyrolysis temperature, the liquid phase yield of wood building formwork is the highest, and the proportion of oxygen and aromatic organic compounds in pyrolysis oil is relatively high. The proportion of combustible components in pyrolysis gas at low temperature is higher than that of wood chips and rice husks. This study provides a useful reference for the resource utilization of waste wood building formwork.

Key words: wood building formwork, biomass, fixed bed, pyrolysis, three-phase product

摘要：

通过在水平固定床反应器内开展废弃木质建筑模板的热解实验，探究热解温度（400~800℃）对废弃木质建筑模板热解产物的影响，另外选取木屑、稻壳两种典型生物质，比较分析了三种原料的热解三相产物分布及性质。研究发现，随热解温度的升高，废弃木质建筑模板和两种典型生物质的固相产率都呈现降低的趋势，而气相产率呈现增加的趋势，液相产物产率于500℃时达到峰值后逐渐降低；各生物炭表面官能团含量不断下降，除稻壳外生物炭孔隙结构趋于丰富；热解油中含氧类重质有机物分子逐渐转化为芳香类及烃类等轻质分子；热解气中可燃组分占比增加；木质建筑模板在400℃时固相产率最高，为40.16%，500℃时热解液相产率最高，达到53.6%，随着温度的进一步升高，气相产率在800℃时达43.3%。相同热解温度下木质建筑模板的液相产率最大，热解油中含氧类及芳香类有机物占比较高；低温工况下热解气中可燃组分占比高于木屑和稻壳。本研究为废弃木质建筑模板的资源化利用提供了有益参考。

关键词: 木质建筑模板, 生物质, 固定床, 热解, 三相产物