松木颗粒热解与高温蒸汽气化半焦产率及形貌特征分析

Semi-coke yield and morphology of pine wood particles during pyrolysis and high temperature steam gasification

中文关键词: 生物质半焦  水蒸气  官能团  比表面积  平均孔径

英文关键词: biomass char  water vapor  functional groups  pecific surface area  average aperture

中文摘要:

      以成型松木颗粒为原料，进行低温热解，研究了热解温度和升温速率对生成的松木半焦产率及官能团的影响。以试验得到的松木半焦进行蒸汽气化试验，对比分析了温度对半焦重整气化形貌特征、比表面积和平均孔径的影响。研究表明：随着热解温度升高，松木半焦脂肪族结构峰消失转化为烃等小分子物质及气化气，进而降低半焦产率。升温速率升高，半焦产率呈先下降后升高的趋势，在800℃升温速率为30K/min时半焦产率最低。不同温度热解和蒸汽气化对比试验表明，温度相对较低时（500℃）热解和蒸汽气化半焦孔隙结构相近，随着温度的升高，蒸汽气化半焦结构发生明显变化，900°C时出现了更小的孔道结构且比表面积增加明显。蒸汽引入使松木半焦和水蒸气发生热解反应的同时发生了脱氢反应，气化半焦形貌出现熔融和烧结现象。

英文摘要:

      The formed pine wood pellets were used for low temperature pyrolysis, and the obtained pine wood semi-coke was subjected to steam gasification test. The effects of pyrolysis temperature and heating rate on the yield of pine wood semi-coke and functional groups were studied. The effects of temperature on the morphological characteristics, specific surface area and average pore diameter of semi-coke reforming and gasification are analyzed. The results show that with the increase of pyrolysis temperature, the pine semi-coke aliphatic structure peak disappears into small molecules such as hydrocarbons and gasification gas, and the yield of semi-coke decreases. The heating rate increased, and the semi-coke yield decreased first and then increased. The semi-coke yield reached the lowest when the heating rate was 30K/min at 800°C. The experimental results different temperature pyrolysis and steam gasification experiments show that the pyrolysis and steam gasification semi-coke pore structure are similar when the temperature is relatively low (500°C), and the vapor gasification semi-coke structure changes significantly with the increase of temperature. A smaller pore structure is formed and the specific surface area is increased more significantly at 900°C. It is indicated that the introduction of steam causes the pyrolysis reaction of pine semi-coke and water vapor ,while the dehydrogenation reaction occurs, and the vaporized semi-coke morphology appears to be molten and sintered.