内循环串行流化床生物质催化热解试验研究

Experimental Investigation on Biomass Catalytic Pyrolysis in an Internal Interconnected Fluidized Bed

在处理量为0.2 kg/h的新型内循环串行流化床(IIFB)上进行了生物质催化热解制油的试验研究.以木屑为原料、石英砂为热载体,研究了在没有催化剂条件下反应温度对热解产物分布的影响;以HZSM-5催化剂与石英砂混合物为床料进行了催化热解试验,并对热解产物和反应后的催化剂进行了表征分析.结果表明:反应温度为515℃时,液体产物的收率最高.HZSM-5催化剂的加入促进了气体以及焦炭的生成,使液体产物的收率降低,且催化剂体积分数越大,影响越显著.催化剂表面的积炭经燃烧反应后被除去,催化剂的稳定性得到改善.热解不可冷凝气体的主要成分为CO和CO2,随着热解温度的升高,CO2产量下降,CO和CH4的产量增加.经HZSM-5催化热解后,生物油中的酸、醛和酮类物质含量明显减少,而小分子的烃类与酚类物质含量明显增加,表明催化剂具有明显的脱氧效果.

Experimental study on biomass catalytic pyrolysis for oil production was carried out on a new type internal interconnected fluidized bed（IIFB） with capacity of 0.2 kg/h.Using sawdust as the raw material and quartz sand as the heat carrier,the effect of reaction temperature on distribution of pyrolysis products was studied without catalyst.Catalytic pyrolysis experiments were carried out by using the mixture of HZSM-5 catalyst and quartz sand as the bed material,after which corresponding pyrolysis products and the used catalyst were characterized and analyzed.Results show that the liquid production is the largest at a reaction temperature of 515 ℃.Addition of catalyst HZSM-5 promotes the formation of gas and char,thus reducing the production of liquids.The more volumetric fraction of catalyst is,the more obvious the effect will be.The deposit char on surface of the catalyst is removed by combustion reaction,and the stability of the catalyst is improved.The main compositions of incondensable pyrolysis gas are CO and CO_2.With the increase of pyrolysis temperature,CO_2 production decreases,while CO production and CH_4 production increase.After catalytic pyrolysis by HZSM-5,the content of acid,aldehyde and ketone matters in bio-oil decreases obviously,while that of hydrocarbon and hydroxybenzene matters increases significantly,indicating obvious deoxidizing effect of the catalyst.