HZSM-5/MCM-41复合分子筛的制备及其对竹木热解的影响

Effect of preparation conditions of HZSM-5/MCM-41 composite molecular sieve on pyrolysis of bamboo sawdust

为了研究介微孔复合分子筛HZSM-5/MCM-41在生物质快速催化热解过程中的协同作用,以竹木为生物质原料,通过裂解气相色谱/质谱联用仪(Py-GC/MS)进行竹木热解实验和在线数据分析,研究不同消解时间-结晶时间和制备温度下复合分子筛HZSM-5/MCM-41对于竹木热解产物的影响。研究结果表明:在总时间一定的基础上,随着消解时间的增加,烃类物质的产率先升高后降低,当消解时间-结晶时间为24 h-24 h时,烃类物质的产率最高;随着制备温度的升高,烃类物质的产率先升高后降低,当制备温度为110℃时,烃类物质的产率达到最高;添加复合分子筛后,除了单环芳烃类物质的产率有极大提高外,酸类、呋喃类、酚类、酮类等含氧化合物的产率均有一定程度的下降;在竹木热解过程中添加复合分子筛HZSM-5/MCM-41有利于热解油品位的提高。

In order to investigate synergistic effect of mesoporous composite molecular sieve HZSM-5/MCM-41 on fast catalytic pyrolysis of biomass, pyrolysis and online data analysis, which use bamboo as raw materials, are conducted with pyrolysis gas chromatograph/mass spectrometry(Py-GC/MS).The bamboo pyrolysis experiment and online data analysis were carried out to study the effect of HZSM-5/MCM-41 composite molecular sieve prepared at different digestion time-crystallization time and temperature on pyrolysis products of bamboo wood. It is clearly shown in the experimental result that, the yield of hydrocarbon raises at first and then declines accompanied by the increase of digestion time. The yield of hydrocarbons is the highest when the digestion time-crystallization time is 24 h-24 h.As the preparation temperature increases, the yield of hydrocarbons first increases and then decreases.When the preparation temperature is 110 ℃, the yield of hydrocarbons reaches the maximum. The addition of compound molecular sieve increases the yield of monocyclic aromatic hydrocarbons and decreases the contents of acids, furans, phenols and ketones as well. Therefore, the addition of HZSM-5/MCM-41 composite molecular sieves is beneficial to the improvement of the pyrolysis oil grade.