不同热裂解温度下ZSM-5对玉米秸秆催化热裂解烃类选择性影响

为探讨不同热裂解温度下ZSM-5对玉米秸秆催化热裂解特性及烃类选择性的影响,本研究利用TGA对比有无ZSM-5时玉米秸秆的热裂解失重曲线,利用Py-GC/MS对比玉米秸秆在450、500、550和600℃下的热裂解和催化热裂解产物分布。结果表明,ZSM-5的使用可以降低玉米秸秆最高分解速率时对应的热裂解温度,降低温度为23℃。未使用ZSM-5时,热裂解产物种类以及烃类选择性均随热裂解温度的升高不断增加,在600℃时,烃类选择性达到最高,为11.33%;使用ZSM-5后,烃类产率随热裂解温度的升高先增加后减少,在550℃时,烃类选择性达到最高,为29.24%。使用ZSM-5后,玉米秸秆催化热裂解主要产物中出现了甲苯、茚、萘、二甲基萘等烃类,甲苯的最高产率为4.76%,萘的最高产率为3.96%。

Effect of ZSM-5 on hydrocarbon selectivity of corn stalk catalytic pyrolysis at different pyrolysis temperatures

In order to study the effect of ZSM-5 on the catalytic pyrolysis characteristic and hydrocarbon selectivity of corn stalk catalytic pyrolysis at different pyrolysis temperatures, the thermogravimetric analysis (TGA) was used to obtain the TG and DTG profiles of corn stalk pyrolysis with and without ZSM-5, and the pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) tests were conducted to analyze the products distribution of corn stalk pyrolysis with and without ZSM-5 at 450, 500, 550, and 600 ℃. The results show that ZSM-5 can decrease the pyrolysis temperature at the highest pyrolysis rate by 23 ℃. Without ZSM-5, both the categories of pyrolysis compounds and the hydrocarbon yield increase with the increase of pyrolysis temperature, and the selectivity of hydrocarbon reaches to the highest value of 11.33% at 600 ℃. However, with ZSM-5, the hydrocarbon yield increases at first and then decreases with the increase of pyrolysis temperature, and the selectivity of hydrocarbon is up to the highest value of 29.24% at 550 ℃. Toluene, indene, naphthalene and 2-methyl-naphthalene are evolved as the main compounds with ZSM-5. And the maximum yields of toluene and naphthalene reach to 4.76% and 3.96%, respectively.