固体酸SO_(4)^(2-)/Al-MCM-41催化木糖制糠醛的研究  

Synthesis of Furfural from Xylose Catalyzed by Solid Acid SO_(4)^(2-)/Al-MCM-41

作　　者：刘秋梅 胡汉文 张素平 LIU Qiumei;HU Hanwen;ZHANG Suping(School of Chemical Engineering,Research Center for Biomass Energy,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学化工学院,生物质能研究中心,上海200237

出　　处：《林产化学与工业》2021年第3期103-111,共9页Chemistry and Industry of Forest Products

摘　　要：采用硫酸对Al-MCM-41固体酸进行改性,制备木糖脱水制糠醛催化剂SO_(4)^(2-)/Al-MCM-41。借助傅里叶变换红外光谱(FT-IR)、氨气程序升温脱附(NH_(3)-TPD)、氮气等温吸附-脱附分析等表征技术对催化剂进行表征。结果表明,硫酸改性成功地在分子筛Al-MCM-41表面引入了SO_(4)^(2-),提高了分子筛的酸性,并且未改变分子筛的介孔结构。考察了催化剂、溶剂、反应温度及反应时间等因素对糠醛收率的影响。结果表明,在水/正丁醇反应体系下(水和正丁醇体积比1∶1,水相中NaCl质量分数2%),以木糖为原料,液固比(溶剂与固体原料比)20∶1(mL∶g),固体酸SO_(4)^(2-)/Al-MCM-41为催化剂,原料与催化剂质量比为2∶1,在190℃反应温度下反应30 min时获得最大糠醛收率62.45%,与分子筛Al-MCM-41作为催化剂相比,糠醛收率同比提高了21.82个百分点。另外,固体酸SO_(4)^(2-)/Al-MCM-41对半纤维素制备糠醛也有较好的催化作用,在更加苛刻的反应条件下获得51.96%的糠醛收率(半纤维素基)。催化剂重复性研究结果表明,固体酸催化剂使用3次时,糠醛收率约为54%。随着催化剂使用次数的增加,催化剂催化能力有一定程度降低,可通过高温焙烧、硫酸浸渍的方式进行催化剂再生。The solid acid Al-MCM-41 was modified by sulfuric acid to prepare the catalyst SO_(4)^(2-)/Al-MCM-41 for furfural production from xylose dehydration.The catalyst was characterized by Fourier transform infrared(FT-IR)spectroscopy,temperature-programmed desorption of ammonia(NH_(3)-TPD),and N2 adsorption-desorption anslysis.The results showed that SO_(4)^(2-) was successfully introduced into the surface of Al-MCM-41 by sulfuric acid modification,which improved the acidity of the molecular sieve without changing the mesoporous structure of the molecular sieve.The influence of factors such as catalyst,solvent,reaction temperature and reaction time on the yield of furfural were investigated.The results showed that the highest yield of furfural was 62.45%in water/n-butanol reaction system(volume ratio of water and n-butanol 1∶1,NaCl mass fraction in water 2%)with xylose as the raw material,ratio of liquor to material 20∶1(mL∶g)solid acid SO_(4)^(2-)/Al-MCM-41 as catalyst and mass ratio of raw material and catalyst 2∶1 at 190℃for 30 min,compared with molecular sieve Al-MCM-41 as catalyst,the yield of furfural increased by 21.82 percentage points.In addition,solid acid SO_(4)^(2-)/Al-MCM-41 also had a good catalytic effect on the preparation of furfural from hemicellulose,and 51.96%furfural yield was obtained from hemicellulose under more severe condition.The results of catalyst recycling study showed that the yield of furfural was about 54%when the solid acid catalyst was used for three times.With the increase of the catalyst use times,the catalytic capacity of the catalyst decreased to a certain extent.The catalyst regeneration could be carried out by means of high temperature roasting and sulfuric acid impregnation.

关 键 词：固体酸 木糖 糠醛 水解 

分 类 号：TQ35[化学工程]