López Mar, Vila Carlos, Santos Valentín, Parajó Juan Carlos
Chemical Engineering Department, University of Vigo (Campus Ourense), Polytechnical Building, As Lagoas, 32004 Ourense, Spain.
Polymers (Basel). 2020 May 27;12(6):1215. doi: 10.3390/polym12061215.
wood samples were subjected to chemical processing for manufacturing furans and organic acids from the polysaccharide fractions (cellulose and hemicellulose). The operation was performed in a single reaction stage at 180 or 190 °C, using a microwave reactor. The reaction media contained wood, water, methyl isobutyl ketone, and an acidic ionic liquid, which acted as a catalyst. In media catalyzed with 1-butyl-3-methylimidazolium hydrogen sulfate, up to 60.5% pentosan conversion into furfural was achieved, but the conversions of cellulose and (galacto) glucomannan in levulinic acid were low. Improved results were achieved when AILs bearing a sulfonated alkyl chain were employed as catalysts. In media containing 1-(3-sulfopropyl)-3-methylimidazolium hydrogen sulfate as a catalyst, near quantitative conversion of pentosans into furfural was achieved at a short reaction time (7.5 min), together with 32.8% conversion of hexosans into levulinic acid. Longer reaction times improved the production of organic acids, but resulted in some furfural consumption. A similar reaction pattern was observed in experiments using 1-(3-sulfobutyl)-3-methylimidazolium hydrogen sulfate as a catalyst.
木材样品经过化学处理,以从多糖组分(纤维素和半纤维素)制造呋喃和有机酸。该操作在180或190°C的单一反应阶段中,使用微波反应器进行。反应介质包含木材、水、甲基异丁基酮和一种酸性离子液体,该酸性离子液体用作催化剂。在用硫酸氢1-丁基-3-甲基咪唑鎓催化的介质中,戊聚糖转化为糠醛的转化率高达60.5%,但纤维素和(半乳)葡甘露聚糖转化为乙酰丙酸的转化率较低。当使用带有磺化烷基链的酸性离子液体作为催化剂时,可获得更好的结果。在含有硫酸氢1-(3-磺丙基)-3-甲基咪唑鎓作为催化剂的介质中,在较短的反应时间(7.5分钟)内实现了戊聚糖几乎定量转化为糠醛,同时己聚糖转化为乙酰丙酸的转化率为32.8%。更长的反应时间提高了有机酸的产量,但导致了一些糠醛的消耗。在使用硫酸氢1-(3-磺丁基)-3-甲基咪唑鎓作为催化剂的实验中观察到了类似的反应模式。