Liquid-phase reforming and hydrodeoxygenation as a two-step route to aromatics from lignin
Liquid-phase reforming and hydrodeoxygenation as a two-step route to aromatics from lignin
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DOI：
10.1039/c3gc41150h
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发表时间：
2013-01-01
期刊：
影响因子：
9.8
通讯作者：
Weckhuysen, Bert M.
中科院分区：
文献类型：
--
作者：
Jongerius, Anna L.;Bruijnincx, Pieter C. A.;Weckhuysen, Bert M.
介绍了一种两步法将有机溶剂、硫酸盐和甘蔗渣木质素转化为低氧含量的单芳族化合物的方法。第一步由在225 ℃下在碱性乙醇-水中在1重量% Pt/γ-Al 2 O3催化剂上的液相重整（LPR）反应中的木质素解聚组成。第一LPR步骤导致有机溶剂、硫酸盐和甘蔗渣木质素的木质素分子量分别降低32%、57%和27%。解聚的木质素反应混合物的GC分析还显示，由有机溶剂、硫酸盐和甘蔗渣木质素分别以11%、9%和5%的产率形成烷基化苯酚、愈创木酚和姜子油型产物。通过乙醇-水溶液的萃取分离的木质素-油在第二转化步骤中进行随后的加氢脱氧（HDO）反应。木质素-油的HDO在十二烷中在300 ℃下在50巴氢气压力下在CoMo/Al 2 O3和MO 2C/CNF催化剂上进行。对两步LPR-HDO方法后获得的产物混合物的GC分析揭示了苯、甲苯、二甲苯和乙基甲基苯等的形成。在观察到的总单体产物（9%）中，25%由这些无氧产物组成。值得注意的是，这样的产物不能通过木质素的直接HDO获得。木质素-油在350 ° C下的HDO导致所有三氧化产物的转化，其中57%的观察到的单体产物现在被鉴定为单氧化酚类。
A two-step approach to the conversion of organosolv, kraft and sugarcane bagasse lignin to monoaromatic compounds of low oxygen content is presented. The first step consists of lignin depolymerization in a liquid phase reforming (LPR) reaction over a 1 wt% Pt/gamma-Al2O3 catalyst at 225 degrees C in alkaline ethanol-water. The first LPR step resulted in a decrease in lignin molecular weight of 32%, 57% and 27% for organosolv, kraft and bagasse lignin, respectively. GC analysis of the depolymerized lignin reaction mixture furthermore showed the formation of alkylated phenol, guaiacol and syringol-type products in 11%, 9% and 5% yields from organosolv, kraft and bagasse lignin, respectively. The lignin-oil that was isolated by extraction of the ethanol-water solution was subjected to a subsequent hydrodeoxygenation (HDO) reaction in the second conversion step. HDO of the lignin-oil was performed in dodecane at 300 degrees C under 50 bar hydrogen pressure over CoMo/Al2O3 and MO2C/CNF catalysts. GC analysis of the product mixture obtained after the two-step LPR-HDO process revealed the formation of, amongst others, benzene, toluene, xylenes and ethylmethylbenzenes. Of the total observed monomeric products (9%), 25% consisted of these oxygen-free products. Notably, such products cannot be obtained by direct HDO of lignin. HDO of the lignin-oil at 350 degrees C resulted in the conversion of all tris-oxygenated products, with 57% of the observed monomeric products now identified as mono-oxygenated phenolics.