Microwave-assisted selective cleavage of C C bond for lignin depolymerization
| Autor: | Dongxue Jin, Guodian Zhu, Xueqing Qiu, Lisha Zhao, Xinping Ouyang, Chen Cheng |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
010405 organic chemistry
Chemistry Depolymerization General Chemical Engineering Dimer Vanillin Energy Engineering and Power Technology 010402 general chemistry Cleavage (embryo) 01 natural sciences Medicinal chemistry 0104 chemical sciences chemistry.chemical_compound Fuel Technology Monomer Lignin Organic chemistry Reactivity (chemistry) Bond cleavage |
| Zdroj: | Fuel Processing Technology. 161:155-161 |
| ISSN: | 0378-3820 |
| DOI: | 10.1016/j.fuproc.2017.03.020 |
| Popis: | Lignin is an alternative renewable feedstock for the production of low molecular weight aromatics. The cleavage of phenyl side-chain C α C β bond is a valid depolymerization pathway to obtain aromatic monomers. The selective cleavage of the C α C β bonds in two lignin model dimers and lignin with ferric sulfate as the catalyst was investigated to narrow the distribution of aromatic monomers. The C α C β bonds in phenolic and non-phenolic dimers were selectively cleaved under microwave irradiation. The acidity promoted the etherification of C α -hydroxyl groups with methanol solvent. Both the etherification and the decomposition of alkenyl products occurred in fast reaction steps, but the formation of alkenyl products was a decomposition-determining step. Density functional theory (DFT) calculations indicated that the phenolic dimer was more thermodynamically favorable to form alkenyl product than non-phenolic dimer, which resulted in the C α C β bond cleavage reactivity of phenolic dimer being higher than that of non-phenolic dimer. Microwave heating contributed to 96.3% of C α C β bond cleavage of organosolv lignin (OL), and a narrow distribution of aromatic monomers which mainly contained vanillin, syringaldehyde, methyl vanillate, and methyl syringate. This work highlights the prospect of microwave-assisted selective cleavage of the C α C β bond to achieve the selective production of aromatic monomers from lignin. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect