| Autor: |
Liu Shi, Yiming Sun, Xian Li, Shuo Li, Bing Peng, Zhenzhong Hu, Hongyun Hu, Guangqian Luo, Hong Yao |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
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| Zdroj: |
Molecules, Vol 28, Iss 22, p 7671 (2023) |
| Druh dokumentu: |
article |
| ISSN: |
1420-3049 |
| DOI: |
10.3390/molecules28227671 |
| Popis: |
A novel gas-pressurized (GP) torrefaction method at 250 °C has recently been developed that realizes the deep decomposition of cellulose in lignocellulosic solid wastes (LSW) to as high as 90% through deoxygenation and aromatization reactions. However, the deoxygenation and aromatization mechanisms are currently unclear. In this work, these mechanisms were studied through a developed molecular structure calculation method and the GP torrefaction of pure cellulose. The results demonstrate that GP torrefaction at 250 °C causes 47 wt.% of mass loss and 72 wt.% of O removal for cellulose, while traditional torrefaction at atmospheric pressure has almost no impact on cellulose decomposition. The GP-torrefied cellulose is determined to be composed of an aromatic furans nucleus with branch aliphatic C through conventional characterization. A molecular structure calculation method and its principles were developed for further investigation of molecular-level mechanisms. It was found 2-ring furans aromatic compound intermediate is formed by intra- and inter-molecular dehydroxylation reactions of amorphous cellulose, and the removal of O-containing function groups is mainly through the production of H2O. The three-ring furans aromatic compound intermediate and GP-torrefied cellulose are further formed through the polymerization reaction, which enhances the removal of ketones and aldehydes function groups in intermediate torrefied cellulose and form gaseous CO and O-containing organic molecules. A deoxygenation and aromatization mechanism model was developed based on the above investigation. This work provides theoretical guidance for the optimization of the gas-pressurized torrefaction method and a study method for the determination of molecular-level structure and the mechanism investigation of the thermal conversion processes of LSW. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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