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Non-catalyzed and Pt/γ-Al2O3-catalyzed hydrothermal cellulose dissolution–conversion: influence of the reaction parameters and analysis of the unreacted cellulose

2009; Royal Society of Chemistry; Volume: 11; Issue: 12 Linguagem: Inglês

10.1039/b915758a

1463-9270

Véronique Jollet, Flora Chambon, Franck Rataboul, Amandine Cabiac, C. Pinel, Emmanuelle Guillon, N. Essayem,

Lignin and Wood Chemistry

Hydrothermal dissolution and/or conversion of cellulose Avicel® occurred at 190 °C under 5 MPa of H2 in the absence of catalyst. This reaction is temperature and time dependent. A dissolution–conversion ratio of 35% was obtained after 24 h of reaction and glucose and HMF were detected as monomeric products in a global yield of less than 5%, indicating that the majority of the products are composed of soluble oligo- and polysaccharides. The unreacted cellulose was analyzed using XRD, 13C solid state NMR, TGA-DTA and SEM and compared to the initial cellulose. We showed that although morphology changes occurred during the reaction, no modification of the crystallinity was observed and that hydrothermal treatment did not affect a specific part of the cellulose polymer. The presence of Pt/γ-Al2O3 increased the initial rate of dissolution–conversion significantly as well as the distribution of the monomeric products. Pt and H2 atmosphere were seen to increase the dissolution–conversion ratio however their role has not been yet well established.