RT info:eu-repo/semantics/article T1 Pressure and temperature effect on cellulose hydrolysis in pressurized water A1 Cantero Sposetti, Danilo Alberto A1 Sánchez Tapia, Ángel A1 Bermejo Roda, Maria Dolores A1 Cocero Alonso, María José AB In this study, the effect of temperature and pressure on cellulose and glucose hydrolysis in a hydrothermal media was analyzed. To do so, cellulose hydrolysis experiments were carried out in a continuous pilot plant capable of operating up to 400 °C and 27 MPa. The reaction times were varied between 0.004 and 40 s. The main products of cellulose hydrolysis were oligosaccharides, cellobiose, glucose and fructose. The concentration profiles of each component followed a similar behavior at a fixed temperature changing pressure. Nevertheless, glucose and fructose hydrolysis reaction to give dehydration of retro aldol condensation products were strongly affected by pressure and temperature. When increasing temperature in the studied range, the reaction of glucose isomerization to fructose and the production of 5-hydroxymethylfurfural (5-HMF) obtained through fructose dehydration were inhibited. On the other hand, 5-HMF production was favored by high proton concentrations due to water dissociation. Thus, at a constant temperature, the production of 5-HMF was increased by rising the ionic product of water (increasing pressure). The production of glycolaldehyde (retro-aldol condensation of glucose) was increased by rising temperature and pressure. The kinetic constants of the cellulose hydrolysis reactions were determined at the experimented conditions using the experimental results. The kinetic constants were plotted against temperature and pressure to determine the activation energy and the activation volume for each reaction, respectively. Pressure seems to have no effect on the cellulose hydrolysis kinetic to simple sugars. However, at supercritical water temperatures the increment in pressure disfavored the glucose isomerization and dehydration reactions. PB Elsevier SN 1385-8947 YR 2015 FD 2015 LK http://uvadoc.uva.es/handle/10324/28442 UL http://uvadoc.uva.es/handle/10324/28442 LA eng NO Chemical Engineering Journal, 2015, Volume 276, pp.145-154 NO Producción Científica DS UVaDOC RD 27-dic-2024