RT info:eu-repo/semantics/doctoralThesis
T1 Sudden supercritical water reactors for biomass upcycling. Native cutin production
A1 Leontijevic, Vesna
A2 Universidad de Valladolid. Escuela de Doctorado
K1 Fluidos
K1 supercritical fluids
K1 Fluidos supercríticos
K1 2204 Física de Fluidos
AB This research demonstrates the potential of supercritical water-based biorefinery techniques to improve biomass processing efficiency, offering sustainable alternatives for high-value material extraction.Chapter 1 of this thesis explores the use of supercritical water (SCW) to process tomato peel biomass, a byproduct of the tomato industry, to extract biopolyester cutin. By carefully controlling reaction conditions (temperatures above 374°C and pressures above 220 bar), the process achieves efficient extraction in as little as one second. Analytical techniques such as Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) confirm the retention of cutin’s structural properties.Chapter 2 enhances the SCWH process by integrating a cyclone reactor, which facilitates simultaneous reaction and separation, reducing downstream processing. Upgrades, including synchronized control valves, improved pressure regulation, and hydrodynamic control, optimize biomass fractionation. Applied to various biomass types, including cellulose, lignocellulosic biomass, and biopolyester-rich sources, the cyclone reactor demonstrated efficiency in separating hydrolysis products. Results indicate that separation efficiency is influenced by hydrodynamic effects, reaction conditions, and biomass composition.Chapter 3 focuses on lignin and lignin-cellulose composites obtained through supercritical water hydrolysis (SCWH). Lignin extracted from birch wood under different conditions was analyzed for surface properties such as wettability and surface energy, crucial for polymer applications. Contact angle measurements using water and diiodomethane confirmed lignin’s hydrophilic nature. Results revealed that controlling cellulose content via SCWH fractionation allows tunable wettability, with pressure variations having minimal effect. These findings contribute to a better understanding of lignin’s interfacial properties, enhancing its application in composite materials.
YR 2024
FD 2024
LK https://uvadoc.uva.es/handle/10324/76331
UL https://uvadoc.uva.es/handle/10324/76331
LA eng
NO Escuela de Doctorado
DS UVaDOC
RD 19-jul-2025