Thermophysical Properties of Lignocellulose: A Cell-scale Study down to 41K

TL;DR

This study investigates the thermal properties of cell-scale lignocellulose from room temperature down to 41 K, revealing anisotropic thermal conductivity and unique temperature-dependent behavior relevant for bio-fuel pyrolysis.

Contribution

It provides detailed measurements of lignocellulose's thermophysical properties at the cell scale across a wide temperature range, highlighting differences from microcrystalline cellulose.

Findings

Thermal conductivity shows slight anisotropy due to cell structure.

Volumetric specific heat decreases slower than microcrystalline cellulose.

Thermal conductivity decreases from 243 K to 317 K and increases from 41 K to 243 K.

Abstract

Thermal energy transport is of great importance in lignocellulose pyrolysis for bio-fuels. The thermophysical properties of lignocellulose significantly affect the overall properties of bio-composites and the related thermal transport. In this work, cell-scale lignocellulose (mono-layer plant cells) is prepared to characterize their thermal properties from room temperature down to 41 K. The thermal conductivities of cell-scale lignocellulose along different directions show a little anisotropy due to the cell structure anisotropy. It is found that with temperature going down, the volumetric specific heat of the lignocellulose shows a slower decreasing trend against temperature than that of microcrystalline cellulose, and its value is always higher than that of microcrystalline cellulose. The thermal conductivity of lignocellulose decreases with temperature from 243 K to 317 K due to increasing phonon-phonon scatterings. From 41 K to 243 K, the thermal conductivity rises with temperature and its change mainly depends on the heat capacity's change.