Optimizing Wood’s Thermal Performance: Lignin Modification for Energy-Efficient Buildings

Delignification and chemical modification of lignin in wood through alkaline and oxidation treatments were investigated with its enhanced thermal performance for energy-saving potential in wood buildings. EnergyPlus simulations are then adopted for applying delignified wood to radiative cooling systems, serving as rooftop radiators to reflect heat to the sky for heat dissipation purposes, to partially replace active energy requirements of wood buildings. Results show that alkaline treatment enhances photon absorption by stabilizing β-O-4′ bonds, leading to more heat absorption, and alkali-treated wood provides an annual building energy saving of up to 4.67 MJ/m² through saving heating systems’ energy. On the other hand, oxidation degrades the aromatic structure of lignin and conjugated double bonds, leading to a reduction in heat absorbance and enhanced radiative cooling properties, which results in a maximum building energy saving of 12.77 MJ/m² through saving cooling systems’ energy. These results highlight the potential for tailoring wood lignin modifications to improve the energy efficiency of wood-based buildings.