Energy-efficient and formaldehyde-free biomass-based boards derived from Pleurotus Ostreatus substrate waste: A novel sustainable utilization strategy

The preparation of formaldehyde-free biomass-based boards from waste mushroom substrate simultaneously tackles environmental pollution from landfill/incineration of mushroom waste and wood resource shortage, offering novel insights for ecological sustainable development. However, current formaldehyde-free biomass-based board production from laboratories suffers from extremely high hot-pressing energy consumption (hot-pressing time ≥ 2 h), conflicting with the energy-saving demands under the “Double Carbon” initiative. This study proposes a novel strategy using citric acid (CA)-epoxidized soybean oil (ESO) for synergistic pretreatment of Pleurotus ostreatus ( P. ostreatus ) substrate powder to prepare mushroom substrate-based boards (MSB) using hot-pressing technique. Both the mechanical properties and water resistance of the prepared MSBs are dramatically improved, and meet the standards for dry-condition furniture-grade and load-bearing particle-boards specified in GB/T 4897–2015, while reducing hot-pressing energy consumption by over 63 % compared with the P. ostreatus substrate-based boards without CA and ESO pretreatment. Further FT-IR spectroscopy measurement reveals that pretreatment agents enhance hot-pressing efficiency via esterification and amidation reactions with lignocellulose/protein in P. ostreatus substrates. The proposed strategy provides a technically and economically viable energy-saving solution for business application of MSBs.