Evaluation of Methods for Recovering Wood Fibers Through Urea–Formaldehyde Resin Removal from Synthetic Resin-Bonded Wood Waste: A Case Study in a Technological Industrial Park in Montevideo, Uruguay

Medium-density fiberboard (MDF) and other resin-bonded wood panels pose significant end-of-life management challenges due to the presence of urea–formaldehyde (UF) resins, which hinder material recovery and circular valorization. This study evaluates hydrolysis-based methods for removing UF resins from waste MDF, melamine-faced MDF, oriented strand board (OSB), and plywood generated in a technological industrial park in Montevideo, Uruguay. The evaluated hydrolysis treatments comprised acid, alkaline, and water hydrolysis at 80 °C under agitation, and steam-assisted hydrolysis in an autoclave. Treatment performance was evaluated using total Kjeldahl nitrogen analysis, elemental analysis, mass loss determination, and semi-quantitative formaldehyde measurements using Quantofix® indicator strips. Among the evaluated treatments, solvent-assisted hydrolysis using 0.1 M oxalic acid achieved the highest resin removal efficiency, reaching nitrogen removal values of up to 95%, while steam-assisted hydrolysis achieved removals above 90% using only distilled water. Treatment efficiency was strongly influenced by the solid-to-liquid ratio (S/L ratio) and the processed mass, highlighting key operational variables for process optimization. Overall, the proposed hydrolysis routes constitute effective pretreatment strategies for producing wood fibers with substantially reduced urea–formaldehyde resin content, thereby supporting the circular valorization of resin-bonded wood waste.