Biochar and Activated Carbon as Formaldehyde Scavengers in Particleboards: A Technical and Environmental Assessment

Activated carbon (AC) and biochar (BC) were incorporated into urea–melamine–formaldehyde (UmF) adhesive at 0.5, 1.0, and 2.0 wt% of adhesive solids to investigate their effects on particleboard performance. This study directly compares AC and BC in the same UmF-bonded particleboard system, combining measurements of formaldehyde release and technical performance with life cycle assessment and exploratory performance-based annualization. Compared with the control, boards containing 1.0% BC exhibited approximately 18% higher mean internal bond strength and 11% lower mean formaldehyde release, while 0.5% BC exhibited approximately 33% higher mean modulus of rupture. AC at 2.0% reduced mean 24 h thickness swelling by approximately 21%. Increasing BC loading to 2.0% did not improve formaldehyde control and slightly increased mean release. These experimental trends indicate that additive selection involves trade-offs rather than uniform improvements across properties. Baseline LCA results showed small differences in impacts per cubic metre of board. Under the assumed service-life model, equal weighting of the selected technical properties, and an equal-raw-impact assumption, BC2 yielded approximately 14% lower annualized impacts than the control. This modeled reduction does not establish an actual extension of service life. The combined assessment highlights the need to distinguish measured performance from assumption-dependent environmental rankings when selecting carbon-based additives.