Greenhouse gas and economic assessments of biochar-based composite panels from forest residues

Among other threats to forests across the western U.S., large-scale outbreaks of mountain pine beetle have generated extensive volumes of low-value forest residues that increase wildfire risk while remaining underutilized as a carbon resource. Converting these residues into high-value biochar products offers a pathway for carbon stabilization and value creation, yet most existing markets for biochar remain relatively low value. This study represents the first system-level assessment of biochar-based composite panels that jointly evaluates life-cycle greenhouse gas (GHG) emissions and techno-economic performance for biochar-based panel products at industrial scale. The modeled system integrates distributed biochar production using portable pyrolysis units with centralized panel manufacturing that uses kraft lignin as a renewable binder. In addition to a base-case (BC) configuration representing conventional biochar-lignin composite panel production, five alternative scenarios are modeled in which panels undergo secondary pyrolysis treatments at different temperatures and processing conditions associated with potential adsorption, structural, or fire-resistant applications. Cradle-to-gate GHG emissions range from 311 to 565 kg CO 2 -eq/m 3 . In addition, an illustrative 100-year carbon retention scenario based on assumed long-term biochar stability results in net GHG balances ranging from −343 to −750 kg CO 2 -eq/m 3 . Minimum selling price values range from 548 to 1101 US$/m 3 depending on panel type and processing conditions. The BC panel configuration falls toward the higher end of conventional particleboard and MDF price benchmarks, while the estimated MSPs of pyrolyzed panel configurations fall within or below the price ranges of selected benchmark materials used in water remediation and fire-resistant composite applications. These comparisons provide market-price context for the modeled MSPs but do not establish functional equivalence or commercial competitiveness, which require experimental validation.