ACQ-treated veneer based composite VBC hardwood hollow utility poles from mid-rotation plantation thinned trees: Life cycle GHG emissions

Hardwood plantations are slow to mature with low financial returns in the early stage. Veneer Based Composite (VBC) products from mid-rotation plantation thinned trees are currently being developed at Griffith University in partnership with the Salisbury Research Centre, Queensland Government, which may offer an opportunity to improve the industry’s profitability and win new markets. Due to shortage in utility solid hardwood poles, VBC poles are proposed as a potential alternative. In this study, greenhouse gas emissions of alkaline copper quaternary (ACQ) preservative-treated VBC pole was assessed using ‘cradle to grave’ life cycle assessment methodology. ACQ preservative was used to extend the service life of wood poles due to wood products are commonly to be degraded in wet environments subject to microbial or insect attack. The manufacturing process considered in this study is based on the current technologies in Salisbury Research Centre. Two (2) end-of-life scenarios were considered: landfilling and incineration with energy recovery. The function unit was a 1-metrelength pole with 115mm internal-diameter and 15mm wall-thickness. Global warming potential (GWP100) was calculated using the IPCC 2007 method. Results indicated disposal stage contributed the most impact. Incineration with energy recovery had the lowest GWP impact (0.337kg-CO2-Eq) followed by landfilling. Transportation distance was identified as a significant parameter affecting the result. Sensitivity analysis indicated that increasing the transportation distance by 100 km would increase the GWP100 by 21% in the incineration option