Environmental Impact of Lumber Production using Life Cycle Assessment: A Case Study of the Production System in South-west Nigeria

Abstract

Life Cycle Assessment (LCA) is a decision support tool that can be used to evaluate the potential environmental impact of a product system. Environmental impact associated with the production of (0.0508×0.1524×3.6576) m lumber referred to as “2by6” in the primary wood industry was evaluated. This assessment is a cradle to gate system with boundaries spanning from the point of raw material extraction in Osun state, to transportation of the lumber product to wood market in Ibadan, Oyo state. The study compared four production scenarios by varying haulage distance and energy source during production at two sawmill facilities located in Ife and Ikire in Osun state. Data obtained from the production system were analysed using GaBi6 software to estimate and classify the emissions into five impact categories. Life Cycle Impact Assessment result (LCIA) showed that Acidification Potential (AP), Global Warming Potential (GWP) and Smog Potential (SP) were the most significant impact indicators observed in the four production scenarios. AP (2.883, 3.352, 3.483, 3.951) kg H+ mole-Equiv, GWP (13.25, 14.44, 15.45, 16.65) kg CO2-Equiv and SP (1.86, 2.15, 2.24, 2.53) kg O3-Equiv. Scenario 4 which involved a longer transportation distance and employed a diesel generator for the milling process showed the least environmental performance. Processes that contributed significant impact were wood waste disposal method employed and the secondary transportation processes during logging activities. In order to achieve a better production system, practices that encourage less waste generation and the use of renewable energy were recommended.Keywords— LCA, lumber production, environmental impact, wood waste