GATE-TO-GATE LIFE-CYCLE INVENTORY OF ORIENTED STRANDBOARD PRODUCTION

A life-cycle Inventory (LCI) for Southeast oriented strandboard (OSB) manufacturing was conducted by surveying four OSB manufacturing plants in the Southeast. The survey responses were returned for 1999 production data and represented approximately 18% of OSB production in the survey region. All LCI data presented herein were based on a standard production unit of 0.88 m 3 OSB panel product (1000 ft 2 , 3/8-inch basis). Southeastern OSB requires 771.6 kg (1701 lb, oven-dry basis) of roundwood raw material input. 545.7 kg (1203 lb) of this input ends in final OSB product, giving a total wood recovery of 71%. The remaining wood input ends as wood residue for fuel, wood residues sold as co-products, and wood waste sent to the landfill. On-site energy requirements for southeastern OSB are 5261 MJ (4.99 million BTU). Heat energy is the largest energy need, 89.6% of which is generated from combustion of wood residues. 182 kWh (655 MJ heat equivalent) of electricity is required for processing OSB. The highest use of fossil fuel (natural gas) is used to reduce VOC emissions in the emission control process at 465 MJ (4.4 million BTU). Considering the carbon cycle for on-site OSB production for a unit of product, OSB requires 396 kg (873 lb) of carbon from wood raw material. Other carbon input is utilized in the form of resins/wax (11.4 kg/25 lb) and fuels (12.3kg/27 lb). OSB holds 290 kg (640 lb or 69% of total carbon input) carbon. A small percentage of carbon (4%) is held in the form of co-products (e.g. mulch and wood residues). The remainder of carbon is released back to nature in the form of non-fossil CO 2 (24%), fossil CO 2 (3%), VOCs and other emissions (0.4%).