Estimate of material recycling flow in the Japanese wood industry

摘要

Concrete methods for estimating the amount of carbon stocked in wood used as housing, furniture, etc , have been discussed for the Second Commitment Period at the Conference of Parties (COP) of the United Nations Framework Convention on Climate Change(UNCCC), because the capacity of carbon sinks by wood utilization can not be ignored in the global carbon circulation. Therefore, we have to establish a method for estimating the amounts of carbon stocked in wood products. In this study, we observed thematerial recycling flow in Japanese wood industry, in order to understand the amounts of material recycling of wood residue. We estimated the volumes of wood residues generated at sawmills, plywood mills, wooden furniture factories, wooden pallet factories, packing factories, precul factories, and glue laminating factories and the volume of their material recycling based on several kinds of statistics and former studies and the result of questionnaire In 2001, the total volume of the wood residues generated in Japanese wood industry was estimated 13.475 million m~3, that is 5.054 million m~3 at sawmills, 0.407 million m~3 at plywood mills, 0.036 million m~3 at wooden furniture factories, 0.006 million m~3 at wooden pallet factories, 0 014 m~3 at packing factories, 0.175 million m~3 atprecttt factories, and 0 032 million m~3 at glue laminating factories. The wood residues of 43% (5.724 million m~3) were recycled as material for pulp and wood composites. The material recycled residues of 98% were generated at sawmills, plywood mills, and precut factories.