Search

..................................

Select Level of Detail

At a Glance

General

Technical

............................

+ Mill Residues - Secondary Mill Residues

............................

Access BioWeb Content

Search

Explore By Topic

Browse Index

............................

BioWeb Glossary

Search

Alphabetical Listing

............................

Contributors Log in

bioweb.sungrant.org » Technical » Biomass Resources » Forest Resources » Mill Residues » Secondary Mill Residues

Secondary Mill Residues	Printer Friendly

The U.S. forestry industry, in the process of harvesting and converting wood into consumer products, generates a number of residue and waste materials that could be used for bioenergy and bioproducts. Forest industry resources include those resulting from operations within forest and timberland areas, as well as materials generated in the conversion of wood into intermediate and final products such a lumber and paper (i.e., mill residues). Primary mills are those that convert roundwood products (i.e., tree trunks and logs) into other wood products and include sawmills that produce lumber, pulp mills, veneer mills, etc. In the process of converting trees into wood products, waste residues are generated consisting of bark, fine wood residues, and coarse wood residues. Secondary mills utilize the products from primary mills to produce other products (e.g., convert board lumber into furniture, cabinets, etc.). While primary and secondary mills are typically separate facilities, both primary wood processing and secondary conversion to finished consumer products can occur in the same facility.    Few estimates exist regarding the amount of secondary mill residues that are generated. This type of data is not routinely collected and must be estimated. The general approach is to multiply a waste generation factor (generally defined as lbs of waste/employee) by the number of employees. Little data is available regarding appropriate waste generation factors and the quality and type (i.e., all workers or just those working with wood) of employment data is often suspect. Use of SIC codes to identify companies often leads to misidentification due either to double counting of companies  listed under more than one SIC code or inclusion or exclusion of companies due to the delay in compiling SIC data (Buggeln, 2002).    Rooney (1998) estimated that 12.5 million dry tons of secondary mill wood residues are generated, but that only 1.2 million dry tons could be available for bioenergy after correcting for assumed recoverability factors, percent of residues contaminated, etc. No economic analysis was conducted.

References
Buggeln, Richard and Timothy Young (February, 2002), Wood Waste Generation by Secondary Wood Products Manufacturers, University of Tennessee Center for Industrial Services, Knoxville, TN. Rooney, T. (1998), Lignocellulosic Feedstock Resource Assessment, NREL/TP-580-24189.