What's New with Wood

Wood can be one of the most difficult to recycle materials in the C&D waste stream. Markets are the main problem, but some recyclers complain that there isn’t enough research into the subject, or they don’t know how to access what already has been done on the subject.

Below are some reports that can shed light on wood recycling. Included is a summary or description of the work and how to get the information. While this list is not all-inclusive, it contains many useful studies. We hope it helps.

FOREST AND WOOD PRODUCTS STUDY, MOUNT WACHUSETT COMMUNITY COLLEGE

"An Investigation of the Potential to Expand the Manufacture of Recycled Wood-Plastic Composite Products in Massachusetts," 2000. Researched by the Forest and Wood Products Institute, Mount Wachusett Community College.

Estimates suggest current production of wood-thermoplastic composite products is about 300 million pounds per year, a three-fold increase from two years ago. Major markets are decking materials, pallets and automobile and window components. Fueled by the decreasing availability of solid wood relative to projected demands, both recovered wood and plastic materials are being investigated as substitutes. The objectives of this project were to identify wood and plastic recycling needs and market opportunities for composite materials manufactured from these materials in Massachusetts; and to develop a strategy for the manufacture of selected products. The investigation concentrated on products with high value-added capability, large potential markets and a projected long-term life.

Approximately 11.6 million tons of wood waste were generated in 1997 according to the EPA. In fact, wood comprises the largest percentage of the residential C&D waste stream—approximately 42 percent of new construction debris—according to the National Association of Home Builders Research Center. Prior to 1990, there was limited recycling of wood waste (e.g., urban wood waste, woody debris from suburban land clearing, and rural forestry residuals) in the United States. Today, EPA estimates there are more than 500 wood processing facilities across the country.

The markets for recovered wood vary across the United States according to regional and local supply and demand. The current market, however, is dominated by mulch and fuel applications, which pay between $12 and $24 per ton for processed wood. Wood waste from construction and demolition activities is attractive as a fuel because of its low moisture content.

Processed or chipped wood also is used as a composting bulk agent and as animal bedding. Salvaged or reused wood products are the highest value items but typically require the highest costs for sorting and processing.

In addition, recovered wood can be used to manufacturer value-added products such as medium density fiberboard and particleboard. These manufacturers demand high-quality feedstocks, however, which can be difficult to achieve on a consistent basis.

The demolition industry is well established and is increasing its efforts to recover wood waste. In addition, the deconstruction industry continues to grow and salvage an increasing percentage of materials from old buildings. Deconstruction efforts recover and reuse wood for flooring, doors, windows and other applications. A number of independent lumber mills have retooled their operations to process reclaimed timbers as well.

Federal and local air and water regulations provide an incentive for wood recovery by discouraging inappropriate burning or discarding of woody debris. A major barrier to increased wood recovery, however, is the lack of grade standards for recovered wood. These standards include grading rules, engineering properties and a grade stamp. There also is a need for technical performance testing to investigate the structural integrity of recovered wood.

ASSOCIATED GENERAL CONTRACTORS INFORMATION ON WOOD RECYCLING

Five hundred wood processing plants are located in the U.S., according to the AGC Web site. "Recycling plants accept ‘clean’ wood (untreated and unpainted). However, recycling technology is improving, and some recycling centers can now accept painted wood. Even nails are not a problem because they separate from the wood during the recycling process."

The AGC urges contractors to "do the math."

"Fees for wood recycling average $40 to $60 per ton compared to regular landfill disposal prices of $70 to $84 per ton. Saving trees saves money! Recycled wood goes a second round as:

Most of the wood pieces from construction projects are ‘scraps’ that become ‘engineered wood.’ This wood is derived from smaller pieces of wood bound together by glue, resin (tar-like substance) or chemicals to make a wood-like product. Such products include particle board, laminated woods and plywood, which are used for non-structural applications."

The AGC site also notes that reasons for contractors to recycle construction waste include:

According to the CIWMB, "construction and demolition (C&D) materials still account for almost 12 percent of the waste stream. State support of local efforts to minimize the disposal of construction- and demolition-generated materials includes providing C&D recycling facility information through the C&D Debris Recyclers Database.

Sampling of solid waste disposed in California for the year 1999 indicated that 12 percent of the material disposed was classified as C&D materials.

Web site visitors also are encouraged to learn more about the 1999 statewide waste characterization study and the waste disposal characterization method.

The following C&D materials were classified in the waste characterization study:

Search for the ‘annual disposal tonnage’ and ‘percent of waste stream’ for the above-mentioned C&D materials in specific California jurisdictions using the solid waste characterization database."

Visitors also are urged to keep up with the status of proposed regulations of construction and demolition inert debris by viewing the U.S. EPA’s C&D Web pages.

The Board’s sustainable (green) building site provides information on environmentally friendly building products and techniques.

This project was undertaken by the Construction Materials Recycling Association (CMRA) in order to provide some direction to waste wood recyclers who want to enter added-value wood recycling markets. Many of these recyclers are producing low-value products, such as alternative daily cover for landfills, boiler fuel or mulch. In many areas of the country these markets are becoming saturated to the point where product prices are dropping and outlets are decreasing, to the detriment of recyclers and of landfill diversion goals. Opening up recycled wood to added-value markets will help increase the demand for the material, increasing prices to improve the economic feasibility of recycling while diverting more materials from landfills.

Recycling of construction waste and demolition debris (C&D) is a regional business. Transportation costs for such bulky materials make it so. The CMRA methodology to increase recycling was to work with one recycler in an area to bring them into added-value recycling and to share the results with other recyclers in the region. U.S. EPA Region 5 agreed to fund the first of these studies, which worked with a Chicago-area recycler, Davin Industries, Inc.

Davin has a relatively clean incoming waste wood stream, which easily lent itself to added-value recycling. Currently the company makes mulch, playground covering and animal bedding. Several markets were looked at.

An analysis was done of the company’s incoming waste stream to determine types of woods and species. Laboratory tests were performed to determine the results of grinding the material into wood flour and other shapes and sizes. In addition, a careful look was taken at reusing the wood in some form or another, as reuse is considered the highest form of recycling.

As could be expected, the results were both promising and disappointing. Reusing the pallet material as pallets again proved to be a low demand market, with little interest and response. However, using the wood in the products as part of a finger-jointing project to make new wood pieces and flooring appears to be a viable market opportunity, with interest expressed by the end markets.

Grinding the wood for new products proved trickier, economically or technically. For example, the entrance of a planned medium density fiberboard plant into the Chicago area promised to take thousands of tons of waste wood as infeed. Probably no better added-value possibility exists for recycled wood. But the price it expects to pay for high-quality chips appears to be far below their value.

Another possibility is the manufacture of wood flour, a product with several uses. One potential Chicago-area outlet was a city-based plastic lumber manufacturer who was eager to accept waste wood flour as a filler for its products. Careful testing and processing showed that the waste wood would work technologically. But business factors—high energy and capital costs, market outlet limited to one player—precluded Davin from following this trail. But this project did prove that waste wood could fit the specifications of that market.

One success is a fire log product that Davin expected to begin manufacturing after the study. There were several barriers to entering the market, but research and testing proved that the barriers can be overcome.

Not so fortunate was the examination into the wood pellet market, which is popular in the northeastern U.S. Illinois consumers currently lack interest in such a pellet product, and it was not pursued.

The exercise involved examination of a variety of existing and conventional markets; virgin timber, coal, propane, cord wood, heating oil and wood fuel pellets and competing fire log products, trying to determine the availability, acceptability and size of the market.

These best practices are proven methods and techniques for technology applications and end use applications for recovered wood, according to Seattle’s Clean Washington Center. "The practices provide guidance for performing operational activities—from the initial materials sourcing, through processing and site storage, product manufacturing, and enduse applications," the Center notes.

"Manufacturing opportunities covered include pulp & paper, panelboard, fiber composites, pressed fuel products and others. End use applications covered include mulch, landscaping, soil amendments, compost bulking, land application and biofuel combustion.

The information documents recycling industry methodology and recommendations for the efficient techniques and improved safety for each of the major recycling processing steps. It is intended to be a guideline for operators of recycling processes on various topics related to without infringing on any organization’s proprietary process technology or techniques."