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Maximizing the Burn

CMRA and NSWMA have crafted standards for grading C&D wood so it can be utilized in combustion systems.
By Matt Soberg | September 20, 2011

Is construction and demolition (C&D) wood debris considered waste?  Do standardized specifications like those for the paper and metal markets exist for C&D wood?  How should industry streamline the C&D wood market? 


Answers to these and other questions can now be found in Construction and Demolition Wood-Derived Product Specifications, the result of a recent collaboration of the Construction Materials Recycling Association and the National Solid Wastes Management Association. 


Issued in May after a year of research and investigation, the specifications are a uniform standard for grading C&D wood product to ensure suitable fuel burn in combustion systems.


Through the formation of stakeholder groups and task forces that included C&D processing, hauling and boiler companies, the organizations had the advantage of obtaining practical industry knowledge and experiences.


The standards were derived from actual specifications currently used by C&D processors and boilers in the marketplace along with various government permitting regulations. “It was a challenging task in the sense of standardizing numerous other specifications, rules and permitting practices,” says Chaz Miller, NSWMA director, state programs.


The organizations intend to promote marketability by standardizing the C&D wood industry. High-quality product will maximize the burn for potential purchasers.  


Necessary Uniform Standard


The CMRA and NSWMA believed it was necessary to create grading specifications to streamline processors and purchasers to foster the C&D wood fuel market. Members of the organizations who process C&D debris communicated the need for a uniform specification to help them negotiate with the boiler market. 


The new standards are designed to make C&D wood a commodity to be purchased and to connect processers with boiler operators to facilitate the market.


“The intent was to make the wood a commodity or a product similar to that of the metal market,” says CMRA Executive Director William Turley. “Wood has value. It is not waste.”


Wood is a primary material generated at demolition sites, and makes up sometimes 30 percent of C&D debris, notes Dan Costello, chair of CMRA’s Material Standards Committee and president of Costello Dismantling.  


Compared to other debris, recyclables and waste, C&D wood seemed to be getting left behind in the industry. Established uniformity existed for the paper and metal markets, while variable practices were inhibiting the wood market, creating a significant need to align C&D wood with other forms of fuel. 
“No specific process regulated C&D companies aiding the transfer and sale of their product for boilers,” says Miller, who is involved with numerous environmental and recycling related projects nationwide including many related specifically to wood debris from construction and demolition activities.


The necessity for standards arose from the need to bridge the gap between sellers and buyers. If companies process material in a different fashion than how boilers intend to burn it as fuel, the two sides cannot connect. This makes the marketplace unpredictable, unreliable and uncertain.
“There must be a meeting of the minds, and hopefully the uniform specifications can aid in this negotiation,” Miller says.


“The specifications will help standardize wood chips processed at C&D processing facilities and expand markets for this valuable biomass fuel,” Costello says.  


Grading C&D Wood Product


The Construction and Demolition Wood-Derived Product Specifications provide a range of specific grades and sizing of C&D wood debris. Certain grades are acceptable in the C&D marketplace. Variable C&D product inhibits the ability for reliable negotiations and sales. 


The specifications define C&D wood-derived product as, “a renewable, biomass product prepared from wood materials generated at construction and demolition sites that is processed to create a commodity that can be used as fuel for a boiler and/or other energy generation technology (e.g. gasification). This product can also include biomass materials such as boxes, crates, pallets and other wood products from industrial and post-consumer sources.”


The product grading system categorizes C&D product on two essential levels: grade and size. According to the specifications, the grade defines the acceptable amount of undesirable materials (those that pollute or inhibit efficient burn). Sizing defines the range of sizes acceptable to purchasers for burning purposes. 


The specifications define three grades of the product, which is based upon the percentage of restricted materials included in the product. Restricted materials include lead-based painted wood, CCA (chromated copper arsenate)-treated wood, plastic, plaster, and all non-combustibles such as rocks, concrete and aggregate. 


The highest grade, Grade 1, is defined as having 1 percent or less restricted material. Any C&D product with 5 percent or greater restricted material receives a Grade 3 rating.


The specifications divide sizes into four categories ranging from very fine material up to 10 inches in any dimension. The smallest, size A, provides that the product must be 3 inches or less in any dimension. Size D is the largest and requires that a minimum of 90 percent of the product must be 6 inches or greater in any dimension. Also, to qualify for size D, all material must be 10 inches or less in any dimension. 


In addition, the specifications stress other dynamics that affect burning. Factors such as moisture content and ash qualities hinder combustion. Suppliers are encouraged to minimize rain exposure during dismantling and processing. 


Proper combustion is achieved with smaller (size A) C&D product, while the better grade (Grade 1) provides more efficient and clean burning. The CMRA and NSWMA encourage all C&D processors to follow the specifications to provide the highest quality product.   


Relationship with EPA


The purpose of grading is to improve product reliability and characteristics of the wood fuel. C&D waste is considered hazardous when it includes lead-based painted woods, treated woods and asbestos materials, therefore the specifications strongly discourage the processing of unwanted materials. The removal of unwanted materials is also aimed at aligning the specifications with U.S. EPA regulations.  
The specifications provide an initial baseline for preparing proper C&D product. They are mindful of EPA rules, and stress to the market the need to independently address all regulations and other laws. The goal is to provide the highest quality C&D product in accordance with all legal regulations.


Nearly simultaneous to the launch of the specifications, the EPA set definitions and regulations specific to C&D debris. According to Miller, the EPA’s regulatory definition of C&D wood and its application to the practical C&D market is not clear and creates some uncertainty.


In response, the CMRA and NSWMA specifically reminded those in the C&D industry to address independently the “identification of non-hazardous secondary materials that are solid waste” 40 CFR Part 241, and the EPA Commercial, Industrial, Solid Waste Incinerator rule when applying the specifications.


Turley strongly stresses that the CMRA is not combative with the EPA but is working diligently to cooperate in the regulatory process. If the specifications can mesh with the EPA regulation

s, it can only standardize the market for the betterment of the C&D businesses and the environment.
Turley notes his desire to see C&D regulated the same as any other traditional fuel. Although uncertainty exists, it appears the EPA regulations may be a step in the right direction in the attempt to define C&D wood product as a fuel. 


Practical Application


In a February report supporting its rule making on C&D materials, the EPA determined that C&D wood residues are commonly used for boiler fuel where the biomass can either be combusted directly or converted through gasification. In comparison to the incineration and ash process, gasification limits conversion so biomass is converted into intermediate products and further used for energy recovery.


The EPA estimated that 164 million tons of building-related C&D debris was generated in 2003. Construction activities produced approximately 47 percent, while demolition activities produced 52 percent. Of the 164 million tons, between 33 million and 49 million tons was C&D wood. 


The EPA found that approximately 50 percent of the C&D wood debris is of acceptable size, quality and condition to be considered available for recovery with limiting factors being contamination. The EPA reported that dry woody materials with 0 percent moisture produces between 15.5 million and 16.4 million Btu per ton.


Although it is too early to tell the ultimate success of the standards, the organizations have received positive feedback from the initial application of the specifications. Along with the consensus that they were necessary, there has been a common understanding that, “it is really about standardizing the process for the marketplace by directing the specifications to companies as producers and boilers as consumers,” Miller says. 


All states are encouraged to use the specifications to aid the market. Although they are not laws and were not intended to be promoted directly to state governments, the most interesting result from its launch was the requests and interest from government agencies, according to Turley. 


It appears that regulatory bodies are attempting to get an idea of what is accepted in the marketplace so that they can properly derive laws and regulations that are applicable to the practical market.
In the future, Turley sees the specifications as a living document that is modified and refined as necessary for the benefit of the C&D industry. He would like to see them have practical and broad applications for making wood a fuel commodity and not a waste.


“The best thing about C&D wood-derived product is its Btu value,” Turley says. “The  other option is the landfill. Which one would you like to take?” His comment epitomizes the need to maximize the burn.

Author: Matt Soberg
Associate Editor, Biomass Power & Thermal
(701) 746-8385
msoberg@bbiinternational.com

 

About the CMRA: The Construction Materials Recycling Association represents companies from many C&D materials recycling industries internationally. CMRA provides support and representation to the industry and CMRA members in legislative and rule making venues that impact the recycling business. CMRA acts as an advocate to promote C&D recycling and the recycling business in every manner possible that benefits CMRA members. The CMRA promotes the safe and economically feasible recycling of more than 325 million tons of C&D materials generated in the U.S. annually.  For more information, go to www.cdrecycling.org.

About the NSWMA: The National Solid Waste Management Association is a trade association representing for-profit companies in North America that provide waste recycling and disposal services, and companies that provide professional and consulting services to the waste services industry. The association promotes the management of waste in a manner that is environmentally responsible, efficient, profitable and ethical, while benefiting the public and protecting employees. It accomplishes this mission by providing its members with education and training opportunities, research, and federal and state advocacy capability.  For more information, go to www.environmentalistseveryday.org.

 

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