Chipping Away at a Standard

A U.S. wood chip standard will provide benefits across the supply chain, enabling the biomass thermal sector to gain more ground in the country’s heating fuel market.
By Anna Simet | August 26, 2016

The rate at which small- and industrial-scale biomass thermal or combined-heat-and-power (CHP) systems are being installed in the U.S. has slowed a bit in the wake of the global oil price depression, but use is still on the rise as schools, universities, hospitals and others continue to choose biomass thermal as a replacement for outdated and inefficient oil boilers. This is particularly true in the Northeast U.S., where, for many years, there has been a growing movement to adopt, expand, incentivize and educate the public of the benefits of modern wood heat. Coincidentally, the region is also home to the most heating oil-addicted states.

New biomass heating system installations are often paired with operators who may not have experience using wood fuel. When exploring locally available options, a user might choose to use whole tree chips as fuel. Or, they may opt to use bole chips. Or microchips, or semi-dry chips. Or precision dry chips. Or screened chips, hog fuel, grindings, clean chips or dirty chips. The list goes on.

With widely varying terminology, definitions and fuel quality are also likely to widely vary, a problem that some industry stakeholders are working hard to resolve. Burlington, Vermont-based Biomass Energy Resource Center, a nonprofit focused on advancing the use of community-scale biomass energy, is heading up a major initiative to do just that—develop and adopt a U.S. wood chip standard much like has been done in Europe.  “We have done a fair amount of work on this topic in the past, just because we feel that the industry will benefit tremendously from doing this,” says Adam Sherman, BERC senior consultant. A national woodchip standard would nicely compliment an ongoing trend away from highly customized systems to more standardized, mass-produced biomass boilers, Sherman says, while also fundamentally addressing the fact that wood chip fuel quality in the past “has been highly anecdotal, and highly subjective in terminology.”

Funded by a U.S. Forest Service Wood Education and Resource Center Grant, other partners working directly on the initiative include Innovative Natural Resource Solutions, the American Society of Agricultural and Biological Engineers, and the Biomass Thermal Energy Council. After some delay in acquiring the grant money, the team is finally moving forward, says Charlie Neibling, partner with INRS. “We’re going to be relying heavily on in-kind support of participants on an advisory committee and many others who we hope will take interest in this project as we proceed,” he says.

Outreach has already begun, and a variety of perspectives are desired and expected. “A need for such a standard may not have dawned on many people—hopefully, we’re ahead of the curve with this,” Neibling says. “I believe that biomass heat and CHP holds tremendous promise in this country. It has hit a bit of a road bump with what happened with low fossil heating fuel prices and other issues, but in the long-term, especially if our government gets it right with carbon accounting, we have tremendous opportunity, and not just with chips but all manner and forms of biomass in heat and CHP.”

Going Mainstream
If a wood heat is to be adopted and deployed as a mainstream energy choice, there must be a push to move it from its narrow niche status into a much more mainstream choice, according to Neibling. “It has to be clean, and it has to be efficient and operate with high reliability and consistent, predictable performance,” he says. “It has to be as close as possible to what you can do with oil, propane and natural gas today, and it has to be easy for people to transition.”

Good combustion and good performance are key, and both are products of well-engineered boilers tight to fuel specification, as well as using fuel that consistently meets that specification. “Day in and day out, week in and week out, the owner, operator, manufacturer, installer and maintainer of that boiler have to know that system is going to operate as advertised, and that ultimately, the regulators have to know that as well,” Neibling says.

The problem is that there is no widely adopted wood chip fuel standard today, even though every other heating fuel—even wood pellets, of late—is governed by quality standards. “There are European and national standards, but they aren’t widely known or adopted,” Neibling says. “They had somewhat limited involvement of North American interests in their development, and we think it’s time we take a run at this in America.”

The wood chip heating sector was mainly large-scale wood chip systems in earlier years, and it was commonplace for manufacturers to say their equipment could be engineered to burn anything, Sherman points out. “That was probably a true statement, but as you scale down and do smaller projects in a less-customized way, you need equipment that can yield predictable, reliable performance and emissions—that’s what this national standard is,” he says. “Someone might say, ‘this is designed to burn clean chips,’ and a supplier might say ‘well, I have hog fuel.’ They’re talking to each other and using terms that they may not know what they mean, the boundaries or parameters. This will get away from that.”

So what would a wood chip standard look like? It would include specifications including chip size, length, width, depth, moisture content, chip energy content and density, acceptable percent overs and unders, fines, existence of nonwood contaminants, and species. “The terminology will allow us all to operate off a common vocabulary,” Neibling says.

Sherman gives the example of users calling their fuel “paper grade” chips. “Historically, that’s what they’ve been called, and at one time they may have been produced to that spec because they were actually used for papermaking,” he says. “But if 90 percent of those chips are going into the wood heating market, they should probably be called something different than paper grade chips. We’ve started looking at grades, A through D, a classification system that addresses these issues and will put specific boundaries on the allowable ranges for each of the quality parameters.”

As more European-designed boilers make their way into the North American market, Sherman says there has been more recognition of a lack of fuel standards. “It’s often a surprise that there isn’t greater clarity on fuel quality, because that’s the norm in Europe, where they have different gradations based on individual quality parameters,” he says. “For ash, they have A1, A2, etc. Then they have particle size gradations, and moisture, there may be a move to simplify it a bit and roll up key quality parameters—for example, if a chip meets X, Y and Z, it’s a grade A.”

 It’s essential to not only develop a chip standard that is technically accurate, but one that will be understood and used, Sherman says. “It should bridge the gap between fuel suppliers and knowing what equipment and materials they can pass through a chipper or grinder, or series of screens, and how they can transport, store and handle material to yield a certain grade of chip. They need to not only understand the technical parameters of each grade, but how to effectively produce them.”

Conversely, engineers, energy experts, and vendors of the combustion and material handling equipment integrated at the facilities that burn that fuel need to understand how to design the systems that work with these different grades of chips, he adds. “It has to have function on both fronts, and I think the stakeholder engagement process and going through the whole ANSI-accredited process will yield a quality technical document, but also development of some ancillary guidance to make sure it has usefulness to both fuel suppliers and users of the fuel.”

The well-recognized and credible standard-setting agency, the American Society of Agricultural and Biological Engineers will be leading efforts in putting together the technical documents. The group is accredited by the American National Standards Institute, and has 14 different areas in which it has developed a U.S. position on the International Organization of Standardization. One of them is solid biofuels, or Technical Committee 238.

Driving Engagement
“For a national ANSI standard for wood chips directly combusted in boilers, we will facilitate the effort just like we have for other groups that have come to us wanting do a standard that fits into one of our standardization areas,” says Scott Cedarquist, director of standards and technical activities at ASABE. “We’ll bring together a group to write a document according to certain rules and format, based upon consensus that has been reached.”

Cedarquist points out that not all stakeholders have to vote the same way as to what’s included in the document, but “most have to be headed in the same direction. There is a comment resolution process, and if there are objections to some components, they have to be dealt with. At the end, we will have a final document for publishing, one that meets requirements that ANSI accredits us to follow, and audits every five years. There are many steps, and our staff will help shepherd this group through it. A lot of our members are already involved in ISO work on other renewable energy initiatives.”

Stakeholder engagement is crucial in the process, Cedarquist emphasizes. “What makes a strong standard are these different perspectives pulled together, and that’s what we do in this process. I think the vision of the leaders on this is to be really all-inclusive, and the challenge could just be the number of comments we get, and the process of synthesizing all of them down to what’s included in the final document.”

Input from individuals working directly in the space, such as Jon Baker, operations manager of Cousineau Forest Products, will be sought. Baker has been in the chip supplying business for 20 years, and his company handles up to one million tons of chips each year, selling to pulp and paper mills, commercial biomass plants and wood pellet manufacturer.

Stakeholder Perspective
“We started in 1996, and we have a facility here in New Hampshire where we have truck scales, trailer tippers, chippers and screening, we can manufacture and store different types of chips at this facility, and we also broker chips from external suppliers as well,” Baker says. The company has its roots in selling chips to pulp mills, but in 2001, began selling chips to schools in Vermont. “CHP units were going up everywhere, and we started providing to them—this last heating season we serviced 30 CHP units in Maine, New Hampshire and Vermont with about 40,000 tons of chips. We take care of the University of Maine at Farmington and Colby College, some government county complexes, jails,  nursing homes, some factories and private businesses…from places that use as little as 250 tons per year to places that use 15,000 tons per year.”

 Much of the orders come from Cousineau’s plant, but the company purchases from external suppliers—sawmills, logging companies or chipping facilities—if the customer is too far away, but still takes care of trucking and quality control. “With so many pulp and paper mills closing, this [biomass heat] has been where the opportunity has been over these past few years. It’s good work, it’s local, and the margins are a bit better than what we did with the paper mill—it’s an area of growth for our company.”

There are, however, distinct differences in quality and labor when it comes to a pulp mill chip, compared to one that might be used at a school. “The pulp mill has to come from wood that has been debarked, the chips have to be screened, the fines removed and the oversized resized or removed, we do make those,” Baker says. “For the schools, we have a whole range—it depends on the boiler system or type of material handling. We have schools and colleges that we can take the chips right out of the woods from a timber harvest, right off the chipper, and others we have to bring to our facility and refine and screen and make a certain size. Generally speaking, they don’t need to be as perfect as the pulp quality chip.”

On a wood chip standard, Baker agrees it would be helpful. “Depending on what boiler manufacturer is putting the system in, or what type of material handling they have, there is quite a different between systems on what type of quality they can handle—it’s mostly in the material handling,” he says. “Most of the time, the boiler will burn it if delivered, but there can be all kinds of issues with the material handling system—the auger systems, conveyors. If there was a standard that everyone followed, perhaps it would take some of those variables out of the equation.”

It may be challenging, however, for some smaller suppliers, in some instances potentially edging them out of a marketshare. “For example, there might be some logging companies that have a contract with a greenhouse or public school in their community, a local spot market they would like to be involved in. If they were too stringent, that could be a barrier to them. If they’re a logger and have a chipper on the landing, there’s only so much they can do. So, it could be an issue for some folks. That would be a concern of mine, if it prevented some small businesses from participating.”

Over the years, Baker adds, he has had the opportunity to provide some input in the design phase on similar initiatives. “I have always tried to stress that when they put these systems in, they have to have material handling systems robust enough to handle varying quality, so more suppliers cab participate,” he says. “It helps keeps the [system] owner’s cost down, because if they need a perfect chip, they have to pay for that. It’s also nice to have options when you’re buying fuel, to not be restricted, and to be able buy what’s readily available in the community and not reach out 100 miles, because the local folks can’t make what you can burn. It makes sense on both ends, the suppliers’ and buyers’.”

Sherman says with development of the standard, the intention is to also provide some ancillary, how-to guidance for chip suppliers. “This would say, for example, if you want to do a grade A chip, you would have to debark, along with the material handling and feedstock sourcing details required to yield that quality.”

On the other side of the equation are boiler suppliers, another important stakeholder group to engage during the standards-making process. According Bede Wellford, Veissmann Manufacturing Co. renewable sales manager, the initiative is much needed. “My very simple and straightforward answer is absolutely yes,” he says. Viessmann currently sells two lines of wood chip boilers in the U.S.—one has the ability to burn up to 30 to 35 percent moisture chips, and the other up to 50 percent moisture, Wellford says. “So there’s an incentive to be able to standardize and reliably purchase so-called ‘dry’ chips,” he says. “And that’s just a piece of it, moisture content. Another component is, if you look at our technical or installation and operation manuals, we provide a complete set of specs. The reason for that is that it’s very important for the operation of the boiler.”

Mechanical dimensions of chip fuel are also significant, according to Wellford. “An auger will move a matchbook-size chip all day long and be very happy, but when you feed it a two-foot-long, inch- and-a-half diameter stick, your chances are 50-50 that it’s going to lodge somewhere and jam the auger,” he says. “I’ve had this experience personally with the very first wood chip boiler that I was involved in commissioning—it had a very robust wedge floor, and the chips got to the first auger with no problem, no matter what they looked like, but when I walked in there I found all of these two-foot-long, two-inch diameter sticks, and big chunks. That can cause problems, and it did. After that, they imposed supplier discipline.”

But in another case at a local high school, a paper-quality chip has been delivered from day one, and there has never been an issue. “Being able to specify the quality of the chips, mechanically, is critical,” Wellford says. “And that’s what a wood chip standard would do.”

On the notion that some boilers “can burn anything,” Wellford says the idea, which is losing its luster amidst the push for a more modern wood heating industry, is “certainly not true of our boilers—we’re very specific about what can and can’t be burned. The quality of the fuel is very important to the quality of the combustion, and the character of the emissions. So, if you burn anything, you can also get anything.”

Neibling and Sherman hold similar opinions. “Europeans concluded long ago that if this technology is to really take hold in the marketplace, we’ve got to move away from this mentality,” Neibling says. And there, the standards are “very cut and dry, and people don’t have problems,” Wellford adds. “That’s the motivation for us as a boiler supplier, to support this.”

The standards team hopes to have them wrapped up by the end of 2017. In the meantime, a significant effort will be made to engage the entire supply chain in the development process, and that includes not only boiler manufacturers and fuel producers, but supply chain intermediators, fuel processers, and consumers, who, in order for the sector to gain more ground, must start looking at wood heat in the same manner they do other traditional means of heating. “That’s a major market barrier, and honing in on and giving both the reality and perception of reliability, security and confidence when consumers make the investment in this technology—that they will get X, Y and Z, and they bank on that, because they have standardized fuel,” Sherman adds. “This will build market confidence, and break down those lingering barriers to making biomass energy more mainstream.”

To find out more about this initiative, visit

Author: Anna Simet
Managing Editor, Biomass Magazine
[email protected]