Making the Grade

With a plethora of different wood pellet standard programs, mills’ quality measures vary depending on which set their customers adopt.
By Lisa Gibson | November 01, 2011

Quality assessment and quality control (QA/QC) measures and parameters of wood pellet mills exporting their products and those selling domestically can vary widely and significantly. The mills’ quality management programs do have one thing in common, though: they all follow the standards and specifications of their customers.

In fact, QA/QC in wood pellet mills all come down to standards, complicated by the fact that most pellet markets, and even individual customers, operate under a different set. U.S. residential heating pellet quality specifications differ from those of Europe, and European commercial and industrial power standards will differ even more from both.

The U.S. will soon have a third-party verification aspect to its wood pellet standards, certified and marked clearly by a quality label on the bag. The Pellet Fuels Institute has been working diligently on the program, hoping it will be the framework for the U.S. EPA’s New Source Performance Standard for residential wood heaters. Ideally, pellet stove manufacturers will specify a certain quality pellet for their equipment, voiding warranties where the specifications weren’t followed.

“All producers who want to serve the domestic market are going to have to comply with that certification or accreditation scheme,” says Chris Wiberg, co-chair of PFI’s standards committee. “That’s quite different from what’s going on overseas for international trade.”

PFI Program

While U.S. pellet producers shipping overseas are generally required to test their product while it’s being loaded onto ships, no industrywide uniform certification to bolster product quality currently exists in their markets. But such a program might make quality recognition and customer satisfaction much easier.

PFI’s new standard program will do just that for the U.S. residential pellet heating market. Although many pellet companies tout the quality of their product and may claim they follow PFI’s current but nonaudited parameters, none have been subjected to an official third-party inspection to test their claims. 

“Everybody is making an effort to maintain that quality,” Wiberg says. “What’s inconsistent is how often they test. Are  they truly going to go with the recommendation of every 1,000 tons? Most people do not. Are they just getting a portion of the overall analysis checked?” PFI currently has nine quality tests and many producers could be performing just four or five, Wiberg explains, resulting in incomplete data. “It’s spotty as to how well different companies have been complying with the program.”

“I think it’s a long time coming,” says Luann Lafreniere, project manager and quality manager for New Hampshire-based New England Wood Pellet, of the new certification requirement. New England Wood Pellet sells its product exclusively on the domestic market. “We are finally going to get recognition that we are a quality-controlled and bigger industry than they think we are,” Lafreniere says.

It’s about consumer protection, she adds, and assuring them that the pellet they use will perform as the producer promises. “I’m a consumer at the end of the day and I know if I buy something, I want to make darn sure I’m getting what I pay for. And right now, anybody can stick anything on their bag and there’s no double check from anybody. So I think this program is a great thing.”

The PFI standards dictate quality parameters for premium, standard and utility grades, including crucial aspects such as ash content, durability, fines, size, moisture content and others. The three-step testing phase will start at the mills, followed by an on-site inspection once per month from an auditor, and ending with verification of the product quality from the accreditation body, the American Lumber Standard Committee. While internal laboratories at all mills are not required, it’s certainly encouraged for the producers’ sake.

“Picture yourself in the shoes of the production facility,” Wiberg explains. “When that auditor shows up, you’re probably going to live and die by those samples and if you don’t have some level of assurance that they’re going to pass, you’re putting yourself at quite a risk that those samples may fail and if so, how much of your product are you now going to have to pull off the shelf? That’s the risk you take.”

PFI’s new program specifies that any nonconforming materials must be identified, documented, segregated, evaluated and disposed of. Mills without internal laboratories, therefore, must be extremely confident in their process, Wiberg says.

The bottom line is, quality assessments need to bedone on-site, whether they’re done in-house or outsourced, he emphasizes. Facilities that have a controlled feed stream may decide not to incur the cost of an internal lab, and instead choose to send out samples every couple weeks. But producers with multiple suppliers and any kind of ongoing issues are definitely encouraged to set up their own internal labs, Wiberg says. “And they may find that their auditors will say, ‘I’m not going to represent you if you don’t put something up inside your house.’” Auditors have a lot at stake in the proper deployment of the program and their inspections.

“It’s the auditors’ stamp that goes on the bag and when the accreditation body investigates a bad product, it’s not the producer they’ll be upset with,” Wiberg explains. “It’s the auditor because they allowed that product in the market.”

Quality Management

To help prevent the dissemination of bad products, a quality management program is integral and includes multiple aspects such as training, documentation, records, management of change, raw material control, equipment and operating processes, inspection criteria, storage, handling, delivery and labeling, among others.

To receive PFI quality certification, the documentation aspect of a quality management program must encompass administrative factors, raw materials receiving, production, quality verification of the finished product, periodic inspections and customer complaints. All those documents must also be kept for a minimum of five years, along with inspection instructions, standard operating and testing procedures, test reports and data generated.

In addition, any producer or plant that wishes to qualify for PFI’s standards must appoint a quality manager, who is trained in quality control procedures and preferably is not responsible for production or finance. 

And New England Wood Pellet quality manager Lafreniere is confident the new standards won’t significantly change the company’s quality control procedures, which she says are already far ahead of the game. “We don’t feel like it’s going to make our product any better because we definitely already have a handle on that,” she says. “But now we just prove it. They want you to prove your process can’t allow you to make anything but your premium pellet.”

New England Wood Pellet will soon put in place an internal quality manual to accompany the new standards program and help train operators to record testing results to auditors’ expectations. “We would like to be one of the first manufacturers to sign on to this pellet fuel auditing program and we’re very confident that we have all the quality steps in place to be able to pass the first audit,” Lafreniere says. “We’ve got all the equipment we need. There will be a little more training maybe with the operators, but just having it in a manual is going to be a specification from the auditors to begin with.”
New England Wood Pellet does internal sampling and testing twice per shift, and sends samples twice weekly to outside labs for verification of its own results. The company looks at fines, length, durability, ash content, moisture content, Btu value and raw material quality. “We pretty much have a handle on the entire process so that nothing gets by us and into the bag,” Lafreniere says.

“QA/QC starts with monitoring raw materials and working with raw material suppliers,” says Greg Cabe, director of product quality for Enviva Biomass, which currently has a customer base composed of primarily European utilities, but could include expansion into the U.S. market. “Within the production process, there is a host of equipment settings that can affect many of the key finished goods properties, including particle size distribution, moisture content, durability, density, and so on.” One of the most important challenges is keeping production settings tuned to any variability in the incoming raw material, such as species or moisture content, he adds. After production, storage methods and material handling can significantly influence potential product degradation and the generation of fines or dust. Cabe added that a host of tests along the way are involved as well. Finally, given that transactions with utilities typically involve tens of thousands of tons of pellets, a final quality compliance test for the customer most often happens concurrent with a shipment, as dictated by contract terms,” Cabe says. “Frequently, it will include testing both on loading and on unloading of the ship.”

Fram Renewable Fuels LLC has testing at every stage of the process, as well, inspecting quality aspects for pellet sale and shipment to Europe. About 125 tests per week will assess quality parameters of the raw material before the dryers, after the dryers, after the hammer mill and again on the finished product, according to Harold Arnold, president and CEO of Fram. “Then, as a check against that, we send it to independent labs once monthly just to compare with what we’re testing,” he says.

Fram supplies power utilities and combined-heat-and-power plants primarily in Belgium, and while its customers don’t require independent testing from a mill standpoint, they do require third-party sampling and testing during ship loading. Currently, those samples are also sent to Europe for testing, but with the opening this month of the Biomass Energy Laboratory in Georgia, more testing on exported U.S. pellets can be done in the U.S. “Part of the transaction settlement process is that you provide that analysis from a third-party lab,” Arnold says. “Having a U.S.-based lab that is doing that may be more convenient.” He adds that once the lab is up and running, he expects it will be used quite extensively.

Wiberg is the new manager of BEL and says it will be able to assist pellet producers in their QA/QC measures, whether they’re working to comply with PFI’s standards, Europe’s EN+ certification, or specifications of certain European power producers.

Sharing the Standards

Specifications of European power producers are crafted by individual companies themselves and do differ, sometimes greatly. Wiberg says it can cause problems for the producers in their quality control. “There’s a lot of confusion there,” he says, adding that some differences are completely incompatible, deterring pellet producers from selling to certain combinations of power companies. “If you meet this spec, it’s mutually exclusive of the other spec,” Wiberg explains, adding that it causes trade barriers. “It just goes to show some of the specs aren’t necessarily well thought out.”

Arnold says no customer specifications have completely conflicted with one another for Fram, and the company simply produces its pellets to the specifications of the strictest customer standard in each category.

Still, it would be simpler if they all adopted a single set of standards. To remedy the problem, the seven largest power producers in Europe that import biomass are working together on a shared set of standards, but it won’t be the end of the problem for all pellet manufacturers. “That’s a really good start, but there are obviously more than seven power companies out there,” Wiberg says. “Everyone else needs to gravitate to that spec.”

Help is on the way. The European Committee for Normalization (CEN) has created 27 solid biomass specifications that are now being published as EN standards. Producers who meet them and are in participating countries will receive EN+ certification. Eventually, all European Union countries will replace their own standards with EN standards.

CEN’s standards don’t currently account for the specifications of the large power producers, but that aspect is in the works, along with amendments to fit all the countries in the world. The International Organization for Standardization (ISO) is working with CEN to globalize them, requiring that all countries step forward and involve themselves in the process, Wiberg explains. “It’s basically the same [CEN] working product, but now opened up to all countries,” he says. “Come one, come all. The trick now is to take CEN standards and build in all the components necessary for all the other countries in the world to say these are suitable as true international standards.”

Ultimately, when the world standards are published, they’ll be known as the ISO/CEN standards and while it’s not required that the U.S. sign on, groups like PFI will be encouraged to adopt their methods. That will come with some growing pains, however, as the specs will be slightly different from PFI’s, as will the test methods.

“It’ll take a couple more years for the ISO to catch up, get all the information from all the different countries, revise them and have them re-issued,” Wiberg says. “Once all that happens, we’ll have dual designated ISO standards we would hope that everyone in the world gravitates to and says, ‘this is what we’re going to have for standards for solid biofuels.’”

Author: Lisa Gibson
Associate Editor, Biomass Power & Thermal
(701) 738-4952