Hammermill Master

Robert White Industries Inc. in Plymouth, Minn., has been designing biomass handling systems for nearly 20 years. Demand for these services is expected to increase as more companies look to biomass sources for their fuel needs.
By Nicholas Zeman
Robert White is well-aware of the damage caused by the emerald ash borer as the insects progress across the Midwest. Because he's in the biomass handling business he also knows that a large source of wood will be available in the near future as a result of these insects. "You only have to follow a very simple train of thought," says White, founder of a Plymouth, Minn., company that provides veteran expertise in the development of renewable energy systems. "It's not a matter of if, but when [the emerald ash borer gets to Minnesota]. When those trees die, they're going to have to be cleared."

Biomass handlers and processors have the task of dealing with the destruction left by non-native insects and invasive species that can enter the United States as a result of global trade. It's thought that the emerald ash borer arrived in the United States as a stowaway on ships loaded with imports from the Orient, and was first discovered near Detroit in the summer of 2002. While the adults nibble on foliage and cause little damage, the larvae of the insect feed on the inner bark of ash trees, disrupting the trees' ability to transport water and nutrients.

Michigan has already lost 20 million ash trees to the borer, which was also discovered in Ohio, Illinois and Indiana. Minnesotans are being warned not to transport or buy firewood from outside of the state to keep the borers at bay. Minnesota has 15 million acres of timberland, covering 29 percent of the state. The forestry industry contributes $7.7 billion a year to the state economy, from the more than 600 mills that process forest material in various ways, according to the USDA's Forest Service. Aspen is the most abundant variety, but there are also millions of ash trees, which could be potential borer victims.

The only good news associated with the emerald ash borers U.S. arrival, is that the resulting diseased and dying wood can be used in biomass-to-power applications, White says.

Experienced Handler, Growing Market
White gained decades of experience handling, storing and condensing biomass when he worked the hammermill for the Jacobson company, which is now part of Carter Day International Inc., in Minneapolis, "I was working for Jacobson grinding up wood scrap and just decided to start my own company in 1989," White says.

A hammermill uses rotating hammers and stationary anvils to smash, crush and tear large biomass pieces into smaller fragments. Hammermills are also used in other industrial applications like crushing automobiles for scrap metal recycling purposes. Jacobson designed and manufactured a complete line of different sized hammermills and reduction systems, so White was able to learn enough about reducing and handling biomass to strike out and start his own company-Robert White Industries Inc. (RWI).

One of the most important lessons he learned was to focus on site specificity. There cannot be a general approach to collecting and crushing biomass. "From an equipment standpoint, you can't use a broad brush," White says. "You have to make sure the correct and appropriate system is designed to solve multiple problems." For instance, it just doesn't pay to ship corn stover more than 80 miles. "So you're looking at one source [of raw biomass], maybe two-certainly not a multitude of sources for processing." Because biomass handling requires, screening, reducing, storing and transportation finesse it's a difficult sector to work in, White says. Therefore, RWI offers solutions to manage all of the following components:

Size reduction: grinders, shredders, hogs, chippers and hammermills
Material handling: belt, chain and screw conveyors, screeners and bagging equipment
Material storage: silos, bins and bunkers and unloading equipment
Combustion systems: wood and biomass fuel heating and boiler systems from 50 to 1,200 horsepower; hot air, water or high-pressure steam systems; chillers for dehumidfication and air-cooling
Fire prevention: high-speed infrared spark detection and extinguishment fire prevention for dust collectors; high-speed abort gates

Historically, biomass utilization was limited to the wood industry, which has burned residues from different manufacturing processes, White says. Recently there has been an expansion as more businesses are searching for ways to utilize biomass and cut back on greenhouse gas emissions. "District Energy St. Paul is now burning wood instead of coal," White says, adding that urban wood waste is an ongoing problem there. A combined-heat-and-power (CHP) plant in St. Paul now uses approximately half of the 600,000 metric tons of wood waste generated in the Twin Cities area. In addition to getting rid of excess biomass and providing stable energy rates for its customers, District Energy St. Paul is realizing the environmental benefits of using biomass. By displacing 80 percent of the coal and oil burned a year, District Energy will reduce sulfur dioxide emissions by roughly 600 tons per year and carbon dioxide fumes by an estimated 28,000 tons per year. White uses this example to illustrate that his services are going to be in greater demand as more and more companies look to biomass sources for their fuel needs.

So far, using biomass to displace fossil fuel as a source of power generation has been limited. However, looking ahead there are opportunities especially in the ethanol industry. White expects that companies like his will contribute in a big way to the overall design model that will lead to the industrialization of cellulosic ethanol. When asked how long it will be before Minnesota has its first cellulosic ethanol plant, "That's over my head," White replies. "Using biomass as a fuel source and using it as a cellulosic ethanol feedstock are two totally different things. I still think it's two or three years away, and whether it's corn stover or wood chips, or forest thinning, I just don't know."

In the meantime, he's been involved in some innovative ethanol projects already. RWI designed the biomass handling systems at both Chippewa Valley Ethanol Co. LLC (CVEC), in Benson, Minn., and Central Minnesota Ethanol Co-op. (CMEC), in Little Falls, Minn. Because there were several other companies involved with the development of these two biomass-to-power projects-Primenergy LLC, Sebesta Blomberg and Associates Inc., and Frontline BioEnergy Inc., for example-a considerable amount of cooperation was required to get these projects off of the ground. "The challenge was to be clear on responsibilities," White says of collaborative projects. "Each company is a specialist at what they do, and provided the very best equipment."

Equipment Distribution, Fire Safety
Because White Industries doesn't manufacture the equipment used in its biomass handling system designs, White has developed a network of trusted suppliers. In the handling and transportation world it's Vecoplan LLC that makes the best equipment to shred and pack biomass, White says. Vecoplan, headquartered in Bad Marienberg, Germany, wasfounded in 1969 as a manufacturer of high-quality wood chippers. The company now has a diverse portfolio of products for processing plastic waste, reclamation and recycling, large extruder purgings and wood processing scrap, etc. "Their equipment can handle and process just about any material," White says. "Vecoplan's diversity of products can fit the best equipment to a specific project, which is important because every customer has different and unique requirements."

In the early 1980s, Vecoplan turned its focus to recycling and in 1982-83 Wolfgang Lipowski, now Vecoplan's technical director, invented the single-shaft rotary grinder. "A couple of my friends actually introduced Vecoplan to the United States around the time I was starting my own company," White says, adding that their products are of excellent quality. "I thought it was the best equipment for the job and I am still using it in my designs."

Another major aspect of biomass handling is fire safety, and RWI offers the best in spark-detection equipment. When dealing with tons of dried wood pellets, dust and other flammable materials, a blaze could become deadly in no time. An effective spark-detection system must monitor every potential path for a spark or ember to ignite through all branches of ducts, along conveyor belts and even on trucks. Once a spark or ember is detected, a curtain of water is applied to extinguish any possibility of ignition. For these important safety purposes, RWI distributes equipment made by Hansentek, a division of Neola Corp., in Mississauga, Ontario.

To design efficient systems for biomass handling and distribute top-of-the-line equipment, White provides what he calls "one-source responsibility" for receiving, conveying, screening, grinding, metal removal and storage of biomass. "RWI can draw on a variety of manufacturers to tailor a processing system to meet each customer's specific needs," White says. "When all of these components are handled by one source, it ensures that everything will match correctly, and operate smoothly."

Nicholas Zeman is a Biomass Magazine staff writer. Reach him at nzeman@bbibiofuels.com or (701) 746-8385.