The Beauty of Biomass Briquettes

Whether it's going mobile with technology for producing biomass briquettes or aligning with a major mining operation eager to reduce its coal use, two U.S. companies describe their efforts to grow their biomass briquetting businesses.
By Jessica Ebert
Nearly two years ago, Brad Cole was put to task. As the owner of Cole's Outdoor Wood Stoves, he was approached by potential customers wanting to know how they could fuel a furnace if they weren't able to go out and chop wood. Not knowing the answer, Cole started researching alternatives. "We were unable to find anything here in the U.S.," he explains. "The only thing we could find was in Europe where they had been doing this process of densifying wood material into a solid biomass fuel for more than 40 years." After a pilgrimage over the "pond" and several visits to various companies involved in manufacturing densification equipment, Cole, who now serves as chief of sales for Iowa-based Renew Energy Systems, and fellow company founders, Chief Executive Officer Steve Smith and Dan Freeman, a millwright and professional welder, purchased equipment from C.F. Nielsen, a Danish manufacturer of briquetting presses. "They have been in the business the longest and were able to produce the equipment that we were looking at," Cole says.

Renew Energy Systems is now the sole U.S. distributor of C.F. Nielsen's technology. In addition, the company has partnered with Kansas-based Alternative Energy Systems, which distributes biomass boilers. "We've aligned our forces now. We produce a solid biomass fuel while AES distributes the biomass gasifier," Cole says.

In addition to distributing briquettes, Renew Energy Systems also produces and markets the fuel. The company leases building space in an industrial warehouse in Osage, Iowa, where it recently began mass producing briquettes from wood wastes such as ground pallets, construction material and cabinetry waste-material that would otherwise be landfilled.

The first step in the production process is grinding the feedstock to a diameter that the briquetter accepts, Smith says. The ground waste is transferred to a large hopper on top of the briquetter where it enters the machine. "The briquetter is essentially a piston engine. It has ports where augers bring the matter in front of a large hammer that's on a crankshaft," Smith explains. "The crankshaft turns and hammers the material through a conical-shaped die". The die is heated to about 225 degrees Fahrenheit and as the material is pressed through it at about 3,000 pounds per square inch of pressure it forms into something akin to a long, relatively thick spaghetti noodle. "When the briquette comes out it is a continuously long, three-inch-wide piece of biomass," Smith explains. At the end of the line, the log is either broken into 9- to 12-inch long chunks of renewable fuel. The chunks are bagged and distributed for use in private wood burners and fireplaces, or broken into hockey puck-sized pieces that can be fed into boilers and used for industrial cogeneration.

Testing that Renew Energy Systems has conducted in collaboration with Twin Ports Testing Inc., a Superior, Wis. testing services company, show the company's briquettes produce on average 7,400 British thermal units per pound. This is about the same energy content typical of wood pellets. However, Cole and colleagues are quick to point out that the initial capital requirement and costs for operating the briquetter are much cheaper than those for a pelletizing process. In addition, briquetter presses can process a wide range of feedstocks and depending on the blend that is put in the hopper, a pound of biomass briquettes can release up to 10,000 BTUs of energy, Cole says. "That's a tremendous fuel output."

The company's technology is currently being trialed at universities in Wisconsin and Iowa and several large power generators in the Midwest are interested in cofiring the briquettes with coal, Cole says. In addition, Renew Energy Systems is working with C.F. Nielsen, to develop a portable briquetting system. The company will soon receive its first unit, which will initially be used to process wood waste on-site on private land in north-central Minnesota. "The portability of this equipment is a huge factor," Smith says. It transcends the economic challenges of transporting feedstocks to a processing site. "We can go after piles of biomass that have been sitting around for years," he says. It may also provide a solution for managing diseased and quarantined wood like the stands that have been infested and killed by the emerald ash borer or the west pine beetle. This wood can't be transported for fear of further contamination but, "there's a lot of interest in converting diseased and quarantined feedstock into a viable fuel," Smith says. "This is part of the reason why we're looking to put this in a 20-foot container and be mobile. We can take the machine to the matter."

This is one approach to successfully mass produce and commercialize biomass briquettes. The business model of Renewafuel LLC, another up-and- coming company specializing in the densification of waste biomass, involves teaming with a company that wants to start meeting its significant energy needs with renewable fuels. Jim Mennell, an environmental lawyer, and founder and managing partner of the Environmental Law Group Ltd. in Minneapolis. is president of Renewafuel and founded the company in 2005. In his practice, he represents a number of large institutions in the Midwest. "There was really a strong interest and a need for some type of alternative to natural gas and coal as a way to power institutions and industrial operations," he says. However, "there were always a number of impediments to that taking place." These challenges ranged from finding consistent and effective alternatives to difficulties in getting permits to use biomass.

In an attempt to overcome some of these obstacles, Mennell teamed with one of his clients, Leon Endres, founder and owner of Endres Processing LLC, a producer of high-quality livestock feed. Endres had experience in aggregating waste food products from restaurants and food manufactures and processing that material into animal feed. "I looked at the way he was collecting materials from all over, mixing them and running them through a series of processes to result in a really consistent, high-spec feed that he could sell to most of the major poultry houses as a feed ingredient," Mennell explains. "I saw that as the recipe for what we could do on the biofuel side."

Renewafuel was ultimately backed by four leverage capital firms including JMH Capital of Boston, to undertake a three-year research and development effort, which included processing different feedstocks, identifying their fuel characteristics and monitoring how the briquettes burn in different systems such as direct-fired units, fluidized beds and pulverized coal applications.

Renewafuel leverages Endres Processing's aggregation network of 75 trucks that collect waste feedstocks from 18 states. The material, including corn stalks, switchgrass, grains, soybean and oat hulls, wood and wood byproducts, is transported to the company's production-scale research and development facility in Battle Creek, Mich., where Renewafuel has tested different biomass blends and collected emissions data. The company has developed a series of proprietary feedstock blends that result in briquettes that can be used in the solid fuel systems typical of industrial or institutional settings with little or no modification. The cubes generate about 8,000 Btus per pound, which is comparable to the energy released from coal mined form the Western United States. The difference is that Renewafuel's solid fuel releases 90 percent less sulfur dioxide, 35 percent less particulate matter and 30 percent less acid gases than coal, as demonstrated in tests at the University of Iowa's power plant. In addition, the briquettes can be customized to the specific requirements of the user.

As the company started moving toward commercializing its product, it began marketing to Cleveland Cliffs Inc., an Ohio-based international mining and processing company. In a strategic investment, Cleveland Cliffs recently acquired a 70 percent controlling interest in Renewafuel. "They became interested in the fuel and wanted to secure it in part as a way to hedge against pending carbon legislation," Mennell explains. "As a large energy user they wanted to ensure that they had a sufficient supply of our fuel products." In addition to supplying biomass briquettes to Cleveland Cliffs, Renewafuel will be a stand-alone business unit that will market and sell the fuel to other users.

To meet the demand for its product, Renewafuel is currently planning to build production facilities near large energy consumers. The first two of these facilities are planned for the Upper Peninsula of Mich. and in eastern Minnesota. Both plants are expected to be on line by the end of the year. "We're hiring additional people and looking to site develop and to grow quickly," Mennell says. "We're adding value to local farms and local businesses. We're creating jobs. We're making a renewable fuel that could potentially reduce energy costs and significantly reduce environmental impacts. It's pretty exciting."

Jessica Ebert is a Biomass Magazine staff writer. Reach her at or (701) 738-4962.