Bioenergy Feedstock Technologies

It has always perplexed us how researchers, facility planners, and even the financial community assume that cellulosic biomass will be readily available at nearly free costs. The millions of acres of bug-killed timber across the Pacific Northwest appeared to be free for the taking. Tree service companies, land clearing contractors, parks districts, and homeowners were paying tipping fees to dump urban greenwood. So, there must not be any value associated with supply or procurement of woody biomass ground to the demanding specifications of bioenergy producers, right? We at Forest Concepts have been developing technologies and products in this space for more than ten years. We know what it takes to get even free wood from the woods, open spaces and greenbelts to a processing facility. We know the science and engineering factors that drive the design of equipment and systems to convert raw woody biomass into precise feedstocks that optimize cost and yield in bioenergy and bio-products facilities. Only very recently has the bioenergy community begun to recognize that feedstock quality and cost can make or break the profitability of firms who will be producing biofuels. It makes a big difference to feedstock supply whether you are producing solid pellet fuels, combustion electrical power, co-firing with coal, cogeneration for combined heat and power, or conversion to second generation liquid transportation fuels.

Our experience and expertise is in the arena of woody biomass from urban, suburban and forest sources. Examples of these urban sources include landscape debris, storm debris, arborist/tree service trimmings, right of way maintenance, land clearing, municipal parks, golf courses and greenbelt maintenance. Examples of forest and suburban sources include wildfire protection, fuels reduction, landscape maintenance, power line and utility corridor management, road building, land clearing, forest management, logging residuals, and forest products industry waste.

Cellulosic biomass materials from these sources can be processed and delivered to primary processors as whole "brush and logs", densified into bales, ground into chips or shredded bulk biomass, or processed into highly densified flowable forms such as pellets or cubes. The preferred form for collection, transport, storage, and handling depends on a variety of logistics and market forces that tend to form many optimal sets depending on the context.

Smallwood Handling - Beginning in 1998, we developed a number of improvements for collection and handling of small diameter roundwood poles that were previously piled and burned during wildfire protection and forest health improvement projects. Significant financial support was provided by the Bureau of Land Management through the National Fire Plan. Our smallwood utility trailer with integral grapple loader provided contractors, agencies and landowners with a flexible way to get materials into and out of project sites. Our AE50 Award winning smallwood pallet bunks unitize small diameter logs in the field and at the plant site, greatly reducing the cost and labor for wood delivery. This smallwood technology is appropriate for community-based bioenergy firms or precision feedstock producers who prefer to start with solid wood and then process it with proprietary methods into precise feedstocks.

Biomass Baling - Along with the smallwood, we were continuously challenged with requests for better ways to gather and process limbs, brush and tree tops which otherwise were a disposal problem. That work culminated with our development under USDA CSREES SBIR support of a suite of biomass baling technologies, product definitions and a working prototype biomass baler in 2008. The Forest Concepts biomass baler technology enables economical collection and delivery of woody biomass from both urban and rural sources to distant users. The cost of baling woody biomass is less than the cost of chipping and shredding. The cost of delivery is less than half of what it would be if the biomass was first chipped and then hauled in specialized trucks.

A core premise of biomass baling is that preservation of piece size at the source, and compression into optimal density bales for transport, handling and storage preserves the attributes of the raw material, and enables receivers to process the woody biomass to their own specifications. Chipping or shredding brush, limbs, etc. at the source precludes most of that value-added opportunity. Development of this technology was supported in-part by the USDA/CSREES/SBIR program under grants 2005-33610-15483 and 2006-33610-17595.

Low-energy Precision Comminution - The engineering team at Forest Concepts has developed a deep competency in the design and operation of low-energy methods for comminution of woody biomass using rotary bypass shears and clipping. The company's equipment for comminuting wood veneer into uniformly sized wood strands is a demonstration of this competency. We have produced more than 4,000 tons of precision wood strands for the erosion control industry using equipment designed by our engineers. In the production of wood strands from veneer, our WoodMuncher™ rotary bypass shear method produces less than 2 percent fine material, and less than 0.1 percent dust. We believe that the principles and methods we use for wood-strand production are readily applicable to comminution of other lignocellulosic materials such as corn stover, wheat straw, switchgrass, woody biomass and other feedstocks.

Beneficiation of Chipped and Shredded Woody Biomass - Bioenergy firms are anxious to use the vast quantities of woody biomass that is available from tree service companies, land clearing contractors, logging slash processors, and other low-cost sources. Unfortunately, such materials contain too much contaminating bark, soil, and grit that preclude direct use for energy and fuel generation. Additionally, the particle size can range from dust to firewood size chunks in any delivered load. Engineers at Forest Concepts are designing an equipment system that will reprocess hog fuel and dirty chips to recover the clean white wood fraction and a mostly pure bark fraction for use by bio-products and bioenergy firms. Development of this technology was supported in-part by the USDA/CSREES/SBIR program under grants 2008-33610-18880. A Phase II proposal is pending.

Emerging Biomass Feedstock Supply Industry

Since we have been in the forestry, forest products, systems development, and biomass arena for more than ten years, our senior staff are frequently asked our views on how the cellulosic biomass feedstock supply industry is likely to evolve. We have an ever-increasing data set of biomass supply opportunities, specifications, cost data, etc. that inform our own business planning activities and those we undertake with others.

Chief Technology Officer Jim Dooley has participated on a number of panels, including:

• 2006 - ASABE Biorefinery symposium - Portland, OR
• 2007 - U.S. Chamber of Commerce policy briefing - Washington, DC
• 2008 - AETC Bioenergy keynote - Louisville, KY
• 2008 - University of British Columbia - Biomass Logistics seminar
• 2008 - ASABE Bioenergy Day - Characterization of woody biomass industry

Recent Publications:

Interfacing Forest Engineering with Bioenergy Production (pdf, 284KB)