Woody biomass size reduction with selective material orientation

Abstract

Background: Roundwood logs from forests and energy plantations must be chipped, ground, or otherwise comminuted into small particles prior to conversion to solid or liquid biofuels. Results & discussion: Rotary veneer followed by cross-grain shearing is demonstrated to be a novel and low energy consuming method for primary breakdown of logs into a raw material having high transport and storage density. Processing of high-moisture raw logs into 2.5–4.2-mm particles prior to drying or conversion consumes less than 20% of the energy required for achieving similar particle size with hammer mills, while producing a more uniform particle shape and size. Conclusion: Energy savings from the proposed method may reduce the comminution cost of woody feedstocks by more than half.

Financial & competing interests disclosure

The authors are employees of Forest Concepts, LLC, which is developing commercial applications of the technologies discussed in this paper. Precision wood particles that are the subject of this paper are covered by three US Patents – US 8158256, US 8039106 and US 8034449 – and other US and international patent applications are pending. Wood products manufactured by the process described in this paper are marketed under the Crumbles^® trade name. Crumbles, Precision Feedstocks^®, WoodStraw^® and Crumbler™ are trademarks of Forest Concepts. This material is based upon research and development that was supported in-part by the US Department of Energy Office of Biomass Programs Small Business Innovation Research Program Contract No. DE-SC0002291. This manuscript is based on a public workshop presented by the lead author as part of the Idaho National Laboratory August 2011 Biomass event. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilized in the production of this manuscript.