A New Slash Bundling Concept for Use in a Southern US Logging System

John Deere’s biomass bundler unit is an effective machine for harvesting forest residues, which can be used as a source of fuelwood and/or a feedstock for biofuel production. This project explored an avenue that could supply a promising source of readily available energy in southeastern forested lands. Typical southern harvesting operations consist of whole-tree harvesting in which trees are felled and then skidded to a landing. Limbs and tops are usually either deposited over the landscape or piled in windrows. The biomass bundler captures the otherwise nonmerchantable material and maximizes the marketability of the entire tree. In order to reduce costs, maximize efficiency, and implement the bundler in a tree-length harvesting operation, this project tested a prototype harvesting system. This venture (1) adapted the John Deere B380 bundler unit to a motorized trailer, (2) designed an optimum landing configuration, and (3) conducted a productivity study of the bundler unit. The unit produced 13.2 tonnes per productive machine hour (PMH; 14.6 tons/PMH) of 250-cm bundles and 14.9 tonnes/PMH (16.4 tons/PMH) of 350-cm bundles, assuming minor delays at a cost of $12.50 to $14.20/tonne ($11.25 to $12.85/ton). There are 368 million dry tons of biomass available annually on a sustainable basis from forest-derived resources in the United States (Perlack et al. 2005). This represents a huge potential resource for energy production (Rummer et al. 2004). With the current energy crisis and with high petroleum prices, all sources of alternative fuels need to be explored. John Deere’s biomass bundler unit is an effective machine for processing forest residues, which can be used as a source of fuelwood and/or a feedstock for biofuel production. Although technologies and markets for such innovative practices have not yet matured, this project aimed to explore a system that could supply a promising source of readily available biomass from southeastern US forested lands. According to the US Department of Energy’s Comprehensive Energy Plan, one of the key goals for the nation is to diversify America’s energy supply. The government aims to promote alternative and renewable sources of energy (Bodman 2005). The Energy Policy Act, part of the energy plan, sets goals of producing 250 million gallons of cellulosic ethanol by 2013 and 1 billion gallons by 2015 (Morris 2006). One of the most prevalent sources of cellulose for ethanol production is forest residues (PerezVerdin et al. 2009). Such ambitious national energy goals require a vast supply of renewable feedstock. In order to maximize the use of forest resources, available material must be efficiently captured. Current forest harvesting practices in the southern United States are proficient in harvesting timber; however, the harvest of forest residues is economically inefficient or nonexistent in most of the conventional harvesting configurations in the region. Typically, these operations consist of whole-tree harvesting in which trees are felled and then skidded to a landing. Limbs and tops are then removed from the tree and either deposited over the landscape or piled in windrows. Most logging crews in the South that capture the forest residues do so using a drum-type chipper. Chipping forest biomass is effective; however, it requires a large amount of capital investment to an already economically stressed industry. In-woods chipping operations require the purchase of a chipper as well as chip vans for transport. A recently developed piece of equipment, the John Deere Slash Bundler, provides an alternative method to capture this otherwise nonmerchantable material and maximize the marketability and utilization of the entire tree. The bundler The authors are, respectively, Inventory Specialist, Weyerhaeuser, NC Timberlands, New Bern, North Carolina (steven.meadows@ weyerhaeuser.com); Associate Professor, Forest Operations, School of Forestry and Wildlife Sci., Auburn Univ., Auburn, Alabama ([email protected]); and Research Engineer, USDA Forest Serv., Auburn, Alabama ([email protected]). This paper was received for publication in March 2011. Article no. 11-00031. Forest Products Society 2011. Forest Prod. J. 61(3):210–215.