Assessing forest biomass for bioenergy: Operational challenges and cost considerations

Abstract

Sustainability assessments and biomass inventories often neglect the operational challenges involved in the harvesting of forest biomass for bioenergy. Thus, concerns that increasing demands for biomass will lead to greater environmental impacts, particularly on soil productivity, need to be considered from an operations perspective that takes into consideration the technical and cost limitations to biomass recovery. We examine operational forest biomass recovery potential of harvest residue (slash) for three sites located north of Kapuskasing, Ontario. The sites are in the Northern Claybelt, which is in the boreal forest and is comprised primarily of lowland black spruce and upland mixedwoods. Supply flows of harvest residues estimated using the Biomass Opportunity Supply Model (BiOS), developed by FPInnovations -Feric Division are compared to validation data collected from the sites. Costs for the supply flows were also estimated using BiOS. After harvesting limitations and planned retentions (such as wildlife trees) were taken into consideration, 41% (41.2 ovendry tonnes/ha) and 59% (99.1 odt/ha) of total above-ground biomass were estimated to remain on site in two mixedwood blocks, and 25% (25.3 odt/ha) in a black spruce block. Thus, considerable biomass was left on the forest floor, contrary to popular perceptions that bioenergy harvesting will result in a "clearing" or potential "vacuuming" of the forest floor. The delivered cost was $53/odt ($2.86/GJ energy equivalent) and $58/odt ($3.14/GJ) for the two upland sites and $59/odt ($3.19/GJ) for the lowland black spruce site. This is higher than conventional hog fuel costs. Although operational and cost considerations thus limit harvest residue recovery, and although there are a number of operational factors that can minimize environmental impacts on soils and biodiversity, sustainable biomass removal guidelines still need to be implemented on sites sensitive to soil damage and nutrient removal.Key words: biomass, bioenergy, harvest, operations, cost, supply chain, sustainable management, soil nutrients, forest residues, BiOS model, Ontario RÉSUMÉ Les évaluations de durabilité et les inventaires de biomasse négligent souvent les défis opérationnels reliés à la récolte de biomasse forestière pour la production de bioénergie. En conséquence, les inquiétudes à l' effet que l'accroissement de la demande de biomasse générera plus d'impacts environnementaux, particulièrement sur la productivité des sols, doivent être étudiées selon une perspective opérationnelle qui prend en considération les limites techniques et financières de la récupération de la biomasse. Nous avons étudié le potentiel opérationnel de récupération de la biomasse forestière à partir des résidus de récolte (rémanents) de trois sites situés au nord de Kapuskasing en Ontario. Les sites se retrouvent sur la zone argileuse du Nord qui fait partie de la forêt boréale et est composée principalement d' épinette noire sur sol marécageux et de forêts mélangées sur terrain plus sec. Les flux d'ap...

The potential of forest biomass as an energy supply for Canada

“…These three latter factors overlap in defining the opportunities for harvesting residue recovery. For example, Ralevic et al (2010) found that it was technically possible to recover only 25% to 59% of the total available volume of harvesting residues on two sites in northern Ontario. The amount of harvesting residue that can be cost-effectively recovered will also depend on a range of economic factors (e.g., Grushecky et al 2007).…”

Le potentiel de la biomasse forestière comme source d’énergie pour le Canada

“…Ainsi, ces trois facteurs concourent à définir le potentiel de récupération des résidus de coupe. Par exemple, Ralevic et al (2010) ont constaté qu'il était techniquement possible de récupérer seulement 25 % à 59 % du volume total de rési-dus de coupe dans deux sites du nord de l'Ontario. La quantité de résidus de coupe qui peut être récupérée de façon rentable dépend également d'une vaste gamme de facteurs économiques (ex : Grushecky et al 2007).…”

Potential opportunities to utilize mountain pine beetle-killed biomass as wood pellet feedstock in British Columbia

“…In a modeling study of the amount of biomass generated by natural disturbances in Canadian forests, Dymond et al (2010) estimated that the MPB outbreak could generate an average of 16.8 M dry tonnes of dead wood per year between 2005 and 2020. It is important to note, however, that biomass availability is often limited by economic factors (Ralevic et al 2010), which suggests that these previous studies may not adequately reflect the actual amounts of biomass that are likely to enter bioenergy feedstock supply chains.…”

“…The payments were designed to allow operators to develop more cost-effective systems for biomass collection in order for the systems to be self-sustaining by the end of the subsidy period (Sedjo 2010, Stubbs 2011. Such a system, if employed in BC, could make the recovery of MPB-killed biomass economically feasible, although given the scale of the MPB outbreak (Eng et al 2006, Ralevic and Layzell 2006, FPB 2007, MFLNRO 2012a), a two-year subsidy would be woefully ineffective given the precarious position of wood pellet producers. A CAN$50 per tonne The Forestry Chronicle Downloaded from pubs.cif-ifc.org by 34.218.44.141 on 05/11/18…”

“…Ralevic and Layzell (2006), using published data (Eng et al 2006), calculated the temporary biomass available as a result of the MPB outbreak. Based on the estimate that 417 M m 3 of merchantable MPB-killed biomass would be recoverable (Eng et al 2006) (i.e., the trees would be harvested while they were still suitable for lumber production), Ralevic and Layzell (2006) estimated that an additional 2.4 M dry tonnes of harvest residues would The Table is modeled after that of Murray (2010). All costs and prices are in CAN$.…”