Utilizing forest harvest residue is an issue of growing urgency in the British Columbia forest industry, In B.C., forest residues at roadside have traditionally been burned to mitigate fire hazard or, occasionally, they have been left to rot. With an increasing demand for energy and concern over climate change and air quality, burning may no longer be the most desirable practice for dealing with residues. Further, there is an increasing demand for harvest residues by both primary and secondary users to fuel the growing bioeconomy in B.C.
Oriented residue piles and constructed burn piles have different characteristics, including fuel size, composition, and fuel arrangement. The comparative ignition trials conducted in this proof-of-concept study suggest that these characteristics influence the fuel environment, with a higher potential for ignition and sustained burning and greater resultant fire intensity in constructed burn piles. The intent of this proof-of-concept trial was to determine whether logging residue piles that have been oriented for biomass extraction (placed in parallel piles by the processor operator during primary harvesting activities) is a significant fuel hazard that requires further abatement.
Recently, many forest companies, especially those located on the BC coast, have become interested in the possible danger that the runoff from log accumulations (log yards) may pose to the local flora and fauna and, ultimately, to humans. This info note attempts to put together practical information about how harmful runoff from log yards is created, how it can be prevented and give a brief overview of mitigation options. In creating this info note, a literature review was completed and a list of useful documents can be found near the end.
The clean air initiative led by the British Columbia Ministry of Environment seeks to develop innovative methods to improve community air quality by utilizing harvest residues and minimizing the volume of fibre burned at roadside. Retaining processed tops as roadside oriented piles is proposed as an alternative to burning debris.
These burn trials have demonstrated that in this unique arrangement of fuels and interaction of site-specific variables, particular areas of the piles will be more vulnerable to ignition sources which can lead to sustained burning and high intensity fire behaviour. In addition to the low fuel moisture conditions, other fuel properties, such as the close proximity of piles, high volume of fine fuels (branches and needles) and orientation of piles to road all contributed to enhanced burning at this site.
In October 2018, FPInnovations conducted burn trials to evaluate and compare the ignition potential and potential fire behaviour in two different configurations of piled harvest residuals. Continued collaborations in 2019 with Mosaic Forest Management and British Columbia Wildfire Service identified and developed a potential prescribed fire site that would allow ignition of harvest debris piled in an oriented configuration to evaluate fire behaviour during a period of higher fire hazard conditions.
The Ministry of Forests, Lands and Natural Resource Operations tasked FPInnovations with developing a Best Management Practices for Integrated Harvest Operations in British Columbia guidebook (Spencer, 2017), with a focus on biomass extraction principles. One of these principles states that it is beneficial for both primary and secondary harvesters to neatly pile logging residue if it is destined for biomass extraction rather than the traditional practice of piling for burning.
Traditional debris piling practices require the piling of logging residues into a conical or windrow-shaped pile and then clearing the area around the pile of all organics. Little care is taken to exclude contaminants (dirt and rocks) from the pile or to keep the residual pieces intact and aligned as the pile is destined for burning. However, if the burn piles are targeted for secondary use (chips, hog, pellet stock) at a later date, contamination and poor alignment of the pieces can significantly decrease the productivity of the secondary harvester (grinding or chipping) and lead to an inferior end product.
FPInnovations completed a trial in December 2016 which examined the productivity and cost of three methods of piling and grinding logging residues (Spencer and Blackburn, 2017). The December trial compared three pile types:
1. Piles built by a log loader for burning after the initial harvest.
2. Piles built by a log loader for biomass extraction after the initial harvest.
3. Piles built by the processor during the processing phase of harvesting.
One concern that arose from this trial was whether having a processor neatly pile residues created a loss in productivity versus the traditional method of throwing or “flinging” the residual tops as far as possible from the processor. Researchers returned to Vanderhoof in March 2017 to monitor the productivity of the two methods (throwing and stacking) for handling residues.
A series of info notes was developed to describe technical and economic aspects of commercially available small-scale combined heat and power (CHP) biomass systems utilized in community and small industrial applications. The first Info note is a primer in which general information about these systems is presented. The second info note presents technical and economic aspects of small-scale gasification and internal combustion CHP units under 165 kWel. The third info note presents the design and economics of biomass supply chains for small-scale CHP systems under 165 kWel.
A series of info notes was developed to describe technical and economic aspects of commercially available small-scale combined heat and power (CHP) biomass systems utilized in community and small industrial applications. The first Info note is a primer in which general information about these systems is presented. The second info note presents technical and economic aspects of small-scale gasification and internal combustion CHP units under 165 kWel. The third info note presents the design and economics of biomass supply chains for small-scale CHP systems under 165 kWel.
