Maximizing the value extracted from wood fibres in the coastal region of British Columbia

Prepared by Dr. Mahmood Ebadian; Biomass and Bioenergy Research Group, University of British Columbia

If you arrive in Vancouver by plane, one sight that will probably catch your eye during your short trip from the airport to Downtown Vancouver is collections of timber floating on the Pacific Ocean and the Fraser River. These collections of timbers are known as log booms, used to collect and transport sawlogs and pulp logs (Figure 1). Log booms have been practiced for decades in the coastal region of British Columbia (BC) to move large volumes of timbers from forests to wood manufacturing facilities. Log booms are towed by tugboats hundreds of meters or kilometers to get to their destination. This practice provides forest companies with a cost-efficient mode of transporting and storing harvested timbers before the delivery to wood manufacturing sites.

Figure 1. Tugboat pushing log boom near Vancouver (Photo by Gordon, Wikimedia Commons)

However, towing log booms in the salt water highway creates a challenge for wood processing facilities. Water transportation exposes wood fibres to chlorine in the water. In addition, soaking sawlogs in the water increases the moisture content in wood fibres. High chlorine and moisture content make these fibres a less attractive feedstock for the residual industry including pulp and paper mills, pellet plants, bioenergy plants (heat and power), animal bedding and landscaping applications. Sawmills in the BC Coast do not usually separate different streams of their byproducts including sawdust, wood shaving and hog fuel as there are no individual markets for their by-products. Mill residues are usually mixed together and the whole mix is regarded as hog fuel. The mix of mill residues results in a large variation in the particle size of fibres in hog fuel (Figure 2). In addition, this hog fuel has a high moisture content (50-70%). The high level of precipitation on the BC Coast also contributes to the high moisture content of hog fuel. In contrast, sawmills in the BC Interior do not mix their mill residues and sell them to various markets based on the quality specifications of their end users. For example, sawdust and wood shavings are the feedstock of choice for pellet production and animal bedding while hog fuel is the raw material for heat and power production as well as landscaping. The separation of residue streams generate more value for forest companies.

Figure 2. A sample of hog fuel in the Coastal BC (Photo by Paul Adams)

The primary consumer of the coastal hog fuel is the pulp and paper industry. Hog fuel is used as feedstock for power boilers of pulp mills to produce heat and power. However, high moisture content and large portions of fine materials (up to 50% of hog fuel mass) have adversely affected the efficiency of boilers. The efficiency of power boilers usually reaches its lowest level during winter when the moisture content of hog fuel can be as high as 70%. The low efficiency of boilers are usually offset by using natural gas. Reduction in the moisture content and separation of fine materials can provide significant cost savings in the energy profile of the coastal pulp mills.

Altentech™ and SMG Wood Pellet, located in Vancouver with operations in the District of Mission in the Lower Mainland region of BC, have been working for the last seven years to develop technology solutions for the low quality of hog fuel in the BC Coastal region. These solutions include size segregation, grinding/shredding, drying and pelletization. This package of technology solutions would provide the opportunity to maximize the value extracted from large volumes of low quality hog fuel in this region. These solutions would also solve the challenges related to removing mill residues from sawmills sites.

The mission of Altentech™ and SMG Wood Pellet is to create multiple markets for the coastal hog fuel by (1) meeting the quality specifications of the pulp mills by removing the small particle-sized fibres and reducing the moisture content to a range of 30-35% (w.b.), (2) creating a new value stream for small particle-sized hog fuel for applications such as pellet and biofuel production and (3) attracting new businesses and technologies to maximize the residual resource utilization and value in any given geographical area. In addition to hog fuel, these solutions can help to maximize the amount of forest residues extracted from forests and produce a marketable wood fibre from these residues. Most of these forest residues are currently piled at the roadside of harvested forest stands and burned to reduce the fire risk and to avoid the risk of disease and pest infestation.

Figure 3. top photo: pile of hog fuel, bottom photo: Altentech™ dryer (Photos by Mahmood Ebadian, SMG Wood Pellet Plant, Mission, BC)

Altentech™ and SMG Wood Pellet are working closely with interested parties in the region to commercialize these technology solutions including BC Bioenergy Network (BCBN), Mission municipality, local communities, the forest sector and Biomass and Bioenergy Research Group (BBRG) at UBC. Commercialization of these solutions generate social, economic and environmental benefits. Jobs creation for the local communities, new income streams from the coastal hog fuel and forest residues, producing low-carbon solid and liquid biofuels (e.g. pellet, biojet and green diesel) are the values generated by these technology solutions.