Can Wood Pellets from Canada’s Boreal Forest Reduce Net Greenhouse Gas Emissions from Energy Generation in the UK?

Abstract

We present the results of a study on the climate forcing effects of replacing coal for power generation in the United Kingdom (UK) with wood pellets produced in northern Ontario, Canada. Continuous wood pellet production from two biomass sources were considered: fiber from increased harvesting of standing live trees (stemwood scenario) and from harvest residue provided by ongoing harvesting operations (residue scenario). In both scenarios, biomass was collected from harvesting operations in two forest management units (FMUs) with contrasting harvest residue treatments: natural decay of slash piles in the Hearst FMU and slash pile burning in the Kenora FMU. Life cycle emissions associated with wood pellets were assessed for production, transportation, and combustion to replace coal at a hypothetical power generating station in the UK. Greenhouse gas (GHG) emissions and removals in wood pellet and coal scenarios were assessed using two methods: global warming potential (GWP)-based mass balance and dynamic life cycle assessment (LCA) approaches. In the stemwood scenario, climate change mitigation from replacing coal with wood pellets was not achieved within the study timeline (2020–2100). In the residue scenario, immediate climate change mitigation was achieved with fiber sourced from the Kenora FMU where the current practice is to burn slash piles; for the Hearst FMU, where slash is allowed to decompose in the forest, climate change mitigation occurred 11.6 and 3.1 years after biomass collection began, as assessed by the mass balance and dynamic LCA methods, respectively. Factors affecting mitigation potential in the studied scenarios are discussed.

A concise review of technologies for converting forest biomass to bioenergy

“…According to Twumasi et al (2022), there is an anticipated rise in biomass consumption of 450,000 metric tons per year in the year 2030 and beyond. This increase is expected to result in a corresponding decrease of around 395,000 metric tons per year in CO2 emissions (Chen et al, 2023). In addition, the combustion of biomass can result in the formation of alkaline ash, which has the potential to impede the release of SO2 emissions through coal and mitigate global acidification (Putra et al, 2023).…”

“…It is worth mentioning that in cases where the rotary drier fails to efficiently eliminate moisture, the pneumatic dryer presents itself as a viable alternative, with an enhanced drying rate of 22% (Palacios-Bereche et al, 2022). According to environmental analysis, the substitution of coal with biomass pellets for power generation is projected to result in an annual reduction of 205 million metric tons of CO2 emissions (Ter-Mikaelian et al, 2023). In 2008, the European Union countries collectively prevented the release of approximately 12.6 million tons of CO2 emissions by utilizing 8.2 million tons of pelleted wood.…”