Turning Waste for Pulp Mills into Methane
Funded through Round 3: Renewable Energy in 2012, this project tested a new anaerobic digestion system that turns organic waste into biogas, which can be used to generate energy. The system was successfully demonstrated at a pulp mill, showing it could reduce waste and produce renewable fuel from industrial by-products.
The project deployed a high-rate anaerobic digestion (AD) system developed by ADI Systems, designed specifically to treat high-strength industrial wastewater and sludge from pulp and paper operations. The system operates in an oxygen-free environment where specialized microorganisms break down organic material, producing biogas rich in methane. This biogas can be captured and used on-site as a renewable fuel for heat or power generation, displacing fossil fuels. What sets this technology apart is its ability to process waste streams with high solids content and complex organics that are typically challenging for conventional treatment systems. Unlike traditional treatment methods that simply clean the waste before releasing it, this system also turns that waste into a valuable energy source. By converting organic waste into energy and significantly reducing the organic load of effluents, the system offers both operational efficiencies and measurable reductions in greenhouse gas emissions.
Understanding the Integration and Market Drivers for Reliable Biogas Production
The project provided valuable insights into both the technical performance and broader feasibility of implementing AD systems in industrial settings like pulp mills. One key lesson was that, despite the high variability and strength of the wastewater, the ADI system was able to maintain stable performance, validating its robustness and adaptability. However, the project also revealed that careful pre-treatment and feedstock conditioning are essential for ensuring long-term microbial stability, especially when dealing with effluents containing residual process chemicals or shock loads.
On the market side, the project highlighted that while the technology offers clear environmental and operational benefits, its adoption is highly dependent on the value placed on biogas energy, waste management costs, and regulatory drivers such as greenhouse gas (GHG) reduction targets. Capital cost remains a significant barrier, particularly for brownfield sites where integration with existing infrastructure can be complex. Nonetheless, the demonstration strengthened the business case by confirming that biogas recovery can meaningfully offset energy costs and that payback periods are improved when facilities can make full use of the energy generated.
What’s next?
Overall, this project, completed in 2016 and derisked the AD in the Alberta pulp mill industry and paved the way for large-scale applications. In 2023, West Fraiser mills sold its Slave Lake mill to Atlas Holdings, and the mill continues to be operated by Alberta-based pulp industry leader Western Forest Products. Along with the mill, Western Forest Products continues to use the anaerobic hybrid digesters demonstrated in this project to recover organic material from the pulp mill’s effluent stream and convert it to biogas. After conditioning, the biogas is used to fuel reciprocating engines, generating 5.2 megawatts of renewable electricity for use in the organization’s pulp operations, reducing its reliance on fossil fuels. Additionally, captured waste heat from the power plant is used to offset natural gas usage in pulp drying, enhancing productivity while significantly reducing emissions and water consumption.