Phase one was a feasibility study into waste to energy technology.
One of the options under consideration was converting compost from the Whitehorse Landfill into methane based biogas. The biogas would fuel a reciprocal engine producing heat and electricity. Energy from this plant would go into the Yukon power grid and reduce reliance on fossil fuels.
Before moving into a demonstration phase to the project partners needed to determine if the compost available in the Whitehorse area is of sufficient quality and makeup to produce the necessary biogas. This entailed testing and analysis by an independent laboratory.
Background:
Turning compost into biogas is a process known as anaerobic digestion. (Anaerobic means living without air). There are two industrial scale methods: wet fermentation and dry fermentation.
Traditional digesters use “wet” waste streams, such as manure. Then large amounts of liquid are added to create a fluid mixture that moves through the system to achieve fermentation.
Dry fermentation technology can use various waste streams as input. This method does not need fluid movement to achieve fermentation. That makes it a feasible solution to a wide range of organic waste management and energy generation needs.
Dry fermentation works on organic waste with a typical moisture content of less than 75%. In a dry system, organic waste is loaded into individual fermenters on a 28-day cycle. The waste rests in a pile while a liquid solution containing the essential micro-organisms (often termed percolate) is applied to it at regular intervals. This solution is recycled to be used again in the system. An in-floor heating system keeps the biomass at a constant temperature of 104°F. This helps it break down faster.
Results:
Tested samples contained less methane than what is usually produced from food and yard waste. Biogas is normally around 60 percent methane, whereas our research samples were between 30 and 47 percent. Based on these results, we are considering doing further testing using some different variables.
Phase Two involved the implementation of the Biogas Preliminary Design.
Yukon Energy seeks to expand electrical generation capacity in Yukon in a manner that is reliable, affordable, flexible and environmentally responsible. The Biogas Preliminary Design explored the potential to implement a biogas plant in Whitehorse that will extract the energy from food waste through a biological process called anaerobic digestion (AD). The purpose of this study component was to build on the work that was done to date and assist Yukon Energy Corporation and Yukon Research Centre in assessing the technical and economic feasibility of generating electricity and heat using a biological process (and displacing diesel generated electricity). Previous studies confirmed feedstock amounts, recommended dry anaerobic digestion, analyzed Whitehorse’s food waste and yard waste feedstock for biogas production volume and quality.
Background:
Yukon Energy currently operates its diesel generation to meet peak loads specifically during the winter months when water availability for hydro generation is limited. As a result YEC is looking at alternative energies that can assist with meeting this shortfall when water availability is limited.
Results:
Due to the limited amount of available organic material and the high cost of operating a Biogas plant; the study concluded that, for the time being, it was not economically viable to operate a plant in Whitehorse.
- Cold Climate Innovation
- Yukon Energy Corporation
- City of Whitehorse