Biothermica - Waste-to-Energy Power Plant

In 1988, the city of Montreal became the owner of this site and installed of a landfill gas collection system. Aware of the site’s energy potential, the city proceeded to a request for proposals and finally selected the Gazmont partnership for the construction and operation of a 25MW landfill gas to electricity power plant.

The Gazmont power plant is under the ownership of Biothermica and has been operated by the Dynatech company since 1996.

The construction of the plant, representing a private investment of $37 million, began in April 1995. It has been in commercial operation since November 1996, selling all of the power produced to Hydro-Quebec.

Landfill gas produced by the decomposition of waste materials in the landfill site is captured by a collection system composed of more than 350 wells and brought to the Gazmont plant, where it is burned in a boiler. The energy produced as steam is transformed into mechanical energy which is finally transformed into electrical energy by an alternator. The electricity is delivered to the Hydro-Québec network at a voltage of 25 kV.

At the turbine exhaust, the steam is condensed in two wet-surface condensers to minimize the formation of steam plumes in winter. The condensed steam is recovered and pumped to the dearator, which takes out the dissolved air. It is then returned to the boiler after pre-heating in a heat exchanger.

Gazmont’s 25 MW plant is the second largest landfill gas-fuelled power plant in Canada. The energy it produces supplies the electricity needs of 10,000 homes. The process used at the Gazmont plant is mainly applicable to large landfill sites, given high capital costs. However, the expertise developed by Gazmont allows the application of other utilization alternatives for smaller sites, such as the combustion of landfill gas in combustion engines.

Environmental benefits

The Gazmont project shows that the control and use of landfill gas can reduce greenhouse gas emissions caused by the decomposition of waste materials and provide a new source of energy which substitutes for the use of traditional fossil fuels.

Utilization of landfill gas at the Gazmont power plant reduces greenhouse gas emissions by about 1 million tons per year. To this day, the plant has accumulated 8 million tons of CO2e in terms of greenhouse gas (GHG) reductions. In 2002, the Gazmont partnership was awarded the ÉcoGESte prize from the government of Quebec for its contribution to reducing the province’s GHG emissions.