Société
en commandite Gazmont
Background
Since 1968, about 35 million tonnes of
municipal waste has been buried in the Miron quarry, making
it one of the largest sanitary landfill sites in North America.
The decomposition of the buried material generates landfill
gas, which if not controlled can cause major problems for people
and the environment. In 1988, the City of Montreal took over
this site and installed a landfill gas collection system in
order to eliminate these problems. Realizing the major energy
potential in this captured gas, the City called for tenders
for its utilization. The City retained the proposal of Gazmont,
a consortium of private companies, to build and operate a 25-megawatt
power plant to produce electricity from the landfill gas at
the Saint-Michel environmental complex (CESM).
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-Québec.
Gazmont is a partnership of two Quebec companies that are recognized
for their solid expertise in the fields of engineering, energy,
and landfill gas: Biothermica and SNC-Lavalin. The power plant
is operated by the Dynatech company.
Main Activities
Gazmont's mission is to produce electricity
from the landfill gas generated at the CESM landfill site. Gazmont
is the tangible expression of the partnership's expertise, which
is to assess landfill gas resources, to design, install and
operate landfill gas collection systems, and to design, build
and finance landfill gas power plants.
Featured Technology
Landfill gas produced by the decomposition
of waste material in the CESM 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 by the boiler goes directly to a steam turbine,
where the thermal energy is transformed into mechanical energy.
Finally, this mechanical energy is 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
air coolers to minimize the formation of steam plumes in winter.
The condensed steam is recovered and pumped to the deaerator,
which takes out the dissolved air. It is then returned to the
boiler after pre-heating in a heat exchanger.
Significance of the Technology
Gazmont's 25-MW plant is the third-largest
landfill gas-fuelled power plant in the world. The energy it
produces supplies the electricity needs of 10,000 homes, from
a resource that is normally viewed as a nuisance.
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 that
substitutes for the use of traditional fossil fuels. This type
of project is perfectly in keeping with the objectives of the
Kyoto Protocol.
Utilization of landfill gas at the Gazmont power plant reduces
greenhouse gas emissions by about 1 million tonnes per year.
Methane (CH4), the principal component of landfill gas, contributes
to global warming 21 times more efficiently than carbon dioxide
(CO2).
Potential Applications of the
Technology
The main application of the process used
in the Gazmont power plant is in large landfill sites, because
of the significant capital costs involved. However, the expertise
developed by the Gazmont partners makes it possible to use other
technologies economically, using landfill gas in internal combustion
engines, for example, at smaller landfill sites.
The
information conveyed is of a promotional and informative nature
and has been adapted into layman’s terms. In no case should
its content be considered complete, exhaustive or free of error
with respect to the technical data it contains.
