If you think landfills are all bad-smelling money pits, you should talk to Comcor Environmental Limited. The firm occupies a small niche within environmental-waste management, as few companies share its focus on landfill-gas emissions and fewer still play as many roles. Comcor started out 26 years ago as a group of conventional, environmental-consulting engineers. It has since morphed into a diversified solution provider, managing and recycling what remains of your trash. “Starting out … we never turned down a job, however small,” says Paul Bulla, vice president of operations. “Some of those early projects came from landfill owners and operators who needed to remediate nasty landfill odours in order to not to be shut down. We get in there, get our hands dirty, get to the root of the problem, and solve it.”
With this persistent attitude, Comcor was able to develop a variety of novel approaches that paved the way for it to become the highly regarded problem solver it is today.
Comcor’s success has rested on its ability to convert landfill gases for productive use. Because of the breakdown of organic wastes, municipal and other landfills typically produce gases made up of approximately 50 percent methane, 50 percent carbon dioxide, and a small amount of nonmethane organic compounds.
Most people have heard of carbon dioxide’s role as a greenhouse gas that contributes to climate change. Apart from environmentalists and regulators, not many know that methane gas is 21 times more damaging when released into the atmosphere, in addition to being explosive in concentrations of 5–15 percent by volume. Regulators now want to measure and reduce the volume of both emissions, but especially methane.
There are four approaches to methane reduction, offering a progressively higher order of benefits. Burning landfill gas destroys the methane in it, which accounts for the open flame or “flare” one can see when passing a landfill. Flaring converts methane into carbon dioxide; burning one tonne of methane is equivalent to removing 21 tonnes of carbon dioxide from the air.
A higher-order form of disposal is to use methane as a fuel in furnaces and boilers. It takes about twice the volume of landfill gas as of natural gas to produce equivalent amounts of energy, and the burner needs to be converted as well, but the environmental payoff is solid and well proven: landfill gas is a renewable and easily sourced fuel, whereas natural gas is a nonrenewable resource that requires underground drilling and other operations that have a much higher environmental impact. Comcor has been directly involved in converting burners and piping landfill gas to companies close to landfills. These companies can typically purchase it at a rate below the market price for natural gas.
THE WORD ON GREEN
Paul Bulla, vice president of operations for Comcor, focuses on the technology and engineering methods for sustainable waste management. He shares some of his other insights on the benefits of greening a landfill.
CLEAN AIR, CLEAN WATER: “Active management of landfills not only reduces greenhouse emissions; it helps lower the risk of groundwater contamination.”
ONGOING MONITORING: “It is hard to make sure that landfill problems stay permanently solved. Active landfills constantly change—they even physically move as trash decomposes and settles and gas levels rise and fall over time, particularly when volumes of waste are added each day. Attention to monitoring, maintaining, and expanding the engineered systems is critical.”
HARNESSING LANDFILL GAS: “Every source of renewable energy is valuable, especially if it also reduces environmental degradation.”
At a still higher order of benefit, landfill gases can also fuel reciprocating engines or gas turbines that generate electricity. Manufacturers like GE produce versions of engines that run on landfill gas. Turbines are only considered when very large volumes of gas are available. Less frequently, the waste-heat generated by landfill-gas-driven engines can also be used directly in industrial applications.
As engineering consultants, Comcor evaluates landfills for municipalities and commercial operators, and often recommends one of the options above. In addition, various landfill owners approach Comcor to put a complete solution together for their landfill’s gas-control needs. In this capacity, Comcor resembles a design-build firm in the construction field. For such projects, Comcor provides additional services such as monitoring, maintenance, and the management of landfill-gas operations, as many small municipalities don’t have the staff or expertise to do it themselves.
What makes Comcor even more unique is that it owns landfill-gas-utilization plants—four now, with a fifth under construction—through an equity partnership with Integrated Gas Recovery Services (IGRS). As a landfill-gas developer, IGRS sells carbon credits and uses the money to reinvest in its operations.
Although it may be in a stinky business, Comcor’s benefit is clear when one looks at the numbers.
“Comcor removes, destroys, or makes productive use of 1.25 million tonnes of carbon dioxide equivalents each year,” Bulla says. “Figuring that a normal passenger car puts out an average seven tonnes of carbon dioxide a year, that is the equivalent of taking 180,000 cars off the road annually.”