It is difficult to tell from this image, but this flare is approximately 40 feet high. At first it may seem to be a LOT of gas burning away for no reason. Although it represents a waste in potential fuel energy, it is doing immense good to the environment. Why? Well it is burning landfill gas. That is the gas given off my decomposing material within a garbage dump. It is mostly Methane. Methane gas is a greenhouse gas that contributes to global warming just like Carbon Dioxide EXCEPT it is 21X worse. Methane is a greenhouse gas 21 times more damaging than simple carbon dioxide. By burning the gas, it is converted, by in large, to carbon dioxide of equal volume. This means that its impact of on global warming is lowered by 21 times what it would have been if released without burning.
So although it appears to be a waste of energy (and is), it is much better than just allowing the landfill to release the gas "naturally". The landfill producing this amount of gas serves the city of Edmonton Alberta Canada. Edmonton is a city of about 800,000 and although this flare is produced by the gas released by its main landfill, there is at least one other landfill servicing this city. In other words, this 40 to 50 foot flare does not represent the byproduct of the entire population's garbage. Another major point to consider is that Edmonton is a world leader in recycling. The amount of material per population disposed of in its landfill is probably lower than nearly all cities in North America.
It gives you a good idea of just how much an issue Landfill Gas is. Currently, this gas is normally used to produce up to 4 megawatts of power using gas turbines and the flaring only occurs when these turbines are not running.
You can see that landfill gas recovery is almost a "no brainer" for any major landfill.
An added benefit is that other potentially cancer causing materials known collectively as BTEX (Benzene, Toluene, Ethyl benzene, and Xylene) are captured from the landfill and can be disposed of in a safe environmentally friendly manner.
Is there a large landfill near your area that has been recently "active"? If so, your community MUST look into recovering landfill gas. The production of electricity using a "free" fuel source helps ensure that the initial capitol investment is quickly recovered. This will be especially true when Carbon Dioxide trading becomes a reality in North America. When such an installation is operated by an existing CO2 producer, such as the operator of a coal fired electricity generation plant, it can be used to offset the total CO2 footprint of the electrical installation by crediting the reduction in greenhouse gasses against their production.
Recent research has shown that even "old", long closed landfill sites can be "stimulated" into producing enough gas to make a recovery operation economical. In these cases, the slow release of methane to the environment is prevented by recovering the gas to produce electricity. Once the recovery operation is in place, the landfill can be "stimulated" to release its "methane potential" over a much shorter period of time. For example, the methane released from an old landfill over 150 years is released over 15 years by "stimulating" methane production by, for example, adding water to the landfill. Other ways of speeding up the anaerobic decomposition of garbage have been tested and proven to be successful. It is this decomposition that releases methane. It is important to note that although the production of methane is stimulated, the overall amount released from a landfill site is not increased, it just releases the total methane over a shorter period - thus producing enough gas to power a gas turbine to produce electricity.
Depending on the economics of a CO2 credit trading system, it may be possible to run a money making operation on a small, long closed landfill by simply collecting the methane and burning it. In a case such as this, the cost of maintaining a properly certified metering station may be the deciding factor. The initial costs are for drilling appropriate wells, inserting well casings, PVC piping to each well with proper valves and sample points, a knockout pot, a compressor, an automated flare, a metering and sample system, a power source for the compressor, and other costs such as security fencing or a structure to enclose the compressor and/or flare system.
I admit that I am not "on top of" all the most recent developments in this area, but I know that it would be a shame if the economics of eliminating the methane released from a "borderline" landfill were such that a project is deemed unviable because of the cost of a metering system. Maintaining a pressure, temperature, and composition compensated "Sales Gas" flow meter can be very expensive. If "certification" for CO2 credits means that the metering system does not take into account the scope of the recovery operation, overly stringent regulations may kill otherwise viable operations. Random testing of gas composition and flow rates by a certified organization should be enough "proof" to provide CO2 credits for smaller "borderline" operations.
Bob James Kaplan
March 2008