Recently, through one of my environmental engineering classes, I had the opportunity to tour the Edmonton Waste Management Centre. The EWMC processes all of the municipal solid waste from the city of Edmonton on site, and uses several different waste management techniques to do so. These include waste separation, recycling, composting and many others. Two of the stages that I think are particularly energy-club related are the landfill gas recovery system and the Enerkem biofuels facility.
The site of the EWMC houses Edmonton’s Clover Bar landfill, which was closed after reaching its capacity in 2009. It now serves as a source of energy for the city of Edmonton, since it produces electricity from landfill gas. All landfills produce gas as they mature and the material they house begins to degrade. The digestion of material produces landfill gas, which is made up primarily of methane and carbon dioxide, in roughly equal parts. Methane is harmful to human health, and is a potent greenhouse gas, so it is necessary to manage landfills once they reach this stage to prevent its release. However, it is also necessary to remove the landfill gases, because they pose an explosion risk if left to accumulate underground. For this reason, landfills are typically outfitted with landfill gas collection systems and, as in the case of the EWMC, a system to produce electricity from the gas. The EWMC is the only system of its kind in Alberta, and manages to satisfy about 1% of Edmonton’s yearly electricity need. This doesn’t seem like a lot on the surface, but when you think about where it’s coming from – a big, old pile of garbage – that ain’t bad. It is also expected that the landfill will continue to produce landfill gas until the year 2060, although the amount produced each year will decrease due to organic material being depleted. Considering that the landfill was only open from 1975 to 2009 (a period of 34 years), and the landfill gas recovery facility is planning to operate over a period of at least 55 years, it seems that we are getting back a lot of what we put in! (1)
In addition, Edmonton’s Waste to Biofuels Chemicals Facility is employing leading edge technology to further extract energy from waste. At the EWMC, some of the waste that cannot be recycled or composted is sent to Enerkem’s facility, which is able to produce 38 million litres of biofuels and chemicals a year from waste that would otherwise be landfilled. This waste, which is composed of things like candy wrappers and plastic bags, is turned into something called “garbage fluff,” by breaking it down into an amalgamated mixture of small pieces. It then enters the facility and, after going through Enerkem’s own process, comes out the other end as biofuel. The facility can produce either methanol or ethanol, both of which are liquid petrochemicals that can be used as fuels for internal combustion engines.1 While they are not widely used at this point, they are being used in some capacity as fuels or fuel additives, and they may produce less hydrocarbon emissions when compared to gasoline or diesel. (2)
In general, my experience at the EWMC was very enjoyable. My classmates and I lovingly compared it to an energy nerd’s version of Willy Wonka’s chocolate factory, with our guide leading us on a wonderful waste-filled adventure. But beyond it being a fun way to spend a few hours, the whole concept of the facility really got my environmental engineer senses tingling. The idea that we now extract energy from our garbage felt very futuristic to me. In fact, in one of the following classes, my professor drew a comparison to the waste fueled generator used in Back to the Future: Part II built by the infamous Doc Brown. I was also impressed at how progressive the city’s approach to waste is. While we still send a large amount of waste to landfills, the EWMC does manage to divert a pretty hefty portion of it. While it’s not perfect, it’s definitely a start. Edmonton’s facility is one of the best in the world, and people come from all over to look at the systems we have. This makes me feel pretty darn good about the city I live in.
The Edmonton Waste Management Centre holds tours for school groups or adults if you are interested in taking a look around. You can make a reservation by calling them at (780) 496-6879.
(1) City of Edmonton 2015. Edmonton Waste Management Centre [online]. Available from http://www.edmonton.ca/programs_services/garbage_waste/edmonton-waste-management-centre.aspx [cited November 1, 2015].
(2) Wiseman, R. 2014. A methanol renaissance in Canada refuels the biofuels debate. Alberta Oil Magazine, September 22, 2014 [online]. Available from http://www.albertaoilmagazine.com/2014/09/refueling-biofuels-debate/ [cited November 1, 2015].