Simulating waste temperatures in an operating landfill in Québec, Canada

Abstract

A bioreactor landfill operated in Sainte-Sophie, Québec, Canada was instrumented to better understand the waste stabilization process in northern climates. Instrument bundles were placed within the waste to monitor temperature, oxygen, moisture content, settlement, total load, mounding of leachate and electrical conductivity. A finite element model was developed to simulate the heat fluxes to and from the waste, as well as heat generation within the waste from both anaerobic and aerobic processes. The results of the analysis suggest the majority of the aerobic activity occurs in the top portion of the waste lift exposed to ambient air. In addition, the model indicates that frozen waste lifts require a significant amount of heat to thaw the liquid fraction. The model also demonstrates that when a lift of cold waste is placed at the bottom of the landfill, the subsurface acts as a significant source of heat.

Treatment of landfill waste, leachate and landfill gas: A review

“…Aerobic biodegradation produces mostly carbon dioxide and water [28]. The effectiveness of the aerobic biodegradation process is dependent on the oxygen concentration, as well as temperature [29,30], moisture content [31], and pH [32], affect all types of biodegradation [33].…”

Heat Transfer Model for an Engineered Landfill in Sainte-Sophie, Quebec, Canada

“…At the Ste. Sophie LFGTE facility, Bonany et al (2013aBonany et al ( , 2013b states that waste placed in a frozen state remained frozen for 1.5 years and the latent heat of fusion was shown to have a large impact on the heat budget of a landfill operated in a cold climate.…”

“…Bonany et al (2012) calculated that the latent heat of fusion of waste would range from 10 to 20% of the latent heat of fusion of water. A latent heat of fusion of 38 kJ/kg (11% of the latent heat of fusion of water) was determined for the waste, based on the calibrated model developed by Bonany et al (2013b).…”

“…The anaerobic and aerobic heat generation rates varied from 0.08-0.38 W/m 3 and 2.5-11.3 W/m 3 respectively (Hanson et al, 2008). Bonany et al (2013b) summarizes the heat generation rates from the literature for anaerobic and aerobic biodegradation ranges from 0.218 -34.79 W/m 3 .…”

“…The two main thermal parameters needed to simulate heat transfer in waste include the thermal conductivity and specific heat capacity. Estimates of these parameters in the literature are summarized in Houi et al (1997) 0.10 1,900 to 3,000 Yoshida et al (1997) 0.53 3,300 Zanetti et al (1997) 0.0445 2,200 Lefebvre et al (2000) 0.10 1,900 to 3,000 Hanson et al (2006) 0.30 719 Hanson et al (2008) 0.6 to 1.5 1,200 to 2,200 Rowe et al (2010) 0.35 to 0.96 1,940 to 2,360 Bonany et al (2013b) 0.67 1400 Faitli et al (2014) 0.24 to 1.15 900 to 2100…”