Quantification Of Greenhouse Gases From Three Danish Composting Facilities

A measurement method combining a controlled trace gas release with downwind concentrations measurements was successfully used to quantify greenhouse gas (GHG) emissions from three Danish open windrow composting facilities. Overall, the results showed that composting of organic waste generate GHG emissions in terms of methane (CH4) and nitrous oxide (N2O) and thus contribute to climate change. At all three facilities significant CH4 emissions were occurring. The CH4 emission varied between 0.50 and 5.73 kg CH4 h-1. The highest CH4 emission (5.73 kg CH4 h-1) were measured at the Aarhus composting facility and was believed to be a result of the windrow lay-out with very broad and high windrows and a low turning frequency. The lowest CH4 emission (0.50 kg CH4 h-1) was measured at Fakse composting area and was most likely a result of the relatively small windrows and frequent weekly turnings. For all three facilities, the N2O emissions were significantly smaller than the CH4 emissions ranging from 0.08 to 1.18 kg N2O h-1.