Determination of methane emissions from biogas plants, using different quantification methods

Reliable and comparable quantification methods are needed for assessing the effectiveness of biogas production utilisation process in mitigating methane (CH4) emissions as well improving database emission inventories. The objective this study was to compare validate CH4 quantified at two agricultural plants, up three days, using diverse on-site (two teams) off-site (three teams), including differential absorption lidar (DIAL), tracer gas dispersion (TDM) inverse modelling (IDM). For plant 1, with a constant combined heat power (CHP) load, average factor varied from 0.3% (on-site approaches) 1.2% (off-site approaches). On-site approaches underestimated overall due many small (unquantified) leakages. All observed factors 2, ranging between 1.9 2.2% CH4. In case, majority emanated just few sources. However, correcting significant influence varying CHP load during measurement campaign revealed differences TDM IDM (DIAL did not participate). It demonstrated that could recover rate known point source (controlled release via diffuser) within an accuracy 93 ± 15% 92 17% (IDM) under favourable similar conditions.