The presence and proportion of the components of the biogas may vary according to different environmental factors such as plant type and raw material. Commonly found impurities and problems are given in the table below.
|CO2||25-50%||– It reduces calorific value.– If the gas is wet it causes corrosion.|
|H2S||0-0,05%||– It has an abrassive effect on equipments and piping systems. – SO2 emissions occur after combustion or H2S emissions occur as a result of incomplete combustion.(The limit value should be 0.1%).|
|NH3||0-0,05%||– NOx emissions resulting from combustion damage the fuel cells.|
|Vapour||1-5%||– It has an abrassive effect on equipments and piping systems.– It causes freezing risk in piping systems and nozzles.|
|Toz||>5 µm||– It clogs nozzles and fuel cells.|
|N2||0-5%||– It reduces calorific value.|
|Siloxane||0-50 mgm-3||– It hurts and corrodes engine systems.|