What emissions can be monitored to ensure that scrubbed emissions comply with the MARPOL % sulphur-in-fuel regulations?
Scheme B of the IMO EGCS Guidelines [10] allow a SO2/CO2 ratio to be continuously monitored and logged to ensure that emissions after an exhaust gas cleaning unit correspond to the % sulphur- in-fuel limits that are in force.
Although the fuel bound sulphur creates both sulphur dioxide and sulphur trioxide, collectively known as SOx, SO2 predominates and comprises >95% of the sulphur based emissions [3]. SOx emissions are therefore quantified by the online monitoring of SO2.
Figure: Position of scrubber system monitoring instruments
