I-DEV0452: Conservative estimation in lieu of direct measurement regarding the methane content for biogas fed to gas engines (FCH4,generator) for the period that suffered measuring equipment malfunctioning

During the verification of the second monitoring period of the registered CDM project activity BAJ Gunung Agung Factory tapioca starch wastewater biogas extraction and utilization project, Lampung Province, Republic of Indonesia (CDM Ref. No. 2673), DNV identified a deviation from the monitoring plan of the project. The monitoring period covered by the verification is from 01 April 2010 to 31 March 2011. The deviation from the registered monitoring plan is regarding the monitoring of methane content biogas fed to gas engines (FCH4,generator).
The monitoring plan in the registered PDD states that this parameter will be “measured periodically by continuously by a gas analyzer”. Post project implementation FCH4,generator has been continuously monitored (by a gas analyzer) and recorded (by SCADA system) except from 18 June 2010 to 25 June 2010 and from 1 December 2010 to 19 January 2011 (58 days) where FCH4,generator has not been measured and monitored via a gas analyzer due to faulty gas analyzer. Of these 58 days, the following 5 days; 18 June 2010 to 20 June 2010, 6 December 2010 and 2 January 2011; are irrelevant due the absence of gas engine operation, thus no biogas flow. Therefore, the relevant deviation days are 53 and it has been confirmed during the site visit (via cross-check of plant operational records and daily SCADA records for biogas) and that these days are comparable to the normal operating period as the volume of wastewater (Qww) and the amount of biogas produced (Qbiogas,produced) during the 53 days are consistent with the rest of the days in the monitoring period. It is proposed that the lowest FCH4,generator reading recorded (63.44%) during the normal operations of the factory be applied to the 53 days for which this deviation is proposed for.

The proposed deviation from the monitoring plan does not require a revision of the monitoring plan or changes from the project activity as described in the registered PDD as the deviation is only for a specific period in the second monitoring period and was due to a faulty monitoring equipment. The monitoring period covered by the second verification is from 01 April 2010 to 31 March 2011. It is confirmed that there are no permanent changes to the project activity as described in the registered PDD.

The impact of this deviation request for parameters as explained above is as follows:-
DNV has verified that the lowest FCH4,generator reading recorded (63.44%) during the normal operations of the factory is lower than the average of FCH4,generator recorded during the during the same period (74.55%).By applying the lowest FCH4,generator reading recorded (63.44%), the emission reduction is reduced by 3.17% compared to applying the average of 74.55%. In addition, and it has been confirmed during the site visit (via cross-check of plant operational records and daily SCADA records for biogas) and that the lowest methane content measurement for parameter “methane content in biogas to be flared (FCH4,flare)” for the same period of time (53 days for the deviation) is 64.08%. Hence, this deviation request is deemed reasonable.