New gas turbines should be of low-NOx type to achieve an emission level of 25 ppmv (dry offgas, 15 % O2) or better. Steam or water injection to achieve a similar level may be considered when this technology is proven for offshore off shore application. The reasons for not achieving a low NOx emission level shall be clearly documented.
5.4
NOx control on engines Functional requirement
Conclusions/references
For larger engines (> 1 MW) that will normally be in operation (not stand-by or emergency use), NOx-reducing measures should be considered, such as • • • •
selection of engine make with a low NOx emission rate, use of gas fuel when possible, use of water emulsion in the diesel, selective catalytic reduction or similar.
5.5
Flaring Functional requirement
Conclusions/references
The process system shall be designed to minimize flaring. This should include, but not be limited to, consideration of the following measures: • • • • •
recycling of gas from high pressure relief relief systems systems during normal operation; recycling of low pressure relief relief systems systems during normal operation (subject to cost-benefit evaluation); process design design that minimizes risk of tripping tripping o off compressors etc.; control and condition monitoring systems to reduce the number of trips; planning of start-up activities to reduce flaring.
5.6
Oil storage and loading Functional requirement
Conclusions/references
FPSO, floating storage units ,shuttle tankers, offshore and onshore loading systems shall be designed to minimize emissions of methane and NMVOC. The following measures should be considered, but not be limited to • • • • •
sequential loading/unloading of oil, optimized geometry of tanks with respect to evaporation of hydrocarbons, loading/discharge rate with respect to evaporation, use of hydrocarbon gas as blanket gas in floating floating storage tanks, with recovery, installation of a VOC VOC recovery plant to return NMVOC to crude oil,
