Impact of 50% Synthesized Iso-Paraffins (SIP) on Middle Distillate Fuel Filtration and Coalescence

Abstract : In October 2009, Secretary of the Navy Ray Mabus directed the Navy to decrease its reliance on fossil fuels. The objective of this test program is to ensure that all proposed alternative fuels perform equally or better than existing petroleum sourced fuels. An alternative sourced fuel currently under-going qualification testing is Synthesized Iso-Paraffins (SIP). The Navy procured SIP that was 98% pure branched paraffin with a fifteen carbon chain called 2,6,10 trimethyldodecane or farnesane. Qualification of F-76/SIP fuel blends is currently being conducted in accordance with Navy SWP44FL-005: Naval Fuels & Lubricants CFT Shipboard Qualification Protocol for Alternative Fuel/Fuel Sources. The single-element test (SET) is a SWP44FL-005 required full scale fuel system test whose purpose is to evaluate the compatibility of alternative sourced fuels with filter/separator systems currently in use by the fleet. The SET evaluates the ability of filter/separators to remove solid contaminant levels of 72 mg/gal and free water levels as high as 3%. Additionally, the differential pressure across the filter separator is measured to ensure no negative structural impacts. A 50%/50% F-76/SIP blend was found to have no negative impacts on filter/separator performance. No effluent sample exceeded the effluent free water or sediment concentration limits. It is recommended that F-76 (derived from conventional material sources) and SIP fuel blends up to 50% SIP be approved for use with EI 1581 5th edition Category M and MIL-PRF-32148 qualified filter separators.