Marine fuel compositions with reduced engine frictional losses
Marine gas oil compositions corresponding to fuels and/or fuel blending components are provided that can provide improved friction properties within an engine. Addition of lubricant base stock to a marine gas oil composition can reduce frictional losses within an engine during operation. The benefits in reduction of frictional losses can be observed based on the difference between the indicated mean effective pressure and the actual work delivered by an engine, where the difference corresponds to the frictional mean effective pressure.
1. A marine gas oil composition comprising 1.0 vol % to 25 vol % of a lubricant base stock, the lubricant base stock comprising a T5 distillation point of 350° C. or more, a kinematic viscosity at 100° C. of 3.0 cSt or more, and a viscosity index of 80 or more, the marine gas oil composition comprising a density at 15° C. of 0.81 g/cm 3 to 0.90 g/cm 3 , a calculated cetane index of 40 or more, and a kinematic viscosity at 40° C. of 2.0 cSt to 11.0 cSt.
2. The marine gas oil composition of claim 1 , wherein the marine gas oil composition comprises a D86 distillation curve that is monotonically increasing.
3. The marine gas oil composition of claim 1 , wherein the marine gas oil composition comprises a D86 distillation curve that does not include an inversion of greater than 1° C.
4. The marine gas oil composition of claim 1 , wherein 50 vol % or more of the lubricant base stock has a distillation point of 380° C. or more.
5. The marine gas oil composition of claim 1 , wherein the lubricant base stock comprises a hydroprocessed deasphalted oil.
6. The marine gas oil composition of claim 5 , wherein the lubricant base stock comprises 50 wt % or more naphthenes.
7. The marine gas oil composition of claim 1 , wherein the lubricant base stock comprises a kinematic viscosity at 100° C. of 3.0 cSt to 6.0 cSt; or wherein the lubricant base stock comprises a kinematic viscosity at 40° c of 14 cSt to 40 cSt; or a combination thereof.
8. The marine gas oil composition of claim 1 , wherein the marine gas oil comprises 1.0 vol % to 12 vol % of the lubricant base stock.
9. The marine gas oil composition of claim 8 , wherein the lubricant base stock comprises a kinematic viscosity at 100° C. of 6.5 cSt to 12 cSt, a kinematic viscosity at 40° C. of 32 cSt to 160 cSt, or a combination thereof.
10. The marine gas oil composition of claim 1 , wherein the marine gas oil comprises 1.0 vol % to 5.0 vol % of the lubricant base stock.
11. The marine gas oil composition of claim 10 , wherein the lubricant base stock comprises a kinematic viscosity at 100° C. of 14 cSt to 40 cSt, a kinematic viscosity at 40° C. of 115 cSt to 875 cSt, or a combination thereof.
12. The marine gas oil composition of claim 1 , wherein the lubricant base stock comprises a viscosity index of 80 to 120.
13. The marine gas oil composition of claim 1 , wherein the lubricant base stock comprises a viscosity index of greater than 120.
14. The marine gas oil composition of claim 1 , wherein the lubricant base stock comprises 1 wt % or less of aromatics.
15. The marine gas oil composition of claim 1 , wherein the marine gas oil composition is clear and bright according to Procedure 1 of ASTM D4176.
16. The marine gas oil composition of claim 1 , wherein the marine gas oil composition comprises a sulfur content of 1000 wppm or less.
17. A method for operating an engine, the method comprising operating the engine using a fuel comprising the marine gas oil composition of claim 1 .
18. The method of claim 17 , wherein the engine comprises a marine diesel engine.
19. The method of claim 17 , the method further comprising operating the engine at a load of 75% or more.
20. The method of claim 17 , the method further comprising operating the engine at a load of 30% or less.