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EP-4737541-A1 - LUBRICATING FLUID FOR INTERNAL COMBUSTION ENGINES FUELED WITH ALTERNATIVE COMBUSTION FUELS HAVING HIGH AUTO-IGNITION TEMPERATURES

EP4737541A1EP 4737541 A1EP4737541 A1EP 4737541A1EP-4737541-A1

Abstract

A lubricating oil composition configured for lubricating an internal combustion engine fueled with an alternative fuel having an auto-ignition temperature greater than about 700K. The lubricating oil composition includes at least a detergent system including at least one overbased metal-containing sulfonate detergent, optionally at least one neutral to low-based metal containing sulfonate detergent, and where the metal provided from the overbased sulfonate detergent is balanced relative to the total detergent metal and/or the composition total base number.

Inventors

  • CAIN, NATHANIEL
  • LOOSMORE, Tara
  • BROWN, Alisdair
  • MYERS, DOMINIC
  • GUPTA, ASHUTOSH

Assignees

  • Afton Chemical Corporation

Dates

Publication Date
20260506
Application Date
20251009

Claims (15)

  1. A lubricating oil composition configured for lubricating an internal combustion engine, the lubricating oil composition comprising: one or more base oils of lubricating viscosity; a detergent system including (i) at least one overbased metal-containing sulfonate detergent providing about 2 to about 12 mmol of metal to the composition; (ii) optionally, at least one neutral to low-based metal containing sulfonate detergent providing at least about 0.02 mmol of metal to the composition; wherein the lubricating oil composition has a total base number (TBN), measured pursuant to ASTM D2896, of at least about 9.5; and wherein a ratio of the percent metal provided from the overbased metal-containing sulfonate detergent relative to the TBN of the lubricating oil composition (ASTM D2896) is about 0.07 or less.
  2. The lubricating oil composition of claim 1 wherein the internal combustion engine is fueled with a fuel having an auto-ignition temperature greater than about 700K, preferably greater than about 800K, more preferably greater than about 850K.
  3. The lubricating oil composition of claim 1 or 2, wherein the detergent system further comprises at least one overbased metal-containing phenate detergent providing up to about 4 mmol of metal to the composition.
  4. The lubricating oil composition of any one of claims 1 to 3, wherein the detergent system provides only calcium, only magnesium, or blends of calcium and magnesium.
  5. The lubricating oil composition of any one of claims 1 to 4, wherein the TBN of the lubricating oil composition is about 10 to about 15 as measured pursuant to ASTM D2896.
  6. The lubricating oil composition of any one of claims 1 to 5, wherein the lubricating oil composition has greater than 0.9 weight percent, preferably greater than 1.2 weight percent, of sulfated ash (SASH) content as measured pursuant to ASTM D874.
  7. The lubricating oil composition of any one of claims 1 to 6, characterized by one or more of the following (i) to (iv): (i) wherein the detergent system provides about 1000 to about 5000 ppm of metal selected from calcium, magnesium, or combinations thereof; (ii) wherein the detergent system provides about 1500 to about 3000 ppm of magnesium; (iii) wherein the composition further includes one or more oil-soluble molybdenum compounds providing about 200 ppm or less of molybdenum; (iv) wherein the detergent system includes at least an overbased magnesium-containing sulfonate detergent having a TBN of at least about 200 (ASTM D2896).
  8. The lubricating oil composition of any one of claims 1 to 7, wherein the one or more base oils of lubricating viscosity include API Group I base oils, API Group II base oils, or combinations thereof.
  9. The lubricating oil composition of any one of claims 1 to 8, wherein the lubricating oil composition has an average measured stochastic pre-ignition (SPI) of about 6 SPI counts or less at 1000 rpm and 12 bar brake mean effective pressure (BMEP).
  10. The lubricating oil composition of any one of claims 2 to 9, wherein the fuel having an auto-ignition temperature greater than about 700K is hydrogen fuel.
  11. A method of lubricating an internal combustion engine when fueled with a fuel having an auto-ignition temperature greater than about 700K to mitigate abnormal combustion events, the method comprising: lubricating a crankcase of an internal combustion engine with a lubricating oil composition according to any one of claims 1 to 10 and combusting a fuel having an auto-ignition temperature greater than about 700K in the internal combustion engine.
  12. An internal combustion engine configured for combustion of hydrogen fuel, the internal combustion engine comprising: an engine crankcase lubricated with a lubricating oil composition according to any one of claims 1 to 10; and hydrogen fuel.
  13. A use of the lubricating composition according to any one of claims 1 to 10 for lubricating an internal combustion engine fueled with a fuel having an auto-ignition temperature greater than about 700K.
  14. The use according to claim 13 wherein the fuel has an auto-ignition temperature greater than about 750K, preferably greater than about 800K, more preferably greater than about 850K, or wherein the fuel is hydrogen.
  15. The use according to claim 13 or 14 for reducing or minimizing stochastic pre-ignition (SPI) and/or for achieving an average measured stochastic pre-ignition (SPI) of about 6 SPI counts or less at 1000 rpm and 12 bar brake mean effective pressure (BMEP).

Description

TECHNICAL FIELD The present disclosure relates to lubricating fluids for internal combustion engines fueled with alternative combustion fuels having high auto-ignition temperatures and methods of lubricating an internal combustion engine using the lubricating fluids when fueled with such alternative combustion fuels. The invention also relates to an internal combustion engine configured for combustion of hydrogen fuel, the internal combustion engine comprising hydrogen fuel and an engine crankcase lubricated with a lubricating oil composition according to the invention, and to the use of the lubricating composition of the invention for lubricating an internal combustion engine fueled with a fuel having a high auto-ignition temperature. BACKGROUND Many engine and vehicle manufacturers are exploring the use of alternative combustion fuels, such as those having high auto-ignition temperatures of about 700K or greater, as an alternative to gasoline or diesel fuels. Such alternative fuels include at least hydrogen fuel, compressed natural gas (CNG), and/or liquid natural gas (LNG). Hydrogen-fueled engines or natural-gas fueled engines have several advantages. For example, existing internal combustion engines can generally be operated using such fuels with little to no modification, which simplifies the implementation due to the ability to utilize a robust and durable engine platform that has a long history and is well understood One challenge in the context of hydrogen-fueled or natural gas-fueled engines, however, is a problem called stochastic pre-ignition (SPI), which tends to be a limiting factor in developing the hydrogen-fueled or natural-gas fueled internal combustion engine for widespread use. SPI in hydrogen-fueled or natural gas-fueled engines is a premature ignition event of the main fuel charge leading to early detonation, misfiring, and/or knock. It is similar to low speed pre-ignition (LSPI) often found in certain turbocharged direct-injection engine gasoline engines, but unfortunately, known solutions to improve LSPI in traditional gasoline-fueled engines do not necessarily translate to improved SPI in hydrogen-fueled or natural gas-fueled engines. SUMMARY In one embodiment, a lubricating oil composition configured for lubricating an internal combustion engine fueled with a fuel having an auto-ignition temperature greater than about 700K is described herein. In embodiments, the lubricating oil composition is effective to reduce or minimize stochastic pre-ignition (SPI). The lubricating oil composition includes one or more base oils of lubricating viscosity; a detergent system including (i) at least one overbased metal-containing sulfonate detergent providing about 2 to about 12 mmol of metal to the composition; (ii) optionally, at least one neutral to low-based metal containing sulfonate detergent providing at least about 0.02 mmol of metal to the composition; and wherein the lubricating oil composition has a total base number (TBN), measured pursuant to ASTM D2896, of at least about 9.5; and wherein a ratio of the percent metal provided from the overbased metal-containing sulfonate detergent relative to the TBN of the lubricating oil composition (ASTM D2896) is about 0.07 or less (or about 0.06 or less). In other approaches or embodiments, the lubricating oil composition described in the previous paragraph includes other features or embodiments in any combination. These other features or embodiments include one or more of the following: wherein the lubricating oil composition further includes at least one overbased metal-containing phenate detergent providing up to about 4 mmol of metal to the composition; wherein the detergent system provides only calcium metal, only magnesium metal, or (in other embodiments) blends of calcium and magnesium; and/or wherein the lubricating oil composition is substantially free of phenate-containing detergents (e.g., less than 0.01 mmol of metal from phenate-containing detergents); and/or wherein the TBN of the lubricating oil composition is about 10 to about 15 as measured pursuant to ASTM D2896; and/or wherein the lubricating oil composition has greater than 0.9 weight percent of sulfated ash (SASH) content as measured pursuant to ASTM D874; and/or wherein the lubricating oil composition has greater than 1.2 weight percent of sulfated ash (SASH) content as measured pursuant to ASTM D874; and/or wherein the detergent system provides about 1000 to about 5000 ppm of metal selected from calcium, magnesium, or combinations thereof (preferably calcium); and/or wherein the detergent system provides about 1500 to about 3000 ppm of magnesium; and/or wherein the composition further includes one or more oil-soluble molybdenum compounds providing about 200 ppm or less of molybdenum; and/or wherein the detergent system includes at least an overbased magnesium-containing sulfonate detergent having a TBN of at least about 200 (ASTM D2896); and/or wherein the one or more base o