Sustainable driveline gear lubricant compositions

Abstract

The invention provides methods of formulating a driveline lubricant with reduced carbon FP using circular lubricant concept, circular driveline lubricants, and methods of lubricating. In one embodiment, the invention provides a method of formulating a driveline lubricant with reduced carbon FP using circular lubricant concept formulation, comprising blending a re-refined base oil; and a polymeric thickener.

Description

240869WG01SUSTAINABLE DRIVELINE GEAR LUBRICANT COMPOSITIONSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority from U.S. Provisional Patent Application No. 63 / 735,602, filed December 18, 2024, the disclosures of which are incorporated herein by reference.FIELD OF THE INVENTION

[0002] The invention is directed to a gear lubricant composition having a reduced carbon footprint.BACKGROUND OF THE INVENTION

[0003] Low carbon footprint lubricants are essential for several reasons. Environmental Impact: Traditional lubricants, often derived from non-renewable fossil fuels, contribute significantly to pollution and greenhouse gas emissions. Low carbon footprint lubricants, typically made from renewable sources like vegetable oils, help reduce these emissions and are more biodegradable, minimizing soil and water contamination. Regulatory Compliance: As environmental regulations become stricter worldwide, industries are under increasing pressure to reduce their carbon footprints. Using eco-friendly lubricants helps companies stay compliant with these regulations, avoiding potential fines and legal issues. Improved Workplace Safety: Eco-friendly lubricants are generally less toxic and pose fewer health risks to workers. This not only enhances safety but also reduces the need for extensive safety measures and protective equipment. Extended Equipment Life: Sustainable lubricants often have superior lubrication properties, reducing friction and wear on machinery. This leads to longer equipment lifespans and lower maintenance costs. Energy Efficiency: Some low carbon footprint lubricants are designed to improve energy efficiency, which can result in significant cost savings over time.

[0004] By adopting low carbon footprint lubricants, industries can play a crucial role in mitigating climate change while also benefiting from improved operational efficiency and compliance with environmental standards. The use of recycled lubricant compositions can greatly reduce the carbon footprint of a lubricant. Proving a sustainable gear lubricant composition which performs at demanding industry standards can be a challenge in terms of lubricating performance. In addition, there have been recent increases in electric vehicle adoption, creating a growing demand for e-fluids having a low carbon footprint. Circular driveline fluids generally involves240869WG01 steps of 1) collecting used oil, 2) analyzing used oil, 3) dehydrating the used oil, 4) light end recovery, 5) fuel stripping, 6) vacuum distillation, and 7) hydrotreating.

[0005] Widodo et al., Environmental Progress & Sustainable Energy Vol 37, No. 6, November / December 2018 reports on recent advances in waste lube oils processing technologies.

[0006] Kupareva et al., J. Chem Technol Biotechnol 2013, 88:1780-1793 provides a review of technology for rerefining used lube oils applied in Europe.

[0007] Separate and apart from the mere recycling of lubricant compositions, recycled lubricant composition must meet the demands for specific applications, advantageously being executed with a low carbon footprint relative to a refined petroleum based lubricant.

[0008] Drivetrain gear lubricant composition present specific lubrication challenges. OEM specifications for Group III based heavy duty transmission fluid requirements is a specification for transmission lubricants designed to meet the demanding requirements of heavy-duty transmissions. This specification ensures optimal performance, protection, and longevity of the transmission components.

[0009] Here are some key points about the specification. High Performance: lubricants are formulated to provide excellent protection against wear, corrosion, and oxidation, ensuring the transmission operates smoothly under various conditions. Extended Drain Intervals: These lubricants support extended drain intervals, reducing the frequency of oil changes and maintenance costs. Temperature Stability: They offer superior performance in both high and low temperatures, maintaining viscosity and protecting components in extreme conditions.

[0010] OEM specifications for Group III based heavy duty transmission fluid requirements lubricants were typically used in transmissions that required high performance and protection under severe service conditions. These included Manual Transmissions: Used in heavy-duty trucks and commercial vehicles; and Automated Mechanical Transmissions (AMTs): These are manual transmissions with automated gear shifting, often found in modern heavy-duty trucks.

[0011] The American Petroleum Institute (API) classifies base oils into five main groups based on their refining process and chemical composition. Group I: These are solvent-refined oils with a low level of saturates and a high level of sulfur. They have a viscosity index (VI) of 80- 120. Group II: These oils are hydrocracked, have a higher level of saturates, lower sulfur content, and a VI of 80-120. They are more refined than Group I oils. Group III: These are also hydrocracked oils but with a VI above 120. They are considered the highest quality of mineral oils. Group IV: These are synthetic oils known as polyalphaolefins (PAOs). They have240869W001 excellent performance characteristics and a high VI. Group V: This group includes all other base oils not included in Groups l-l V, such as esters and other synthetics.

[0012] Each group has unique properties that make them suitable for different applications. While PAO synthetic oils have excellent performance characteristics, they are typically from fossil sources and offers similar carbon FP (foot print) as other fossil sourced base oils.

[0013] The circular lubricant concept using re-refined (reclaimed) base oil can reduce the consumption of fossil resources and reduce carbon emission. It is important to demonstrate that re-refined base could be used to formulate a driveline gear lubricant with a high renewable content and low carbon footprint yet with adequate oxidative stability, low temperature properties satisfying particularly the stringent Eaton heavy duty transmission fluid requirements.

[0014] Accordingly, while the need to lubricate the drivetrains of modern society continues, efforts to achieve this result while reducing the impact on the global carbon footprint are ongoing.BRIEF SUMMARY OF THE INVENTION

[0015] In a first embodiment, the invention is to a method of formulating a driveline lubricant with reduced carbon FP using circular lubricant concept formulation, comprising: blending i) a re-refined base oil; and ii) a polymeric thickener.

[0016] According to another embodiment of the invention is a circular driveline fluid, comprising: i) a re-refined base oil; and ii) a polymeric thickener.

[0017] According to another embodiment of the invention is a method of lubricating a driveline gear system with a circular driveline fluid. Applicants have discovered that using re-refined Group II+ / III base oil GVT-130 from Safety-Kleen, together with a polymeric thickener such as BMBcert™ Glissopal polyisobutene Polymer as thickener and formulated SAE 75W-90 meets the OEM specifications for Group III based heavy duty transmission fluid requirements.

[0018] Advantages Provided by the Invention are as follows. Re-refined based oil GVT-130 from Safety-Kleen and BMBcert™ Glissopal polyisobutene Polymer was used to formulate SAE50 heavy duty transmission fluid with high renewable content and low carbon footprint. Safety-Kleen GVT-130 re-refined base oil was used which provides renewable content. BMBcert™ polymer is used to increase the renewable carbon content. Synative DPHA ester is used as co-solvent and seal swell agent. It could be replaced with another renewable ester to further reduce the carbon footprint of the formulation. Formulated product meets OEM240869WG01 specifications for Group III based heavy duty transmission fluid requirements with good low temperature properties and oxidative stability.DETAILED DESCRIPTION OF THE INVENTION

[0019] A circular driveline fluid process is disclosed where a collected oil is processed and formulated into a suitable driveline fluid.Re-refined base oil

[0020] Collected oil is typically analyzed for quality, dehydrated to remove water, followed by removal of lightweight chemicals by extraction. Heavier fuels are removed by stripping under heat and vacuum to extract middle weight oils, followed by vacuum distillation. The remaining oil is subject to reduction with hydrogen to remove sulfur, nitrogen, chlorine, heavy metals and other impurities. An example of a commercial oil collector / processor, in North America is Safety-Kleen, providing GVT-130 as Group II / II+ and Group III re-refined base oil.Polymer thickener

[0021] The re-refined based oil may not have a suitable viscosity such that a polymer thickener is added in an amount of 20-50 mass%, more preferably 30-40 mass% even more preferably about 33 mass%, mass% being based on a weight of said circular driveline lubricant.

[0022] In order to reduce the carbon footprint of the circular driveline fluid a polymer thickener prepared from a 100% renewable feedstock is preferably used. GLISSOPAL® BMBcert™ is a type of highly reactive polyisobutene (HR-PIB) produced by BASF. This product is derived from 100% renewable feedstock, contributing to sustainability by reducing greenhouse gas emissions and saving fossil resources.

[0023] The “BMBcert™” designation stands for “Biomass Balanced,” indicating that the product is part of BASF’s biomass balance approach. This method involves substituting fossil resources with renewable raw materials in the production process, significantly lowering the product’s carbon footprint while maintaining the same quality and performance as conventional products.

[0024] A high viscosity biorenewable PAO40 from Elevance (LanXess) WTP40 with reduced carbon FP, is no longer available in the market.Additives

[0025] The circular driveline fluid may further comprise known additives known to those of skill in the art of driveline fluids, such as additive packages to provide for thermal oxidation stability ,240869W001 seal comparability, extreme pressure coper corrosion protection and foam suppression (such as Hitec® from Afton, Anglamol® from Lubrizol), pour point depressant (Hitec® 5739 from Afton Chemicals, Irgaflo from BASF), a defoamer (Foam Ban ® from Munzing Chemie) and a butylated octylated diphenylamine liquid antioxidant (Irganox® from BASF Corp).Properties of finished lubricant from Re-Refined base oils

[0026] The combination of re-refined based oil and polymeric thickener provides for a driveline lubricant having a low carbon footprint and suitable properties such as meeting SAE 75W-90 performance.KV40 cSt 23.5Kv100, cSt 4.7VI 122Color number 0.5 Appearance bright and clear Pour Point °-18

[0027] Having generally described this invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only, and are not intended to be limiting unless otherwise specified.EXAMPLES

[0028] Heavy duty transmission fluids meeting OEM specifications for Group III based heavy duty transmission fluid requirements with more than 75 wt.% reclaimed content, was formulated using re-refined Group III base oil GVT-130 from Safety-Kleen and BMBcert™ Glissopal polyisobutene Polymer, and the new formulated oil has more than 78% CO2e reduction vs formulated from fresh Group III.Lab blend 22-023240869WG01Note:

[0029] #1 (22-023s1-1) and #2 (22-023s1-2) are formulated with re-refined Safety-Kleen GVT- 130 Group III base oil and BMBcert Glissopal Polyisobutylene and has very high renewable content, #3 (22-023s1-3) and #4 (22-023s1-4) are formulated with virgin Group III base oil and BMBcert Glissopal Polyisobutylene, all 4 candidates perform similarly in terms of oxidative stability, low temperature performance, and meet the requirement of OEM specifications for Group III based heavy duty transmission fluid requirements.

[0030] The circular driveline fluid had physical properties comparable to those of a driveline fluid prepared from fresh Group III base oil (such as from PetroCanada VHVI).

[0031] Numerous modifications and variations on the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

Claims

240869WG01CLAIMSWhat is claimed is:1 . A method of formulating a driveline lubricant with reduced carbon FP using circular lubricant concept formulation comprising: blending i) a re-refined base oil; and ii) a polymeric thickener.

2. The method according to claim 1 , wherein said re-refined base oil is a Group III base oil.

3. The method according to claim 1 , wherein said re-refined based oil is obtained by at least one of distillation and hydrotreating / hydrocracking; and continuous solvent extraction of a recycled used oil followed by distillation.

4. The method according to claim 1 , wherein said polymeric thickener is a biorenewable thickener.

5. The method according to claim 1 , wherein said polymeric thickener is BMB certified.

6. The method according to claim 1 , further comprising blending an additive package.

7. A circular driveline fluid comprising: i) a re-refined base oil; and ii) a polymeric thickener.

8. The circular driveline fluid according to claim 7, wherein said re-refined base oil is a Group III base oil.

9. The circular driveline fluid according to claim 7, wherein said re-refined based oil is obtained by at least one of240869W001 distillation and hydrotreating / hydrocracking; and continuous solvent extraction of a recycled used oil followed by distillation10. The circular driveline fluid according to claim 7, said polymeric thickener is a biorenewable thickener.

11. The circular driveline fluid according to claim 7, wherein said polymeric thickener is BMB certified.

12. The circular driveline fluid according to claim 7, further comprising an additive package.

13. A method of lubricating a driveline gear system comprising: operating a driveline gear system with the circular driveline fluid according to claim 7.

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