Engine Lubricants BHARGAVI. N 3
rd Year in Mechanical Engineering
1. Introduction Ø The automotive and heavy duty diesel industries are going through a period of rapid change: v More hardware changes in the pipeline than in last 50 years. Ø The lubricant industry is changing accordingly. Ø The purpose of this presentation is to discuss: v The key drivers behind this change. v Resulting challenges for the lubricant/additive industry. v How the lubricant/additive industry is responding to these challenges These factors are generally governed by following two factors: ü Industry Drivers and Consequences. ü Key Trends and Challenges in Lubricant Formulations.
2. Industry Drivers and Consequences In this factor of industry drivers and consequences the following factors plays a key role in rapid changing in lubricant requirement.
3. Key Trends and Challenges in Lubricant Formulations The key trends and challenges involved in lubricants selection follow the following steps: 1. Emissions 2. Extended Drain 3. Fuel Economy 4. Alternate Fuels
4. Emission Control Strategies Ø Approaches vary with OEMs but involve some combination of v Exhaust Gas Recirculation (EGR) – without or with external cooling. v Diesel Particulate Filter (DPF). v Selective Catalyst Reduction (SCR). v Caterpillar use proprietary ACERTTM system. Ø Different approaches lead to specific and fragmented lubricant needs Ø Nevertheless certain trends are common to most diesel engine lubricants: v Higher soot loading in the oil due to EGR. v Restrictions on SAPS (Sulphated Ash, Phosphorus and Sulphur) to protect after-treatment devices
4. (a) Restricted SAPS Environment Ø Sources of SAPS v Sulphated Ash – Metal detergents, ZDDP antiwear additives. v Phosphorus – ZDDP antiwear additives. v Sulphur – ZDDP, certain metal detergents, additive diluents, basestock. Ø Phosphorus – The industry is fully cognizant of the impact of "P" loading on catalyst in efficiency gasoline powered vehicles v Long term trend is to reduced ZDDP in the oil v Extent of reduction will be determined by engine durability v Significant reductions beyond current levels will require development of new phos-free anti-wear technologies Ø Sulphur – With "S" largely eliminated from diesel fuel in developed markets, and the widespread use of Group II and III basestocks, focus on sulphur content is now on the additive system.
4. (b) Role of Metal Detergents in SAPS Constrained Environment Ø Metal detergents are metallic salts of organic materials such as sulphonate, phenate and salicylate v Some also contain metallic carbonate core to impart basicity or acid neutralization capability to the oil. v Common metals are calcium and magnesium. Ø Detergents play an important role in providing essential piston cleanliness and acid neutralization capability v Correct choice can also play a role in reducing ash and sulphur.
4. (c) Detergent Comparison | Sulphonate | Phenate | Salicylate |
| Piston Cleanliness Top Bottom | NO YES | YES NO | YES NO |
| Rust Control | YES | NO | YES |
| Antioxidancy | NO | YES | YES |
| Sulphur-Free | NO | NO | YES |
v Specially tailored salicylates for crankcase lubricants can offer significant advantages, especially in extended drain and SAPS constrained applications.
4. (d) The Struggle to Reduce Ash: Calcium versus Magnesium v Existing magnesium detergents can play an important role in reducing ash content in the oil. v However, large step-change reductions in ash from the current levels will require development of non-metallic detergent and TBN systems.
5. Extended Drain Ø Extended drain oils have broad appeal to the lubricant industry v Optimum use of natural resources. v Cost of ownership - reduced downtime for fleet operators, reduced cost of disposal. v Marketing feature for OEMs. Ø Drain intervals are in part constrained by v Emission control systems – soot loading in EGR engines, DPF. v Concerns about engine durability. Ø Key enablers v High quality basestocks – Group III, conventional as well as very high VI Group III's (eg, from GTL). v Advanced additive technologies such as salicylate detergents, enhanced low S/P anti-wear and new antioxidant technologies. v Interestingly, viscosity modifiers also play key role – a fact generally not well understood in the industry.
6. Fuel Economy Ø Fuel efficiency has been an important consideration for the vehicle manufactures for quite some time. Ø Escalating fuel costs in recent times have further raised the profile of FE in the automotive as well as the heavy duty diesel engine industry. Ø Large share of the FE gains will accrue from innovations in hardware designs. Ø However, lubricants can also play an important role in minimizing energy losses in the engine and, indeed the entire drive train. Ø However, evolving engine designs pose new challenges: v Low Friction Engines. v Advanced Surface Treatment / Coatings. Ø Low viscosity lubricants are becoming an increasingly important element in the race for higher FE.
6. (a)Fuel Economy Retention Ø Lubricants have to deliver FE performance throughout their life in the engine, not just when they are fresh. Ø Formulation levers: v Durable friction modifiers. v Antiwear system. v Low volatility. v Antioxidants. v Dispersants – particularly for soot induced viscosity control in HD diesel engine oils. Ø Group III basestocks will play a major role in FE retention due to their: v low volatility. v superior antioxidant response. v high viscosity index.
7. Alternate Fuel Ø Use of biomass derived fuels to extend conventional fuels is gaining momentum: v Renewable energy source. v Security of energy supply. v Often price supported through government incentives. Ø Gasoline – Use of ethanol is growing, particularly in NA: v 10% ethanol has been used as oxygenate in gasoline for long time. v Recently E85 (85% ethanol) has been gathering momentum. v Some Brazil experience suggests that E85 will require oil formulators to address issues such as rust and emulsion. Ø Diesel – Issues are much bigger here compared to gasoline because of the wide chemical and physical variety of alternatives being proposed.
8. Conclusion Ø As the needs and expectations of the engine OEMs and the lubrication industry are changing, the additive industry is rapidly adapting to the changes around it. Ø Evolutionary approaches will continue to play a role in lubricant formulations of the future. Ø However, real step-out changes in the additive technologies are taking place to address the longer term needs of the industry. Ø Such changes will affect not just one or two classes of additives, they will affect almost every major type of additive component used in oil formulations. Ø To use the orchestra analogy – we are not just changing the string or the brass section, we are slowly but surely changing the entire orchestra! Ø These are challenging times for everyone in the value chain – OEMs, oil marketers and additive suppliers. Ø Passion for innovation and perseverance will be key assets in this environment.
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