INFLUENCE OF DIESEL BIOFUELS ON ENGINE OILS DETERIORATION – EXTENDED METHODS OF ENGINE OILS ASSESSMENT Zbigniew Stepien * Wieslawa Urzedowska Stanislaw Oleksiak OIL AND GAS INSTITUTE

Outline  INTRODUCTION  ASSUMPTIONS AND MATERIALS  OIL AGING TEST CYCLES  OIL ANALYSIS METHODOLOGY  RESULTS  SUMMARY

INTRODUCTION FAME (Biodiesel) advantages  advantages - renewability, - high lubricity, - high flashpoint, - low sulphur content and no aromatics, - good biodegradable property, - non-toxic, - relatively high cetane number, - lower particulate exhaust emissions and lower life cycle CO2 emissions than Diesel disadvantages  disadvantages reduced oil performance and durability

ASSUMPTIONS AND MATERIALS Test engines:  The first: Euro 2, 6–cylinder, turbocharged HD Diesel engine, displacement 6.87 l, maximum power 191 kW at 2300 rpm, maximum torque 1000 Nm in the range of 1350 – 1700 rpm  The second: Euro 4, high speed direct injection (HSDI), 4 – cylinder, turbocharged LD Diesel engine, displacement 2.0 l, maximum power 96 kW at 3800 rpm, maximum torque 330 Nm at 1800 rpm.

ASSUMPTIONS AND MATERIALS Fuels: Typical Polish commercial low sulfur (up to 0,001 % S) Diesel fuel meeting requirements of EN 590 standard and containing 3,5 % (V/V) FAME acc. to EN This fuel has been utilized to prepare three test Diesel biofuels containing 7%, (V/V) FAME - B7 20% (V/V) FAME - B20 30% (V/V) FAME - B30.

ASSUMPTIONS AND MATERIALS Engine oils: For HD Diesel 1. fully mineral lubricating oil SAE 15W-40 blended in API Group I base stock and fulfilled the requirements of ACEA A2-96/B2-98/E2-96; API CG-4/SJ; CCMC D4/PD-2/G4 standards. (identified as “OM”) 2. fully synthetic oil SAE 5W-40, blended in API Group IV (PAO) base stock, and fulfilled the requirements of ACEA E5/E4/E3; API CI-4 PLUS/CI-4/CH- 4/CG-4/CF/SL/SJ; JASO DH-1 standards. (identified as “OS”) For LD HSDI Diesel engine 1. mineral lubricating oil SAE 5W-30 blended in API Group II + base stock (from hydrocracking) and fulfilled the requirements of ACEA A-1/B-1; API SL; ILSAC GF- 3 standards. (identified as “OMH”) 2. synthetic oil SAE 5W-30, blended in mixed API Group IV (PAO) base stock (25%) and API Group III base stock (75%), and fulfilled the requirements of ACEA A-1/B-1 standards. (identified as “OSS”)

OIL AGING TEST CYCLES HD- and LD engine test cycles

OIL ANALYSIS METHODOLOGY Analysis:  kinematic viscosity, TBN, TAN, dispersion degree of degradation products, wear metals levels and fuel dilution level  oil soot content (DIN ),  high temperature dynamic viscosity (HTHS) CEC L  carbon residue (EN- ISO 10370)  FT-IR spectroscopy  thin film oxidation stability (modified version of ASTM D 4742)  resistance to oxidation stability of engine lubricating oils - ASTM D 7545 modification test of (PetroOXY)

RESULTS Kinematic viscosity changes of studied lubricating oils in HD engine

RESULTS Acid number changes of studied lubricating oils in HD engine

RESULTS Oxidation stability changes of studied lubricating oils in HD engine

RESULTS Oxidation stability in thin film changes of studied lubricating oils in HD engine

RESULTS Oxidation stability (by FT-IR analysis) changes of studied lubricating oils in HD engine

RESULTS Kinematic viscosity changes of studied lubricating oils in LD engine

RESULTS Acid number changes of studied lubricating oils in LD engine

RESULTS Oxidation stability changes of studied lubricating oils in LD engine

RESULTS Oxidation stability in thin film changes of studied lubricating oils in LD engine

RESULTS Oxidation stability (by FT-IR analysis) changes of studied lubricating oils in LD engine

SUMMARY CONCLUSIONS 1. Applied extended methods were found to be useful in more discerning and multidirectional assessment of engine oils performance change during engine simulating tests 2. Extended methods enabled for better discriminating of proceeds in engine oils degradation processes and indication of oil operating run time after which loss of oil performance potential is essential from point of view its further operating run 3. One of the key factor related to engine oil degradation is biodiesel oil dilution range and level of FAME included in biodiesel blends 4. The results obtained in our investigations indicates for kind of lubricating oil base stock and its improvement way as well type of engine and its service conditions as very important factors affected for a degree of engine oil performance depreciation 5. Reliable evaluation of FAME impact for modern engine oil accelerated aging require multidirectional assessment by using also non standard test methods about increased sensitivity and measuring accuracy 6. More and more complicated, not always beneficial interactions between modern engine oils and alternative fuels will be require developing a new test methods for dependable distinguishing of the stages of used oil degradation

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