A NEXT GENERATION LANDFILL AND BIOGAS LUBRICANT FOR TODAY S DEMANDING HIGH BMEP ENGINES John Palazzotto Chevron Oronite Company, LLC
Landfill Gas Basics LFG is Dynamic! n Methane as GHG is over 20 X more potent by weight than CO 2 n Landfills: 2 nd largest human-made source of methane in the U.S. (~23%) n Purifying LFG into pipeline quality natural gas is extremely expensive! n Gas quality is inconsistent and ever changing n Lower energy content fuel (typical CH 4 ~920 BTU, LFG ~ 450 550 BTU) n Each OEM has its unique specifications & concerns n Contains a variety of contaminants CH Primarily CH 4 (~50%) and CO 2 (~50%) 4 R-SiO H <1% non-methane organic compounds CFC 2 S CO Halogens 2 H 2 O H 2 S H 2 O vapor (saturated) Landfill Cell Trace gases can include Siloxanes Chloro-flouro-carbons (CFC s) Liner HCl, HF, H 2 SO 4 Combustion process creates unique and exotic acids To Engine Engine, Turbine, Boiler, Kiln, Etc. Concrete Cap Plastic Lining Gas Conditioners and Scrubbers Blower Filters Gas Supply Cap (Clay / Topsoil) Compacted Backfill LANDFILL Perforated PVC Pipe Washed Gravel Well Depth: 50-200 Feet or More Supply From Other Wells
Problem with Modern Engines n Engine power output has been raised approximately 50% for the same engine displacement n Increased engine BMEP has placed additional stress on the lubricant and reduced the Oil Drain Interval n Lubricant capacity has not increased with the demand for power out of the engine frame, essentially it has remained static n Since landfill gas contains contaminates the gas stream introduces additional ash to the combustion chamber n Increased combustion chamber deposits leads to tendency to detonate and more frequent maintenance cycle
Developmental Background n A landfill gas site s desire to: Achieve appropriate drain intervals in high BMEP engines, to better align with site specific maintenance intervals. Optimize Chemistry to reduce piston and combustion chamber deposits and generate an increased ODI n Phase 1 trial Used oil analysis program to compare test oil life versus current products Multiple oil drains in 3 engines supported a larger increase in oil life versus current products 20 + % n Phase 2 trial Full durability test with additional oil life testing Continued UOA to exhibit improved oil life performance n Expand testing to other engine models upon successful service additional engines at site, other OEM s, Biogas, etc.
Product Development Targets n LFG product development targets & formulating goals Improved oil drain interval (ODI); upgraded BN retention and low acid rise Low sulfated ash (SASH); less than 0.60 weight % Good piston cleanliness & deposit control; ring groove, piston lands & undercrown Protection against the corrosive effects of acids
Piston Comparison 3500 Low versus High BMEP 13.1 Bar 19.2 Bar
For Product Development, where do you start? n Set limits to conform to majority of OEM s specifications n Build test products to meet the targets set n Bench test formulations in specific screener tests that apply to aggressive fuels n Initiate oil life field testing in severe applications on promising candidates n Take promising candidate(s) to full durability field trials n Closely monitor UOA and engine conditions n Perform intermediate engine inspections n Remove components, evaluate at end of test period n Compile documents for OEM endorsement
Oil Physicals & Chemical Properties
Weight Percent Sulfated Ash 1.0 Lower Value = Reduced Oil Ash Contribution 0.9 Weight Percent Sulfated Ash ASTM D874 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 Oil A Oil B Oil C New LFG
Actual Test Engines
Actual Sample Gas Analysis Data CO 2 39% CH 4 51% N 2 8% O 2 1%
Typical Current LFG Lubricant Performance
Typical New LFG Lubricant Performance
Example of Piston Deposit Rating Comparison *ASTM Rating method
GE Jenbacher Type 420 LFG Piston New LFG Technology
GE Jenbacher Type 416 Biogas Piston New LFG Technology
Cummins QSV 91-18 LFG Piston New LFG Technology
Cylinder Head Replacement Interval Commercial Oil Start of Test Rebuild 1 st replacement 2,123 hrs 2 nd replacement 3,337 hrs 3 rd replacement 2,167 hrs 4 th replacement 2,001 hrs Average replacement 2,407 hours New LFG Start of Test Rebuild 1 st replacement 4,999 hrs 2 nd replacement 4,591 hrs Average replacement 4,795 hours New LFG required 50 % less cylinder head replacement over test duration!
Summary New LFG / Biogas Technology n Higher BMEP gas engines operating in landfill & biogas service place increased demand and requirements on lubricants n Numerous operators and locations experiencing reduced ODI as well as increased maintenance due to ash deposits and rapid BN depletion n Lubricants need to be optimized for the specific service, especially in today s demanding environment for improved performance characteristics n New low sulfated ash additive technology oils need be to developed for severe landfill & biogas service which can provide the following lubricant attributes: Extended ODI over currently available lubricants on the market Sulfated ash content lubricant that can meet OEM specifications below elevated levels (0.60 wt.%) Provides superior piston deposit control Protects against corrosive wear
Acknowledgements & Thanks go to - Caterpillar, GE Jenbacher, & Cummins My colleagues at Chevron Oronite which include: Alan Beckman Clement Drouot Jeff Booth Marty Brown Rafael Castro Richard Blosseville