Biodiesel quality adjustments by additives and anti-oxidants

APEC Biodiesel Standard

Raoul Goosenraoulg@wol.co.za

In co-operation with HART ENERGY CONSULTINGwww.hartenergyconsulting.com

25 October 2007

Biodiesel vs PetroleumBiodiesel (FAME) DIFFERENT (to petroleum)

Chemistry is fundamentally different, so properties, performance & durability differences follow

So, risk for vehicles and vehicle technology of todayBiodiesel supply limited and growing slowly

so vehicles are designed for conventionalmodified or passed for biofuels with restrictions

Biodiesel standards are driven towards conventional diesel standards, ie. Performance

Coming from older standards base as vegetable oilsRequires specific standards for

Biodiesel – feedstock & process dependentBlends

AND ADDITIVES CAN ADDRESS

AdditivesDefinition:

“Agents that are added to fuels in a concentration of < 1%

Substances present in higher concentration, the term "fuel components" is more appropriate.”

Fuel additive categories:Multifunctional Diesel - market performanceRefinery Specification AdditivesAnti-Oxidant and Stability Control Additives

Additives may be designed for petroleum based fuels or increasingly are specifically modified for use with Bio-Fuel components

Additives: Effect & NeedChanging fuel parameters can cause unforeseen wear, deposit or combustion problems with corresponding impacts on engine performance and emissionsFuel additives can selectively restore specific performance characteristics of the fuelTest methods & standards can be established that correlate to long-term performance given sufficient time and data

Environmental concerns led to the introduction of Ultra Low Sulphur City Diesel in Sweden in 1991 and a subsequent rapid increase of fuel injection equipment (FIE) failuresrapid introduction of lubricity additives provided the solution….classic example of a reactive approachlubricity additive experience in Europe and correlation exercises with fuel pump wear have shown the HFRR test with a 460µm WSD to be a reliable and appropriate level to protect current fuel injection systems and on which to develop future systems

Biodiesel performance issuesAdditives: Biodiesel IssuesLow temperature operability – DIFFICULT TO ADDRESS

Elastomer compatability – NOT GENERALLY ADRESSED BY ADDITIVES

FIE (Fuel Injector Equipment) component compatability – METAL DEACTIVATORS & STABILITY

Deposit formation & storage stability – ADDRESSEngine oil dilution- NOT GENERALLY ADRESSED BY ADDITIVES

Exhaust (tailpipe) emissions – NO HARM

Lubricity – NOT NEEDED

Conductivity – ONLY FOR BLENDS

Cetane Number – MAYBE ONLY FOR BLENDS

Foaming – ONLY FOR BLENDS

Coldflow Additives for Biodiesel

The temperature at which pure (B100) biodiesel starts to gel varies significantly depending on the mix of esters and therefore the feedstock oil used to produce the biodiesellow erucic acid RME starts to gel at -10 °Cbiodiesel from tallow gels at +16 °C

There are a very limited number of products that will significantly lower the gel point of B100 biodiesel, particularly for high molecular mass biodiesels

Coldflow : RME with different diesels

Coldflow : RME vs SME blends

Coldflow Additives Effect: B100

Coldflow Additives : Treat rate

Coldflow Additives Effect

Stability and Oxidation

unsaturated fatty acid (feedstock dependent)loss of hydrogen >>> free radicalfree radical >>> fatty acid peroxide radicalfatty acid peroxide >>> hydroperoxidehydroperoxide >>> aldehydes, ketones

this process can be halted by an antioxidant converting the original free radical back to the fatty acid by donating hydrogen

Stability and Oxidationoxidation will be catalysed by trace metals

metal deactivator prevents this

Different fatty acid chemistries may respond better to different AO chemistries

formulated AO including mixed chemistries give a wider spectrum of protection

Anti-oxidants effective: Differences

Stability and Oxidation

Test Fuel: Commercial diesel fuel blended the FAME meets EN14214 by 5vol%

Test Fuel: Same FAME above with 400ppm of anti-oxidant (20ppm as B5)

Anti-oxidant additives effective

2nd Japan/Korea Petroleum Technology Seminar, October 24, 2006 in SEOUL, KOREA

Ref: JAMA

Tests

Anti-oxidant additives effective

Ref: JAMA

Tests

Anti-oxidant additives effective

Ref: JAMA

Tests

Oxidation Standard Development

ASTM Working GroupSignificant additional work is planned Test method precision and comparison

Rancimat and D 2274 Ability of each method to predict benefits of anti-oxidants in reducing sediments and deposits

Comparison of bench scale results to actual field operations with B20 and lower blends Determination if control of B100 stability is sufficient for all blend levels with all petrodieselControl at the B100 level is preferred

Anti Anti-oxidants are most easily added to B100 Blending is done at terminal

Monitor acid number as surrogate for stability

Detergency of Biodiesel

Summary

Biodiesel presents challenges for the automotive industryA need to define performance standards that ensure acceptable quality and operation of bio-fuels in the market placeFuel additives provide the only solutions for some performance issues that are faced by bio-fuels

Anti- oxidants for stability (rather than Iodine Number)Cold flow improvers for low temperature useRest are occasional or specific market use of additives

Standards need to be developed based on performance criteria to ensure that the full benefits of fuel additives are realised.

THANK YOU APEC Biodiesel Standard

Raoul Goosenraoulg@wol.co.za

In co-operation with HART ENERGY CONSULTINGwww.hartenergyconsulting.com

25 October 2007

Biodiesel additive development opportunities

APEC Biodiesel Standard

Raoul Goosenraoulg@wol.co.za

In co-operation with HART ENERGY CONSULTINGwww.hartenergyconsulting.com

25 October 2007