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 Petroleum

� Biodiesel (FAME) DIFFERENT (to petroleum)� Chemistry is fundamentally different, so properties,

performance & durability differences follow

� So, risk for vehicles and vehicle technology of today� Biodiesel supply limited and growing slowly

� so vehicles are designed for conventional� modified or passed for biofuels with restrictions

� Biodiesel standards are driven towards conventional diesel standards, ie. Performance� Coming from older standards base as vegetable oils

� Requires specific standards for � Biodiesel – feedstock & process dependent� BlendsAND ADDITIVES CAN ADDRESS

�Definition: � “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 performance�Refinery Specification Additives�Anti-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

� Changing fuel parameters can cause unforeseen wear, deposit or combustion problems with corresponding impacts on engine performance and emissions

� Fuel additives can selectively restore specific performance characteristics of the fuel

� Test 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) failures

� rapid introduction of lubricity additives provided the solution….classic example of a reactive approach

� lubricity 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

Additives: Effect & Need

Biodiesel performance issues�Low 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 – ADDRESS�Engine 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

Additives: Biodiesel Issues

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 biodiesel

� low erucic acid RME starts to gel at -10 °C

� biodiesel 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 Additives for Biodiesel

Coldflow : RME with different diesels

Coldflow : RME vs SME blends

Coldflow Additives Effect: B100

Coldflow Additives : Treat rate

Coldflow Additives Effect

� unsaturated fatty acid (feedstock dependent)

� loss of hydrogen >>> free radical

� free radical >>> fatty acid peroxide radical

� fatty acid peroxide >>> hydroperoxide

� hydroperoxide >>> 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 Oxidation

oxidation 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

Stability and Oxidation

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

Ref: JAMA

Tests

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

Anti-oxidant additives effective

Ref: JAMA

Tests

Anti-oxidant additives effective

Ref: JAMA

Tests

ASTM Working Group� Significant 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 petrodiesel

� Control 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

Oxidation Standard Development

Detergency of Biodiesel

� Biodiesel presents challenges for the automotive industry

� A need to define performance standards that ensure acceptable quality and operation of bio-fuels in the market place

� Fuel 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 use� Rest 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.

Summary

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