1. Biodiesel: role of standard
Alternative Fuel
Biodiesel: role of standard
Caswell Hlongwane

2. WHAT IS BIODIESEL FUEL
Def: ASTM D 6751 Fuel comprised of mono-alkyl esters of long chain fatty acids derived from vegetables or animal fats, designated B100

3. NOTATION
Bxx: a blend of biodiesel with petroleum-based diesel fuel with xx representing volume percentage of biodiesel fuel

4. ALLOWED FEEDSTOCKS: vegetable oils
Soybean oil
Sunflower oil
Canola oil
Spent oil
Biofuels Industrial Strategy of the Republic of South Africa, Dec 2007

5. HOW IS BIODIESEL FUEL PRODUCED

6. HOW IS BIODIESEL PRODUCED
React three moles of vegetable oil with six moles methanol and one mole of potassium or sodium hydroxide
Boil the mixture whiles stirring for 3hrs
Wash biodiesel layer four times with water
Recover unused methanol by simple distillation
Purify biodiesel by vacuum distillation
Store over magnesium sulfate
Add antioxidants to improve oxidative stability of biodiesel

7. Regulated Specification
IS BIODIESEL PRODUCED FIT TO BE BLENDED WITH DIESEL FUEL
SANS 1935: 2004
Regulated Specification
Petroleum Products Act (120/1977):Regulations: petroleum products specification and standards, gazetted June 23, 2006

8. Six general observations Twenty six test methods
SANS 1935: requirements, total of 30
Six general observations
Twenty six test methods

9. Methods only specific to biodiesel fuel, 14
BIODESEL FUEL TEST METHODS
Methods only specific to biodiesel fuel, 14
Standard test method for each property
Type of test
Reasons why limits are set for each tested property

10. ESTER CONTENT
Specification defines minimum mass percentage of 96.5% FAME
Standard test method recommended by SANS 1935 is EN 14103
GC-FID test method

11. Why set minimum ester content for biodiesel
Proving illegal admixture with other substances when neat
In conjunction with EN 14078, one is able to determine tax allowance when blended with petroleum-based diesel fuel

12. FREE GLYCEROL
SANS 1935 stipulates maximum value of 0.02% mass fraction of free glycerol in biodiesel
Standard test method for determination of free glycerol is EN 14106
GC-FID test method

13. Why set a maximum limit for free glycerol in biodiesel fuel
Free glycerol separates from biodiesel during storage and in fuel tanks
Free glycerol attracts other polar compounds such as soaps, monoglycerides, etc., and causes damage to the fuel injection system
Free glycerol corrodes metals in the fuel system
Free glycerol is also know to clog the fuel filter

14. METHANOL CONTENT
SANS 1935 limits methanol content to a maximum of 0.20% by mass
Standard test method is EN 14110
GC-FID headspace test method

15. WHY LIMIT METHANOL IN BIODIESEL
Low flash point of methanol poses safety risk during:
Storage
Transportation

16. Iodine Number and Linolenic acid methyl ester
Iodine number is a measure of total unsaturation of biodiesel
SANS 1935 limits total iodine number to a maximum of 120 gI2/100g biodiesel using EN 14111, a titration method
SANS 1935 also limits linolenic acid methyl ester to a maximum 12 % by mass using EN 14103, GC-FID test method

17. Why Regulate the Degree of Unsaturation of FAME in Biodiesel
Fuels with high iodine number polymerize at high temps and form deposits on
Injector nozzles
Piston ring grooves
These polymers also reduce lubricity of FAME
Highly unsaturated FAMEs have low oxidation stability leading to degradation products that lead to poor engine operability

18. ACID VALUE
Measure of neutralization number of mineral acids and FFA in biodiesel
SANS 1935 limits acid value of biodiesel to a maximum of 0.50 mg/g biodiesel
Standard test method is EN 14104
Titration test method: KOH/EtOH, Phenolphthalein

19. ACID VALUE: why regulate
Corrosion within the engine
Deposits within the engine

20. PHOSPHORUS CONTENT
Phosphorus in biodiesel comes from phospholipids contained in the feedstock

21. PHOSPHORUS CONTENT IN BIODIESEL
SANS 1935 limits phosphorus in biodiesel fuel to a maximum of 10 ppm
The standard test method recommended is EN 14107
ICP-OES

22. PHOSPHORUS IN BIODIESEL: why regulate
Phosphorus decreases efficiency of oxidation catalytic converters
Increased emission of particulate matter

23. Alkali metals end up in biodiesel during production
Biodiesel Alkali & Alkali Earth Metal Content
Alkali metals end up in biodiesel during production
Alkali earth metals mostly originate from use of hard water during washing stage
SANS 1935 limits alkali and alkali earth metals to a sum maximum of 5 ppm, respectively
ICP-OES

24. Na and K form ash in the engine
Why Limit Amounts of Group I and II Metals
Na and K form ash in the engine
Ca and Mg are responsible for getting the injector pump sticky

25. Problems that may arise with the use biodiesel fuel that does not meet SANS 1935
Tax evasion
Damage to the fuel injection system
Corrosion of metals in the fuel system
Clogging of fuel filter
Safety risks during storage and transportation
Sticky injector pump
Deposits on injector nozzles and piston ring grooves
Poisoned oxidation catalytic convertor
Increased emission of particulate matter
Ash formation in the engine

26. SUMMARY: why do we need biodiesel fuel standard
Guideline for production process
Guarantee users a quality fuel
Approved tool for assessment of safety risks and environmental pollution
Offer engine and automobile manufactures assurances to release warranties for their vehicles to be operated on specific fuels

27. References
Biodiesel: the comprehensive handbook, Martin Mittelbach and Claudia Remschmidt, 2004
Petrol and Diesel in South Africa, SAPIA, 2008
Significance of tests for petroleum products, Ed 7, Salvatore J Rand, 2003
The biodiesel handbook, Gehard Knothe, Jon van Gerpen, and Jurgen Krahl, 2005
SANS 1935:2004, Ed 1, Automotive biodiesel fuel, Standards South Africa
Biofuels industrial strategy of the republic of South Africa, Department of Minerals and Energy, 2007
Petroleum Products Act (120/1977):Regulations: petroleum products specification and standards, gazetted June 23, 2006

28. The End
Thank you