BIODIESEL BASICS

WHAT IS BIODIESEL?

Biodiesel is the name of a clean burning alternative fuel, produced from domestic, renewable resources. It contains no petroleum diesel, but it can be blended at any level with petroleum diesel to create a biodiesel blend. Biodiesel can be used in compression-ignition (diesel) engines with little or no modifications. 

Technically, biodiesel is defined as mono-alkyl esters of long chain fatty acids derived from vegetable oils, animal fats, or cooking grease. These acids are known as FAME (Fatty Acid Methyl Ester).

HOW IS BIODIESEL MADE?

Biodiesel is made by transesterification. Oil or fat is collected and reacted with methyl alcohol using sodium hydroxide as a catalyst to form methyl ester. 

WHAT IS BIODIESEL MADE FROM?

Biodiesel is made from a variety of feedstocks including:

  • Vegetable
    • Soybean Methyl Ester (SME)
  • Rapeseed (canola) Methyl Ester (RME)
    • Palm Methyl Ester (PME)
  • Cottonseed
    • Sunflower
    • Peanut
  • Animal
    • Poultry
    • Fish
    • Lard
  • Yellow greases
    • Recycled cooking oil

WHAT ARE THE DIFFERENT GRADES OF BIODIESEL? 

Most biodiesel is a blend of FAME and petroleum based diesel fuel. For example, B2 is 2% FAME with 98% diesel fuel; B5 is 5% FAME with 95% diesel fuel; and, B20 is 20% FAME with 80% diesel fuel. 

WHAT IS THE ASTM STANDARD FOR B100 AND B20?

The ASTM standard for B100, 10% FAME, is 6751. The ASTM standard for B20-B6 is D7467. The standard for B5-B1 is the same as regular diesel fuel D975. There is no standard for B21-B99.

WHICH BIODIESEL BLEND SHOULD I USE?

Biodiesel blends higher than B20 should not be considered a direct replacement for diesel fuel. Most auto, engine, and fuel injection original equipment manufacturers (OEMs) in the US strongly discourage the use of blends over B20. Moreover, many of these same companies state that warranties may be voided if engine component failure can be directly attributable to the use of blends over B20. Most OEMs approve B2 or B5. All fuel injection equipment (FIE) manufacturers approve B5. Some OEMs approve B20. Consult your engine manufacturer for additional information.  

HOW MUCH DOES BIODIESEL COST?

Biodiesel costs approximately $1 per gallon more to produce than diesel fuel. Federal subsidies allow biodiesel to compete effectively against diesel fuel. 

WHAT ARE THE BENEFITS OF BIODIESEL?

Biodiesel has many benefits including:

  • Renewable energy source
  • Reduced dependence on foreign oil
  • Reduced exhaust emissions
  • Enhanced lubricity 
  • Enhanced cetane
  • Enhanced detergency

WHAT ARE THE DRAWBACKS OF BIODIESEL?

Biodiesel has many drawbacks including: 

  • Cost
    • Biodiesel is slightly more expensive than diesel fuel. 
  • Energy
    • Biodiesel contains slightly less energy than diesel fuel. 
  • Quality
    • Biodiesel varies in quality. Many suppliers are not BQ 9000 certified.*
    • Biodiesel often contains methanol. Methanol used over prolonged periods causes premature failure of wear-related fuel components. 
    • Biodiesel often contains water. Biodiesel is a hygroscopic, which means it has a tendency to absorb water from the air. This leads to fuel line plugging when temperatures reach 32F. Water also promotes the growth of bacteria and fungi causing slime and sludge leading to further fuel filter plugging.
  • Cold Weather Operability
    • Biodiesel tends to gel at higher temperatures than diesel fuel. This leads to fuel filter and fuel line plugging, especially during colder temperatures. 
  • Corrosive
    • Biodiesel is a corrosive fuel. This causes premature failure of metal components including fuel pumps and injectors. Of particular concern are yellow metals such as bronze, copper, lead, tin, and zinc which are susceptible to corrosion.
  • Shelf life
    • Biodiesel has a shorter shelf-life than diesel fuel and should be used within 6 months of manufacture.  A good rule of thumb is to use biodiesel within the first 2 months of being purchased.
  • Rubber Components
    • Biodiesel may cause elastomers and various seal materials to harden or swell prematurely leading to premature failure. Natural and butyl rubber are particularly susceptible to failure.  
  • Thermal Stability
    • Thermal and oxidative stability of biodiesel is inferior to diesel fuel.

*BQ 9000 is a voluntary accreditation program for biodiesel sponsored by the National Biodiesel Accreditation Program. The program helps suppliers improve fuel testing and reduce the chance of producing or distributing inadequate fuel.

WHICH E-ZOIL PRODUCTS IMPROVE BIODIESEL PERFORMANCE?

BIO-AID

BIO-POWER

D-GEL

BIO-BLAST

STORZALL

WHICH E-ZOIL PRODUCTS ARE RIGHT FOR ME?

Fuel Filter Plugging - BIO-AID, BIO-POWER, D-GEL

Fuel Gelling - BIO-POWER, D-GEL

Fuel Freezing - BIO-AID, D-GEL

Corrosion - BIO-AID, BIO-BLAST

Microbial Growth - BIO-AID, BIO-BLAST

Shelf Life - BIO-AID, STORZALL

CONCLUSION

Biodiesel offers both advantages and disadvantages. The key to deploying this fuel successfully is to source it from a reputable supplier, preferably one that is BQ 9000 certified. If necessary, request a Certificate of Analysis (COA) from the supplier for quality verification purposes. If biodiesel is being added to fuel tank that previously contained diesel fuel, make sure the tanks are cleaned prior to adding biodiesel. Finally, the use of additives will reduce or eliminate many common problems associated with using biodiesel.