The different types of biodiesel are primarily defined by their blend concentration with petroleum diesel fuel.
Introduction to Biodiesel
Biodiesel is a renewable, biodegradable fuel manufactured domestically from vegetable oils, animal fats, or recycled restaurant grease. It is a cleaner-burning alternative to petroleum diesel fuel.
Biodiesel Blends: The Common Types
While pure biodiesel (B100) is a distinct fuel, it is most commonly used in blended forms. These blends, indicating the percentage of biodiesel mixed with petroleum diesel, are often referred to as different "types" or concentrations available for use, particularly in transportation.
The percentage of biodiesel in a blend is indicated by a "B" number. For example, B20 means the fuel is 20% biodiesel and 80% petroleum diesel.
Common Biodiesel Blend Types
Here are the most common biodiesel blends as defined by their percentage of biodiesel content:
| Blend Name | Percentage of Biodiesel | Typical Use |
|---|---|---|
| B5 | Up to 5% | Common transportation fuel |
| B20 | 6% to 20% | Common transportation fuel |
| B100 | 100% (Pure Biodiesel) | Primarily used as blendstock |
- B5: This blend contains up to 5% biodiesel and 95% petroleum diesel. It is widely used and requires little to no modification to existing diesel engines.
- B20: Consisting of 6% to 20% biodiesel and 80% to 94% petroleum diesel, B20 is a common blend used in fleets (like buses and trucks) and increasingly in retail pumps. Many vehicle manufacturers support the use of B20.
- B100: This is pure, unblended biodiesel. According to references, B100 (pure biodiesel) is typically used as a blendstock to produce lower percentage blends like B5 and B20. It is rarely used as a transportation fuel directly due to potential performance issues in some engines, especially in cold weather, and compatibility concerns with certain fuel system components.
Why Different Blends?
Using different blends allows for flexibility based on factors like:
- Engine compatibility and warranty requirements
- Climate conditions (lower blends perform better in cold weather)
- Cost and availability
- Environmental goals (higher blends reduce emissions)
Choosing the appropriate biodiesel blend is important for optimal engine performance and longevity.
