Biodiesel types? B100 B99? RME, PME, FAME?

Question

Can someone tell me more about the various types of biodiesel, and which is for automobiles? Which is not the best for automobiles also? Any extra information on biodiesel is fine too. Also, estimates as to what is the average price (if buying in bulk, at least 250,000 gallons, but over the course of a year)?

Answer 1

B100, B99, B5 etc refers to the percentage blend of bio-diesel in the fuel- B5 is 5% Bio-diesel 95% Mineral diesel, B20 is 20% Bio-diesel 80% Mineral diesel, etc.

Bio-diesel is a fuel comprised of mono-alkyl esters of long-chain fatty acids, derived from vegetable oil or animal fats. During production the re-agent for the reaction to create bio-diesel is either Methanol or Ethanol.

The definitions largely associated with bio-diesel are as follows:

BTL- Bio-mass-to-liquid. This is bio-diesel created from oils sourced from Algae

CEE- Coconut Ethyl Ester. This is bio-diesel created from coconut oil using ethanol.

CME- Coconut Methyl Ester. This is bio-diesel created from coconut oil using methanol.

FAEE- Fatty-Acid Ethyl Ester. This is a broad term for bio-diesel using ethanol.

FAME- Fatty-Acid Methyl Ester. This is a broad term for bio-diesel using methanol.

POEE- Palm Oil Ethyl Ester. This is bio-diesel created from palm oil using ethanol.

POME- Palm Oil Methyl Ester. This is bio-diesel created from palm oil using methanol.

REE- Rapeseed Ethyl Ester. This is bio-diesel created from Rapeseed using ethanol.

RME- Rapeseed Methyl Ester. This is bio-diesel created from Rapeseed using methanol.

These definitions continue in a similar vein- SEE/SME refers to Soybean, TEE/TME is Tallow and UVOEE/UVOME is Used Vegetable Oil.

As far as use in vehicles is concerned, the key factors are Polyunsaturated Fat content and Saturated Fat content of the source oil/fats. Polyunsaturated Fat contribute to better cold-flow of the bio-diesel, and also polymerisation. Saturated Fat contribute towards stability, and also solidity. PME, for example, is a highly stable fuel, but is solid at low temperatures (20C and below) so is unsuitable in colder climates. Olive-Methyl Esters (from Olive Oil) on the other hand, have a much lower melting point (so will be liquid at temperatures as low as -10C) but polymerise rapidly, leading to greater levels of deposits which are difficult to clean from the engine and injectors.

The ideal source oil is Rapeseed, as it is a compromise on the various different qualities. It will run in any diesel engine at low temperatures, and won't clog fuel lines/injectors. Unfortunately, it is expensive, so many bio-diesel producers look to other sources for greater profit margins.

As far as a price is concerned, Bio-diesel generally hangs 20p/20c below the price of Mineral diesel.