B20, Transesterification, FAME — Here’s Your Biodiesel Dictionary


Like any industry, biodiesel has its own jargon that can be confusing to a newcomer. Don’t let this be a barrier to learning more about how biodiesel could benefit your operation with its lower emissions, strong performance and competitive price. Here are definitions of common terms in the biodiesel industry.

The Fuels

Biodiesel — A cleaner-burning alternative to petroleum diesel that is made from renewable resources that would otherwise have no further use, including recycled cooking oil, waste animal fats and vegetable oils.

Renewable diesel — A renewable fuel that is chemically similar to petroleum diesel but with much lower emissions. It is made from the same feedstocks as biodiesel but has a different production process and meets a different specification.

Advanced biofuel — Fuels made from advanced feedstocks like vegetable oil and recycled cooking oil that reduce lifecycle greenhouse gas emissions by 50% or more. Biodiesel and renewable diesel are advanced biofuels.

The Production Process

Feedstock — The raw material used to create fuel. For biodiesel and renewable diesel, these are renewable resources such as recycled cooking oil, vegetable oils and waste animal fats.

Transesterification — A chemical process in which feedstock is reacted with an alcohol (typically methanol) to make biodiesel.

Fatty acid methyl esters — The chemical name for biodiesel, often abbreviated as FAME. A FAME molecule is comprised of a fatty acid and an alcohol.

Distillation — The process of purifying a liquid using evaporation and condensation. Distillation is one of the ways biodiesel is purified, and distilled biodiesel has several benefits, including superior cold weather performance.

Feedstock flexibility — The ability to produce high-quality biodiesel from a variety of feedstocks. This is something only the most skilled producers can do, and the benefits to customers include capturing each feedstock’s best properties, more predictable pricing and a more environmentally friendly fuel.

The Blends

B5, B10, B20 — A fuel that is a blend of biodiesel and petroleum diesel is commonly abbreviated to a “B” and then the percentage of biodiesel in that fuel. B20, for example, is 20 percent biodiesel and 80 percent petroleum.

Neat biodiesel — Biodiesel that has not been blended with another fuel. It is 100 percent biodiesel and is also called B100.

The Specifications

ASTM — The organization that sets international standards for a variety of materials. The specification for biodiesel is ASTM D6751. Renewable diesel falls under ASTM D975, the diesel specification.

Cloud Point — The temperature at which wax crystals cause fuel to appear cloudy. The higher the Cloud Point, the sooner the fuel starts to gel. It is one way to measure cold weather performance.

Cetane number — A measure of a fuel’s combustion speed and a common indicator of fuel quality. The higher the Cetane number, the shorter the ignition time. Biodiesel and renewable diesel have a higher Cetane number than petroleum diesel.

Lubricity —The ability of a lubricant to reduce friction and prevent wear in an engine. Ultra-low sulfur diesel has very little lubricity, whereas biodiesel has great lubricating characteristics.

The Emissions

Greenhouse gases — Gases, such as carbon dioxide, that trap heat in the atmosphere, contributing to global warming.

Carbon monoxide — An odorless, colorless, poisonous gas that forms by the burning of fossil fuels. In some cities, up to 95 percent of all carbon monoxide emissions come from motor vehicles1.

Hydrocarbons — An organic compound containing carbon and hydrogen. In the presence of nitrogen oxides (NOx) and sunlight, unburned hydrocarbons create ground-level ozone, which harms lungs and creates urban smog.

Particulate matter — Particulates — including solids and liquid droplets— from exhaust systems harm the climate and human health. Fine particles can penetrate deep into a person’s lungs and even enter the bloodstream.


Put Your Knowledge to Use

Now that you know your biodiesel terminology, learn more about the financial, environmental and performance benefits of biodiesel.






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