National Biodiesel Day

Facts About National Biodisel Day

Vegetable Oil Fuels Were Demonstrated Before Diesel’s Engine

Chemists carried out the first documented transesterification of vegetable oil in 1853, decades before Rudolf Diesel built his engine.

Patrick Duffy and others showed that reacting plant oils with alcohol produced thinner, more combustible “fatty acid esters,” essentially an early form of biodiesel, even though there was no practical engine to use them yet.  

Biodiesel Molecules Are Chemically Distinct From Straight Vegetable Oil 

Modern biodiesel is made by reacting triglycerides in fats and oils with an alcohol, usually methanol, in the presence of a catalyst to form fatty acid methyl esters (FAME) and glycerin.

This process lowers viscosity and improves cold-flow and combustion characteristics so the fuel can meet technical standards like ASTM D6751 and EN 14214 for use in diesel engines.  

Biodiesel Can Cut Lifecycle Greenhouse Gases by More Than Half 

When produced from common feedstocks such as soy oil, used cooking oil, or animal fats, biodiesel typically reduces lifecycle greenhouse gas emissions by 50 to 86 percent compared with petroleum diesel.

The U.S. Department of Energy attributes these savings to the fact that the plants or waste sources for biodiesel originate from contemporary carbon rather than releasing carbon long stored underground in fossil fuels.  

Tailpipe Pollution Changes, Not Disappears, With Biodiesel 

Switching from petroleum diesel to biodiesel blends generally cuts particulate matter, carbon monoxide, and unburned hydrocarbons from vehicle exhaust, but it can slightly increase nitrogen oxides (NOx) in some engines and duty cycles.

Regulatory reviews by the U.S. Environmental Protection Agency found that a pure biodiesel (B100) fuel can reduce particulate emissions by about 47 percent while increasing NOx by about 10 percent, which is why engine calibration and after-treatment systems remain important.  

Used Cooking Oil Has Become a Major Industrial Feedstock

Recycled restaurant grease and used cooking oil once treated purely as waste are now important raw materials for biodiesel and related renewable diesel.

In the United States, the Department of Energy estimates that waste fats, oils, and greases account for roughly 10 to 15 percent of biodiesel feedstocks, reducing landfill disposal and helping improve the overall carbon intensity of the fuel.  

Biodiesel Production Is Tied Closely to Agricultural Markets

In many countries, biodiesel is produced primarily from vegetable oils such as soybean oil in the United States and rapeseed oil in the European Union.

Analysts at the International Energy Agency note that mandates for biodiesel blending can influence crop planting decisions and oilseed prices, linking transport fuel policy directly to farm economics and food-versus-fuel debates.  

Engine Compatibility Depends on Blend Level and Materials

Most modern diesel engines can run on blends up to B20 (20 percent biodiesel, 80 percent petroleum diesel) with little or no modification, but higher blends can interact with certain elastomers and older fuel-system materials.

Technical guidance from the National Renewable Energy Laboratory notes that biodiesel’s solvent properties can loosen deposits in fuel systems and that long-term use of high blends in older engines may require upgraded hoses, seals, and careful cold-weather management.