FAMEbiodiesel

FAME biodiesel, or fatty acid methyl ester biodiesel, is a renewable diesel substitute produced by transesterifying fats or oils with methanol to yield fatty acid methyl esters (FAME) and glycerol. The characteristic reaction is triglyceride plus methanol producing three FAME molecules and glycerol. Production typically uses base catalysts such as NaOH or KOH, a methanol-to-oil ratio around 6:1 to 9:1, and temperatures near 50–60°C. Feedstocks include vegetable oils (such as soybean, rapeseed/canola, palm oil), as well as waste cooking oil and animal fats. Oils with high free fatty acids may require pretreatment or acid-catalyzed steps to prevent soap formation.

FAME biodiesel is used as a diesel blend stock or substitute in diesel engines and can be produced to meet regional fuel standards. It generally has a higher cetane number and improved lubricity compared with petroleum diesel, but a lower energy content, leading to reduced engine fuel economy. It also tends to have poorer cold-flow properties and can be more susceptible to oxidation, dry gas formation, and moisture-related issues; blends may require storage considerations and stabilizers.

Standards and quality control for FAME biodiesel include ASTM D6751 in the United States and EN 14214 in the European Union, which specify parameters such as ester content, viscosity, acid value, flash point, sulfur content, and overall purity. Glycerol, a by-product, is recovered and sold, but supply can influence biodiesel economics. Environmental considerations include lifecycle greenhouse gas reductions, which depend on feedstock and land-use changes. Regulation and incentives, such as fuel standards and renewable fuel mandates, influence adoption and production volumes.