Biodiesel

🌱 BIODIESEL – SUMMARY


🔹 What is Biodiesel?

  • Biodiesel is a renewable, biodegradable fuel made from vegetable oils, animal fats, or waste cooking oils.

  • It is produced by transesterification—a chemical reaction between oils/fats and an alcohol (usually methanol) in the presence of a catalyst.

  • Biodiesel can be used in diesel engines with little or no modification.


🔹 Production Process: Transesterification

  1. Feedstock Preparation

    • Oils/fats are filtered and pre-treated to remove impurities and water.

  2. Reaction with Alcohol & Catalyst

    • Vegetable oil or fat reacts with methanol and a catalyst (usually sodium hydroxide or potassium hydroxide).

    • Triglycerides are converted into fatty acid methyl esters (FAME) (biodiesel) and glycerol (by-product).

  3. Separation

    • Biodiesel and glycerin separate by gravity or centrifuge.

  4. Washing & Drying

    • Biodiesel is washed to remove residual catalyst, soap, and methanol.

    • Dried to meet quality standards.


🔹 Common Feedstocks

FeedstockDescription
Vegetable oils (soybean, palm, sunflower, rapeseed)Primary sources globally
Animal fats (tallow, lard)Secondary sources
Waste cooking oilsSustainable, cost-effective
Algae oils (emerging tech)Potential high-yield source

🔹 Advantages of Biodiesel

  • Renewable and reduces dependence on fossil fuels.

  • Biodegradable and non-toxic.

  • Lower emissions of particulates, carbon monoxide, and unburned hydrocarbons.

  • Can improve engine lubrication.

  • Compatible with existing diesel engines (B5, B20 blends common).


🔹 Challenges

  • Feedstock availability and cost.

  • Cold flow properties (can gel in low temperatures).

  • Storage stability.

  • Production scale-up and infrastructure.


🔹 Key Quality Standards

  • ASTM D6751 (USA)

  • EN 14214 (Europe)

  • IS 15607 (India)


🔹 By-products

  • Glycerin (Crude Glycerol): Used in pharmaceuticals, cosmetics, animal feed.

  • Soapstock: Sometimes generated during feedstock pretreatment.


🔹 Biodiesel Plant Equipment

  • Feedstock tanks and filters

  • Reactors (batch or continuous)

  • Methanol recovery system

  • Separation units (centrifuges, settlers)

  • Washing and drying units

  • Quality control lab


🔹 Market & Trends

  • Growing global demand due to environmental regulations.

  • Increasing use of waste oils and non-food feedstocks.

  • Advances in enzyme and heterogeneous catalysis for greener production.

  • Development of second- and third-generation biofuels (algae, biomass).