Biofuel Production from Algae

Biofuel from Algae

• Algae are targeted by biofuel manufacturers due to their high oil content.
• Extracted oil from algae is known as "green crude," which requires further processing to be usable as fuel.

Trans-Esterification Process

• Trans-esterification is essential for converting green crude into biodiesel.
• This process involves adding alcohol and a chemical catalyst to the crude oil.
• A chemical reaction occurs, forming a blend of biodiesel and glycerol.

Final Processing Steps

• The processing culminates by separating glycerol from the biodiesel mixture.
• The end result is biodiesel that is ready for use as a renewable fuel source.

Algal Deposits in Scotland

• A deposit rich in immature algae from the Central Valley of Scotland has potential for biofuel production.
• The extraction method includes retorting Torbanite, an oil shale also known as Boghead Coal.
• Retorting mobilizes organic matter, yielding an oil-like extract.

Analysis of Extracts

• The oil-like extract has been evaluated using gas chromatography techniques.
• The resultant gas chromatogram indicates characteristics similar to those of mature, relatively light crude oil.

Composition of Oils

• Oils consist of hydrocarbons, non-hydrocarbons that resemble hydrocarbons, and metals.
• Petroleum and its products are complex mixtures with thousands of compounds.

Oil Fractions

• Four primary fractions identified in oils:
  • Aliphatics (paraffin-naphthenes)
  • Aromatics
  • Nitrogen–Oxygen–Sulfur (NSO) compounds
  • Asphaltenes
• Asphaltenes are insoluble in solvents and resistant to biodegradation.

Hydrocarbon Types

• Aliphatic hydrocarbons include:
  • Normal alkanes (n-alkanes)
  • Branched alkanes (isoalkanes)
  • Cyclic alkanes (naphthenes)
• Isoalkanes, naphthenes, and aromatics have lower biodegradability compared to n-alkanes.

Hydrocarbon Saturation

• Saturated hydrocarbons are primarily composed of single carbon-carbon bonds, making them stable and unreactive.
• General formula for alkanes: CnH2n+2, where n is the number of carbon atoms.
• Condensed structural formula examples:
  • Butane: CH3CH2CH2CH3 or CH3(CH2)2CH3.

Isoprenoids

• Isoprenoids are branched saturated hydrocarbons used to infer depositional environments.
• Key isoprenoid compounds:
  • Pristane (Pr)
  • Phytane (Ph)
• Both compounds derive from the common precursor Phytol, with Pristane forming in oxidizing environments and Phytane in reducing environments.

This quiz explores the process of biofuel production using algae, including the extraction of 'green crude' oil and the trans-esterification process. Understand the chemical reactions involved and the final separation of biodiesel and glycerol. Test your knowledge on this innovative energy source.