Explanation

Explanation of Chemical Concepts
http://biofuel.org.uk/how-are-biofuels-produced.html

Christian N, Joseph BN. 2009. Our Energy Future: Resources, Alternatives, and the Environment. New Jersey, US: John Wiley& Sons, Inc.

Biofuels are derived from biomass and these biomasses are produced directly or indirectly produced from photosynthesis. Biofuels are different from fossil fuels as they are produced from Biomass that is produced from living organisms or very recently living organisms

2 types of first generation biofuels

1) Ethanol, made from crops containing high concentrations of sugar, perform yeast fermentation on them to produce ethanol

2) Biodiesels, made from plants with a high concentration of vegetable oil that undergo esterification with alcohol to produce monoalkylesters

1) Production of sugar in plants

CO2 + H2O + Sunlight→ CnH2nOn + O2 

Fermentation of Sugars to Ethanol by yeast:

 

Glucose or sucrose (6C) in plants will be broken down to 2 pyruvate (3C) molecules via glycolysis. In alcohol fermentation, the 2 pyruvate molecules are reduced to Ethanol and Carbon Dioxide.

This Ethanol is then used for various functions such as fuel or for the esterification of fatty acids to make biodiesels.

http://hyperphysics.phy-astr.gsu.edu/hbase/Biology/ferment.html

Combustion of Ethanol as fuel 

C2H5OH + 3 O2 → 2 CO2 + 3 H2O + heat

Ethanol in the presence of excess oxygen is broken down to carbon dioxide, water and heat.

2) Production of Biodiesels from Oil or Fats

The fatty acids in the oil will be reacted with excess alcohol (ethanol or methanol) to form monoalkyl esters which are the biodiesels

 

https://en.wikipedia.org/wiki/Biodiesel_production#/media/File:Transesterification_of_triglycerides_with_ethanol.png

 

http://biofuel.org.uk/how-do-biofuels-burn.html