Claim 5 “Biodiesel produces as much or more emissions of carbon dioxide, compared to petroleum diesel, and therefore is not any ‘greener’ than petroleum diesel.” Jason Salazar, Andrew Peabody, Tram Nguyen, Samantha Tanner

Overview  Compare the emission of carbon dioxide in combustion of petrodiesel and biodiesel.  Decide whether biodiesel is in fact ‘greener’ than petrodiesel.  Compare the lifecycle of carbon dioxide emissions in petrodiesel and biodiesel.

Definitions of ‘greener’  Beneficial to the environment: green recycling policies.  Favoring or supporting environmentalism: green legislators who strengthened pollution controls. The American Heritage® Dictionary of the English Language, Fourth Edition.

Petrodiesel Combustion  2C 12 H O 2 → 24CO H 2 O + E  340g petrodiesel → 1060g carbon dioxide  1g petrodiesel → 3g carbon dioxide

Petrodiesel Combustion  2C 12 H O 2 → 24CO H 2 O + E  340g petrodiesel → 1060g carbon dioxide  1g petrodiesel → 3g carbon dioxide

Biodiesel Combustion  C 20 H 36 O O 2 → 20CO H 2 O + E  310g Biodiesel → 880g Carbon Dioxide  1g Biodiesel → 3g Carbon Dioxide

Biodiesel Combustion  C 20 H 36 O O 2 → 20CO H 2 O + E  310g Biodiesel → 880g Carbon Dioxide  1g Biodiesel → 3g Carbon Dioxide

Petrodiesel vs. Biodiesel  1g of either petrodiesel or biodiesel both create about the same amount of carbon dioxide at 3grams.  Carbon dioxide is among the least effective (at heat trapping) of the greenhouse gases.

Global Atmospheric Concentration of Greenhouse Gases (1992) Intergovernmental Panel on Climate Change, 1996.

Photosynthesis

6CO H 2 O + light → C 6 H 12 O 6 + 6O 2 + 6H 2 O Carbon Dioxide + Water + Light energy → Glucose + Oxygen + Water

Net CO 2 Life Cycle Emissions NREL, 1998.

References  The American Heritage® Dictionary of the English Language, Fourth Edition.  An Overview of Biodiesel and Petroleum Diesel Life Cycles. National Renewable Energy Laboratory,  Wikipedia: The Free Encyclopedia. 23 Oct Wikimedia Foundation. 23 Oct  Intergovernmental Panel on Climate Change, Climate Change 1995: The Science of Climate Change Cambridge, UK: Cambridge University Press,  Campbell, Biology 7th Ed. New York: Benjamin Cummings,  18 Nov  27 Nov Which do you want next to your home?