Environmental Enlightenment #184
By Ami Adini -
Reissued May 18, 2015

This is a SHORT, LIGHT and SIMPLE newsletter. Its purpose is to rekindle in the initiated terminology they have once learned, and enlighten the uninitiated on terms they may have heard but never known the meaning of.

Combustion of Fossil Fuel – A Global Impact

My colleague, Jim Jacobs, a renowned environmental scientist with Environmental Bio-Systems of northern California, enlightened me on that every gallon of gasoline when burned generates 20 pounds of carbon dioxide (CO2) that is released to the atmosphere.

Gasoline is a complex mixture of over 500 hydrocarbons that may have between 5 to 12 carbons.  Given below are illustrations of three molecules of the gasoline family.

Take propylbenzene for example:  
  9 carbons (C) and 12 hydrogens (H)  
  Thus:  C9H12  
Upon combustion, hydrocarbon molecules convert to carbon dioxide (CO2) and water (H2O)
Every carbon atom engages two oxygens.
Every two hydrogen atoms capture one oxygen.
Thus, one propylbenzene molecule will become:
  C9H12   9 CO2  + 6 H2O  
One (1) molecule of propylbenzene
  Converts to:
    Nine (9) molecules of Carbon Dioxide
        Six (6) molecules of Water

Mass is amount of matter.

Atoms are little particles of matter.

Every atom has its own characteristic mass.

You can measure the atomic mass in any unit of your choice: be it gram, pound or kernels of olives.

For our purpose we select a system where hydrogen atom represents one (1) unit of mass.


In this system:
  • The mass of the hydrogen atom is 1
  • The mass of the carbon atom is (approx) 12
  • The mass of the oxygen atom is (approx) 16

The mass of the C9H12 molecule will be:
    C9H12 Mass   =    9 x 12    +   12 x 1   =    120
  The mass of a CO2 molecule will be:
    CO2 Mass   =    1 x 12    +   2 x 16   =    44
  We now see that
    the combustion of 1 molecule of propylbenzene
      that has 120 units of mass
          9 molecules of carbon dioxide
            with a combined mass of 9 x 44  =  396 mass units.
  The ratio is:
    396 / 120    =   3.3
It means:
    Burning of one (1) pound of propylbenzene generates three and three-tenths (3.3) pounds of carbon dioxide
  One gallon of gasoline weighs (approx) 6.7 pounds.
  If gasoline was all propylbenzene:
    For every gallon of gasoline (6.7 pounds) combusted
we would generate 3.3 x 6.7 = 22.1 pounds of CO2

Another fact to note is that all fossil fuel, be it petroleum, coal or natural gas, is hydrocarbons, and that in the burning of hydrocarbons we tie free oxygen to the products of the combustion.

In the above example, combustion of one molecule of propylbenzene (120 atomic mass units) ties 24 atoms of oxygen (having 16 atomic mass units each).

Thus a total of 24 x 16 = 384 atomic mass units of oxygen get tied up in the CO2 and H2O generated by the combustion.

The ratio is:
  384 / 120     =    3.2

We get that for every gallon of gasoline (6.7 pounds) combusted there’s 3.2 x 6.7 = 21.4 pounds of free oxygen eliminated from the air and engaged in bondage with water and carbon dioxide

Nature can break down the CO2 and water back to their elemental components and release the captured oxygen to the atmosphere. HOWEVER, Nature never equipped itself to free up the oxygen at the rate that we are now tying it up.

One can therefore conclude that before the rest of the world starts mass driving of cars, building power plants and heating homes with gas it would behoove its more advanced societies to strive hard in the quest after non-hydrocarbon-based fuels. 

As the old way is leading into cul de sac, we see global efforts accelerating to solve this fast-becoming acute problem of survival for the inhabitants of Earth.

You can find past issues of "Environmental Enlightenment" at www.amiadini.com Wealth of information about environmental site assessments in the real estate transactions and issues concerning assessment and cleanup of contamination in the subsurface soil and groundwater.

Call me if you have any questions. There are no obligations.

Ami Adini
Ami Adini & Associates, Inc.
Environmental Consultants
Underground Storage Tank Experts
818-824-8102; 818-824-8112 fax

Ami Adini is a mechanical engineer, California Registered Environmental Assessor, Level II (Exp.), and president of AMI ADINI & ASSOCIATES, INC. (AA&A), an environmental consulting firm specializing in all phases of environmental site assessments and rehabilitation of contaminated sites. AA&A specializes in practical solutions to environmental concerns using the highest standards of ethics and integrity while providing its clients with maximum return on their investments.