William Kovarik
Radford University
and
Matthew E. Hermes
Kennesaw State University

Fuels and Society: B. Sixty Years of Tetraethyllead
How the Best Known Poison on Earth Remained in the Gasoline Supply for Sixty Years

This unit links the physical and chemical properties of atmospheric pollutants and tetraethyllead to the controversial decisions made in the early years of the automotive age.

You will learn about the early development of autos and their fuel.

You will understand the decisions based on chemical principles that engineers made to develop autos and fuels that were compatible.

Analysis of alternate strategies resulted in invention of tetraethyllead and the decisions to use it in spite of toxicity.

What would you have done if you were GM, Standard OIl or DuPont in the 1930'3 to the 1980's? Would you have kept tetraethyllead on the market as the primary source of antiknock performance?

The Facts: From the mid 1920's until the mid 1980's motor gasoline fuel contained an additive, tetraethyllead, that improved fuel performance by preventing preignition in the cylinders of the engine. Preignition resulted in damaging and efficiency and power reducing knocking.

Tetraethyllead is a toxic liquid that killed more than 40 chemical workers during its early development and manufacturing. Nevertheless, motor companies, oil companies and the government authorized the manufacture, distribution and use of tetraethyllead in gasoline throughout the world. Pb(C2H5)4 Tetraethyllead (TEL)

The Chemistry: Automotive fuels derived from petroleum propel our cars by converting the energy of combustion to heat and work. The challenge for an efficient, powerful engine is to maximize the work available. The second law of thermodynamics teaches this can be done by making engines with a high compression ratio. But problems of uneven fuel combustion and knocking must be overcome through fuel reformulation or by finding an appropriate additive.

The Questions: How did lead compounds, whose extreme toxicity were known for more than a century before they were introduced into gasoline, become an accepted and everyday component of the fuels we use - and of the air we breathe and the ground upon which we walk?

Students will go through a series of units outlined in the concept map and end with a case discussion on how automakers, oil companies and the government might have better dealt with the issues of gasoline quality in the early 20th century.

Begin with the unit on the the story of 1. Charles Kettering, Thomas Midgley and Tetraethyllead or click on any area of the concept map below.