Happy accidents

Thanks to “a guy working on hydraulic pressure in Italian Renaissance water gardens, we have the combustion engine,” said James Burke in his book “Connections.”¹

In this passage, Burke was illustrating the roundabout way innovation often occurs, with some improvements resulting from decades of gradual enhancements, usually building on the ideas of countless other people.

John Lienhard, in his daily essays “The Engines of Our Ingenuity,” on National Public Radio and in his book by the same title, also espouses that opinion, saying that by the time Rudolf Diesel built and improved his automobile engine during 1890-97, Carl Benz’s internal combustion engine-powered auto had been on the road since 1885, Austrian Siegfried Marcus’ since 1864, and Frenchman Beau de Rochas’ since 1862. In 1826, English engineer Samuel Brown “adapted an old Newcomen steam engine to burn gas to power his auto” in London, Lienhard explained.²

“The first steam-powered road vehicles were made in the 18th Century,” he wrote. Prior to that, inventors had experimented with cars powered by springs, compressed air, even windmills. Leonardo da Vinci sketched and Homer, in remote antiquity, wrote about such self-powered vehicles.

Accidents happen

Other discoveries occur quite by accident, however, when the discoverer is astute enough to recognize the significance of the discovery, according to Royston M. Roberts in his book “Serendipity, Accidental Discoveries in Science.”³

For example, chemists Charles Friedel and James M. Crafts, working together in Paris in 1877, were trying to prepare amyl iodide by treating amyl chloride with aluminum and iodine. Their process instead produced large amounts of hydrogen chloride and, unexpectedly, hydrocarbons. Using aluminum chloride instead of aluminum produced the same unexpected results, showing that the presence of the metal chloride was essential to the process.

This laboratory accident eventually resulted in development of many products, including a superior aviation gasoline. It contained toluene and other alkylated aromatic hydrocarbons that made it instrumental in the success of British and American pilots in World War II, giving them “a critical performance edge” despite the superiority of Germany’s fighter planes.

Two other accidental discoveries in gasoline technology resulted in major improvements, one in the early days of its development and the other more recent.

Charles F. (Boss) Kettering was seeking a gasoline additive to prevent knocking in the 1912-16 Cadillac engines. He and Thomas Midgley, a research associate with Delco Co., thought the knock was a delayed explosion caused by incomplete gasoline combustion. They thought coloring the gasoline a deep red would cause it to absorb radiant energy more quickly and vaporize early enough to prevent the knock.

In December 1916, Midgley went to the chemical laboratory for some red dye, but found none so he used iodine for the gasoline colorant. The iodine stopped the knocking but was expensive and too corrosive, Roberts said, so the men continued searching for an additive and “after many trials and failures,” in 1921 discovered tetraethyl lead, which, when dissolved in gasoline, constitutes ethyl fluid. It worked well as an antiknock agent for more than 60 years but has since been discontinued because of the danger it poses to the environment.

Methane to gasoline

A serendipitous discovery by two Mobil Oil Co. research chemists led to the production of gasoline from natural gas in New Zealand in 1986. The plant is enabling New Zealand to become 50% self-sufficient in liquid fuels.

The conversion is a two-step process whereby the first step is to convert methane to methanol by adding one atom of oxygen to a molecule of methane, and the second step is conversion of methanol to gasoline. Although Step 2 would appear to be more complicated than the first, it is not because of an accidental discovery.

On Mar. 10, 1972, William H. Lang and Clarence Chang were trying to make neopentane from isobutane (C₄H₁₀) and methanol using a crystalline silica-alumina catalyst ZSM-5. Lang wrote: “All of the methanol and part of the isobutane were converted to liquid hydrocarbons but no detectable neopentane. Having previously conducted research in the reforming of naphtha, I immediately recognized the composition of the hydrocarbon products as high-octane gasoline.”

The long-term success of the process might depend on improvements to the first step to reduce its cost, Roberts wrote.

But what a helpful accident developing Step 2.