[Kim Byung-min's Science Village] There Are Plenty of Reasons to Be Respected When You Keep Boundaries

Engine Tapping 'Knocking' Phenomenon Addressed
1927 Lead-Added Flexible Gasoline Sold
About 5,000 People Die Annually from Poisoning

Byungmin Kim, Science Writer

“Do I really have to use premium gasoline?”

A friend who recently bought a luxury car asked me this question one day. Since my background is related to chemistry, I occasionally receive such questions. The engines of recently released vehicles mainly focus on reducing greenhouse gas emissions and improving fuel efficiency. Despite their technical sophistication, they sometimes require consumers to pay close attention.

My friend seemed curious about the manufacturer's warning to use fuel with a high octane rating. Gasoline, also called petrol, is usually a liquid fuel composed of a mixture of two types of hydrocarbon compounds. These two substances are chemically known as heptane and octane, both pure substances made only of carbon and hydrogen. The octane rating referred to by oil refiners indicates the octane content. This content determines the grade of the fuel.

My friend was worried that using regular gasoline would cause engine knocking. There are differences in fuel types depending on the oil company, some gas stations do not offer premium fuel, and there is also a price difference. His concern was about the appropriate threshold for fuel.

On the internet, there is talk that “high octane” solves the knocking problem. Perhaps because of this, most consumers understand “octane” as a fuel additive. In fact, octane is the German pronunciation of “octane.” It is the same substance but pronounced differently in German and English. In a way, this is a part that academia has not yet fully standardized.

When it comes to knocking, a figure important in the history of chemistry comes to mind?someone with a natural talent for creating regrettable outcomes.

Knocking is a phenomenon where the fuel injected into the engine cylinder explodes at an unintended time, causing a sound and vibrations of 4 to 7 Hz. The term comes from the sound resembling hammering.

In the early 20th century, automotive technology was different from today. Vehicles mainly relied on carburetors for control. The term “carburetor” is familiar to many; it is a component sensitive to temperature, environment, and fuel. Moreover, refining technology at the time made it difficult to expect high-quality fuel. Knocking was inevitable and must have been a great burden for vehicle users.

In 1921, Thomas Midgley (1889?1944), working at General Motors (GM) research lab in Ohio, USA, was conducting industrial chemical research. While studying the compound tetraethyl lead, he discovered that this substance could significantly suppress engine knocking. It was already known that lead was dangerous. At that time, lead was used in most consumer products, just as it had been used in toothpaste tubes in the past.

Eventually, GM, chemical company DuPont, and Standard Oil formed a joint venture to mass-produce tetraethyl lead. The fuel sold at gas stations under the name “Ethyl” was leaded gasoline. Because of the negative perception of lead, the fuel name omitted lead and used the brand name Ethyl instead.

Lead poisoning has been well known in human and chemical history since ancient times. Mild symptoms include muscle stiffness, while severe cases cause brain dysfunction, loss of visual or auditory nerves, and even death. The fall of Rome and the erratic behavior and hearing loss of the great musician Ludwig van Beethoven (1770?1827) were caused by lead poisoning.

Fuel made by adding lead to gasoline is called “yunyeon gasoline,” where “yeon” means lead (鉛). Claire Patterson (1922?1995) was the person who linked countless unexplained victims to the hazards of yunyeon gasoline. Patterson was a figure who tried to calculate the age of the Earth by measuring the half-life of uranium isotopes in the mid-20th century.

He found high concentrations of lead in most samples and identified the cause through geological surveys by era. He upheld the ethical line expected of a scientist. Although the Clean Air Act was enacted in the US, the sale of yunyeon gasoline continued until 1986. From the start of Ethyl sales in 1927, about 5,000 people died annually from lead poisoning for over 60 years.

In South Korea, yunyeon gasoline was completely phased out in 1993. Currently, all gasoline is unleaded. Midgley must have known that the lead content in exhaust gases from the additive fuel would increase atmospheric lead concentration. Surely, he had an ethical line as a scientist. But he remained silent. What made him cross that line?

CFCs Destroying the Ozone Layer
A Huge Price Paid by Future Generations

Having tasted success with “black gold” (oil), Midgley trusted the wealth brought by science and technology and crossed another line. This destroyed not only humanity but also the Earth's environment. He created chlorofluorocarbon compounds (CFCs), known to us as the refrigerant “Freon gas.” Like yunyeon gasoline, this substance exacted a harsh price. Compared to the greenhouse effect of carbon dioxide, Freon gas is 10,000 times stronger and can destroy over 30,000 times its own amount of ozone. These substances were released into the atmosphere for half a century. Ultimately, future humanity and nature are still paying a long-lasting price.

Science must be cautious from the perspective of environmental justice. This is because those who benefit from the discovery of substances and those who suffer harm are often different. Surely, someone knows the just and appropriate line. However, if there is even a slight suspicion, crossing the line that should not be crossed often happens. Greed certainly plays a role there.

These lines are not exclusively the domain of scientists. We also encounter or create countless tempting lines in our life journeys. Recently, as time spent at home has increased, so have deliveries and parcel shipments. The area in front of homes is overflowing with disposable plastic waste. The appropriate line of consumption has collapsed. Of course, the COVID-19 pandemic is partly responsible.

Then how was it before? When collective consciousness is shared, some things become dangerous. This is because guilt lessens when both benefits and losses are shared equally. Changing only myself does not seem to change the world. Ultimately, we were sliding into a boiling pot without any worry. We do not think that humans cannot live on Earth. We probably believe things will somehow turn out well. This is not certainty but hope disguised as optimism. We do not try to think about what might happen next. Even though everything that exists now could be turned upside down.

Internal Combustion Engine Cars Disappear, Electric Cars Become Mainstream
Electric Cars Are Not 100% Eco-Friendly

The pandemic and global climate phenomena cannot be easily summarized or generalized. However, seeing the accumulating waste, the centrifugal force that breaks things down seems to be growing stronger, causing anxiety. The unbearable pandemic has been compounded by economic and political chaos. It is a time when even ordinary lives of individuals and nations are hard to maintain. Perhaps that is why we see only indifferent faces under slogans appealing for the Earth's future. Maybe this indifference is the best way to endure these war-like times. Still, we must establish and maintain appropriate lines. Because arranging lines of good will is necessary to bring about better outcomes.

Now, I think I should answer my friend's question. It is true that premium fuel with an octane ratio of 94% or higher is advantageous for preventing knocking, but regular gasoline in Korea also has a high octane content of over 90%. Moreover, recent vehicles have sensors and automatic control devices that regulate the fuel ignition timing. Rather, so-called “harsh driving” puts strain on the engine. Maintaining a stable engine speed and changing engine oil on time are sufficient for engine care.

However, the important line we must keep in using transportation may lie elsewhere. Electric cars, which have emerged recently along with the climate crisis, come to mind easily. Electric cars do not directly contribute to greenhouse gas emissions. Furthermore, internal combustion engines will disappear in the near future, so knocking will also disappear. But what is the electricity used to charge electric cars made from? I cannot clearly see an appropriate line here. The best we can do is to drive less...

Hallym University Adjunct Professor, School of Nano Convergence