The over one billion automobiles in existence owe much of their functionality to basic chemical reactions. In the U.S. alone there are over 250,000,000 cars in operation, a vast majority of which were built in the last 15 years.
The chemical processes behind moving vehicles are simpler than you think. Here’s a breakdown of what’s going on under the hood.
Fuel Injection Without an injection of fuel to a vehicle’s engine, it won’t run. There are several different types of fuel injection including direct injection, sequential, single-point, and multi-point, among others. Most engines are fed when pressurized, atomized fuel vapor is distributed to their cylinders. From there, a spark ignites the fuel atoms themselves – typically comprised of petroleum that’s been enhanced with stabilizing additives – causing the gasses to combust. This combustion causes the molecules to expand and, most importantly, to release heat.
Chemical Cooling Systems Nearly all modern vehicles use a system of liquid cooling to keep temperatures in the engine block stable. As the engine puts off heat, a network of tubes filled with coolant syphon heat from the surrounding air. What kind of coolant works best? Ideal cooling liquids must have a high relative boiling point as well as a low freezing point; today, an ethylene glycol + water solution is the most commonly-used commercial coolant. (Ethylene glycol is colloquially known as “antifreeze”.) Generally, a 1/1 solution of (CH₂OH)₂ and H₂O provides a good balance of cold-tolerance and heat-resistance, but in extremely cold climates a higher concentration of ethylene glycol is advisable.
Electric Battery Packs Electric vehicles use a completely different chemical process than traditional fuel injection systems. Battery packs for electric cars are becoming increasingly dense with energy, and today’s most cutting-edge versions are made using lithium-ions. There are several different kinds of electric batteries commercially available, though, including lead-acid, nickel metal hydrides, and molten salt. Chemical solutions are underway to make electric battery packs safer and more stable, including the addition of silicon to batteries’ anodes.