Direct distillate gasoline has a low octane rating and is not suitable for vehicles with powerful engines. Its quality is improved by various additives, but they are usually toxic.
Almost all gasolines are enriched with additives, including antiknock agents. Tetraethyl lead is the most famous, effective and toxic. Therefore, manganese-organic compounds have become an excellent alternative to him. These are new generation safe additives.
Cracking gasoline is a radical way to improve its quality.
Oil includes many fractions with different temperatures boiling. They condense alternately as they heat up. Gasoline is also among these fractions. Getting gasoline by this method is called direct distillation.
To obtain high-quality gasoline, heavy high-boiling oil fractions, for example, fuel oil, are cracked. This method of producing gasoline is a significant alternative to direct distillation.
Due to cracking, up to 70% of gasoline is obtained from oil (direct distillation does not allow obtaining more than 20% of it). Cracked gasoline is blue and red, while straight-run gasoline is yellow and pink.
Additives to straight run gasoline impart a characteristic odor. Low-octane gasolines are less resistant to detonation. In engines running on straight-run gasoline, exhaust valves and pistons quickly burn out. These broken parts create vibration, black exhaust and a distinctive metallic sound. Cracked gasolines are endowed with significant knock resistance.
Cracking gasoline is detected by chemical research carried out in specialized laboratories.
- Gasolines differ from each other in color.
- Direct distillation gasolines give off a specific odor.
- In cars running on gasoline of direct distillation, parts in the engine quickly wear out.
- Cracking gasoline is resistant to detonation.
- It is possible to distinguish cracked gasoline from low-octane gasolines in a chemical laboratory.