So different cities are different, and because the maximum price of refined oil has been set, private and state-owned retailers can only compete on this price, but private enterprises are often lower than PetroChina and Sinopec because of their flexible purchase channels.
Brief introduction of gasoline history
/kloc-in the 0/9th century, people didn't realize the importance of gasoline. At that time, kerosene was widely used for lighting. At that time, petroleum refining relied on a simple distillation process to separate components with different boiling points from petroleum. Kerosene has a high boiling point and is safe to use when igniting. It has become the main product of crude oil refining, while gasoline and other components are usually burned as fuel.
/kloc-in the middle and late 9th century, internal combustion engines using gasoline were successfully manufactured, and 1886 gasoline engines were successfully used as vehicle power. Therefore, the importance of gasoline is increasing day by day. But only 20% gasoline can be extracted from crude oil by distillation. 19 1 1 year, American standard oil company solved the problem of low gasoline production.
The thermal cracking process invented by William Burton and Robert Humphries is used to crack heavy gas oil into light gasoline and other fractions, thus improving the gasoline yield as a whole. The thermal cracking process was authorized by American patent in 19 13. The subsequent catalytic cracking process further improved the gasoline yield and higher octane number than the thermal cracking process.