Questions about oil

Gasoline is made from petroleum processed several times, and then the gasoline fractions obtained from the three processes are blended according to national standards and refined oil standards. The very beginning of petroleum refining is atmospheric and vacuum distillation. The fraction obtained in the first step is a straight-run gasoline fraction; the gasoline of this fraction is unqualified because it not only has a low octane number but also contains sulfur. The atmospheric heavy oil, vacuum distillate oil and residual oil obtained by atmospheric and vacuum distillation are sent to a catalytic cracking unit or a hydrocracking unit for secondary processing to produce a secondary gasoline fraction; although the gasoline of this fraction has a higher octane number, However, the sulfur content and nitrogen content will be very high and cannot yet meet national standards. The cracked gasoline enters the refining device to reduce the sulfur content and nitrogen content of the gasoline, improve the stability of the gasoline, and reduce the raw rubber of the gasoline; this is the so-called third-process gasoline. If the octane number of gasoline is too low, naphtha in atmospheric and vacuum pressure can be used for catalytic reforming to increase the octane number of gasoline. Mix the triple-processed gasoline and reformed gasoline with straight-run gasoline. Finally, there is the refined oil we buy.

If the saturated vapor pressure or lightning of gasoline does not meet the standards, operations such as oil and gas re-distillation are required.