Generally, only 10 to 40% of light oil products such as gasoline, kerosene and diesel can be obtained after atmospheric and vacuum distillation of crude oil, and the rest are heavy distillate oil and residual oil. If you want to get more light oil products, you must carry out secondary processing of heavy distillates and residual oil. Catalytic cracking is the most commonly used process for producing gasoline and diesel. Gasoline and diesel are mainly produced through this process. This is also the most important production link for general petroleum refining companies.
1.Raw materials
Residual oil and wax oil account for about 70%. Catalytic cracking generally uses vacuum distillate oil and coked wax oil as raw materials. However, with the increasing weight of crude oil and the increasing demand for light oil, most petrochemical companies have begun to Add vacuum residual oil to the raw material, or even directly use normal pressure residual oil as the raw material for refining.
2.Products
Gasoline, diesel, slurry (heavy distillate), liquid propylene, and liquefied gas; each account for 42% of gasoline, 21.5% for diesel, 5.8% for propylene, 8% for liquefied gas, and 12% for slurry.
3.Basic concepts
Catalytic cracking is the main process for processing heavy oil (such as residual oil) into light oil (gasoline, kerosene, diesel) in the presence of a catalyst. It is the main secondary processing method in the oil refining process. It is a chemical processing process.
4.Production process
The residue and wax oil pass through the raw oil buffer tank and enter the riser, settler, and regenerator to form oil and gas, which then enter the fractionation tower.
Part of the oil and gas enters the crude gasoline tower, absorption tower, and air compressor, enters the condensed oil tank, passes through the reabsorption tower, stabilization tower, and finally undergoes gasoline refining to produce gasoline.
Part of the oil and gas enters the diesel stripper through the fractionation tower, and then the diesel is refined to produce diesel. Part of the oil and gas enters the oil slurry cycle through the fractionation tower, and finally produces oil slurry.
Part of the oil and gas enters the liquid hydrocarbon buffer tank through the fractionation tower, passes through the desulfurization adsorption tank, sand filter tower, water washing tank, demercaptan extraction tower, pre-alkali washing tank, amine liquid recovery device, desulfurization extraction tower, buffer tower, and finally enters the liquid state Hydrocarbon tank, forming liquefied gas.
Part of the oil and gas passes through the liquid hydrocarbon buffer tank and enters the depropanizer tower, reflux tower, deethanizer tower, refined propylene tower, reflux tank, and finally enters the spherical tank in the propylene area to form liquid propylene. Liquid propylene is further processed in the polypropylene workshop to produce polypropylene.
March 22, 2024
