oil and natural gas as raw materials to produce basic organic chemical raw materials and further synthesize a variety of chemical products. Its raw materials mainly come from natural gas, refinery gas, liquid petroleum products or crude oil。The main production units in petroleum refinery usually include: crude oil distillation (normal distillation, vacuum distillation) thermal cracking, catalytic cracking, hydrocracking, petroleum coking, catalytic reforming and refinery gas processing, petroleum product refining, etc., mainly producing gasoline, jet fuel, kerosene, diesel oil, fuel oil, lubricating oil, petroleum wax, petroleum asphalt, petroleum coke and various petrochemical raw materials
