Patent ID: 8277640

Claim:
A process for thermal cracking of heavy petroleum oil, in which when a thermal cracking facility having a cracking furnace to heat the heavy petroleum oil, two or more of trains each comprising first and second reaction vessels to which the heavy petroleum oil heated in the cracking furnace is introduced and one distillation tower to separate gaseous substances discharged from the respective reaction vessels of each train is operated, each train is operated by repeating a cycle comprising drawing the heavy petroleum oil from the cracking furnace, feeding the drawn heavy petroleum oil into the first reaction vessel and feeding the drawn heavy petroleum oil into the second reaction vessel after completion of feeding the drawn heavy petroleum oil into the first reaction vessel, steam is blown into each reaction vessel from the bottom of each reaction vessel while feeding the heavy petroleum oil and is directly brought in contact with the heavy petroleum oil to be thermally cracked, gaseous cracked substances produced and steam in each reaction vessel are discharged from the top outlet of each reaction vessel to be introduced into the distillation tower, and separation by distillation is carried out in the distillation tower, wherein phase delay is provided for the cycle repeated in each train so that the thermal cracking facility is operated with the different initiation time of feeding to the first reaction vessel in each train.