A thermal cracking process for selectively producing petrochemical products from hydrocarbons which comprises the steps of: burning hydrocarbons with oxygen in the presence of steam to produce a hot gas of from 1300 DEG to 3000 DEG C. comprising steam; feeding hydrogen to the hot gas; further feeding starting hydrocarbons to the hot gas comprising the steam and hydrogen so that the starting hydrocarbons containing hydrocarbon components of higher boiling points are, respectively, fed to higher temperature zones so as to thermally crack the respective hydrocarbons under different conditions while keeping the cracking temperature at 650 DEG to 1500 DEG C., the total residence time at 5 to 1000 milliseconds, the pressure at 2 to 100 bars, and the partial pressure of hydrogen, after thermal cracking of a hydrocarbon comprising hydrocarbon components whose boiling point exceeds 200 DEG C., at least 0.1 bar; and quenching the resulting reaction product.
展开▼
