METHOD OF PRODUCTION OF LOWER OLEFINS Russian patent published in 2005 - IPC

FIELD: methods of thermal pyrolysis of hydrocarbon raw materials in tubular furnaces; chemical and petrochemical industries.

SUBSTANCE: proposed method includes preliminary thermal pyrolysis of liquid hydrocarbon raw material at 820-835°C continued for 48-120 h at contact time of 0.4-0.6 s and mass ratio of water steam=1:0.40-0.65. Subsequent joint thermal pyrolysis of gaseous hydrocarbons and liquid hydrocarbon raw material is performed at content of 5-15 mass-%, temperature of 830-840°C, contact time of 0.4-0.5 s and mass ratio of water steam=1:0.60-0.65. Used as gaseous hydrocarbons is mixture of hydrocarbons C₂-C₄ of the following composition, mass-%: methane, 0.01-0.20; ethane, 0.85-1.25; propane, 60.00-97.00; sum of C₄-1.50-30.00; used as liquid hydrocarbon raw material is directly-distilled gasoline fraction at boiling limits of 28-160°C. Proposed method ensures increased yield of lower olefins C₂-C₃ due to increased degree of conversion of light hydrocarbon alkanes C₂-C₄.

EFFECT: enhanced efficiency of thermal pyrolysis process.

2 cl, 1 tbl, 8 ex