METHOD OF PRODUCTION OF UNSATURATED HYDROCARBONS Russian patent published in 2005 - IPC

FIELD: thermal pyrolysis of hydrocarbon raw material; chemical and petrochemical industries; production of lower olefins in tubular furnaces.

SUBSTANCE: proposed method consists in preliminary thermal pyrolysis of directly-distilled gasoline fraction in tubular furnace at temperature of 825-835°C continued for 24-320 h, contact time of 0.4-0.5 s and ratio of water steam=1.0:0.4-0.5 followed by thermal pyrolysis of light hydrocarbon raw materials, for example alkanes C₂-C₄ in the same coils of tubular furnace at temperature 835-845°C, contact time of 0.4-0.5 and mass ratio of water steam= 1.0:0.3-0.4. Proposed method makes it possible to increase inter-regeneration time of furnace, thus increasing yield of ethylene and propylene due to deposition of amorphous isotropic coke on inner walls of coils.

EFFECT: enhanced efficiency.

2 cl, 1 tbl, 7 ex