ETHYLENE PRODUCTION PROCESS Russian patent published in 2006 - IPC C10G69/06 

FIELD: petrochemical processes.

SUBSTANCE: object of invention is production of ethylene via pyrolysis of hydrocarbon feedstock. Pyrolytic production of hydrocarbon feedstock heavier than ethane (liquid hydrocarbons including liquefied gases) is conducted at 750-870°C in tubular furnace to form ethylene-containing fraction. From pyrolysis products, C₃-C₅-hydrocarbon fraction is isolated and subjected to liquid-phase hydrogenation into paraffins in presence of palladium catalyst at hydrogen-to-C₃-C₅-fraction molar ratio 0.8-2.5, while recycling a part of hydrogenised C₃-C₅-fraction into hydrogenation reactor at ratio to initial C₃-C₅-fraction fed into reactor between 10:1 and 20:1. Thereafter, hydrogenation products are introduced into pyrolysis process as additionally raw material preliminarily combined with fresh hydrocarbon feedstock. Hydrogenation process is conducted at 60-140°C and pressure 30-50 atm resulting if degree of hydrogenation 80-99.9%. Hydrocarbon feedstock may be, for example, selected from propane, n-butane, wide fraction of light hydrocarbons, and gasoline.

EFFECT: considerably simplified process due to diminished number of columns in gas separation stage and increased yield of ethylene at lesser amount of raw material supplied to pyrolysis stage.

2 cl, 1 tbl, 2 ex