METHOD FOR DECOKING OF TUBULAR FURNACES FOR HYDROCARBON STOCK PYROLYSIS Russian patent published in 2001 - IPC

FIELD: petrochemical processes. SUBSTANCE: periodical non-stop tubular furnace decoking process is accomplished by cyclic pyrolysis of hydrocarbons mixed with water steam, each working cycle consisting of two periods differing from each other by composition of pyrolysis mixture, which, during the second period, contains no sulfur. During the first period, pyrolysis mixture can be composed of hydrocarbon mixture with sulfur and steam or sulfur-free hydrocarbon mixture with steam plus first additive. During the second period, hydrocarbon mixture is mixed with steam and contains second additive. The first additive contains substance selected from group including phosphorus-containing compounds or sulfur- containing compounds, whereas the second one can contain either alkali or alkali-earth metal compounds. EFFECT: optimized use of activating additives. 9 cl, 1 dwg