PURPOSE: To utilze the distillation residue of liquid thermal cracking by-product as heating source for coke particles as well as convert them into low-calorific gas in the method of manufacturing olefins by thermally cracking heavy oils using coke particles as heating medium.
CONSTITUTION: In the method of manufacturing olefins such as ethylene consisting of two coke particles fluid beds, the reaction tower 1 in which heavy oils such as crude oil are thermally cracked using heated coke as heating medium, and the heating tower 2 in which fuel and part of coke particles are burned to heat the coke particles, between which towers the coke particles being circulated, by-product residue is introduced into the combustor 16 to cause its partial combustion to take place at an excessive fuel ratio of 20W100% by using air. The high-temperature (1400W1800°C) low-calorific gas thus generated is then introduced into the heating tower 2 from its side to heat the coke particles by heat exchange, and air is introduced into the heating tower 2 from its lower air inlet to burn the increment of coke deposited on the boke particles due to the thermal cracking of crude oil in the reaction tower 1 in order to heat the coke.
OOTA MASUO
SUGANO SEIROKU
