THERMAL DECOMPOSITION OF HEAVY OIL USING FLUIDIZED LAYER OF COKE PARTICLE

摘要

PURPOSE:To make prolonged operation of thermal decomposition of heavy oil possible at a suppressed coking rate for a reaction tower overhead system, by varying linear velocity of introduced gas such as for fluidization at a plurality of nozzles in each part with a reaction tower space velocity being kept constant. CONSTITUTION:Nozzles 7 and 8 for supplying a feed stock and a coke/oil slurry are equipped with an inlet 13 for dispersing steam. In addition, two types of nozzles, i.e. a small-diameter nozzle 14 and a large-diameter nozzle 15 for adjusting linear velocity of injected steam are provided. When coke particle size and an amt. of retained coke in the fluidized bed tend to increase, an amt. of steam supplied to the nozzle 13 or 14 is increased to decrease an amt. of gas to the nozzle 15 by that amt. Thus the coke particle is more crushed and worn while keeping the space velocity constant, or it is possible to decrease an amt. of attachment from the introduced oil and to decrease coke particle size. When the coke particle size tends to decrease, it is recommendable to carry out the operation reverse to the procedure as mentioned above.