PROCESS FOR PRODUCING LOW-CARBON OLEFINS BY GASEOUS PHASE CATALYTIC CRACKING OF HEAVY OIL WITH MULTI-STAGES IN MILLISECONDS

摘要

The invention provides a process for producing low-carbon olefins by gaseous phase catalytic cracking of heavy oil with multi-stages in milliseconds, comprising: a high-efficiency atomizing nozzle sprays the preheated heavy oil into an upper portion of the downflow modification reaction tube, the produced oil mist is mixed with a high temperature heat carrier flowing downward from a return controller for pyrolysis, and then the pyrolysis products are subject to a gas-solid separation at the bottom of the downflow modification reaction tube; then the coked heat carrier obtained by the separation enters into a lower portion of a modification regeneration reactor to conduct a regeneration reaction, the obtained regeneration gas and the high temperature heat carrier are subject to a gas-solid separation on the top of the modified regeneration reactor, then the high temperature heat carrier returns to a top of the downflow reaction tube to participate in circulation, the regeneration gas is subject to heat exchange and then output; and the high temperature oil and gas produced by the pyrolysis reaction directly flows into the millisecond cracking reactor and conducts a cracking reaction with the regenerated cracking catalyst and subject to a gas-solid separation; then the cracking catalyst to be regenerated enters a lower portion of the crack regeneration reactor and performs a regeneration reaction, the obtained flue gas and the high temperature crack catalyst are subject to a gas-solid separation at the top of the crack regeneration reactor, the high temperature crack catalyst returns to the millisecond cracking reactor to participate the circulation reaction, the flue gas is subject to heat exchange and then output; the crack oil and gas produced by the cracking reaction enter into the subsequent separation devices to separate out the low carbon olefins.