Process for producing low-carbon olefins by gaseous phase catalytic cracking of heavy oil with multi-stages in milliseconds

Abstract

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.

1 . A process for producing low-carbon olefins by gaseous phase catalytic cracking of heavy oil with multi-stages in milliseconds, wherein:
 1) a high-efficiency atomizing nozzle sprays the heavy oil preheated to 150° C.-350° C. from a feed inlet of a downflow modification reaction tube into an upper portion of the downflow modification reaction tube, the produced oil mist is mixed with a high temperature solid heat carrier at a temperature ranging from 650° C.-1,200° C. flowing downward from a first return controller for milliseconds, so as to heat, vaporize and pyrolyze the oil mist and obtain an oil and gas and a solid heat carrier to be regenerated, the pyrolysis reaction temperature is within a range of 480° C.-850° C.;   2) the oil and gas as well as the solid heat carrier to be regenerated flow rapidly and downward to a first rapid gas-solid separator at the bottom of the downflow modification reaction tube to carry out a gas-solid separation to obtain a coked solid heat carrier to be regenerated and a high temperature oil and gas;   3-1) the coked solid heat carrier to be regenerated flows through a first flow controller and enters into a lower portion of a modification regeneration reactor to conduct a regeneration reaction with a regeneration agent, the temperature of the regeneration reaction is within a range of 680° C.-1,250° C.; then the regeneration gas and high temperature solid heat carrier produced by the regeneration reaction are subject to a gas-solid separation in a first gas-solid separator on top of the modification regeneration reactor, then the high temperature solid heat carrier with a carrier/oil ratio of 1-14 passes through the first return controller and flows into a top of the downflow modification reaction tube and enter into the downflow modification reaction tube so as to participate in circulation and cracking of the heavy oil; the regeneration gas from the first gas-solid separator is subject to heat exchange and then output;   3-2) the high temperature oil and gas from the first rapid gas-solid separator is not condensed but directly flowing in the gaseous phase into a millisecond cracking reactor and mixing with a regeneration cracking catalyst having a temperature of 600° C.-850° C. to carry out a gas phase catalytic cracking reaction, the cracking reaction temperature is within a range of 530° C.-750° C., then a cracking oil and gas and a cracking catalyst to be regenerated produced by the cracking reaction are subject to gas-solid separation in milliseconds;   4-1) the cracking catalyst to be regenerated flows through a second flow controller and enters a lower portion of the crack regeneration reactor and performs a regeneration reaction with air, the temperature of the regeneration reaction is 630° C.-900° C., a flue gas and a high temperature crack catalyst produced by the regeneration reaction are subject to a gas-solid separation in a second gas-solid separator at the top of the crack regeneration reactor; the high temperature crack catalyst with a catalyst/oil ratio of 1-8 passes through a second return controller and flows into the millisecond cracking reactor to participate the circulation reaction, and the flue gas is subject to heat exchange and then output;   4-2) the cracking oil and gas produced by the cracking reaction enter into the subsequent separation devices to separate out the low carbon olefins and aromatic hydrocarbons.   
     
     
         2 . The process for producing low-carbon olefins by gaseous phase catalytic cracking of heavy oil with multi-stages in milliseconds according to  claim 1 , wherein the heavy oil is one selected from a group consisting of vacuum residue oil, atmospheric pressure residue oil, distillate, crude oil, coal tar, shale oil and oil sand bitumen. 
     
     
         3 . The process for producing low-carbon olefins by gaseous phase catalytic cracking of heavy oil with multi-stages in milliseconds according to  claim 1 , wherein the regenerant agent is an oxidizing agent or a mixture of an oxidizing agent and water vapor, wherein the oxidizing agent is one of oxygen, air and oxygen-enriched air; and the regeneration gas is syngas or flue gas. 
     
     
         4 . The process for producing low-carbon olefins by gaseous phase catalytic cracking of heavy oil with multi-stages in milliseconds according to  claim 1 , wherein the solid heat carrier is one of semi-coke microspheres, calcium aluminate porous microspheres, magnesium aluminate spinel porous microspheres, aluminum silicate porous microspheres, calcium silicate porous microspheres, magnesium silicate porous microspheres, porous microsphere carriers loaded with alkali metals or/and alkaline-earth metals or a mixture thereof. 
     
     
         5 . The process for producing low-carbon olefins by gaseous phase catalytic cracking of heavy oil with multi-stages in milliseconds according to  claim 1 , wherein the first gas-solid separator and the second gas-solid separator are one selected from the group consisting of an inertial separator, a horizontal cyclone separator, and a vertical cyclone, respectively. 
     
     
         6 . The process for producing low-carbon olefins by gaseous phase catalytic cracking of heavy oil with multi-stages in milliseconds according to  claim 1 , wherein the cracking catalyst is one selected from a group consisting of a FCC molecular sieve catalyst, a shape selective molecular sieve catalyst and an alkaline solid porous catalyst or a mixture thereof. 
     
     
         7 . The process for producing low-carbon olefins by gaseous phase catalytic cracking of heavy oil with multi-stages in milliseconds according to  claim 1 , wherein the modification regeneration reactor is one selected from a group consisting of a riser regenerator, a turbulent fluidized bed regenerator and a bubbling fluidized bed regenerator. 
     
     
         8 . The process for producing low-carbon olefins by gaseous phase catalytic cracking of heavy oil with multi-stages in milliseconds according to  claim 1 , wherein the millisecond cracking reactor is one selected from a group consisting of a downflow tube reactor, a horizontal inertia rotary separation reactor and a cross-staggered short contact reactor. 
     
     
         9 . The process for producing low-carbon olefins by gaseous phase catalytic cracking of heavy oil with multi-stages in milliseconds according to  claim 1 , wherein the first rapid gas-solid separator and the second rapid gas-solid separator are one selected from an inertial separator and a horizontal cyclone separator, respectively. 
     
     
         10 . The process for producing low-carbon olefins by gaseous phase catalytic cracking of heavy oil with multi-stages in milliseconds according to  claim 1 , wherein the crack regeneration reactor is one selected from a group consisting of a riser regenerator, a turbulent fluidized bed regenerator and a bubbling fluidized bed regenerator.