Process and apparatus for producing lower carbon olefins and BTX by catalytic pyrolysis of hydrocarbon-containing feedstock oil

Abstract

A process includes: cutting a hydrocarbon-containing feedstock oil into a light distillate oil and a heavy distillate oil; introducing the light distillate oil and a first catalyst into a down-flow reactor to produce a stream; subjecting the stream to a gas-solid separation to produce a first reaction hydrocarbon product and a first spent catalyst; or, introducing the stream into a fluidized bed reactor, and then subjecting to a gas-solid separation to produce a second reaction hydrocarbon product and a second spent catalyst; introducing a continuous catalyst, the heavy distillate oil and a second catalyst into an up-flow reactor, and then subjecting to a gas-solid separation to produce a third reaction hydrocarbon product and a third spent catalyst; separating out lower carbon olefins and light aromatics from reaction hydrocarbon products, separating out a light olefin fraction, and returning the light olefin fraction to the fluidized bed reactor or the up-flow reactor.

1 . A process for producing lower carbon olefins and light aromatics by catalytic pyrolysis of hydrocarbon-containing feedstock oil, wherein the process comprises the steps of:
 S1, cutting the hydrocarbon-containing feedstock oil into a light distillate oil and a heavy distillate oil, wherein the weight ratio of the light distillate oil to the heavy distillate oil (light distillate oil/heavy distillate oil) is X;   S2, introducing the light distillate oil and a first catalyst into a first down-flow reactor to perform a first catalytic pyrolysis to produce a stream after the first catalytic pyrolysis; Optionally S2′, introducing the stream after the first catalytic pyrolysis into a fluidized bed reactor to perform a second catalytic pyrolysis to produce a stream after the second catalytic pyrolysis;   S3, subjecting the stream after the first catalytic pyrolysis to a gas-solid separation to produce a first reaction hydrocarbon product and a first spent catalyst, or subjecting the stream after the second catalytic pyrolysis to a gas-solid separation to produce a second reaction hydrocarbon product and a second spent catalyst;   S4, introducing a continuous catalyst, the heavy distillate oil and a second catalyst into a second up-flow reactor to perform a third catalytic pyrolysis, and then subjecting to a gas-solid separation to produce a third reaction hydrocarbon product and a third spent catalyst; the continuous catalyst is at least a part of the first spent catalyst or at least a part of the second spent catalyst; the weight ratio of the second catalyst to the continuous catalyst (second catalyst/continuous catalyst) is R;   S5, separating out lower carbon olefins and light aromatics from any of the first reaction hydrocarbon product, the second reaction hydrocarbon product and the third reaction hydrocarbon product or a mixture of the first reaction hydrocarbon product and the third reaction hydrocarbon product or a mixture of the second reaction hydrocarbon product and the third reaction hydrocarbon product, and separating out a light olefin fraction, and returning the light olefin fraction to the second up-flow reactor of step S4 or the fluidized bed reactor of step S2′,   wherein R and X satisfy the following relation:
   (4.84× T 0−3340)/(780+5× T 0−6× T 3)< R/X <(0.968× T 0−630)/(668+0.2× T 0−1.2× T 3)
 
   T0 is the temperature (unit:° C.) when the second catalyst enters step S4, and T3 is the outlet temperature (unit:° C.) of the second up-flow reactor.   
     
     
         2 . The process according to  claim 1 , wherein the outlet temperature T3 of the second up-flow reactor is 530-650° C.; and/or
 the temperature T0 when the second catalyst enters step S4 is 690-750° C. 
 
     
     
         3 . The process according to  claim 1 , wherein, in step S1, the hydrocarbon-containing feedstock oil is cut into the light distillate oil and the heavy distillate oil at the cut point of any temperature between 100-400° C., so that the weight ratio of the light distillate oil to the heavy distillate oil (light distillate oil/heavy distillate oil) is X. 
     
     
         4 . The process according to  claim 1 , wherein, in the first down-flow reactor, the conditions of the first catalytic pyrolysis comprise: the outlet temperature of the first down-flow reactor is 610-720° C., the gas-solid residence time is 0.1-3.0 seconds, the catalyst-oil ratio is 15-80; and/or
 in the fluidized bed reactor, the conditions of the second catalytic pyrolysis comprise: the reaction temperature in the fluidized bed reactor is 600-690° C., the weight hourly space velocity is 2-20 h −1 ; and/or 
 in the second up-flow reactor, the conditions of the third catalytic pyrolysis comprise: the gas-solid residence time is 0.5-8 seconds, the catalyst-oil ratio is 8-40. 
 
     
     
         5 . The process according to  claim 1 , wherein,
 in the first down-flow reactor, the conditions of the first catalytic pyrolysis comprise: the outlet temperature of the first down-flow reactor is 650-690° C., the gas-solid residence time is 0.5-1.5 seconds, the catalyst-oil ratio is 25-65; and/or   in the fluidized bed reactor, the conditions of the second catalytic pyrolysis comprise: the reaction temperature in the fluidized bed reactor is 640-670° C., the weight hourly space velocity is 4-12 h −1 ; and/or   in the second up-flow reactor, the conditions of the third catalytic pyrolysis comprise: the gas-solid residence time is 1.5-5 seconds, the catalyst-oil ratio is 10-30.   
     
     
         6 . The process according to  claim 1 , wherein,
 in presence of step S2′, in step S3 of the gas solid separation, the separated catalyst is stripped to produce the second spent catalyst; and/or   in step S4, the continuous catalyst and the second catalyst are firstly mixed, and then the subsequent catalytic pyrolysis reaction is performed; and/or   in step S4, the light olefin fraction obtained from step S5 contacts a mixture of the second catalyst and the continuous catalyst earlier than the heavy distillate oil; the light olefin fraction contacts a mixture of the second catalyst and the continuous catalyst 0.3-1.0 seconds earlier than the heavy distillate oil; and/or   the process includes step S0 before step S1, wherein the hydrocarbon-containing feedstock oil is subjected to the desalination and dehydration treatment, and the resulting dehydrated and desalinized hydrocarbon-containing feedstock oil is introduced into step S1 for cutting.   
     
     
         7 . The process according to  claim 1 , wherein the process further comprises:
 in step S4 of the gas solid separation, the separated catalyst is stripped to produce the third spent catalyst; and/or   the third spent catalyst and optionally the first spent catalyst or the second spent catalyst not entering the second up-flow reactor are subjected to coke-burning and regeneration at a temperature of 690-750° C. to produce a regenerated catalyst; and/or   any of the first reaction hydrocarbon product, the second reaction hydrocarbon product and the third reaction hydrocarbon product or a mixture of the first reaction hydrocarbon product and the third reaction hydrocarbon product or a mixture of the second reaction hydrocarbon product and the third reaction hydrocarbon product is separated to produce dry gas, C3 fraction, C4 fraction, light gasoline, heavy gasoline, diesel and slurry oil, from which lower carbon olefins and light aromatics are produced by separation, and a light olefin fraction is separated out; and/or   in absence of step S2′, in step S5, the light olefin fraction is separated out from any of the first reaction hydrocarbon product and the third reaction hydrocarbon product or a mixture of two, and the light olefin fraction is returned to the second up-flow reactor of step S4; in presence of step S2′, in step S5, the light olefin fraction is separated out from any of the second reaction hydrocarbon product and the third reaction hydrocarbon product or a mixture of two, and the light olefin fraction is returned to the fluidized bed reactor of step S2′.   
     
     
         8 . The process according to  claim 1 , wherein the hydrocarbon-containing feedstock oil is one of or a mixture of two or more of crude oil, coal liquefaction oil, synthetic oil, tar sand oil, shale oil, tight oil and animal and vegetable oil and fat, or their respective partial fractions, or hydro-upgraded oils of their respective heavy fractions. 
     
     
         9 . The process according to  claim 1 , wherein the first catalyst and the second catalyst each independently comprise an active component and a support, the active component is at least one of ultra-stabilized Y zeolite optionally containing rare earth, ZSM-5 zeolite, pentasil silica-rich zeolite and beta zeolite, said support is at least one of alumina, silica, amorphous silica alumina, zirconia, titania, boron oxide and alkali-earth oxide. 
     
     
         10 . The process according to  claim 1 , wherein the first catalyst and the second catalyst each independently comprise a regenerated catalyst, and/or the whole of the first spent catalyst or the whole of the second spent catalyst is used as the continuous catalyst. 
     
     
         11 . An apparatus for producing lower carbon olefins and light aromatics by the catalytic pyrolysis of a hydrocarbon-containing feedstock oil, wherein the apparatus comprises the following units:
 a hydrocarbon-containing feedstock oil-cutting unit, wherein the hydrocarbon-containing feedstock oil is cut into a light distillate oil and a heavy distillate oil, so that the weight ratio of the light distillate oil to the heavy distillate oil (light distillate oil/heavy distillate oil) is X,   a first down-flow reaction unit, wherein the light distillate oil and a first catalyst are introduced to the upper part of the reaction unit to perform the first catalytic pyrolysis, and a stream after the first catalytic pyrolysis is obtained from the lower part of the reaction unit;   an optional fluidized-bed reaction unit, wherein the stream after the first catalytic pyrolysis is introduced to perform the second catalytic pyrolysis to produce a stream after the second catalytic pyrolysis;   a first gas solid separation unit, wherein the stream after the first catalytic pyrolysis is introduced to perform the gas solid separation to produce a first reaction hydrocarbon product and a first spent catalyst, or wherein the stream after the second catalytic pyrolysis is introduced to perform the gas solid separation to produce a second reaction hydrocarbon product and a second spent catalyst;   a second up-flow reaction unit, wherein a continuous catalyst, a second catalyst and the heavy distillate oil are introduced from the lower part of the reaction unit to perform the third catalytic pyrolysis, and a stream after the third catalytic pyrolysis is obtained from the upper part of the reaction unit, the continuous catalyst is at least a part of the first spent catalyst or at least a part of the second spent catalyst, the weight ratio of the second catalyst to the continuous catalyst (second catalyst/continuous catalyst) is R,   a second gas solid separation unit, wherein the stream after the third catalytic pyrolysis is introduced to perform the gas solid separation to produce a third reaction hydrocarbon product and a third spent catalyst;   a separation unit, wherein any of the first reaction hydrocarbon product, the second reaction hydrocarbon product and the third reaction hydrocarbon product or a mixture of the first reaction hydrocarbon product and the third reaction hydrocarbon product or a mixture of the second reaction hydrocarbon product and the third reaction hydrocarbon product is introduced, and lower carbon olefins and light aromatics are separated out, and a light olefin fraction is separated out, and the light olefin fraction is returned to the second up-flow reaction unit or the fluidized-bed reaction unit;   wherein R and X satisfy the following relation:
   (4.84× T 0−3340)/(780+5× T 0−6× T 3)< R/X <(0.968× T 0−630)/(668+0.2× T 0−1.2× T 3)
 
   T0 is the temperature (unit:° C.) when the second catalyst enters the second up-flow reaction unit, and T3 is the outlet temperature (unit:° C.) of the second up-flow reaction unit.   
     
     
         12 . The apparatus according to  claim 11 , which further comprises a regeneration unit, wherein the third spent catalyst and optionally the first spent catalyst or the second spent catalyst not entering the second up-flow reactor are introduced to perform the coke-burning and regeneration at a temperature of 690-750° C. to produce a regenerated catalyst. 
     
     
         13 . The apparatus according to  claim 11 , wherein if the apparatus comprises the fluidized-bed reaction unit, the first gas solid separation unit further comprises a stripping unit, wherein the catalyst obtained from the gas solid separation is subjected to stripping to produce a second spent catalyst. 
     
     
         14 . The apparatus according to  claim 11 , wherein the second gas solid separation unit further comprises a stripping unit, wherein the catalyst obtained from the gas solid separation is subjected to stripping to produce a third spent catalyst. 
     
     
         15 . The apparatus according to  claim 11 , wherein the apparatus further comprises a dehydration and desalination unit, wherein the hydrocarbon-containing feedstock oil is subjected to the desalination and dehydration treatment, and the resulting dehydrated and desalinized hydrocarbon-containing feedstock oil is introduced to the hydrocarbon-containing feedstock oil-cutting unit to be cut. 
     
     
         16 . The apparatus according to  claim 11 , wherein the position where the continuous catalyst and the second catalyst are introduced into the second up-flow reaction unit is upstream the feed inlet of the light olefin fraction. 
     
     
         17 . The apparatus according to  claim 11 , wherein in the second up-flow reaction unit, the feed inlet of the light olefin fraction from the separation unit is upstream the feed inlet of the heavy distillate oil.