U.S. patent application number 16/386914 was filed with the patent office on 2019-10-17 for process for producing low-carbon olefins by gaseous phase catalytic cracking of heavy oil with multi-stages in milliseconds.
This patent application is currently assigned to China University of Petroleum (East China). The applicant listed for this patent is China University of Petroleum (East China). Invention is credited to Yuanjun Che, Wen Feng, Yuan Jiang, Xinmei Liu, Yingyun Qiao, Yuanyu Tian, Jinhong Zhang.
Application Number | 20190316041 16/386914 |
Document ID | / |
Family ID | 63382173 |
Filed Date | 2019-10-17 |
United States Patent
Application |
20190316041 |
Kind Code |
A1 |
Tian; Yuanyu ; et
al. |
October 17, 2019 |
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.
Inventors: |
Tian; Yuanyu; (Qingdao,
CN) ; Qiao; Yingyun; (Qingdao, CN) ; Zhang;
Jinhong; (Qingdao, CN) ; Liu; Xinmei;
(Qingdao, CN) ; Che; Yuanjun; (Qingdao, CN)
; Jiang; Yuan; (Qingdao, CN) ; Feng; Wen;
(Qingdao, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
China University of Petroleum (East China) |
Qingdao |
|
CN |
|
|
Assignee: |
China University of Petroleum (East
China)
Qingdao
CN
|
Family ID: |
63382173 |
Appl. No.: |
16/386914 |
Filed: |
April 17, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10G 2300/1077 20130101;
C10G 2300/4081 20130101; C10G 11/05 20130101; C10G 2300/1074
20130101; C10G 2300/4006 20130101; C10G 11/182 20130101; C10G
2400/30 20130101; C10G 7/00 20130101; C10G 2400/20 20130101 |
International
Class: |
C10G 11/05 20060101
C10G011/05; C10G 7/00 20060101 C10G007/00; C10G 11/18 20060101
C10G011/18 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 17, 2018 |
CN |
201810341227.0 |
Claims
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.degree. C.-350.degree. 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.degree. C.-1,200.degree. 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.degree. C.-850.degree. 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.degree. C.-1,250.degree. 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.degree. C.-850.degree. C. to carry out a gas phase catalytic
cracking reaction, the cracking reaction temperature is within a
range of 530.degree. C.-750.degree. 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.degree.
C.-900.degree. 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.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The application claims priority to Chinese Application No.
201810341227.0, filed on Apr. 17, 2018, entitled "Process for
Producing Low-carbon Olefins by Gaseous Phase Catalytic Cracking of
Heavy Oil with Multi-stages in Milliseconds", which is specifically
and entirely incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention provides a process for producing low-carbon
olefins by gaseous phase catalytic cracking of heavy oil with
multi-stages in milliseconds, it belongs to the technical field of
heavy oil processing.
BACKGROUND OF THE INVENTION
[0003] The low-carbon olefins such as ethylene, propylene, butene
and butadiene are vital basic organic chemical materials,
especially the production capability of ethylene is often regarded
as a symbol of the development level of petrochemical industry in a
country and region. Due to the explosive development of energy
storage battery technologies and the imminent implementation of the
"National VI" vehicle exhaust emission standards in the People's
Republic of China (PRC), which is so-called the world's most
stringent standards for vehicle exhaust emission, the electric
vehicles have emerged as the rising alternative of the fuel oil
vehicles by virtue of the advantages such as the near zero
pollution during the driving process, energy saving, low cost of
use and may be easily intelligentized, it has become an
irreversible development trend that the fuel oil vehicles will be
replaced by the electric vehicles, the subsequent result will be a
sharp decline of the oil consumption in the transportation
industry, thus it is urgent for the petroleum processing
enterprises to transform its production mode from "fuel oil
dominated pattern" to "chemical products dominated pattern".
[0004] At present, about 95% of ethylene and 66% of propylene in
the world are produced by a tube furnace steam pyrolysis process
using lightweight raw materials such as natural gas, naphtha or
light diesel oil. However, in view of the gradual depletion of
conventional crude oil resources since the 21.sup.st century, the
crude oil supply in the world has presented the development trends
of heavy weight and inferior quality, leading to a relative
deficiency of light weight cracking raw materials, while the
worldwide market demand for low-carbon olefins is growing rapidly.
In order to alleviate the imbalance between the supply and demand,
broaden the raw materials for producing the low-carbon olefins, and
make better use of heavy feedstock oil, the development of
"chemical products dominated pattern" technical routes that use
heavy oil as a raw material to directly produce low-carbon olefins
through catalytic cracking process has become the focus and hotspot
of research in the petroleum refining industry at home and abroad,
however, there are very few mature technologies that can be
industrialized.
[0005] The heavy oil exhibits the resource characteristics, such as
being rich in polycyclic aromatic hydrocarbons, having large
carbon-hydrogen ratio, viscosity and density, and an excessively
high content of sulfur, nitrogen, oxygen, residual carbon, heavy
metals and mechanical impurities, being easy to condense and coke,
the resource characteristics impose tremendous challenges on the
conventional routes of processing heavy oil, most of the existing
heavy oil processing technologies are difficult to meet the
efficient and clean requirements of processing with "chemical
products dominated pattern". The delayed coking is currently the
preferred technology for processing the inferior heavy oil, but it
faces many challenges, such as high yield of inferior high-sulfur
coke, low yield of coker gatch, being difficult to process it with
"chemical products dominated pattern", the environment protection
pressure resulting from emission of a large amount of volatiles,
and safety hazard of shot coke. When the catalytic cracking and
hydrocracking technology is used for processing inferior heavy oil,
it confronts with many difficult problems, such as the low
conversion rate, the undesirable selectivity and low yield of the
olefin products, fast deactivation and excessively large
consumption of catalysts, poor stability of the processing
apparatus, and high processing costs; when the technology of
deasphalting with solvents is used for processing the inferior
heavy oil, the yield of deasphalted oil is low, and the processing
with "chemical products dominated pattern" suffers from many
difficulties, moreover, the efficient utilization channels of large
amount of hard asphalt become the bottleneck of its
industrialization; the technology of heavy oil suspended bed
hydrogenation can theoretically meet the requirements of efficient
and clean pretreatment of inferior heavy oil, but the defects shall
be settled urgently such as low conversion rate, excessively high
consumption of hydrogen, low removal rate of heavy metals, tail oil
processing and low-cost hydrogen source; in addition, the matching
of the processing technology and devices are still flawed, there is
not successful large-scale industrial application at present;
moreover, the hydrogenation wax oil needs a secondary processing to
achieve the processing with "chemical products dominated pattern",
and the reciprocating circulation of hydrogenation and
dehydrogenation results in the excessively high energy consumption
and the poor economic performance.
[0006] Many technologies of catalytic cracking heavy oil for
producing low-carbon olefins have been developed in recent years,
and have attracted the widespread concern and demonstration
applications in the industry, for example, the DCC/CPP process
developed by the Sinopec Research Institute of Petroleum
Processing; the PetroFCC process developed by the Universal Oil
Products (UOP) Company in the Unites States of America (USA); the
High Severity Fluidized Catalytic Cracking (HS-FCC) process and the
THR technology developed by the Japan Petroleum Energy Center
(JPEC); the TCSC process developed by the German Institute of
Organic Chemistry; the INDMAX (UCC) process developed by the Indian
Oil Corporation (IOC), the Maxofin process jointly developed by the
Exxon Mobil and the Kellog, and the two-stage riser catalytic
cracking (TMP) process proposed by China University of Petroleum
(CUP). Compared with steam cracking process, the technologies of
catalytic cracking heavy oil for producing low-carbon olefins have
the advantages such as widened feedstock ranges of olefins, low
reaction temperature, easy adjustment of the product distribution,
and low energy consumption. On the one hand, these catalytic
cracking processes should adopt the operation modes with high
temperature, short residence time, large catalyst/oil ratio and
water/oil ratio. On the other hand, both the composition of raw
materials and the properties of catalyst are key factors affecting
the yield and distribution of the catalytic cracking products
during the catalytic cracking operation process. However, the
active components of the shape selective catalyst for heavy oil
catalytic cracking are mainly ZSM-5 and Y-type molecular sieves,
whose pore structures have a small size, so the diffusion of large
heavy oil molecules are limited during the mass transfer process,
and it is difficult for the large heavy oil molecules to enter into
the molecular sieves to conduct a shape-selective cracking;
moreover, the acidic molecular sieves have a strong hydrogen
transfer performance, which leads to a limited increase in the
yield and selectivity of the olefins. In addition, the heavy oil
macromolecules accumulated on the surface of the molecular sieves
are prone to overcracking under the action of the acid site,
resulting in poor product distribution or coking and condensation,
thereby blocking the pore channels of catalyst. At present, the
existing industrial shape selective catalysts are used to prepare
low-carbon olefins through catalytic cracking of the inferior
materials such as atmospheric pressure residue oil, vacuum residue
oil, deasphalted oil, which often leads to many problems, for
example catalyst poisoning, poor atomization effect, large amount
of generated coke, and significantly lowered conversion rate and
selectivity.
[0007] In addition, during the existing process of heavy oil
thermal processing, the hydrocarbon reaction mainly occurs in the
form of liquid phase reaction. In the gaseous phase, hydrocarbon
molecules can be quickly dispersed after being split into free
radicals, while the free radicals in the liquid phase are
surrounded by neighboring molecules which resemble a "cage", and
the condensation polymerization will be intensified. In order to
disperse the formed free radicals, it is necessary to overcome the
additional potential barrier so as to diffuse out of the "cage",
which is the so-called "cage effect". Such a "cage effect" may
alter the activation energy and reaction rate of the liquid phase
reaction relative to the gaseous phase reaction.
[0008] How to eliminate the residual carbon in heavy oil and remove
the heavy metal pollution and maximize the acquired amount of
low-carbon olefins has become a major issue which shall be urgently
resolved in the transformation and upgrading process of processing
oil with "chemical products dominated pattern" in China.
SUMMARY OF THE INVENTION
[0009] In order to overcome the shortcomings of the existing
technology of processing heavy oil with "chemical products
dominated pattern", an object of the invention is to develop a
process for producing low-carbon olefins by gaseous phase catalytic
cracking of heavy oil with multi-stages in milliseconds, which can
significantly improve the yield and selectivity of low carbon
olefins, overcome the "cage effect" of the liquid phase reaction,
reduce an influence of heat and mass transfer on catalytic
cracking, and greatly decrease the amount of generated coke and
energy consumption in the cracking process.
[0010] The process adopted by the invention utilizes millisecond
pyrolysis of heavy oil in the downflow pipe to maximize production
of the oil and gas, this high is temperature oil and gas is used
for preparing low carbon olefins by directly subjecting to high
temperature millisecond shape selective catalytic cracking instead
of subjecting to the condensation and separation, thereby fully
utilizing heat of the oil and gas produced by the pyrolysis; the
process can significantly improve the yield and selectivity of low
carbon olefins, overcome the "cage effect" of the liquid phase
reaction, reduce an influence of heat and mass transfer on
catalytic cracking, and greatly decrease the amount of generated
coke and energy consumption in the cracking process, thereby
achieving the high-yield and efficient processing of heavy oil with
"chemical products dominated pattern".
[0011] The process for producing low-carbon olefins by gaseous
phase catalytic cracking of heavy oil with multi-stages in
milliseconds in the invention is characterized as follows:
[0012] 1) a high-efficiency atomizing nozzle sprays the heavy oil
preheated to 150.degree. C.-350.degree. 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.degree. C.-1,200.degree. 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.degree. C.-850.degree. C.;
[0013] 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;
[0014] 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.degree.
C.-1,250.degree. 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; while the regeneration gas from the
first gas-solid separator is subject to heat exchange and then
output;
[0015] 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.degree.
C.-850.degree. C. to carry out a gaseous phase catalytic cracking
reaction, the temperature of cracking reaction temperature is
within a range of 530.degree. C.-750.degree. C., then a cracking
gas and a cracking catalyst to be regenerated produced by the
cracking reaction are subject to gas-solid separation in
milliseconds;
[0016] 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.degree.
C.-900.degree. C., a flue gas and a high temperature crack catalyst
produced in this 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; while the flue gas is subject to heat
exchange and then output;
[0017] 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.
[0018] In the present invention, the involved term "milliseconds"
refers to a time of 600 ms or less.
[0019] Specifically, the used term "mixing . . . in milliseconds"
refers to the mixing time below 600 ms.
[0020] The used term "millisecond cracking reactor" means a crack
reactor having a reaction time less than 600 ms.
[0021] The used term "gas-solid separation in milliseconds"
generally refers to that the gas-solid separation time is below 600
ms.
[0022] In the present invention, the term "carrier/oil ratio"
refers to the weight ratio of the used amount of solid heat carrier
to the used amount of heavy oil.
[0023] The inventors of the present invention have discovered that
the pyrolysis reaction may be provided with sufficient heat by
controlling a ratio of the high temperature solid heat carrier to
the used amount of heavy oil to be within a range of 1-14:1. When
the numerical value of the "carrier/oil ratio" is less than 1, it
may easily result in that the heat supply is insufficient, the
reaction temperature is excessively low, and the crude oil cannot
be completely converted into high temperature oil and gas in
gaseous phase, which affects the overall yields of three olefins
(i.e., "ethylene, propylene and butane") and three aromatic
hydrocarbons (i.e.,"benzene, toluene, xylene") of the device. When
the numerical value of the "carrier/oil ratio" is greater than 14,
it may easily cause that the heat supply is excessive, the crude
oil is excessively cracked, the amount of generated coke is
increased, the pyrolysis dry gas is increased, and the olefin
selectivity of the subsequent reaction is deteriorated.
[0024] In the invention, the used term "catalyst/oil ratio" refers
to the weight ratio of the used amount of cracking catalyst to the
used amount of heavy oil. When the numerical value of the
"catalyst/oil ratio" is less than 1, it may easily result in that
the heat supply is insufficient, the reaction temperature is
excessively low, and the high temperature oil and gas in gaseous
phase cannot be completely cracked, which affects the overall
yields of three olefins (i.e., "ethylene, propylene and butane")
and three aromatic hydrocarbons (i.e.,"benzene, toluene, xylene")
of the device. When the numerical value of the "catalyst/oil ratio"
is greater than 8, it may easily cause that the heat supply is
excessive, the high temperature oil and gas in gaseous phase is
excessively cracked, the cracking dry gas is increased, and the
selectivity of olefins is deteriorated.
[0025] In the present invention, the expression "modification" used
in the term "downflow modification reaction tube" refers to a
process in which the heavy metals, asphalt, sulfur and nitrogen are
removed from the crude oil, and the purified crude oil is converted
to the high temperature oil and gas in gaseous phase.
Correspondingly, the term "modification regeneration reactor"
refers to a reactor involving regeneration of coke carrier obtained
by a process in which the heavy metals, asphalt, sulfur and
nitrogen are removed from the crude oil, and the purified crude oil
is converted to the high temperature oil and gas in gaseous
phase.
[0026] In order to describe the present invention more clearly, the
terms "rapid gas-solid separator" and "gas-solid separator" are
used, their difference is that the rapid gas-solid separator has a
separation time less than that of the gas-solid separator. For
example, the separation time of the rapid gas-solid separator is
less than 1/3 of the gas-solid separation time.
[0027] In the present invention, 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.
[0028] In the invention, 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.
Generally, the mixture of the oxidizing agent and water vapor may
have a water vapor content of 15-40% by weight.
[0029] In the present invention, the regeneration gas is syngas or
flue gas.
[0030] In the invention, 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.
[0031] In the present invention, 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.
[0032] In the invention, 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.
[0033] In the present invention, the cracking catalyst is one of a
FCC molecular sieve catalyst, a shape selective molecular sieve
catalyst such as ZSM-5 molecular sieve catalyst, and an alkaline
solid porous catalyst or a mixture thereof.
[0034] In the invention, 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.
[0035] In the invention, 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.
[0036] In the invention, 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.
[0037] The features of the present invention will be described in
detail with reference to the specific embodiments.
BRIEF DESCRIPTION OF DRAWINGS
[0038] FIG. 1 is a schematic diagram of a technological process in
the invention.
DESCRIPTION OF THE REFERENCE SIGNS
[0039] 1-1. first gas-solid separator;
[0040] 2-1. first return controller;
[0041] 3. high-efficiency atomizing nozzle;
[0042] 4. downflow modification reaction tube;
[0043] 5-1. first rapid gas-solid separator;
[0044] 6. pyrolysis gas outlet;
[0045] 7-1. first flow controller;
[0046] 8. millisecond cracking reactor;
[0047] 1-2. second gas-solid separator;
[0048] 2-2. second return controller;
[0049] 5-2. second rapid gas-solid separator;
[0050] 7-2. second flow controller;
[0051] 9. regenerant inlet;
[0052] 10. modification regeneration reactor;
[0053] 11. heat exchanger;
[0054] 12. regeneration gas outlet;
[0055] 13. crack regeneration reactor;
[0056] 14. air inlet;
[0057] 15. flue gas outlet.
[0058] The technological characteristics of the present invention
will be described in detail below with reference to FIG. 1 and the
embodiment examples.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0059] Each of the following examples specifies a process for
producing low-carbon olefins by gaseous phase catalytic cracking of
heavy oil with multi-stages in milliseconds according to the flow
diagram shown in FIG. 1. The flow diagram shown in FIG. 1
specifically comprises:
[0060] 1) a high-efficiency atomizing nozzle 3 sprays the heavy oil
preheated to 150.degree. C.-350.degree. C. from a feed inlet of a
downflow modification reaction tube 4 into an upper portion of the
downflow modification reaction tube 4, the produced oil mist is
mixed with a high temperature solid heat carrier at a temperature
ranging from 650.degree. C.-1,200.degree. C. flowing downward from
a first return controller 2-1 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.degree. C.-850.degree. C.;
[0061] 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 5-1 at the bottom of the downflow modification reaction
tube 4 to carry out a gas-solid separation to obtain a coked solid
heat carrier to be regenerated and a high temperature oil and
gas;
[0062] 3-1) the coked solid heat carrier to be regenerated flows
through a first flow controller 7-1 and enters into a lower portion
of a modification regeneration reactor 10 to conduct a regeneration
reaction with a regeneration agent flowing is from a regenerant
inlet 9, the temperature of the regeneration reaction is within a
range of 680.degree. C.-1,250.degree. C.; 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 1-1 on top of the modification regeneration reactor 10,
then the high temperature solid heat carrier with a carrier/oil
ratio of 1-14 passes through the first return controller 2-1 and
flows into a top of the downflow modification reaction tube 4 and
enter into the downflow modification reaction tube 4 so as to
participate in circulation and cracking of the heavy oil, the
regeneration gas from the first gas-solid separator 1-1 is subject
to heat exchange with a heat exchanger 11 and then output from a
regeneration gas outlet 12;
[0063] 3-2) the high temperature oil and gas from the first rapid
gas-solid separator 5-1 is not condensed but directly flowing in
the gaseous phase into a millisecond cracking reactor 8 and mixing
with a regeneration cracking catalyst having a temperature of
600.degree. C.-850.degree. C. from a second return controller 2-2
to carry out a gas phase catalytic cracking reaction, the
temperature of cracking reaction temperature is within a range of
530.degree. C.-750.degree. C., then a cracking gas and a cracking
catalyst to be regenerated produced by the cracking reaction pass
through a second rapid gas-solid separator 5-2 to carry out a
gas-solid separation in milliseconds;
[0064] 4-1) the cracking catalyst to be regenerated flows through a
second flow controller 7-2 and enters a lower portion of the crack
regeneration reactor 13 and perform a regeneration reaction with
air flowing from an air inlet 14, the temperature of the
regeneration reaction is 630.degree. C.-900.degree. C., the
obtained flue gas and the high temperature crack catalyst are
subject to a gas-solid separation in a second gas-solid separator
1-2 at the top of the crack regeneration reactor 13; the high
temperature crack catalyst with a catalyst/oil ratio of 1-8 passes
through the second return controller 2-2 and flows into the
millisecond cracking reactor 8 to participate the circulation
reaction; and the flue gas is subject to heat exchange with a heat
exchanger 11 and then output from a flue gas outlet 15;
[0065] 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.
[0066] The first gas-solid separator 1-1 on top of the modified
regeneration reactor and is the second gas-solid separator 1-2 on
top of the crack regeneration reactor may be identical or
different, and are one selected from the group consisting of an
inertial separator, a horizontal cyclone separator, and a vertical
cyclone, respectively.
[0067] The first rapid gas-solid separator 5-1 at the bottom of the
downflow modification reaction tube 4 and the second rapid
gas-solid separator 5-2 at the bottom of the millisecond cracking
reactor 8 may be identical or different, and are one selected from
the group consisting of an inertial separator and a horizontal
cyclone separator, respectively.
[0068] In the following examples and comparative examples, the
calculation formula of a yield of low carbon olefins is as
follows:
[0069] The yield of low carbon olefins=a total yield of three
olefins (i.e., "ethylene, propylene and butane")
[0070] Both of the fisrt gas-solid separator and the second
gas-solid separator use a vertical cyclone; both of the fisrt rapid
gas-solid separator and the second rapid gas-solid separator use a
horizontal cyclone separator.
[0071] Both the modified regeneration reactor and the crack
regeneration reactor are riser regenerators.
[0072] The millisecond cracking reactor is a downflow tube
reactor.
EXAMPLE 1
[0073] The inferior heavy oil treated in the example is a vacuum
residue oil of Shengli thickened oil, and its residual carbon
content is 15%. The key property parameters are shown in Table
1:
TABLE-US-00001 TABLE 1 Density (kg/m.sup.3, 20.degree. C.) 1,002.1
Viscosity (mm s.sup.-1, 100.degree. C.) 671 Residual carbon content
(wt. %) 15.0 Carbon content (wt. %) 86.2 Hydrogen content (wt. %)
6.8
[0074] The solid heat carrier is calcium aluminate porous
microspheres having a particle size ranging from 15 to 150
micrometers.
[0075] The cracking catalyst is a shape selective molecular sieve
catalyst, specifically ZSM-5 catalyst having a particle size
ranging from 15 to 150 microns.
[0076] The process flow is as follows:
[0077] 1) the inferior heavy oil preheated to 200.degree. C. is
sprayed from a feed inlet of a downflow modification reaction tube
4 into an upper portion of the downflow modification reaction tube
4, the produced oil mist is mixed with a high temperature solid
heat carrier (calcium aluminate porous microspheres) having a
temperature 950.degree. C. flowing downward from the first return
controller 2-1 for milliseconds, so as to heat, vaporize and
pyrolyze the heavy oil, the pyrolysis reaction temperature is
510.degree. C.;
[0078] 2) the oil and gas as well as the solid heat carrier to be
regenerated flow rapidly and downward to the bottom of the downflow
modification reaction tube 4 to carry out a gas-solid
separation;
[0079] 3-1) the coked solid heat carrier to be regenerated enters
into a modification regeneration reactor 10 to conduct a
regeneration reaction with air at the temperature of 970.degree.
C.; the regeneration gas and high temperature solid heat carrier
produced by the regeneration reaction are subject to a gas-solid
separation, then the high temperature solid heat carrier with a
carrier/oil ratio of 10 returns to the downflow modification
reaction tube 4 so as to participate in circulation and cracking of
the heavy oil, the regeneration gas is subject to heat exchange and
then output;
[0080] 3-2) the high temperature oil and gas in the downflow
modification reaction tube 4 is not condensed but directly flowing
in the gaseous phase into the millisecond cracking reactor 8 and
mixing with the regeneration cracking catalyst (ZSM-5 catalyst)
having a temperature of 800.degree. C. to carry out a gas phase
catalytic cracking reaction, the temperature of cracking reaction
temperature is 730.degree. C., then the cracking gas and the
cracking catalyst to be regenerated carry out a gas-solid
separation in milliseconds;
[0081] 4-1) the cracking catalyst to be regenerated enters the
crack regeneration reactor 13 and perform a regeneration reaction
with air at the temperature of 800.degree. C., the obtained flue
gas and the high temperature crack catalyst are subject to a
gas-solid separation; then the high temperature crack catalyst with
a catalyst/oil ratio of 6 returns to the millisecond cracking
reactor 8 to participate the circulation reaction; while the flue
gas is subject to heat exchange and then output;
[0082] 4-2) the cracking oil and gas produced by the cracking
reaction are subject to the subsequent separation to produce the
low carbon olefins and aromatic hydrocarbons respectively.
[0083] The results show that the process in Example 1 has a total
yield of three olefins (i.e., "ethylene, propylene and butane") up
to 37% for inferior heavy oil having a residual carbon content of
15%, wherein the yields of propylene and ethylene are 20% and 12%,
respectively.
COMPARATIVE EXAMPLE 1
[0084] This comparative example is used to illustrate the process
of preparing three olefins from the catalytic cracking of pyrolyzed
wax oil.
[0085] The above-mentioned inferior heavy oil in Example 1 is
initially subject to a delayed coking to obtain 4% of coking
liquefied gas, 13.5% of coking gasoline, 27% of coking diesel, 30%
of coking wax oil, 22.5% of coke, and 3% of coking dry gas by
weight.
[0086] The solid heat carrier is calcium aluminate porous
microspheres having a particle size ranging from 15 to 150
micrometers.
[0087] The key property parameters of the coking wax oil are shown
in Table 2.
TABLE-US-00002 TABLE 2 Density (kg/m.sup.3, 20.degree. C.) 890.5
Viscosity (mm s.sup.-1, 100.degree. C.) 21 Residual carbon content
(wt. %) 2.3 Carbon content (wt. %) 82.5 Hydrogen content (wt. %)
7.8
[0088] The process flow of preparing three olefins (i.e.,
"ethylene, propylene and butane") from the catalytic cracking of
pyrolyzed wax oil is as follows:
[0089] 1) the coking wax oil preheated to 200.degree. C. is sprayed
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 (calcium aluminate porous microspheres) at a temperature
950.degree. C. flowing downward from the first return controller
for milliseconds, so as to heat, vaporize and pyrolyze the coking
wax oil, the pyrolysis reaction temperature is 550.degree. C.;
[0090] 2) the oil and gas as well as the solid heat carrier to be
regenerated flow rapidly and downward to the bottom of the downflow
reaction tube to carry out a gas-solid separation;
[0091] 3) the coked solid heat carrier to be regenerated enters
into a regeneration reactor to conduct a regeneration reaction with
air at the temperature of 970.degree. C.; the regeneration gas and
high temperature solid heat carrier produced by the regeneration
reaction are subject to a gas-solid separation, then the high
temperature solid heat carrier with a carrier/oil ratio of 10
returns to the downflow reaction tube so as to participate in
circulation and pyrolyze of the coking wax oil, the regeneration
gas is subject to heat exchange and then output;
[0092] 4) the high temperature oil and gas in the downflow reaction
tube are subject to the subsequent separation to produce the low
carbon olefins and aromatic hydrocarbons respectively.
[0093] The results show that a total yield of three olefins (i.e.,
"ethylene, propylene and butane") prepared from the catalytic
cracking of pyrolyzed wax oil is 33%, io wherein the yields of
propylene and ethylene are 16% and 14%, respectively. If calculated
according to the heavy oil, the total yield of three olefins
obtained by this process is only about 10%.
[0094] It is demonstrated from a comparison of Example 1 of the
invention with Comparative example 1 that the process of the
invention can obtain a higher yield is of three olefins, and avoids
that the reheating, temperature rise and atomization of the wax oil
in the traditional combined process of pyrolysis modification--wax
oil catalytic cracking, but it still has a common problem, namely
the "cage effect" of the liquid phase reaction results in an
increased condensation polymerization, thereby reducing the yield
and selectivity of low carbon olefins.
[0095] In addition, the invention has a short processing procedure,
which is specifically reflected that it is not necessary for the
crude oil subjecting to electric desalting and atmospheric pressure
and vacuum distillation treatments, and the crude oil is directly
used as a feedstock of the catalytic cracking, the steel
consumption of the apparatus is low, the fixed investment is
greatly reduced; the atmospheric pressure operation is simple, it
is convenient to start or shut down the apparatus, the operational
continuity is desirable, and the apparatus has strong adaptability
for processing a variety of oils.
EXAMPLE 2
[0096] The inferior heavy oil is identical with that in Example
1.
[0097] The solid heat carrier is aluminum silicate porous
microsphere having a particle size ranging from 15 to 150
micrometers.
[0098] The cracking catalyst is a ZSM-5 molecular sieve catalyst
having a particle size ranging from 15 to 150 micrometers.
[0099] 1) The inferior heavy oil preheated to 150.degree. C. is
sprayed from a feed inlet of a downflow modification reaction tube
4 into an upper portion of the downflow modification reaction tube
4, the produced oil mist is mixed with a high temperature solid
heat carrier (aluminum silicate porous microspheres) having a
temperature 900.degree. C. flowing downward from the first return
controller 2-1 for milliseconds, so as to heat, vaporize and
pyrolyze the heavy oil, the pyrolysis reaction temperature is
580.degree. C.;
[0100] 2) the oil and gas as well as the solid heat carrier to be
regenerated flow rapidly and downward to the bottom of the downflow
modification reaction tube 4 to carry out a gas-solid
separation;
[0101] 3-1) the coked solid heat carrier to be regenerated enters
into a modification is regeneration reactor 10 to conduct a
regeneration reaction with air at the temperature of 920.degree.
C.; the regeneration gas and high temperature solid heat carrier
produced by the regeneration reaction are subject to a gas-solid
separation, then the high temperature solid heat carrier with a
carrier/oil ratio of 5 returns to the downflow modification
reaction tube 4 so as to participate in circulation and cracking of
the heavy oil, the regeneration gas is subject to heat exchange and
then output;
[0102] 3-2) the high temperature oil and gas in the downflow
modification reaction tube 4 is not condensed but directly flowing
in the gaseous phase into the millisecond cracking reactor 8 and
mixing with the regeneration cracking catalyst (ZSM-5 catalyst)
having a temperature of 700.degree. C. to carry out a gas phase
catalytic cracking reaction, the temperature of cracking reaction
temperature is 620.degree. C., then the cracking gas and the
cracking catalyst to be regenerated carry out a gas-solid
separation in milliseconds;
[0103] 4-1) the cracking catalyst to be regenerated enters the
crack regeneration reactor 13 and perform a regeneration reaction
with air at the temperature of 800.degree. C., the obtained flue
gas and the high temperature crack catalyst are subject to a
gas-solid separation; then the high temperature crack catalyst with
a catalyst/oil ratio of 4 returns to the millisecond cracking
reactor 8 to participate the circulation reaction; and the flue gas
is subject to heat exchange and then output;
[0104] 4-2) the crack oil and gas produced by the cracking reaction
are subject to the subsequent separation to produce the low carbon
olefins and aromatic hydrocarbons respectively.
[0105] The results show that the process in Example 2 has a total
yield of three olefins (i.e., "ethylene, propylene and butane") up
to 45% for inferior heavy oil having a residual carbon content of
15%, wherein the yields of propylene and ethylene are 25% and 16%,
respectively.
COMPARATIVE EXAMPLE 2
[0106] The inferior heavy oil is treated according to the process
of Example 1, except that the high temperature solid heat carrier
with a carrier/oil ratio of 16 is controlled to pass through the
first return controller and flow into a top of the is downflow
modification reaction tube and enter into the reaction to
participate circulation and cracking of the heavy oil.
[0107] The result reveals that a total yield of three olefins
(i.e., "ethylene, propylene and butane") reaches 33%, wherein the
yields of propylene and ethylene are 16% and 11%, respectively.
COMPARATIVE EXAMPLE 3
[0108] The inferior heavy oil is treated according to the process
of Example 1, except that the high temperature solid heat carrier
with a carrier /oil ratio of 0.5 is controlled to pass through the
first return controller and flow into a top of the downflow
modification reaction tube and enter into the reaction to
participate circulation and cracking of the heavy oil.
[0109] The result reveals that a total yield of three olefins
(i.e., "ethylene, propylene and butane") is 35%, wherein the yields
of propylene and ethylene are 18% and 13%, respectively.
COMPARATIVE EXAMPLE 4
[0110] The inferior heavy oil is treated according to the process
of Example 1, except that the pyrolysis reaction temperature is
controlled to be 1,000.degree. C.
[0111] The result reveals that a total yield of three olefins
(i.e., "ethylene, propylene and butane") is 30%, wherein the yields
of propylene and ethylene are 16% and 12%, respectively.
EXAMPLE 3
[0112] The inferior heavy oil processed in the example is identical
with that in Example 1.
[0113] The solid heat carrier is the porous microsphere carrier
loaded with sodium(Na), the porous microsphere carrier has a
particle size ranging from 15 to 150 micrometers.
[0114] The cracking catalyst is a FCC molecular sieve catalyst
having a particle size ranging from 15 to 150 micrometers.
[0115] 1) The inferior heavy oil preheated to 300.degree. C. is
sprayed from a feed inlet of a downflow modification reaction tube
4 into an upper portion of the downflow modification reaction tube
4, the produced oil mist is mixed with a high temperature solid
heat carrier (porous microsphere carrier loaded with sodium) having
a temperature 800.degree. C. flowing downward from the first return
controller 2-1 for milliseconds, so as to heat, vaporize and
pyrolyze the heavy oil, the pyrolysis reaction temperature is
660.degree. C.;
[0116] 2) the oil and gas as well as the solid heat carrier to be
regenerated flow rapidly and downward to the bottom of the downflow
modification reaction tube 4 to carry out a gas-solid separation;
3-1) the coked solid heat carrier to be regenerated enters into a
modification regeneration reactor 10 to conduct a regeneration
reaction with air at the temperature of 1,120.degree. C.; the
regeneration gas and high temperature solid heat carrier produced
by the regeneration reaction are subject to a gas-solid separation,
then the high temperature solid heat carrier with a carrier/oil
ratio of 12 returns to the downflow modification reaction tube 4 so
as to participate in circulation and cracking of the heavy oil, the
regeneration gas is subject to heat exchange and then output; 3-2)
the high temperature oil and gas in the downflow modification
reaction tube 4 is not condensed but directly flowing in the
gaseous phase into the millisecond cracking reactor 8 and mixing
with the regeneration cracking catalyst (FCC molecular sieve)
having a temperature of 700.degree. C. to carry out a gas phase
catalytic cracking reaction, the temperature of cracking reaction
temperature is 720.degree. C., then the cracking gas and the
cracking catalyst to be regenerated carry out a gas-solid
separation in milliseconds;
[0117] 4-1) the cracking catalyst to be regenerated enters the
crack regeneration reactor 13 and perform a regeneration reaction
with air at the temperature of 830.degree. C., the obtained flue
gas and the high temperature crack catalyst are subject to a
gas-solid separation; then the high temperature crack catalyst with
a catalyst/oil ratio of 1 returns to the millisecond cracking
reactor 8 to participate the circulation reaction; and the flue gas
is subject to heat exchange and then output;
[0118] 4-2) the cracking oil and gas produced by the cracking
reaction are subject to the subsequent separation to produce the
low carbon olefins and aromatic hydrocarbons respectively.
[0119] The results show that the process in Example 2 has a total
yield of three olefins (i.e., "ethylene, propylene and butane") up
to 37% for inferior heavy oil, wherein the yields of propylene and
ethylene are 16% and 18%, respectively.
[0120] The invention provides a process for producing low-carbon
olefins by gaseous phase catalytic cracking of heavy oil with
multi-stages in milliseconds, the process utilizes a rapid alkaline
catalytic pyrolysis of the inferior heavy oil to maximize
production of the oil and gas, this high temperature oil and gas is
used for preparing low carbon olefins by directly subjecting to
high temperature millisecond shape selective catalytic cracking
instead of subjecting to the condensation and separation, thereby
fully utilizing heat of the pyrolysis oil and gas; the process
overcomes the "cage effect" of the liquid phase reaction, reduces
an influence of heat and mass transfer on catalytic cracking, and
greatly decreases the amount of generated coke and energy
consumption in the cracking process; the reaction temperature and
time may be easily adjusted and controlled, and the characteristic
that the alkaline catalytic pyrolysis of heavy oil produces a large
amount of olefins may be used for shape selective catalysis ,
thereby significantly improving the yield and selectivity of low
carbon olefins.
* * * * *