CN112760131B - Oil gas recovery method and device - Google Patents
Oil gas recovery method and device Download PDFInfo
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- CN112760131B CN112760131B CN201911065679.1A CN201911065679A CN112760131B CN 112760131 B CN112760131 B CN 112760131B CN 201911065679 A CN201911065679 A CN 201911065679A CN 112760131 B CN112760131 B CN 112760131B
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- 238000011084 recovery Methods 0.000 title claims abstract description 75
- 238000000034 method Methods 0.000 title claims abstract description 39
- 238000000926 separation method Methods 0.000 claims abstract description 168
- 239000003502 gasoline Substances 0.000 claims abstract description 147
- 229930195733 hydrocarbon Natural products 0.000 claims abstract description 55
- 150000002430 hydrocarbons Chemical class 0.000 claims abstract description 55
- 239000004215 Carbon black (E152) Substances 0.000 claims abstract description 51
- 239000002250 absorbent Substances 0.000 claims abstract description 21
- 230000002745 absorbent Effects 0.000 claims abstract description 19
- 239000000463 material Substances 0.000 claims abstract description 13
- 239000007788 liquid Substances 0.000 claims description 131
- 239000007791 liquid phase Substances 0.000 claims description 65
- 239000012071 phase Substances 0.000 claims description 65
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 claims description 40
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 claims description 40
- 239000003921 oil Substances 0.000 claims description 38
- 238000000605 extraction Methods 0.000 claims description 35
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 30
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 28
- 238000010992 reflux Methods 0.000 claims description 28
- 238000006477 desulfuration reaction Methods 0.000 claims description 25
- 230000023556 desulfurization Effects 0.000 claims description 25
- 229910052799 carbon Inorganic materials 0.000 claims description 21
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 19
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 claims description 16
- 150000001412 amines Chemical class 0.000 claims description 16
- LSDPWZHWYPCBBB-UHFFFAOYSA-N Methanethiol Chemical compound SC LSDPWZHWYPCBBB-UHFFFAOYSA-N 0.000 claims description 15
- 239000001569 carbon dioxide Substances 0.000 claims description 15
- 239000012535 impurity Substances 0.000 claims description 13
- 239000003513 alkali Substances 0.000 claims description 12
- 238000005406 washing Methods 0.000 claims description 12
- 239000002002 slurry Substances 0.000 claims description 11
- 230000003009 desulfurizing effect Effects 0.000 claims description 9
- 238000004523 catalytic cracking Methods 0.000 claims description 8
- 238000001816 cooling Methods 0.000 claims description 8
- 239000002283 diesel fuel Substances 0.000 claims description 8
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 8
- 239000001294 propane Substances 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims description 7
- 238000011144 upstream manufacturing Methods 0.000 claims description 7
- 239000003518 caustics Substances 0.000 claims description 5
- 238000009835 boiling Methods 0.000 claims description 3
- 238000004939 coking Methods 0.000 claims description 3
- 230000003111 delayed effect Effects 0.000 claims description 3
- 239000000295 fuel oil Substances 0.000 claims description 2
- 238000002156 mixing Methods 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims 1
- 238000005265 energy consumption Methods 0.000 abstract description 11
- 239000007789 gas Substances 0.000 description 152
- 239000000047 product Substances 0.000 description 42
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 15
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 15
- 230000009102 absorption Effects 0.000 description 12
- 238000010521 absorption reaction Methods 0.000 description 12
- 230000000087 stabilizing effect Effects 0.000 description 10
- 238000003795 desorption Methods 0.000 description 8
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 3
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 3
- 239000005977 Ethylene Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000006227 byproduct Substances 0.000 description 2
- 238000004517 catalytic hydrocracking Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000010828 elution Methods 0.000 description 2
- 238000005187 foaming Methods 0.000 description 2
- 230000009103 reabsorption Effects 0.000 description 2
- 238000005057 refrigeration Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 230000006641 stabilisation Effects 0.000 description 2
- 238000011105 stabilization Methods 0.000 description 2
- PVXVWWANJIWJOO-UHFFFAOYSA-N 1-(1,3-benzodioxol-5-yl)-N-ethylpropan-2-amine Chemical compound CCNC(C)CC1=CC=C2OCOC2=C1 PVXVWWANJIWJOO-UHFFFAOYSA-N 0.000 description 1
- QMMZSJPSPRTHGB-UHFFFAOYSA-N MDEA Natural products CC(C)CCCCC=CCC=CC(O)=O QMMZSJPSPRTHGB-UHFFFAOYSA-N 0.000 description 1
- 238000012824 chemical production Methods 0.000 description 1
- -1 compound amine Chemical class 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000011112 process operation Methods 0.000 description 1
- 238000011027 product recovery Methods 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C10G53/00—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more refining processes
- C10G53/02—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more refining processes plural serial stages only
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- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
Abstract
The invention belongs to the field of petrochemical industry, and particularly discloses a method and a device for recovering oil gas, wherein gasoline, C4 and components below C4 are separated in advance before light hydrocarbon separation, so that gasoline is not required to be adopted in the subsequent flow to absorb liquefied gas components, the consumption of absorbent circulation is saved, and meanwhile, the material flow does not contain H in the light hydrocarbon separation process2S, the material requirement of a light hydrocarbon separation and recovery system is reduced, and the safety of the whole process is ensured; meanwhile, the invention has simple process flow, mild operation condition and less energy consumption.
Description
Technical Field
The invention belongs to the field of chemical industry, and particularly relates to an oil gas recovery method and device.
Background
Light hydrocarbon refers to the components of methane, ethane, ethylene, propane, propylene, carbon and the like obtained in the petrochemical process, and the light hydrocarbon separation process is always the key point of attention of the petrochemical process. The existing process with high gas yield such as catalytic cracking, hydrocracking, delayed coking and the like usually adopts absorption stabilization to recover liquefied gas (C3/C4) components to realize liquefied gas components and dry gas (H)2/C1/C2) and stabilizing the gasoline to ensure the qualified vapor pressure of the gasoline.
The absorption stabilizing process mainly comprises four towers: the absorption tower, the reabsorption tower, the desorption tower and the stabilizing tower, wherein the recovery rate of the liquefied gas is controlled by the absorption tower and the reabsorption tower, and the specification of the liquefied gas is ensured by the desorption tower (controlling the content of carbon five) and the stabilizing tower (controlling the content of carbon five). The main characteristic is that gasoline is used as absorbent under certain pressure (1.3 MPaG-1.6 MPaG) and normal temperature, most of liquefied gas components and a small amount of carbon dioxide in the rich gas are absorbed, and then the absorbed light components such as carbon dioxide are desorbed under proper conditions. Therefore, the method of absorption and desorption can realize the separation of the carbon two and the carbon three under the milder operation condition, and avoid the adoption of a rectification method (with higher pressure, lower temperature and refrigeration requirement) to separate the carbon two and the carbon three, thereby reducing the investment and the energy consumption; the cost is that the top gas of the desorption tower contains certain components such as liquefied gas and the like besides carbon dioxide, and the desorption gas returns to the absorption tower again, so that the circulation of the components of the liquefied gas between absorption and desorption is caused, and the energy consumption of an absorption stabilizing system is increased.
Through research and analysis, the prior absorption stabilization process method has the following defects:
(1) the absorption stabilizing system adopts stable gasoline as an absorbent to recover liquefied gas components, absorbs the components at normal temperature without refrigeration, and has large gasoline circulation amount in order to ensure the recovery rate of the liquefied gas.
(2) Gasoline circulates among the gasoline absorption tower, the desorption tower and the stabilizing tower, the temperature of the bottoms of the ethane desorption tower and the stabilizing tower is higher, the thermal load of a reboiler at the bottom of the tower is larger, and the energy consumption is higher.
(3) The stabilizing tower (debutanizer) is arranged at the tail end, the flow path of the gasoline is long, and the energy consumption is high;
(4) the desulfurization is arranged on a dry gas and liquefied gas product line, and an absorption stabilizing system contains H2S, the requirement on the material is high, and potential safety hazards may exist in normal operation.
The present invention has been made to solve the above-mentioned problems occurring in the prior art.
Disclosure of Invention
The invention aims to provide a device and a method for separating and recovering liquefied gas from light hydrocarbon, which have simple process flow and mild operation conditions, can realize the high-efficiency separation and recovery of three-carbon and four-carbon components, and simultaneously, a light hydrocarbon recovery system does not contain H2S, the material requirement of the light hydrocarbon recovery system is reduced, and the operation is safer.
In order to achieve the above object, the present invention provides a method for oil and gas recovery, the method comprising:
(1) separation: oil gas from an upstream device after reaction is sent to a fractionating tower for separation, oil slurry, diesel oil and recycle oil are respectively extracted from the bottom and a lateral line of the fractionating tower, gas phase at the top of the fractionating tower is sent to a first-stage gas-liquid separation tank after being cooled, gas phase at the top of the tank is sent to a second-stage gas-liquid separation tank after being condensed again, liquid phase part at the bottom of the tank is sent to the top of the fractionating tower, and the rest part of the liquid phase part is sent to a light gasoline separating tower; compressing the gas phase at the top of the secondary gas-liquid separation tank, and then sending the gas phase to a light and heavy gasoline separation tower, and boosting the pressure of the liquid phase at the bottom of the tank, and then sending the liquid phase to the light and heavy gasoline separation tower;
(2) separating light gasoline and heavy gasoline: the material from the second-stage gas-liquid separation tank enters a light and heavy gasoline separation tower, the gas phase distilled from the tower top is condensed and enters a tower top reflux tank I, the gas phase at the top of the tower top reflux tank I is compressed and then sent to a light hydrocarbon-light gasoline separation tower, the liquid phase at the bottom of the tank is pressurized and then sent to the light hydrocarbon-light gasoline separation tower, and at least part of the liquid phase at the bottom of the light and heavy gasoline separation tower is taken as a heavy gasoline product for extraction;
(3) light hydrocarbon-light gasoline separation: feeding the material flow from the top reflux tank I of the light and heavy gasoline separation tower into a light hydrocarbon-light gasoline separation tower, feeding the gas phase distilled from the top of the tower into a top reflux tank II, compressing and cooling the gas phase at the top of the top reflux tank II, feeding the gas phase to a gas-liquid separation tank, pressurizing the liquid phase at the bottom of the tank, feeding the gas phase to the gas-liquid separation tank, and extracting the liquid phase at the bottom of the tank as light gasoline;
(4) second gas-liquid separation: mixing the materials in a gas-liquid separation tank, balancing gas and liquid, separating gas phase and liquid phase again, and then respectively removing impurities;
(5) gas-phase impurity removal: gas phase at the top of the gas-liquid separation tank is sequentially subjected to H removal in a rich gas desulfurization tower by taking lean amine liquid as an absorbent2S and CO2In the gas-rich alkaline washing tower, alkali liquor is used to remove mercaptan and small amount of H2S and CO2Then sending the mixture to an aftercooler;
(6) liquid phase impurity removal: the liquid phase at the bottom of the gas-liquid separation tank is sequentially removed with lean amine liquid as an absorbent in a liquid hydrocarbon desulfurization tower2S and CO2In the liquid hydrocarbon sweetening reactor, alkali liquor is used to remove mercaptan and small quantity of H2S and CO2Then sending the mixture to an aftercooler;
(7) and (3) cooling: the gas phase and the liquid phase are preliminarily mixed and cooled in a postcooler and then are sent to a feeding tank;
(8) feeding: after the mixture flow from the aftercooler is mixed and gas-liquid balanced in a feeding tank, the gas phase at the top of the tank is sent to a liquefied gas recovery tower, and the liquid phase at the bottom of the tank is sent to a demethanizer;
(9) demethanization: removing methane from the liquid phase at the bottom of the feed tank in a demethanizer, simultaneously removing a small part of components with the content of C2 and above C2, sending the gas phase at the top of the demethanizer to a liquefied gas recovery tower, and sending the liquid phase at the bottom of the demethanizer to a deethanizer;
(10) deethanizing: separating C2 component from the liquid phase at the bottom of the demethanizer in a deethanizer, collecting the separated mixed C2 component from the top of the deethanizer or sending the component to a liquefied gas recovery tower, and sending the liquid phase components with C3 and above C3 at the bottom of the deethanizer to a depropanizer;
(11) depropanizing: further separating the liquid phase component from the bottom of the deethanizer in a depropanizer, and extracting the separated C3 component from the upper part of the depropanizer as a C three product and the bottom of the depropanizer as a C four product;
(12) and (3) recovering liquefied gas: in the liquefied gas recovery tower, heavy gasoline is used as an absorbent to recover liquefied gas components in a gas phase in the tower, the gas phase at the top of the liquefied gas recovery tower is extracted as a dry gas product, and a liquid phase at the bottom of the liquefied gas recovery tower returns to the light and heavy gasoline separation tower.
The invention has wide application range, and the oil gas (comprising components H2, C1-C4 light hydrocarbon, gasoline, heavy oil and the like) in the common processes with higher light hydrocarbon yield such as catalytic cracking, delayed coking, flexicoking, slurry bed hydrocracking and the like in chemical production can be separated by using the device of the invention to recycle liquefied gas from light hydrocarbon.
As a preferable scheme of the invention, the excess heat of the high-temperature oil gas at the outlet of the reactor is better utilized. The method comprises the steps of firstly, further separating oil gas in an upstream device by using a fractionating tower, wherein the operation temperature of the top of the fractionating tower is 100-140 ℃, and the pressure is 0.1-0.35 MPaG. The top of the fractionating tower is provided with two stages of gas-liquid separation, gas phase extracted from the top of the fractionating tower is sequentially subjected to cooling, gas-liquid separation and re-cooling, and after the process of gas-liquid separation again, most of gasoline is separated in the first stage gas-liquid separation tank and then directly sent to the light gasoline separation tower and the heavy gasoline separation tower, so that the gasoline is prevented from being cooled and heated for many times, and the investment and the energy consumption are reduced. After two-stage gas-liquid separation, the gas phase is sent to a light gasoline separation tower through pressure boosting, the operation temperature of a first-stage gas-liquid separation tank at the top of the fractionating tower is 60-85 ℃, and the pressure is 0.07-0.32 MPaG; the operation temperature of the second-stage gas-liquid separation tank at the top of the fractionating tower is 35-50 ℃, and the pressure is 0.03-0.28 MPaG.
As a preferable scheme of the invention, in order to further separate the light gasoline and the heavy gasoline, the operation temperature of the top of the light gasoline and the heavy gasoline separating tower is 55-80 ℃, the operation temperature of the bottom of the light gasoline and the heavy gasoline separating tower is 130-170 ℃, and the operation pressure is 0.2-0.6 MPaG; the operating temperature of the top of the light hydrocarbon-light gasoline separating tower is 55-85 ℃, and the operating pressure is 1.0-1.3 MPaG; the initial boiling point of the heavy gasoline is 65-85 ℃, and the dry point of the light gasoline is 60-80 ℃.
In the invention, in order to meet the requirement of related product recovery, the gas-phase and liquid-phase hydrocarbons need to be subjected to impurity removal independently before next separation, and the impurity removal mainly comprises amine elution H2S and alkali washing to remove mercaptan. Because the effects of gas-phase desulfurization and mercaptan removal are better under high pressure, and the volume of desulfurization equipment is smaller under high pressure, the light hydrocarbon produced by second gas-liquid separation is divided into gas phase and liquid phase, and then impurity removal is respectively carried out, and because the content of heavy hydrocarbon (C3/C4 hydrocarbon) in the gas phase separated under high pressure is less, the amount of heavy hydrocarbon which is possibly condensed into amine liquid is also less when desulfurization is carried out, the foaming of the amine liquid can be effectively avoided, and the stable operation of the device is ensured. Preferably, the operation temperature of the rich gas desulfurization tower is 35-45 ℃, and the operation pressure is 2.0-2.8 MPaG; the operating temperature of the liquid hydrocarbon desulfurization tower is 35-45 ℃, and the operating pressure is 2.0-2.8 MPaG; the operating temperature of the feeding tank is 5-20 ℃, and the operating pressure is 1.9-2.7 MPaG. In the present invention, amine elution H2S can be carried out by adopting a compound amine liquid solvent (namely, a modified solvent based on MDEA) and carrying out H2S and CO2In which H is2S can be removed to less than 10ppmw, CO2The removal efficiency can reach 90-99 wt%, and the amine washing part realizes H2S and CO2After the high-efficiency removal, the gas-phase hydrocarbon and the liquid-phase hydrocarbon can effectively enter the stream of the alkaline washing mercaptan removal reactor to remove H2S and CO2And further reducing the consumption of alkali liquor.
Because the main recovery target of the invention is C3/C4 components, and C2 components are not required to be recovered, according to the principle that the saturated vapor pressure of the C3/C4 components is lower, most of the C3/C4 components can be condensed by directly adopting one-time gas-liquid separation under the process operation condition adopted by the invention, and then the condensate is subjected to demethanization, deethanization and depropanization processes in turn. According to the invention, the temperature of the feeding tank is preferably 5-20 ℃ and the pressure is preferably 1.9-2.7 MPaG.
In the invention, the uncondensed gas phase is sent to a liquefied gas recovery tower to recover the entrained liquefied gas components, preferably, the temperature of the liquefied gas recovery tower is 5-20 ℃, and the pressure is 1.9-2.7 MPaG; the absorbent is a stable gasoline product extracted from the bottom of the light and heavy gasoline separation tower, and does not need to be supplemented from the outside of the system.
In order to ensure the quality of the downstream recovered carbon-three product, reduce the content of C2 components and reduce the circulating amount of each component, the invention is sequentially provided with a demethanizer and a deethanizer.
As a preferable scheme of the invention, the temperature of the top of the demethanizer is 10-30 ℃, the pressure is 2.2-3.0 MPaG, and the temperature of the bottom of the demethanizer is 60-100 ℃; the temperature of the top of the deethanizer is 5-20 ℃, the pressure is 2.6-3.2 MPaG, and the temperature of the bottom of the deethanizer is 95-120 ℃; the tower top temperature of the depropanizing tower is 50-65 ℃, the pressure is 1.6-2.0 MPaG, and the tower bottom temperature is 95-120 ℃. Because the temperature of the bottom of the demethanizer and the deethanizer is low and the circulation amount of each component is low, the load of a reboiler at the bottom of the tower can be reduced, and the energy is saved.
As a preferable scheme of the invention, when the carbon dioxide product needs to be recovered, the carbon dioxide product obtained from the top of the deethanizer can be directly led out, subjected to impurity removal and sent to a downstream ethylene device for further recovery, the carbon dioxide product mainly comprises ethylene and ethane and contains about 20 v% of propylene, and the recovery rate of the carbon dioxide component is 50-60 wt%.
As a preferable embodiment of the present invention, in order to further separate propylene having a purity of not less than 99.6 vol%, the mixed C3 component may be further rectified, and specifically, the method further includes:
(13) and (3) propylene rectification: and (3) sending the carbon product extracted from the upper part of the depropanizing tower to a propylene rectifying tower for further rectification, wherein the gas phase at the top of the propylene rectifying tower is extracted as a propylene product, and the liquid phase at the bottom of the propylene rectifying tower is extracted as a propane product. Wherein, the temperature of the propylene rectifying tower is preferably 45-60 ℃, and the pressure is preferably 1.7-2.0 MPaG.
In another aspect, the present invention provides an apparatus for recovering oil and gas, the apparatus comprising: the system comprises an oil gas feeding pipeline, a fractionating tower, a primary heat exchanger, a primary gas-liquid separating tank, a secondary heat exchanger, a secondary gas-liquid separating tank, a compressor I, a light and heavy gasoline separating tower, a compressor II, a light hydrocarbon-light gasoline separating tower, a compressor III, a cooler, a gas-liquid separating tank, a rich gas desulfurizing tower, a rich gas alkaline washing tower, a liquid hydrocarbon desulfurizing tower, a liquid hydrocarbon sweetening reactor, an after cooler, a feeding tank, a demethanizer, a deethanizer, a depropanizer and a liquefied gas recovery tower;
wherein, the oil gas feed pipeline is connected with the fractionating tower,
the top of the fractionating tower is provided with a first-stage heat exchanger, a first-stage gas-liquid separation tank, a second-stage heat exchanger and a second-stage gas-liquid separation tank, a diesel oil extraction pipeline and a recycle oil extraction pipeline are arranged on the lateral line, and an oil slurry extraction pipeline is arranged at the bottom of the fractionating tower; the top of the fractionating tower is sequentially connected with a first-stage heat exchanger and a first-stage gas-liquid separation tank in series, the top of the first-stage gas-liquid separation tank is sequentially connected with a second-stage heat exchanger and a second-stage gas-liquid separation tank in series, and the bottom of the fractionating tower is respectively connected with the fractionating tower and the light and heavy gasoline separation tower; the top of the second-stage gas-liquid separation tank is sequentially connected with a compressor I and a light and heavy gasoline separation tower in series, and the bottom of the tank is connected with the light and heavy gasoline separation tower;
the top of the light and heavy gasoline separation tower is provided with a reflux tank I, the top of the reflux tank I is sequentially connected with a compressor II and a light hydrocarbon-light gasoline separation tower, the bottom of the tank is connected with a booster pump and then connected with the light hydrocarbon-light gasoline separation tower, and the bottom of the light and heavy gasoline separation tower is provided with a heavy gasoline extraction pipeline;
a reflux tank II is arranged at the top of the light hydrocarbon-light gasoline separation tower, the top of the reflux tank II is sequentially connected with a compressor III, a cooler and a gas-liquid separation tank, and the bottom of the tank is connected with a booster pump and then connected with the gas-liquid separation tank;
the top of the gas-liquid separation tank is sequentially connected with a rich gas desulfurization tower, a rich gas alkaline washing tower and an after-cooler, and the bottom of the tank is sequentially connected with a liquid hydrocarbon desulfurization tower, a liquid hydrocarbon sweetening reactor and an after-cooler;
the upper part of the rich gas desulfurization tower is provided with a lean amine liquid feeding pipeline, and the upper part of the rich gas caustic tower is provided with an alkali liquid feeding pipeline;
the aftercooler is connected with the feeding tank;
the top of the feeding tank is connected with a liquefied gas recovery tower, and the bottom of the feeding tank is connected with a demethanizer;
the top of the demethanizer is connected with a liquefied gas recovery tower, and the bottom of the demethanizer is connected with a deethanizer;
a carbon dioxide extraction pipeline is arranged at the top of the deethanizer, the carbon dioxide extraction pipeline is optionally connected with a liquefied gas recovery tower, and the bottom of the deethanizer is connected with a depropanizer;
the upper part of the depropanizing tower is provided with a C3 product extraction pipeline, and the bottom of the depropanizing tower is provided with a C4 product extraction pipeline;
the tower top of the liquefied gas recovery tower is provided with a dry gas extraction pipeline, the tower bottom of the liquefied gas recovery tower is connected with a light and heavy gasoline separation tower, and the upper part of the liquefied gas recovery tower is provided with an absorbent feeding pipeline.
As a preferable scheme of the invention, the device also comprises a propylene rectifying tower, and the C3 product extraction line is connected with the propylene rectifying tower; and a propylene product extraction pipeline is arranged at the top of the propylene rectifying tower, and a propane product extraction pipeline is arranged at the bottom of the propylene rectifying tower.
As a preferable scheme of the invention, the heavy gasoline extraction pipeline is divided into two branches, wherein one branch is used as an absorbent feeding pipeline of a liquefied gas recovery tower; and reboilers are arranged at the bottoms of the demethanizer and the deethanizer.
Compared with the prior art, the invention has the following advantages:
(1) according to the invention, most of the liquefied gas components are directly condensed and recovered, rather than gasoline being used as an absorbent to recover the liquefied gas components, the gasoline circulation amount is greatly reduced, and thus the energy consumption is greatly reduced. The invention can ensure that the recovery rates of the carbon three component and the carbon four component are both more than 99 wt%, and the content of C2 in the propylene product obtained by further separation is not more than 200 ppmv.
(2) The invention fully utilizes the heat of the compressed rich gas to separate the light gasoline and the heavy gasoline, reduces the energy consumption required by the separation of the light gasoline and the heavy gasoline, simultaneously, ensures that the gasoline is not required to be adopted to absorb the components of the liquefied gas in the subsequent flow, and saves the consumption of the circulation of the absorbent.
(3) The top of the fractionating tower adopts two-stage condensation cooling, and most of gasoline is directly separated from a first-stage gas-liquid separation outlet at a higher temperature and is sent to a light gasoline separating tower and a heavy gasoline separating tower, so that the energy consumption required by light gasoline and heavy gasoline separation is reduced, a large amount of gasoline is prevented from being cooled and heated repeatedly, and the investment and the energy consumption are reduced.
(4) The invention can respectively desulfurize the gas phase and the liquid phase and remove mercaptan, and the gas phase is desulfurized under higher pressure, so the equipment volume is smaller, the investment is lower, and the desulfurization effect is good; meanwhile, the content of heavy hydrocarbon (C3/C4 hydrocarbon) in the gas phase is reduced, the amount of heavy hydrocarbon which can be condensed into the amine liquid is less, the amine liquid can be effectively prevented from foaming, and the smooth operation of the device is ensured.
(5) In the invention, hydrogen sulfide and mercaptan are removed before entering the light hydrocarbon separation system and cannot be brought to a downstream light hydrocarbon recovery part, so that the problem of corrosion related to the light hydrocarbon recovery part caused by hydrogen sulfide is avoided, and meanwhile, the concentration of downstream hydrogen sulfide is greatly reduced, thereby improving the safety; the hydrogen sulfide and the carbon dioxide are separated in advance, so that the load and the energy consumption of a downstream light hydrocarbon recovery system can be reduced, and simultaneously, CO is generated2Is removed, and the quality of downstream products can be improved.
(6) In the invention, the liquefied gas recovery tower adopts heavy gasoline to recover a small amount of liquefied gas components, and the liquefied gas components in the tower mainly comprise four carbon components, so that the effect of recovering the four carbon components by using the heavy gasoline is good, five or more carbon components in dry gas discharged from the top of the liquefied gas recovery tower can be greatly reduced, and the loss of the five or more carbon components is correspondingly reduced.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Drawings
The above and other objects, features and advantages of the present invention will become more apparent by describing in more detail exemplary embodiments thereof with reference to the attached drawings, in which like reference numerals generally represent like parts throughout.
FIG. 1 shows a process flow diagram for the separation and recovery of liquefied gas by catalytic cracking of light hydrocarbons in example 1 of the present invention.
Fig. 2 shows a process flow diagram of catalytic cracking light hydrocarbon separation and liquefied gas recovery in example 2 of the present invention.
Description of reference numerals:
1. a fractionating column; 2. a primary heat exchanger; 3. a first-stage gas-liquid separation tank; 4. a secondary heat exchanger; 5. a secondary gas-liquid separation tank; 6. a compressor I; 7. a light and heavy gasoline separation tower; 8. a compressor II; 9. a light hydrocarbon-light gasoline separation tower; 10. a compressor III; 11. a cooler; 12. a gas-liquid separation tank; 13. a rich gas desulfurization tower; 14. a rich gas caustic wash tower; 15. a liquid hydrocarbon desulfurization tower; 16. a liquid hydrocarbon sweetening reactor; 17. an aftercooler; 18. a feed tank; 19. a demethanizer; 20. a deethanizer; 21. a depropanizer; 22. a propylene rectification column; 23. a liquefied gas recovery column;
s1, oil gas from an upstream device; s2, lean amine liquid; s3, an amine-rich solution; s4, alkali liquor; s5, alkali liquor to be regenerated; s6, dry gas; s7, propylene products; s8, propane product; s9, preparing a carbon four product; s10, light gasoline; s11, crude gasoline; s12, heavy gasoline; s13, diesel oil; s14, recycling oil; s15, oil slurry; s16, a carbon two product.
Detailed Description
Preferred embodiments of the present invention will be described in more detail below. While the following describes preferred embodiments of the present invention, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein.
The properties of the feed oil and gas in the following examples are shown in tables 1 and 2:
TABLE 1 flow of high temperature oil and gas at the inlet of the fractionating column
TABLE 2 Properties of gasoline, Diesel and slurry oils in the feed
Example 1
Oil gas recovery device: the system comprises an oil gas feeding pipeline, a fractionating tower 1, a primary heat exchanger 2, a primary gas-liquid separation tank 3, a secondary heat exchanger 4, a secondary gas-liquid separation tank 5, a compressor I6, a light and heavy gasoline separation tower 7, a compressor II 8, a light hydrocarbon-light gasoline separation tower 9, a compressor III 10, a cooler 11, a gas-liquid separation tank 12, a rich gas desulfurizing tower 13, a rich gas alkaline washing tower 14, a liquid hydrocarbon desulfurizing tower 15, a liquid hydrocarbon sweetening reactor 16, an after-cooler 17, a feeding tank 18, a demethanizer 19, a deethanizer 20, a depropanizer 21, a propylene rectifying tower 22 and a liquefied gas recovery tower 23;
wherein, the oil gas feed pipeline is connected with the fractionating tower 1,
the top of the fractionating tower is provided with a primary heat exchanger 2, a primary gas-liquid separation tank 3, a secondary heat exchanger 4 and a secondary gas-liquid separation tank 5, a diesel oil extraction pipeline and a recycle oil extraction pipeline are arranged on the lateral line, and an oil slurry extraction pipeline is arranged at the bottom of the fractionating tower; the top of the fractionating tower is sequentially connected with a first-stage heat exchanger 2 and a first-stage gas-liquid separation tank 3 in series, the top of the first-stage gas-liquid separation tank 3 is sequentially connected with a second-stage heat exchanger 4 and a second-stage gas-liquid separation tank 5 in series, and the bottom of the fractionating tower is respectively connected with the fractionating tower 1 and the light and heavy gasoline separation tower 7; the top of the second-stage gas-liquid separation tank 4 is sequentially connected with a compressor I6 and a light and heavy gasoline separation tower 7 in series, and the bottom of the tank is connected with the light and heavy gasoline separation tower 7;
the top of the light and heavy gasoline separation tower 7 is provided with a reflux tank I, the top of the reflux tank I is sequentially connected with a compressor II 8 and a light hydrocarbon-light gasoline separation tower 9, the bottom of the tank is connected with a booster pump and then connected with the light hydrocarbon-light gasoline separation tower 9, and the bottom of the light and heavy gasoline separation tower 7 is provided with a heavy gasoline extraction pipeline;
a reflux tank II is arranged at the top of the light hydrocarbon-light gasoline separation tower 9, the top of the reflux tank II is sequentially connected with a compressor III 10, a cooler 11 and a gas-liquid separation tank 12, and the bottom of the reflux tank II is connected with a booster pump and then connected with the gas-liquid separation tank 12;
the top of the gas-liquid separation tank 12 is sequentially connected with a rich gas desulfurizing tower 13, a rich gas alkaline washing tower 14 and an after-cooler 17, and the bottom of the tank is sequentially connected with a liquid hydrocarbon desulfurizing tower 15, a liquid hydrocarbon sweetening reactor 16 and the after-cooler 17;
the upper part of the rich gas desulfurization tower 13 is provided with a lean amine liquid feeding pipeline, and the upper part of the rich gas caustic wash tower 14 is provided with an alkali liquid feeding pipeline; the after-cooler 17 is connected with a feeding tank 18; the top of the feeding tank 18 is connected with a liquefied gas recovery tower 23, and the bottom of the tank is connected with a demethanizer 19;
the top of the demethanizer 19 is connected with a liquefied gas recovery tower 23, the bottom of the demethanizer is connected with a deethanizer 20, and the bottom of the tower is provided with a reboiler; the top of the deethanizer 20 is connected with a liquefied gas recovery tower 23, the bottom of the deethanizer is connected with a depropanizer 21, and the bottom of the tower is provided with a reboiler; the upper part of the depropanizing tower is connected with the propylene rectifying tower 22, and the bottom of the depropanizing tower is provided with a C4 product extraction pipeline;
a propylene product extraction pipeline is arranged at the top of the propylene rectifying tower 22, and a propane product extraction pipeline is arranged at the bottom of the tower; the top of the liquefied gas recovery tower 23 is provided with a dry gas extraction pipeline, the bottom of the liquefied gas recovery tower 23 is connected with the light and heavy gasoline separation tower 7, the upper part of the liquefied gas recovery tower 23 is provided with an absorbent feeding pipeline, and the absorbent feeding pipeline is connected with one of the stable gasoline extraction pipelines.
The oil gas recovery is carried out by adopting the process flow shown in figure 1, and the specific process comprises the following steps:
(1) separation: oil gas (product composition is shown in tables 1 and 2) from an outlet of a reactor of an upstream catalytic cracking device is sent to a fractionating tower 1 for separation, oil slurry, diesel oil and recycle oil are respectively extracted from the bottom and a lateral line of the fractionating tower 1, gas phase at the top of the tower is cooled and then sent to a first-stage gas-liquid separation tank 3, gas phase at the top of the tank is condensed again and then sent to a second-stage gas-liquid separation tank 5, liquid phase part at the bottom of the tank is sent back to the top of the fractionating tower 1, and the rest part is sent to a light gasoline separation tower 7; the gas phase at the top of the second-stage gas-liquid separation tank 5 is compressed and then sent to a light and heavy gasoline separation tower 7, and the liquid phase at the bottom of the tank is boosted and then sent to the light and heavy gasoline separation tower 7; the operation temperature at the top of the fractionating tower 1 is 100-140 ℃, and the pressure is 0.1-0.35 MPaG; the operation temperature of the primary gas-liquid separation tank 3 is 60-85 ℃, and the pressure is 0.07-0.32 MPaG; the operation temperature of the secondary gas-liquid separation tank 5 is 35-50 ℃, and the pressure is 0.03-0.28 MPaG;
(2) separating light gasoline and heavy gasoline: the material from the second-stage gas-liquid separation tank 5 enters a light and heavy gasoline separation tower 7, the overhead distillate gas phase is condensed and enters an overhead reflux tank I, the gas phase at the top of the overhead reflux tank I is compressed and then sent to a light hydrocarbon-light gasoline separation tower 9, the liquid phase at the bottom of the tank is pressurized and then sent to the light hydrocarbon-light gasoline separation tower 9, part of the liquid phase at the bottom of the light and heavy gasoline separation tower 7 is extracted as a heavy gasoline product S12, and the rest part of the liquid phase is sent to a liquefied gas recovery tower 23 as an absorbent; the operation temperature of the top of the light and heavy gasoline separating tower 7 is 55-80 ℃, the operation temperature of the bottom of the tower is 130-170 ℃, the operation pressure is 0.2-0.6 MPaG, and the initial boiling point of heavy gasoline is 65-85 ℃;
(3) light hydrocarbon-light gasoline separation: the material flow from the top reflux tank I of the light and heavy gasoline separation tower 7 enters a light hydrocarbon-light gasoline separation tower 9, the gas phase distilled from the top of the tower enters a top reflux tank II, the gas phase at the top of the top reflux tank II is sent to a gas-liquid separation tank 12 after being compressed and cooled, the liquid phase at the bottom of the tank is sent to the gas-liquid separation tank 12 after being pressurized, and the liquid phase at the bottom of the tank is taken as a light gasoline product S10 to be extracted; the operating temperature of the light hydrocarbon-light gasoline separating tower 9 is 55-85 ℃, the operating pressure is 1.0-1.3 MPaG, and the dry point of the light gasoline is 60-80 ℃;
(4) second gas-liquid separation: after the materials are mixed and gas-liquid balanced in the gas-liquid separation tank 12, the gas phase and the liquid phase are separated again, and then impurities are respectively removed;
(5) gas-phase impurity removal: the gas phase on the top of the gas-liquid separation tank 12 is sequentially rich in gasThe lean amine liquid S2 is used as absorbent in the desulfurizing tower 13 for removing H2S and CO2In the rich gas caustic tower 14, alkali liquor S4 is used for removing mercaptan and a small amount of H2S and CO2Then sent to an aftercooler 17; the operation temperature of the rich gas desulfurization tower 13 is 35-45 ℃, and the operation pressure is 2.0-2.8 MPaG;
(6) liquid phase impurity removal: the liquid phase at the bottom of the gas-liquid separation tank 12 is sequentially subjected to H removal in a liquid hydrocarbon desulfurization tower 152S and CO2After mercaptan is removed in a liquid hydrocarbon mercaptan removal reactor 16, the liquid hydrocarbon mercaptan removed liquid is sent to an after-cooler 17; the operating temperature of the liquid hydrocarbon desulfurization tower 15 is 35-45 ℃, and the operating pressure is 2.0-2.8 MPaG;
(7) and (3) cooling: the gas phase and the liquid phase are preliminarily mixed and cooled in an after-cooler 17 and then are sent to a feeding tank 18;
(8) feeding: after the mixture flow from the after-cooler 17 is mixed and gas-liquid balanced in the feeding tank 18, the gas phase at the top of the tank is sent to a liquefied gas recovery tower 23, and the liquid phase at the bottom of the tank is sent to a demethanizer 19; the operating temperature of the feeding tank 18 is 5-20 ℃, and the operating pressure is 1.9-2.7 MPaG;
(9) demethanization: the liquid phase from the bottom of the feed tank 18 is removed with methane in the demethanizer 19, at the same time, a small part of components with the carbon number of 2 and more than 2 are removed, the gas phase at the top of the demethanizer 19 is sent to the liquefied gas recovery tower 23, and the liquid phase at the bottom of the demethanizer is sent to the deethanizer 20; the temperature of the top of the demethanizer 19 is 10-30 ℃, the pressure is 2.2-3.0 MPaG, and the temperature of the bottom of the tower is 60-100 ℃;
(10) deethanizing: separating C2 components from the liquid phase at the bottom of the demethanizer 19 in a deethanizer 20, collecting the separated mixed C2 components from the top of the deethanizer 20, sending the components to a liquefied gas recovery tower 23, and sending the liquid phase components with C3 and C3 at the bottom of the deethanizer 21; the temperature of the top of the deethanizer 20 is 5-20 ℃, the pressure is 2.6-3.2 MPaG, and the temperature of the bottom of the deethanizer is 95-120 ℃;
(11) depropanizing: the liquid phase component from the bottom of the deethanizer 20 is further separated in the depropanizer 21, the separated C3 component is extracted from the upper part of the depropanizer 21 and then sent to the propylene rectifying tower 22, and the liquid phase component is extracted as a carbon four product S9 from the bottom of the depropanizer; the temperature of the top of the depropanizer 21 is 50-65 ℃, the pressure is 1.6-2.0 MPaG, and the temperature of the bottom of the depropanizer is 95-120 ℃;
(12) and (3) recovering liquefied gas: in the liquefied gas recovery tower 23, heavy gasoline is used as an absorbent to recover liquefied gas components in a gas phase in the tower, the gas phase at the top of the liquefied gas recovery tower 23 is extracted as a dry gas product S6, and a liquid phase at the bottom of the liquefied gas recovery tower is returned to the light and heavy gasoline separation tower 7; the temperature of the liquefied gas recovery tower 23 is 5-20 ℃, and the pressure is 1.9-2.7 MPaG;
(13) and (3) propylene rectification: c3 components extracted from the upper part of the depropanizing tower 21 are sent to a propylene rectifying tower 22 for further rectification, the gas phase at the top of the propylene rectifying tower 22 is extracted as a propylene product S7, and the liquid phase at the bottom of the propylene rectifying tower is extracted as a propane product S8; the temperature of the propylene rectifying tower 22 is 45-60 ℃, and the pressure is 1.7-2.0 MPaG.
The properties of the product isolated by the above process are shown in tables 3, 4 and 5.
TABLE-3
TABLE 4
TABLE 5 Properties of the Diesel and slurry products
Example 2
The oil gas recovery is carried out by adopting the process flow shown in figure 2, and only the difference from the example 1 is that:
(10) deethanizing: the liquid phase from the bottom of the demethanizer 19 is further separated into C2 components in the deethanizer 20, the separated mixed C2 components are extracted from the top of the deethanizer 20, a carbon dioxide product S16 is obtained as a byproduct, and the liquid phase components at the bottom of the deethanizer 19 and above C3 are sent to the depropanizer 21.
The light hydrocarbons in the catalytic cracking reaction were separated by the above-described method, and the composition and properties of each product were separated as shown in tables 6 to 8.
TABLE 6
TABLE 7
TABLE 8 Properties of the Diesel and slurry products
Therefore, the invention separates light dydrocarbon to recover liquefied gas through mild operation conditions, realizes high-efficiency separation and recovery of C three and C four components, the recovery rate is more than 99 wt%, and the content of C2 in the propylene product obtained by further separation is not more than 200 ppmv. In addition, as can be seen from the example 2, the invention can also obtain a carbon dioxide product as a byproduct, and the recovery rate of the carbon dioxide product can reach 50-60%.
Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.
Claims (10)
1. A method of oil and gas recovery, the method comprising:
(1) separation: oil gas from an upstream device is sent to a fractionating tower for separation, oil slurry, diesel oil and recycle oil are respectively extracted from the bottom and a lateral line of the fractionating tower, gas phase at the top of the fractionating tower is sent to a first-stage gas-liquid separation tank after being cooled, gas phase at the top of the tank is sent to a second-stage gas-liquid separation tank after being condensed again, liquid phase part at the bottom of the tank is sent to the top of the fractionating tower, and the rest part is sent to a light gasoline separation tower; compressing the gas phase at the top of the secondary gas-liquid separation tank, and then sending the gas phase to a light and heavy gasoline separation tower, and boosting the pressure of the liquid phase at the bottom of the tank, and then sending the liquid phase to the light and heavy gasoline separation tower;
(2) separating light gasoline and heavy gasoline: the material from the second-stage gas-liquid separation tank enters a light and heavy gasoline separation tower, the gas phase distilled from the tower top is condensed and enters a tower top reflux tank I, the gas phase at the top of the tower top reflux tank I is compressed and then sent to a light hydrocarbon-light gasoline separation tower, the liquid phase at the bottom of the tank is pressurized and then sent to the light hydrocarbon-light gasoline separation tower, and at least part of the liquid phase at the bottom of the light and heavy gasoline separation tower is taken as a heavy gasoline product for extraction;
(3) light hydrocarbon-light gasoline separation: feeding the material flow from the top reflux tank I of the light and heavy gasoline separation tower into a light hydrocarbon-light gasoline separation tower, feeding the gas phase distilled from the top of the tower into a top reflux tank II, compressing and cooling the gas phase at the top of the top reflux tank II, feeding the gas phase to a gas-liquid separation tank, pressurizing the liquid phase at the bottom of the tank, feeding the gas phase to the gas-liquid separation tank, and extracting the liquid phase at the bottom of the tank as light gasoline;
(4) second gas-liquid separation: mixing the materials in a gas-liquid separation tank, balancing gas and liquid, separating gas phase and liquid phase again, and then respectively removing impurities;
(5) gas-phase impurity removal: gas phase at the top of the gas-liquid separation tank is sequentially subjected to H removal in a rich gas desulfurization tower by taking lean amine liquid as an absorbent2S and CO2Removing mercaptan in a rich gas alkaline washing tower by using alkali liquor, and then sending the rich gas alkaline washing tower to an aftercooler;
(6) liquid phase impurity removal: the liquid phase at the bottom of the gas-liquid separation tank is sequentially subjected to H removal in a liquid hydrocarbon desulfurization tower2S and CO2Removing mercaptan in a liquid hydrocarbon mercaptan removal reactor by adopting alkali liquor, and then conveying the liquid hydrocarbon mercaptan removal reactor to a post-cooler;
(7) and (3) cooling: the gas phase and the liquid phase are preliminarily mixed and cooled in a postcooler and then are sent to a feeding tank;
(8) feeding: after the mixture flow from the aftercooler is mixed and gas-liquid balanced in a feeding tank, the gas phase at the top of the tank is sent to a liquefied gas recovery tower, and the liquid phase at the bottom of the tank is sent to a demethanizer;
(9) demethanization: removing methane from the liquid phase at the bottom of the feed tank in a demethanizer, simultaneously removing a small part of components with the content of C2 and above C2, sending the gas phase at the top of the demethanizer to a liquefied gas recovery tower, and sending the liquid phase at the bottom of the demethanizer to a deethanizer;
(10) deethanizing: separating C2 component from the liquid phase at the bottom of the demethanizer in a deethanizer, collecting the separated mixed C2 component from the top of the deethanizer or sending the component to a liquefied gas recovery tower, and sending the liquid phase components with C3 and above C3 at the bottom of the deethanizer to a depropanizer;
(11) depropanizing: further separating the liquid phase component from the bottom of the deethanizer in a depropanizer, and extracting the separated C3 component from the upper part of the depropanizer as a C three product and the bottom of the depropanizer as a C four product;
(12) and (3) recovering liquefied gas: in the liquefied gas recovery tower, heavy gasoline is used as an absorbent to recover liquefied gas components in a gas phase in the tower, the gas phase at the top of the liquefied gas recovery tower is extracted as a dry gas product, and a liquid phase at the bottom of the liquefied gas recovery tower returns to the light and heavy gasoline separation tower;
the temperature of the top of the demethanizer is 10-30 ℃, the pressure is 2.2-3.0 MPaG, and the temperature of the bottom of the demethanizer is 60-100 ℃;
the temperature of the top of the deethanizer is 5-20 ℃, the pressure is 2.6-3.2 MPaG, and the temperature of the bottom of the deethanizer is 95-120 ℃.
2. The method of claim 1, further comprising:
(13) and (3) propylene rectification: and (3) sending the carbon product extracted from the upper part of the depropanizing tower to a propylene rectifying tower for further rectification, wherein the gas phase at the top of the propylene rectifying tower is extracted as a propylene product, and the liquid phase at the bottom of the propylene rectifying tower is extracted as a propane product.
3. The method of claim 1, wherein the hydrocarbons of the upstream plant contain H2The device comprises C1-C4 light hydrocarbon, gasoline, diesel oil and heavy oil, wherein the upstream device is at least one of catalytic cracking, catalytic cracking and delayed coking.
4. The method of claim 1,
the operation temperature of the top of the fractionating tower is 100-140 ℃, and the pressure is 0.1-0.35 MPaG;
the operation temperature of the primary gas-liquid separation tank is 60-85 ℃, and the pressure is 0.07-0.32 MPaG; the operation temperature of the secondary gas-liquid separation tank is 35-50 ℃, and the pressure is 0.03-0.28 MPaG;
the operation temperature of the top of the light and heavy gasoline separation tower is 55-80 ℃, the operation temperature of the bottom of the light and heavy gasoline separation tower is 130-170 ℃, and the operation pressure is 0.2-0.6 MPaG; the operating temperature of the light hydrocarbon-light gasoline separating tower is 55-85 ℃, and the operating pressure is 1.0-1.3 MPaG; the initial boiling point of the heavy gasoline is 65-85 ℃, and the dry point of the light gasoline is 60-80 ℃;
the operation temperature of the rich gas desulfurization tower is 35-45 ℃, and the operation pressure is 2.0-2.8 MPaG; the operating temperature of the liquid hydrocarbon desulfurization tower is 35-45 ℃, and the operating pressure is 2.0-2.8 MPaG;
the operating temperature of the feeding tank is 5-20 ℃, and the operating pressure is 1.9-2.7 MPaG.
5. The method according to claim 1, wherein the depropanizer has a top temperature of 50-65 ℃, a pressure of 1.6-2.0 MPaG, and a bottom temperature of 95-120 ℃.
6. The method according to claim 1, wherein the liquefied gas recovery tower has a temperature of 5 to 20 ℃ and a pressure of 1.9 to 2.7 MPaG; the absorbent is a heavy gasoline product extracted from the bottom of the light and heavy gasoline separation tower, and does not need to be supplemented from the outside of the system.
7. The method according to claim 2, wherein the temperature of the propylene rectification column is 45-60 ℃ and the pressure is 1.7-2.0 MPaG.
8. An apparatus for use in the method of any one of claims 1 to 7, the apparatus comprising: the system comprises an oil gas feeding pipeline, a fractionating tower, a primary heat exchanger, a primary gas-liquid separating tank, a secondary heat exchanger, a secondary gas-liquid separating tank, a compressor I, a light and heavy gasoline separating tower, a compressor II, a light hydrocarbon-light gasoline separating tower, a compressor III, a cooler, a gas-liquid separating tank, a rich gas desulfurizing tower, a rich gas alkaline washing tower, a liquid hydrocarbon desulfurizing tower, a liquid hydrocarbon sweetening reactor, an after cooler, a feeding tank, a demethanizer, a deethanizer, a depropanizer and a liquefied gas recovery tower;
wherein, the oil gas feed pipeline is connected with the fractionating tower,
the top of the fractionating tower is provided with a first-stage heat exchanger, a first-stage gas-liquid separation tank, a second-stage heat exchanger and a second-stage gas-liquid separation tank, a diesel oil extraction pipeline and a recycle oil extraction pipeline are arranged on the lateral line, and an oil slurry extraction pipeline is arranged at the bottom of the fractionating tower; the top of the fractionating tower is sequentially connected with a first-stage heat exchanger and a first-stage gas-liquid separation tank in series, the top of the first-stage gas-liquid separation tank is sequentially connected with a second-stage heat exchanger and a second-stage gas-liquid separation tank in series, and the bottom of the fractionating tower is respectively connected with the fractionating tower and the light and heavy gasoline separation tower; the top of the second-stage gas-liquid separation tank is sequentially connected with a compressor I and a light and heavy gasoline separation tower in series, and the bottom of the tank is connected with the light and heavy gasoline separation tower;
the top of the light and heavy gasoline separation tower is provided with a reflux tank I, the top of the reflux tank I is sequentially connected with a compressor II and a light hydrocarbon-light gasoline separation tower, the bottom of the tank is connected with a booster pump and then connected with the light hydrocarbon-light gasoline separation tower, and the bottom of the light and heavy gasoline separation tower is provided with a heavy gasoline extraction pipeline;
a reflux tank II is arranged at the top of the light hydrocarbon-light gasoline separation tower, the top of the reflux tank II is sequentially connected with a compressor III, a cooler and a gas-liquid separation tank, and the bottom of the tank is connected with a booster pump and then connected with the gas-liquid separation tank;
the top of the gas-liquid separation tank is sequentially connected with a rich gas desulfurization tower, a rich gas alkaline washing tower and an after-cooler, and the bottom of the tank is sequentially connected with a liquid hydrocarbon desulfurization tower, a liquid hydrocarbon sweetening reactor and an after-cooler;
the upper part of the rich gas desulfurization tower is provided with a lean amine liquid feeding pipeline, and the upper part of the rich gas caustic tower is provided with an alkali liquid feeding pipeline;
the aftercooler is connected with the feeding tank;
the top of the feeding tank is connected with a liquefied gas recovery tower, and the bottom of the feeding tank is connected with a demethanizer;
the top of the demethanizer is connected with a liquefied gas recovery tower, and the bottom of the demethanizer is connected with a deethanizer;
a carbon dioxide extraction pipeline is arranged at the top of the deethanizer, the carbon dioxide extraction pipeline is optionally connected with a liquefied gas recovery tower, and the bottom of the deethanizer is connected with a depropanizer;
the upper part of the depropanizing tower is provided with a C3 product extraction pipeline, and the bottom of the depropanizing tower is provided with a C4 product extraction pipeline;
the tower top of the liquefied gas recovery tower is provided with a dry gas extraction pipeline, the tower bottom of the liquefied gas recovery tower is connected with a light and heavy gasoline separation tower, and the upper part of the liquefied gas recovery tower is provided with an absorbent feeding pipeline.
9. The apparatus of claim 8, further comprising a propylene rectification column, wherein the C3 product take-off line is connected to the propylene rectification column; and a propylene product extraction pipeline is arranged at the top of the propylene rectifying tower, and a propane product extraction pipeline is arranged at the bottom of the propylene rectifying tower.
10. The apparatus of claim 8, wherein the heavy gasoline production line is bifurcated, one of which serves as an absorbent feed line to a liquefied gas recovery column;
and reboilers are arranged at the bottoms of the demethanizer and the deethanizer.
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| WO2019072803A1 (en) * | 2017-10-12 | 2019-04-18 | Haldor Topsøe A/S | Process for purification of hydrocarbons |
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| US5015364A (en) * | 1989-06-21 | 1991-05-14 | Mobil Oil Corporation | Method and means for refinery gas plant operation |
| WO2015094948A1 (en) * | 2013-12-18 | 2015-06-25 | Saudi Arabian Oil Company | Production of upgraded petroleum by supercritical water |
| CN106316752A (en) * | 2015-06-24 | 2017-01-11 | 中石化广州工程有限公司 | A kind of separation method of methanol conversion to propylene reaction product |
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