CN103988035A - Method and apparatus for removing nitrogen from cryogenic hydrocarbon composition - Google Patents

Method and apparatus for removing nitrogen from cryogenic hydrocarbon composition Download PDF

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Publication number
CN103988035A
CN103988035A CN201280061161.0A CN201280061161A CN103988035A CN 103988035 A CN103988035 A CN 103988035A CN 201280061161 A CN201280061161 A CN 201280061161A CN 103988035 A CN103988035 A CN 103988035A
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Prior art keywords
stripping
nitrogen
liquid
vapor
steam
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CN201280061161.0A
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Chinese (zh)
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A·M·C·R·桑托斯
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Shell Internationale Research Maatschappij BV
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Shell Internationale Research Maatschappij BV
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2245/00Processes or apparatus involving steps for recycling of process streams
    • F25J2245/90Processes or apparatus involving steps for recycling of process streams the recycled stream being boil-off gas from storage
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25JLIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2280/00Control of the process or apparatus
    • F25J2280/02Control in general, load changes, different modes ("runs"), measurements

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  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Separation By Low-Temperature Treatments (AREA)
  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

Abstract

Nitrogen is removed from a cryogenic hydrocarbon composition. A least a first portion of the cryogenic hydrocarbon composition is fed to a nitrogen stripper column as a first nitrogen stripper feed stream. A nitrogen-stripped liquid is drawn from the nitrogen stripper column. At least a step of depressurizing the nitrogen-stripped liquid to a flash pressure is included so as to produce a liquid hydrocarbon product stream and a process vapour. The process vapour is compressed, and selectively split into a stripping portion and a non-stripping portion. A stripping vapour stream comprising at least the stripping portion is passed into the nitrogen stripper column. A vapour fraction is discharged as off gas. The vapour fraction comprises a discharge fraction of overhead vapour from the nitrogen stripper column, and at least the bypass portion from the non-stripping portion of the compressed vapour. The bypass portion bypasses a stripping section positioned in the nitrogen stripper column.

Description

For remove the method and apparatus of nitrogen from low temperature hydrocarbon compositions
Technical field
The present invention relates to a kind of for the method and apparatus from low temperature hydrocarbon compositions separation of nitrogen.
Background technology
Liquefied natural gas (LNG) forms the important example economically of this low temperature hydrocarbon compositions.Natural gas is available fuel source, and the source of various hydrocarbon compounds.Due to many reasons, conventionally wish at the source place of natural gas flow or approach the source of natural gas flow, liquefied natural gas in LNG plant.For example, than gas form, natural gas is easier to as fluid storage and in the interior conveying of long distance, because it occupies less volume, and without under high pressure storing.
WO 2011/009832 has described a kind of method of the heterogeneous hydrocarbon stream for the treatment of being produced by natural gas, wherein by more lower boiling component (as nitrogen) from as described in separate heterogeneous hydrocarbon stream, there is the more liquefied natural gas stream of this more lower boiling component of low content to produce.It utilizes two continuous gas/liquid separation devices that operate under different pressures.Heterogeneous hydro carbons is flow to material to the first gas/liquid separation device under the first pressure.The bottom of described the first gas/liquid separation device is spread and is handed to the second gas/liquid separation device, and described the second gas/liquid separation device provides the steam under the second pressure lower than under described the first pressure.Steam compresses in overhead stream compressor, and is back to described the first gas/liquid separation device as stripping steam flow.
Compression Volatile Gas from low-temperature storage tank can be added into described stripping steam flow.Described first liquid/gas separator comprises the have contact intensifier contact zone of (as tower tray or filler), described contact zone flow to the entrance of the first gas/liquid separation device for heterogeneous hydro carbons and for the entrance of stripping steam flow between gravity setting.
Low-pressure fuel air-flow is made by the overhead vapor stream of discharging from described the first gas/liquid separation device, and described low-pressure fuel air-flow is passed to burner.
A shortcoming of the method and apparatus described in WO 2011/009832 is, if the amount of stripping steam significantly changes (can be this situation in the time that factory converts between Holdover mode and loading pattern operation), the balance in the first gas/liquid separation device may be by disturbance.
Summary of the invention
The invention provides a kind of method of removing nitrogen from low temperature hydrocarbon compositions, described low temperature hydrocarbon compositions comprises the liquid phase containing nitrogen and methane, and described method comprises:
-the low temperature hydrocarbon compositions comprising containing the liquid phase of nitrogen and methane is provided;
-the first nitrogen stripping device incoming flow under stripping pressure is fed to nitrogen stripping tower, described nitrogen stripping tower comprises the inner stripping of at least one that be arranged in nitrogen stripping tower portion section, the Part I that described the first nitrogen stripping device incoming flow comprises low temperature hydrocarbon compositions;
-liquid from the liquid storage spatial extraction of the nitrogen stripping tower of described stripping portion section below through nitrogen stripping;
-prepare at least liquid hydrocarbon product stream and process steam by the described liquid through nitrogen stripping, at least comprise the step to flashing pressure by the described liquid pressure-reducing through nitrogen stripping;
-described process steam is compressed to at least stripping pressure, obtain thus compressed vapour;
-described compressed vapour is optionally separated into stripping part and does not comprise the non-stripping part of stripping part, the by-passing part that described non-stripping part comprises described compressed vapour;
-level place below described stripping portion section gravity is passed to stripping steam flow in nitrogen stripping tower, and described stripping steam flow at least comprises the stripping part of described compressed vapour;
-intermediate vapor is passed through to condenser, thereby make described intermediate vapor and auxiliary refrigerant stream indirect heat exchange, and intermediate vapor described in partial condensation, wherein said intermediate vapor at least comprises the non-stripping part of described compressed vapour, and wherein said heat exchange comprises that heat is passed to auxiliary refrigerant with certain cooling load from described intermediate vapor to flow, excess liq is formed by described intermediate vapor thus, and remains in gas phase from least described by-passing part of described compressed vapour thus;
-discharge the vapor fraction as waste gas, described vapor fraction comprises the discharge cut available from the overhead vapor of the headroom of described nitrogen stripping tower, and at least comprises described by-passing part; And
-by described being back at least partly of liquid recycle sections liquid hydrocarbon product stream, wherein said liquid recycle sections comprises at least part of of described excess liq;
The wherein discharge from described Selective Separation to the by-passing part the vapor fraction of described waste gas, described by-passing part is walked around at least one inner stripping portion section.
On the other hand, the invention provides a kind of for remove the device of nitrogen from low temperature hydrocarbon compositions, described low temperature hydrocarbon compositions comprises the liquid phase containing nitrogen and methane, described device comprises: for removing nitrogen from low temperature hydrocarbon compositions, described low temperature hydrocarbon compositions comprises the liquid phase containing nitrogen and methane, and described device comprises:
-being connected to the low temperature feeding line in the source of low temperature hydrocarbon compositions, described low temperature hydrocarbon compositions comprises the liquid phase containing nitrogen and methane;
-nitrogen stripping the tower that is communicated with described low temperature feeding line fluid, the liquid storage space that described nitrogen stripping tower comprises at least one inner stripping portion's section of being arranged in nitrogen stripping tower and limits below described stripping portion section gravity;
-comprise the discharge pipe line of the liquid through nitrogen stripping of intermediate relief device, the discharge pipe line of the described liquid through nitrogen stripping is communicated with the liquid storage space fluid of described nitrogen stripping tower, and arrange in order to receive through the liquid of nitrogen stripping and by the liquid pressure-reducing through nitrogen stripping from described liquid storage space, described intermediate relief device is at the stripping that comprises nitrogen stripping tower on the interface on the pressure side and between flashing pressure side;
-be communicated with described intermediate relief device be arranged at the liquid hydrocarbon product pipeline in flashing pressure side, flow to discharge the liquid hydrocarbon product being produced by the described liquid through nitrogen stripping;
-be communicated with described intermediate relief device be arranged at the process steam pipeline in flashing pressure side, to receive the process steam being produced by the described liquid through nitrogen stripping;
-be arranged at the process compressor in described process steam pipeline, it arranges in order to receive described process steam and to compress described process steam, provide compressed vapour with the process compressor discharge place at described process compressor, described process compressor is at stripping on the described interface on the pressure side and between flashing pressure side;
-bypass diverter, its upstream side is communicated with to receive compressed vapour with the floss hole fluid of described process compressor thus, the first waste side of described bypass diverter is via stripping vapor line and the second entrance system and be communicated with described nitrogen stripping tower fluid, described the second entrance system is arranged at the level place of the gravity below of described stripping portion section, and arrange in order to receive at least stripping part from the described compressed vapour of described process compressor, the second waste side of described bypass diverter is communicated with the steam bypass line fluid of the non-stripping part that contains described compressed vapour,
-be communicated with the condenser arranging with described steam bypass line fluid to bring the intermediate vapor at least comprising from the non-stripping part of described steam bypass line, described condenser comprises heat exchange surface, and described heat exchange surface provides the indirect heat exchange between described intermediate vapor and auxiliary refrigerant stream to contact;
-the discharge pipe line that is communicated with the headroom of described condenser and described nitrogen stripping tower, it arranges the vapor fraction as waste gas in order to discharge, described vapor fraction comprises available from the overhead vapor of the headroom of described nitrogen stripping tower and the by-passing part that comprises non-condensing steam, and described non-condensing steam is controlled oneself by the intermediate vapor of described condenser; And
-liquid recirculation line, described liquid recirculation line at its upstream side is communicated with described condenser fluid, and is communicated with described liquid hydrocarbon product pipeline liquid in its downstream;
Wherein bypass path is extended between described bypass diverter and described discharge pipe line, and wherein said bypass path is walked around described at least one inner stripping portion section.
Brief description of the drawings
Use embodiment and with reference to accompanying drawing, below further illustrating the present invention, in the accompanying drawings:
Fig. 1 schematically shows process chart, and it represents to introduce the method and apparatus of one embodiment of the invention; With
Fig. 2 schematically shows process chart, and it represents to introduce the method and apparatus of another embodiment of the present invention.
In these figure, identical Reference numeral will be used in reference to same or similar parts.In addition, single Reference numeral is by for determining pipeline or pipeline and the stream being transmitted by this pipeline.
Detailed description of the invention
This description relates to from comprise the low temperature hydrocarbon compositions containing the liquid phase of nitrogen and methane removes nitrogen.At least Part I of low temperature hydrocarbon compositions is fed to nitrogen stripping tower as the first nitrogen stripping device incoming flow.Extract the liquid through nitrogen stripping from nitrogen stripping tower.At least comprise the step to flashing pressure by the described liquid pressure-reducing through nitrogen stripping, thereby produce liquid hydrocarbon product stream and process steam.Compression process steam, and it is optionally separated into stripping part and non-stripping part.Below the gravity that is arranged at the stripping portion section in nitrogen stripping tower, the stripping steam flow that at least comprises stripping part is passed in nitrogen stripping tower.The intermediate vapor of the non-stripping part that at least comprises compression process steam is passed through to condenser, form excess liq from described intermediate vapor thus, and remain in gas phase from least by-passing part of compressed vapour thus.Vapor fraction is as toxic emission, and described vapor fraction comprises the discharge cut from the overhead vapor of nitrogen stripping tower, and comprises at least by-passing part from compressed vapour, and described by-passing part is walked around the stripping portion section being arranged in nitrogen stripping tower.Liquid recycle sections comprises at least part of of described excess liq.The liquid hydrocarbon product that is back at least partly of liquid recycle sections is flowed.
Separation contains the non-stripping part from the by-passing part of compression process steam, and at least by-passing part is passed to waste gas, an advantage walking around thus the stripping portion section being arranged in nitrogen stripping tower is, the excessive of stripping steam that nitrogen stripping tower can avoid flowing through stripping portion section flows.This excessive flowing can cause the disturbance of equilibrium condition.Due to non-stripping part is passed through to condenser, therefore avoid being separated in the valuable part (as common steam methane) of the process steam in non-stripping part and passed through waste gas loss, but can and be added into excess liq by condensation again, described excess liq is finally returned to liquid hydrocarbon product stream.
Vapor fraction in waste gas has calorific value conventionally.Preferably, regulate the cooling load of condenser, to regulate and control the calorific value of vapor fraction of discharge.The ability of regulation and control calorific value is favourable, and it allows antagonism to stablize the calorific value of the vapor fraction in waste gas than the flow of the overhead vapor from nitrogen stripping tower and/or the variation of composition or fluctuation from the flow of the by-passing part of compression process steam and/or composition.In the time that LNG factory is operated by Holdover mode operational transformation to loading pattern, can expect the variation of flow and composition in LNG equipment.In loading pattern process, not only vapor flow rate is higher, and also poorer (containing especially more nitrogen) of composition.Regulate both abilities of cooling load in by-passing part and condenser to contribute to process the ability that other steam loads in loading pattern process.
Process steam can comprise steam methane, and described steam methane is forming the part of thick liquiefied product before.Due to many reasons, can in liquefying factory, LNG form at the steam methane that forms before the part of thick liquiefied product.In the course of normal operation of natural gas liquefaction facility, formed by (slightly) liquiefied product with following form containing the steam of methane:
-flashed vapour, it obtains the flash distillation of thick liquiefied product in comfortable decompression process; And
-Volatile Gas (boil-off gas), it must be freed from the thermal evaporation that is added into the heat of liquiefied product and cause, and described heat is for example for entering storage tank, the ducted heat leak of LNG, and the form of inputting from the heat of the LNG of factory pump.In described operator scheme (being called Holdover mode operation) process, storage tank is filled by Liquefied Hydrocarbon series products in the time that Liquefied Hydrocarbon series products leaves equipment, and does not carry out any conveyor load operation simultaneously.When in Holdover mode, produce at the equipment side of storage tank containing the steam of methane.
The operator scheme of the LNG equipment in the time there is lasting conveyor load operation (ship loading operation conventionally) is called loading pattern operation.In loading pattern operating process, for example due to boats and ships tank initially cooling, by connecting storage tank and the pipeline of boats and ships and the heat leak of container, and from the heat input of LNG loading pump, Volatile Gas produces in addition in the boats and ships side of storage tank.
The solution proposing can be processed these steams in Holdover mode and loading pattern operating process.It has combined the condensation again of removing nitrogen and excessive steam methane from low temperature hydrocarbon compositions.In the situation of a small amount of factory of needs fuel (if use is from the situation of the electric drive factory of the electric power of external electrical network), this has formed good solution.
In the time that process steam can comprise the one or both in flashed vapour and Volatile Gas, it is specially adapted to Volatile Gas.The flow of Volatile Gas is limited by the variation of typical LNG factory most.Due to proposed solution allow by compressed vapour optionally stripping become stripping part and non-stripping part, therefore it allows optionally to make to exceed as the required any process steam of stripping steam to walk around the stripping portion section in nitrogen stripping tower.This makes proposed solution be particularly suitable for making Volatile Gas to hold (accommodate) in process steam.
Fig. 1 shows a kind of device that comprises one embodiment of the invention.Low temperature feeding line 8 is communicated with nitrogen stripping tower 20 fluids via the first entrance system 21.The first feeding line 10 optionally connects the first entrance system 21 of low temperature feeding line 8 and nitrogen stripping tower 20 via initial flow current divider 9, described initial flow current divider 9 is arranged between low temperature feeding line 8 and the first feeding line 10.
Liquefaction system 100 can be arranged at the upstream of low temperature feeding line 8.Liquefaction system 100 is as the source of low temperature hydrocarbon compositions.Liquefaction system 100 is communicated with low temperature feeding line 8 fluids via main depressurized system 5, and described main depressurized system 5 is communicated with liquefaction system 100 via thick liquiefied product pipeline 1.In the illustrated embodiment, main depressurized system 5 is made up of dynamic cell (as decompressor turbine 6) and static cell (as joule Thomson valve 6), but other variants are possible.Preferably but necessarily, form any compressor, particularly any coolant compressor of part of the hydro carbons liquefaction process in liquefaction system by one or more Motor Drive, and can't help any steam turbine and/or gas turbine Mechanical Driven.This compressor can be only by one or more Motor Drive.
Nitrogen stripping tower 20 comprises the inside stripping portion section 24 being arranged in nitrogen stripping tower 20.Overhead vapor discharge pipe line 30 is communicated with nitrogen stripping tower 20 via the headroom 26 in nitrogen stripping tower 20.
Discharge pipe line 40 through the liquid of nitrogen stripping is communicated with nitrogen stripping tower 20 via the liquid storage space 28 in nitrogen stripping tower 20, and described liquid storage space 28 is below the gravity of stripping portion section 24.
Nitrogen stripping tower 20 can comprise vapor/liquid contact intensifier, separates and denitrogenation to improve component.Depend on the nitrogen amount in Tolerance and the low temperature feeding line 8 of the nitrogen in nitrogen stripping liquid, can conventionally altogether need the theoretical stage between 2 to 8.In a particular, need 4 theoretical stages.This contact intensifier can, with the form of tower tray and/or filler, provide with the form of structuring or destructuring filler.Vapor/liquid contacts the part of the inner stripping of suitably forming at least partly of intensifier portion section 24.
Intermediate relief device 45 is arranged in the discharge pipe line 40 of the liquid of nitrogen stripping, and fluid is connected to nitrogen stripping tower 20 thus.In intermediate relief device 45 functions, be attached to liquid-level controller LC, described liquid-level controller LC cooperates with the liquid storage space 28 of nitrogen stripping tower 20.
Intermediate relief device 45 is arranged on the interface of the stripping that comprises nitrogen stripping tower 20 on the pressure side and between flashing pressure side.Flashing pressure side comprises liquid hydrocarbon product pipeline 90 and process steam pipeline 60, described liquid hydrocarbon product pipeline 90 arranges the liquid hydrocarbon product being produced by the liquid 40 through nitrogen stripping in order to discharge and flows, and described process steam pipeline 60 arranges the process steam being produced by the liquid 40 through nitrogen stripping in order to receive.In the embodiment illustrated, flashing pressure side also comprises the low-temperature storage tank that is connected to liquid hydrocarbon product pipeline 90 210 for storing liquid hydrocarbon product stream, optional Volatile Gas supply line 230 and optional end flash separator 50.
If this end flash separator 50 (as the situation in the embodiment of Fig. 1) is provided, it can be configured to be communicated with nitrogen stripping tower 20 fluids via intermediate relief device 45 with through the discharge pipe line 40 of the liquid of nitrogen stripping.End flash separator 50 can be connected to low-temperature storage tank 210 via liquid hydrocarbon product pipeline 90 subsequently.Cryogenic pump 95 can be present in liquid hydrocarbon product pipeline 90, to assist that liquid hydrocarbon product is delivered to low-temperature storage tank 210.
If initial flow current divider 9 is provided, low temperature feeding line 8 is also connected to as lower at least one: through discharge pipe line 40, liquid hydrocarbon product pipeline 90 and the process steam pipeline 60 of the liquid of nitrogen stripping.For this purpose, the second feeding line 11 at its upstream side be connected to optional initial current divider 9.Described the second feeding line 11 is walked around nitrogen stripping tower 20.Bypass flow flow control valve 15 is arranged in the second feeding line 11.Bypass flow flow control valve function is connected to the flow governor FC being arranged in the first feeding line 10.Suitably, the second feeding line 11 is fed to optional end flash separator 50.
A benefit of the second optional feeding line 11 and optional initial current divider 9 is, less in the comparable following situation of size of nitrogen stripping tower 20: low temperature feeding line 8 is directly connected and diverterless with the first feeding line 10, make whole low temperature hydrocarbon compositions enter nitrogen stripping tower 20 via the first entrance system 21.
As shown in the embodiment of Fig. 1, process steam pipeline 60 can be connected to optional end flash separator 50 via flashed vapour pipeline 64 and flash vapor stream brake control valve 65, and is connected to low-temperature storage tank 210 via optional Volatile Gas supply line 230.Rear one advantage connecting is, its allow by condenser and again condensation from the Volatile Gas of low-temperature storage tank 210 at least partly, this further discusses hereinafter.
Also process compressor 260 is disposed to stripping on the pressure side and flashing pressure side between interface on.Preferably, process compressor 260 is by Motor Drive.Process compressor 260 is arranged in process steam pipeline 60, with receiving course steam compression process steam.Compressed vapour discharge pipe line 70 exports 261 fluids with the process compressor discharge of process compressor 260 and is connected.Suitably, process compressor 260 is provided with Anti-surge Control and recycle cooler, when process compressor (does not show in the drawings) and uses described recycle cooler in the time recycling and in start-up course.
Stripping vapor line 71 is communicated with nitrogen stripping tower 20 fluids via the second entrance system 23, and described the second entrance system 23 is configured in the level place of the gravity below of stripping portion section 24, and preferably above liquid storage space 28.Stripping vapor line 71 is connected to compressed vapour discharge pipe line 70 via bypass diverter 79.Stripping cap relief valve 75 is arranged in stripping vapor line 71.
Optionally, outside stripping steam supply pipeline 74 is set to be communicated with the second entrance system 23 fluids of nitrogen stripping tower 20.In one embodiment, as shown in Figure 1, optional outside stripping steam supply pipeline 74 is connected to compressed vapour discharge pipe line 70.Outside stripping flow of vapor control valve 73 is arranged in optional outside stripping steam supply pipeline 74.In one embodiment, optional outside stripping steam supply pipeline 74 is suitably connected in liquefaction system 100 or the hydrocarbon steam pipeline of liquefaction system 100 upstreams.
Bypass diverter 79 is also communicated with condenser fluid via steam bypass line 76 at least.Steam bypass control valve (BCV) 77 is preferably disposed in steam bypass line 76.Steam bypass line 76 contains the non-stripping part from the compressed vapour of compressed vapour discharge pipe line 70.Condenser can be the indirect heat exchanger of any type being communicated with bypass diverter 79 fluids via steam bypass line 76.This condenser be advantageously used in condensation again from the compression process steam of compressed vapour discharge pipe line 70 at least partly.
Fig. 1 has shown embodiment easily, and wherein condenser is with the form setting of the evaporator overhead condenser 35 in nitrogen stripping tower 20 outsides.Evaporator overhead condenser 35 is set to be communicated with overhead vapor discharge pipe line 30 and steam bypass line 76 both fluids, flow with partial condensation intermediate vapor, described intermediate vapor flows except containing any overhead vapor of discharging from nitrogen stripping tower 20, also contains the non-stripping part from steam bypass line 76.The heat exchange surface that the indirect heat exchange that condenser comprises to be provided between intermediate vapor and auxiliary refrigerant stream 132 contacts, heat can be passed to auxiliary refrigerant stream 132 from intermediate vapor with certain cooling load thus.Auxiliary refrigerant stream flow control valve 135 is arranged in auxiliary refrigerant pipeline 132.
In the embodiment of Fig. 1, steam bypass line 76 suitably extends along bypass path, the extension between bypass diverter 79 and overhead vapor discharge pipe line 30 at the upstream side of evaporator overhead condenser 35 of described bypass path.Bypass path is extended between bypass diverter 79 and overhead vapor discharge pipe line 30 and/or vapor fraction discharge pipe line 80.Bypass path is without the inside stripping portion section 24 in nitrogen stripping tower 20.By this mode, can avoid the inner stripping of non-stripping part process portion section 24, this helps avoid the balance in disturbance nitrogen stripping tower 20.
Still with reference to Fig. 1, top separator 33 is arranged on the downstream of overhead vapor discharge pipe line 30.Overhead vapor discharge pipe line 30 is disposed in top separator 33.Top separator 33 arranges in order to separate any NC vapor fraction from any condensate fraction of overhead vapor.
Vapor fraction discharge pipe line 80 arranges to discharge above-mentioned vapor fraction.Vapor fraction discharge pipe line 80 is communicated with headroom 26 both fluids of condenser and nitrogen stripping tower 20.In the embodiment (as the embodiment of Fig. 1) that intermediate vapor contains overhead vapor and non-stripping steam therein, vapor fraction discharge pipe line 80 is communicated with headroom 26 both fluids of condenser and nitrogen stripping tower 20 inherently.Bypass path extends to vapor fraction discharge pipe line 80 in this embodiment.
A benefit of steam bypass line 76 is, in the time there is excessive process steam, it can process together with waste gas in vapor fraction discharge pipe line 80, and can not upset the material balance in nitrogen stripping tower 20.
Condenser is also communicated with liquid recirculation line 13 fluids.Liquid recirculation line 13 and liquid hydrocarbon product pipeline 90 fluid connections.Fluid connection means liquid recirculation line 13 and is connected to any suitable position, and at least a portion of liquid recycle sections can flow to liquid hydrocarbon product pipeline 90 from described position, and remains in liquid phase simultaneously.Therefore, liquid recirculation line 13 can for example be connected directly to following one or more: nitrogen stripping tower 20, low temperature feeding line 8, the first feeding line 10, optional the second feeding line 11, the discharge pipe line 40 through the liquid of nitrogen stripping, optional end flash separator 50 and liquid hydrocarbon product pipeline 90.Recycle valve 14 is disposed in liquid recirculation line 13.
Optionally, nitrogen stripping tower 20, except comprising inner stripping portion section 24, also comprises inner rectifying portion section 22.Inside rectifying portion section 22 is arranged in nitrogen stripping tower 20, and gravity is higher than stripping portion section 24.Headroom 26 is preferably defined as above the gravity of rectifying portion section 22.The first entrance system 21 gravity are arranged between inner rectifying portion section 22 and inner stripping portion section 24.Headroom 26 is above the gravity of rectifying portion section 22.
Optional inside rectifying portion section 22 can comprise the vapor/liquid contact intensifier that is similar to inner stripping portion section 24, separates and denitrogenation further to improve component.
Return-flow system can be set and enter nitrogen stripping tower 20 with the level place of part 36 above rectifying portion section 22 that at least reflux that allows condensate fraction.In the embodiment of Fig. 1, return-flow system comprises condensate fraction discharge pipe line 37, optional reflux pump 38 and condensate fraction current divider 39, described condensate fraction discharge pipe line 37 fluids are connected to the bottom of top separator 33, and described optional reflux pump 38 is arranged in condensate fraction discharge pipe line 37.Condensate fraction current divider 39 is via backflow part pipeline 36 with reflux inlet system 25 and fluid is connected condensate fraction discharge pipe line 37 and nitrogen stripping tower 20, and fluid connects condensate fraction discharge pipe line 37 and liquid recirculation line 13.Optional Modelling of Flow with Recirculation valve 32 by the control of Modelling of Flow with Recirculation controller (not shown) function can preferably be arranged in backflow part pipeline 36.
Nitrogen stripping tower 20 comprises in the embodiment of optional inside rectifying portion section 22 therein, liquid recirculation line 13 preferably via the recirculation path (if recirculation path is set) without rectifying portion section 22 with liquid hydrocarbon product pipeline 90 fluid connections.In this way, liquid recirculation line 13 assists to avoid too much liquid to be fed to rectifying portion section 22, and avoids recycled liquid through rectifying portion section 22.This is conducive to be avoided the balance in disturbance nitrogen stripping tower 20.
Cooling load controller 34 can be set to control cooling load, described cooling load is heat is passed to auxiliary refrigerant stream speed from intermediate vapor.Suitably, cooling load controller 34 is configured to control cooling load with respect to need to the responding waste gas heat pH indicator pH of heating power.In the embodiment illustrated, cooling load controller 34 presents with the form of pressure controller PC and auxiliary refrigerant stream flow control valve 135, in described pressure controller PC and auxiliary refrigerant stream flow control valve 135 functions, is coupled to each other.
Burner 220 is suitably arranged in the downstream of vapor fraction discharge pipe line 80, to receive at least fuel meat of the vapor fraction in vapor fraction discharge pipe line 80.Burner can comprise multiple fuel elements, and/or it can comprise as lower one or more: for example stove, boiler, incinerator, dual-fuel diesel engine or their combination.Boiler and dual-fuel diesel engine can be attached to generator.
Can control the amount of methane in waste gas to meet the specific requirement to methane.This is suitable as preferably not higher than the fuel gas stream under the fuel gas pressure of stripping pressure, even in to the variable situation of the needs of calorific value waste gas.
Vapor line 87 is optionally configured to receive at least steam recycle sections from the steam of top discharge pipeline 30.Vapor line 87 is walked around nitrogen stripping tower 20, and charging is got back to as lower at least one: liquid hydrocarbon product pipeline 90 and process steam pipeline 60.Steam recirculation flow brake control valve 88 is preferably disposed in vapor line 87.A benefit of the vapor line 87 proposing is, it allows optionally to increase the nitrogen content in liquid hydrocarbon product stream 90.If optional end flash separator 50 is set, vapor line 87 is suitably fed to end flash separator 50.
Suitably, the structure of optional vapor line 87 comprises optional vapor fraction current divider 89, described vapor fraction current divider 89 can be arranged in vapor fraction pipeline 80, thereby allows the controlled fluid between vapor fraction pipeline 80 and vapor line 87 to be communicated with.
Cold recovery heat exchanger 85 can be arranged in vapor fraction discharge pipe line 80, with before vapor fraction 80 is fed to any burner by flowing with cold recovery cold that 86 heat exchanges keep that vapor fraction 80 had.
In one embodiment, cold recovery stream 86 can comprise the effluent of the hydrocarbon feed stream in the hydrocarbon feed pipeline 110 that is derived from liquefaction system 100, or can be made up of described effluent.Gained through cooling effluent can be for example with low temperature feeding line 8 in the combination of low temperature hydrocarbon compositions.Therefore the productivity ratio that, the cold recovery heat exchange in cold recovery heat exchanger 85 has supplemented low temperature hydrocarbon compositions.In another embodiment, cold recovery stream 86 can comprise in overhead vapor discharge pipe line 30 (preferably in the part of overhead vapor discharge pipe line 30, overhead vapor is passed to evaporator overhead condenser 35 from nitrogen stripping tower 20 by described part) overhead vapor, or can be formed by described overhead vapor.Reduce thus the required power from the auxiliary refrigerant stream 132 in evaporator overhead condenser 35.
Liquefaction system 100 in this description is up to the present to the utmost schematically to be described.It can represent any suitable hydro carbons liquefaction system and/or process, particularly prepare any gas deliquescence process of liquefied natural gas, and the present invention is not limited to the concrete selection of liquefaction system.The example of suitable liquefaction system uses unitary system refrigerant cycle process (to be generally cold-producing medium-SMR process of single mixing, as be described in the PRICO in Gastech (Dubai) the K R Johnsen and the article " LNG Production on floating platforms " of P Christiansen that propose in 1998, but be likely also one-component cold-producing medium, for example, be also described in the BHP-cLNG process in the aforementioned article of Johnsen and Christiansen); Two refrigerant circulation processes (for example conventional propane-mixing-cold-producing medium process of being conventionally abbreviated as C3MR, as being for example described in United States Patent (USP) 4,404, in 008, or for example (an one example is described in United States Patent (USP) 6 to double-mixed refrigerant-DMR – process, in 658,891), or two cyclic processes that for example wherein each refrigerant circulation contains one-component cold-producing medium); Process with three or more the compressor bank based on for three or more kind of refrigeration cycle (an one example is described in United States Patent (USP) 7,114,351 in).
Other examples of suitable liquefaction system are described in: United States Patent (USP) 5,832,745 (ShellSMR), United States Patent (USP) 6,295,833, United States Patent (USP) 5,657,643 (both are the variant of Black and Veatch SMR), United States Patent (USP) 6,370,910 (Shell DMR).Another suitable example of DMR is so-called Axens LIQUEFIN process, in the people's such as P-Y Martin that the 22nd the World Gas Conference (2003) of Tokyo propose as being for example described in the article that is entitled as " LIQUEFIN:AN INNOVATIVE PROCESS TO REDUCE LNG COSTS ".Other three suitable cyclic processes comprise for example United States Patent (USP) 6, 962, 060, WO2008/020044, United States Patent (USP) 7, 127, 914, DE3521060A1, United States Patent (USP) 5, 669, 234 (commercial being called, is optimized cascade process), United States Patent (USP) 6, 253, 574 (the commercial fluid-mixing cascade processes that are called), United States Patent (USP) 6, 308, 531, U. S. application announces 2008/0141711, the people " Large capacity single train AP-X (TM) Hybrid LNG Process " such as Mark J.Roberts, Doha, QAT, Gastech, 2002 (13-16 days in October, 2002).Provide these to advise illustrating applicability widely of the present invention, and be not intended to for exclusive list exclusive and/or possibility.
Preferably but necessarily, form any compressor, particularly any coolant compressor of part of the hydro carbons liquefaction process in liquefaction system by one or more Motor Drive, and can't help any steam turbine and/or gas turbine Mechanical Driven.This compressor can be only by one or more Motor Drive.Be not that all examples as listed above use motor as coolant compressor driver.Be apparent that any driver that can use except motor replace motor with greatest benefit in the present invention.
An example (wherein liquefaction system 100 is based on for example C3MR or Shell DMR) is briefly shown in Fig. 2.It uses low temperature heat exchanger 180, it is the form of Wound-rotor type heat exchanger in this case, and described Wound-rotor type heat exchanger comprises bottom and top hydrocarbon products tube bank (being respectively 181 and 182), bottom and top LMR tube bank (being respectively 183 and 184) and HMR tube bank 185.
Bottom is connected thick liquiefied product pipeline 1 and hydrocarbon feed pipeline 110 with top hydrocarbon products tube bank 181 with 182 fluids.The pre-cooled heat exchanger 115 of at least one freezing hydro carbons can be arranged in the hydrocarbon feed pipeline 110 of upstream of low temperature heat exchanger 180.
The main refrigerant of mix refrigerant form provides in main refrigerant circuit 101.Main refrigerant circuit 101 comprises and is consumed refrigerant lines 150 and compressed refrigerant lines 120, describedly be consumed the main aspiration end that refrigerant lines 150 connects low temperature heat exchanger 180 shell-side 186 of low temperature heat exchanger 180 (in this case for) and main refrigerant compressor 160, described compressed refrigerant lines 120 connects main refrigerant compressor 160 exhaust outlets and MR separator 128.One or more heat exchangers are arranged in compressed refrigerant lines 120, comprise in the present embodiment at least one ambient heat exchanger 124 and the pre-cooled heat exchanger 125 of at least one freezing main refrigerant.MR separator 128 is restrained 183 fluids via light refrigerant fraction pipeline 121 with bottom LMR and is connected, and is connected with HMR tube bank via recasting cryogen fraction line 122.
The pre-cooled heat exchanger 125 of the pre-cooled heat exchanger 115 of described at least one freezing hydro carbons and described at least one freezing main refrigerant is by pre-cooled cold-producing medium freezing (respectively via pipeline 127 and 126).Identical pre-cooled cold-producing medium can be shared by identical pre-cooled refrigerant circulation.In addition, the pre-cooled heat exchanger 115 of described at least one freezing hydro carbons and the pre-cooled heat exchanger 125 of described at least one freezing main refrigerant capable of being combined become a pre-cooled heat exchanger unit (not shown).With reference to United States Patent (USP) 6,370,910 as nonrestrictive example.
Optional outside stripping steam supply pipeline 74 (if setting) can be suitably at the point in the downstream of the point of the upstream of the pre-cooled heat exchanger 115 of described at least one freezing hydro carbons, the pre-cooled heat exchanger 115 of described at least one freezing hydro carbons, or (for example possibly, if provide two or more freezing hydro carbons pre-cooled heat exchanger) some place between two continuous pre-cooled heat exchangers of freezing hydro carbons is connected to hydrocarbon feed pipeline 110, to obtain the part from the hydrocarbon feed stream of hydrocarbon feed pipeline 110.
Transition point place between top (182,184) and bottom (181,183) tube bank, HMR tube bank 185 is connected with HMR pipeline 141 fluids, in described HMR pipeline 141, configures HMR control valve 144.HMR pipeline 141 is communicated with shell-side 186 fluids of low temperature heat exchanger 180, and via shell-side 186 and with in bottom hydrocarbon products tube bank 181 and bottom LMR tube bank 183 and HMR tube bank 185 each heat exchange setting and be consumed refrigerant lines 150 fluids and be communicated with.
Above upper bundle 182 and 184, approach the top of low temperature heat exchanger 180, LMR tube bank 184 is connected with LMR pipeline 131 fluids.The one LMR return line 133 is set up fluid and is communicated with between LMR pipeline 131 and the shell-side 186 of low temperature heat exchanger 180.LMR control valve 134 is disposed in a LMR return line 133.The one LMR return line 133 via described shell-side 186 and with the heat exchange setting of each and HMR tube bank 185 in each and LMR tube bank 183 and 184 in upper and lower hydrocarbon products tube bank 182 and 181 be consumed refrigerant lines 150 fluids and be communicated with.
Fig. 2 has shown a possible source of auxiliary refrigerant.LMR pipeline 131 is divided into auxiliary refrigerant pipeline 132 and a LMR return line 133.The 2nd LMR return line 138 is at its upstream end for example, via the evaporator overhead condenser (evaporator overhead condenser 35 of Fig. 1, or integral inner evaporator overhead condenser 235 as shown in Figure 2) be connected with auxiliary coolant lines 132 fluids, and the 2nd LMR return line 138 described in downstream suitably via a HMR pipeline 141 finally be consumed refrigerant lines 150 and be connected.
Similar around the pipeline shown in pipeline and Fig. 1 of nitrogen stripping tower 20 in Fig. 2, and statement no longer in detail.Optional pipeline (comprising the second optional feeding line 11, optional outside stripping steam supply pipeline 74 and optional vapor line 87) can be provided, but for clear and do not reproduce in Fig. 2.
But, should note, a difference of the embodiment of Fig. 2 and the embodiment of Fig. 1 is, evaporator overhead condenser 35, top separator 33 and return-flow system are implemented with the form of integral inner evaporator overhead condenser 235, in the headroom 26 of described integral inner evaporator overhead condenser 235 internal configurations in nitrogen stripping tower 20.This inside top condenser 235 itself is known in the art.Liquid recirculation line 13 is set to and partially liq earial drainage tower tray 27 fluid connections, and described partially liq earial drainage tower tray 27 is arranged at the inside at the nitrogen stripping tower 20 above the gravity of rectifying portion section 22 and below the gravity of inside top condenser 235.The functional equivalent of the condensate fraction current divider 39 of partially liq earial drainage tower tray 27 and Fig. 1.
No matter whether be the form of (outside) evaporator overhead condenser 35 or inside top condenser 235, condenser is preferably set to be communicated with headroom 26 both fluids of steam bypass line 76 and nitrogen stripping tower 20, preferably contains from the non-stripping part of steam bypass line 76 with available from the overhead vapor of the headroom 26 of nitrogen stripping tower 20 thus through the intermediate vapor of condenser.
For operating as follows from comprising the apparatus and method of removing nitrogen containing the low temperature hydrocarbon compositions of the liquid phase of nitrogen and methane:
The low temperature hydrocarbon compositions 8 comprising containing the liquid phase of nitrogen and methane is provided, and described low temperature hydrocarbon compositions 8 is preferably under the initial pressure of 2 to 15 absolute pressure bar (bara) and preferably at the temperature lower than-130 DEG C.
Low temperature hydrocarbon compositions 8 can be available from natural gas or oil reservoir or coal bed.Select as one, low temperature hydrocarbon compositions 8 also can be originated available from another, comprises for example synthetic source, as Fischer-Tropsch process.Preferably, low temperature hydrocarbon compositions 8 comprises at least methane of 50mol%, more preferably the methane of 80mol% at least.
In typical embodiment, can be by making hydrocarbon feed stream 110 realize the temperature lower than-130 DEG C through liquefaction system 100.In this liquefaction system 100, the hydrocarbon feed of the charging steam that comprises hydrocarbon-containifirst stream 110 can be for example in low temperature heat exchanger 180 with main refrigerant flow heat exchange, the charging steam of liquefaction feed stream is to provide the thick fluidized flow in thick liquiefied product pipeline 1 thus.Required low temperature hydrocarbon compositions 8 can be subsequently available from thick fluidized flow 1.
Main refrigerant flow can produce by the main refrigerant in circulation main refrigerant circuit 101, and the cold-producing medium 150 being consumed is thus compressed in main refrigerant compressor 160, thereby forms compressed cold-producing medium 120 by the cold-producing medium 150 being consumed.Via the one or more heat exchangers that are arranged in compressed refrigerant lines 120, heat extraction in the compressed cold-producing medium of discharge from autonomous coolant compressor 160.The compressed cold-producing medium of this generating portion condensation, it is separated into light refrigerant fraction 121 and heavy refrigerant fraction 122 in MR separator 128, described light refrigerant fraction 121 is become to be grouped into by the steam of the compressed cold-producing medium of partial condensation, and described heavy refrigerant fraction 122 is made up of the liquid component of the compressed cold-producing medium of partial condensation.
Light refrigerant fraction 121 is continuously via bottom LMR bundle 183 and top LMR bundle 184 and through low temperature heat exchanger 180, and heavy refrigerant fraction 122 via HMR bundle 185 through low temperature heat exchangers 180 until transition point.When through other tube bank of these points, point other light and heavy refrigerant fraction is cooling by the light and heavy refrigerant fraction of evaporation again in shell-side 186 (thereby producing the cold-producing medium 150 being consumed), and this has completed circulation.Meanwhile, hydrocarbon feed stream 110 is continuously via bottom hydro carbons bundle 181 and top hydro carbons bundle 182 and through low temperature heat exchanger 180, and liquefied and excessively cold by the light and heavy refrigerant fraction of identical evaporation.
Depend on source, hydrocarbon feed stream 110 can contain the component of the difference amount except methane and nitrogen, comprises that one or more non-hydrocarbons components except water are (as CO 2, Hg, H 2s and other sulphur compounds); For example, with one or more hydro carbons heavier than methane (ethane, propane and butane especially, and the pentane of possible less amount and aromatic hydrocarbons).The hydro carbons that molecular weight is at least the molecular weight of propane can be described as C herein 3+ hydro carbons, the hydro carbons that molecular weight is at least the molecular weight of ethane can be described as C herein 2+ hydro carbons.
If needed, the 110 pretreatment of hydrocarbon feed stream are to reduce and/or to remove one or more undesirable components, as CO 2and H 2s, or experienced other steps, as precharge etc.This step is well known to a person skilled in the art, and their mechanism is not further being discussed herein.Therefore, the composition of hydrocarbon feed stream 110 depends on the type of gas and position and applied one or more pretreatment and changes.
Thick fluidized flow 1 can be included in the nitrogen between the 1mol% to 5mol% under the liquefaction pressure under the original temperature between-165 DEG C to-120 DEG C and between common 15bara to 120bara.In many cases, original temperature can be between-155 DEG C to-140 DEG C.In described narrower range, cooling load required in liquefaction system 100 is lower than cooling load required under lower temperature, and under the pressure higher than 15bara cross cold enough height to avoid being decompressed to the excessive generation of the flashed vapour between 1 to 2bara.
Can be by thick fluidized flow 1 is mainly decompressed to initial pressure by liquefaction pressure, and obtain low temperature hydrocarbon compositions 8 by thick fluidized flow 1.The first nitrogen stripping device incoming flow 10 is derived from low temperature hydrocarbon compositions 8, and is fed to the nitrogen stripping tower 20 under stripping pressure via the first entrance system 21.
Stripping pressure is generally equal to or lower than initial pressure.In preferred embodiments, stripping pressure selection is between 2 to 15 absolute pressure bar.Preferably, stripping pressure is 4bara at least, because use slightly higher stripping pressure, the stripping steam in stripping vapor line 71 can be benefited from some the other enthalpys (form of the heat of compression) that are added into process streams 60 in process compressor 260.
Preferably, stripping pressure is 8bara at the most, to be conducive to the separative efficiency in nitrogen stripping tower 20.In addition,, if in the scope of stripping pressure between 4 to 8bara, the waste gas in vapor fraction pipeline 80 can be easy to as so-called low-pressure fuel gas stream without further compression.
In one embodiment, the original temperature of thick fluidized flow 1 is-161 DEG C, and liquefaction pressure is 55bara.Main decompression can complete in two stages: first use the movement segment of expansion turbine 6, so that pressure is reduced to about 10bara from 55bara, then use Joule Thomson valve 7 in process segment, to be further decompressed to the pressure of 7bara.In this case, stripping pressure is assumed to be 6bara.
Overhead vapor stream 30 headrooms 26 available from nitrogen stripping tower 20.Available from the vapor fraction 80 of overhead vapor stream 30 the discharge cut that comprises overhead vapor 30 as toxic emission.Suitably, at least fuel meat of vapor fraction 80 is passed to not higher than the burner 220 under the fuel gas pressure of stripping pressure.
Extract the liquid 40 through nitrogen stripping from the liquid storage space 26 of nitrogen stripping tower 20.Temperature through the temperature of the liquid 40 of nitrogen stripping usually above the first nitrogen stripping device incoming flow 10.Conventionally, expection is the temperature higher than the first nitrogen stripping device incoming flow 10 through the temperature of the liquid 40 of nitrogen stripping, and is between-140 DEG C to-80 DEG C, is preferably between-140 DEG C to-120 DEG C.
Then preferably use intermediate relief device 45 that the liquid through nitrogen stripping 40 is decompressed to flashing pressure, described flashing pressure is lower than stripping pressure, and suitably in the scope between 1 to 2 absolute pressure bar.Preferably, in the scope of flashing pressure between 1.0 to 1.4bara.Under the difference between slightly higher flashing pressure and stripping pressure, the stripping steam in stripping vapor line 71 can be benefited from some other heats of compression that are added into process streams 60 in process compressor 260.
Intermediate relief device 45 can be controlled by liquid-level controller LC, described liquid-level controller LC is set as: if more than in the liquid storage space 26 of nitrogen stripping tower 20, the fluid level of accumulation is increased to target level, described liquid-level controller LC increases by the flow of intermediate relief device.As the result of decompression, temperature is reduced to below-160 DEG C conventionally.The liquid hydrocarbon product stream 90 making thus can keep under atmospheric pressure conventionally in the low-temperature storage tank of open insulation.
Also production process steam 60.Process steam 60 can comprise the flashed vapour 64 being produced by the decompression of the liquid 40 through nitrogen stripping and/or the decompression of bypass incoming flow 11 (below further discussing afterwards).
The Part I that the first nitrogen stripping device incoming flow 10 comprises low temperature hydrocarbon compositions 8.It can contain whole low temperature hydrocarbon compositions 8, but in practice, preferably low temperature hydrocarbon compositions 8 is divided into Part I 10 and the Part II 11 with the composition identical with Part I 10 and phase.Described Part II is preferably on the pressure side diverted to the suitable position flashing pressure side with the form of bypass incoming flow from stripping.
Can use bypass flow flow control valve 15 to control split ratio, described split ratio is defined as the flow with respect to the Part II of the flow of the low temperature hydrocarbon compositions in low temperature hydrocarbon compositions pipeline 8.Described bypass flow flow control valve 15 can be controlled by flow governor FC, to keep the first nitrogen stripping device incoming flow 10 to enter the predeterminated target flow in nitrogen stripping tower 20.If there is the superfluous flow that exceedes target flow, flow governor FC will increase the part of opening of bypass flow flow control valve 15, if there is underfed than target flow, flow governor FC will reduce to open part.
As general principle, split ratio can advantageously be chosen as between 50% to 95%.For nitrogen content higher in low temperature hydrocarbon compositions, conventionally recommend lower value, and for lower nitrogen content, preferably higher value.In one embodiment, the nitrogen content in low temperature hydrocarbon compositions 8 is 3.0mol%, and selected split ratio is 75% thus.
Subsequently the Part II that is derived from initial flow current divider 9 being fed at least one in discharge pipe line 40, liquid hydrocarbon product pipeline 90 and the process steam pipeline 60 of the liquid of nitrogen stripping, and before walking around nitrogen stripping tower 20, also described Part II is decompressed to described flashing pressure simultaneously.Suitably, optional Part II is passed in optional end flash separator 50.
Process steam 60 can comprise Volatile Gas.Volatile Gas 230 conventionally comes from heat is added into liquid hydrocarbon product stream 90, and a part for liquid hydrocarbon product stream 90 is evaporated and formation Volatile Gas thus.In typical LNG factory, the generation of Volatile Gas can exceed the flow several times of flashed vapour, particularly in the process with so-called loading pattern operation engineering, therefore, if Shortcomings need to be contained in whole methane in Volatile Gas to use to the scene of heating power, important advantageously not only condensation flashed vapour, also condensation Volatile Gas more again.
In order to promote Volatile Gas to be passed to process steam stream 60, preferably, optional Volatile Gas supply line 230 connects vapor space and the process steam pipeline 60 in low temperature storage pipe 210.In order to promote flashed vapour 64 to be passed to process vapor stream 60, and further liquid hydrocarbon product stream 90 is denitrogenated, preferably, after the liquid pressure-reducing of nitrogen stripping, to be fed to through the liquid of nitrogen stripping in optional end flash separator, in described optional end flash separator, under flash separation pressure, be separated into liquid hydrocarbon product stream 90 and flashed vapour 64 through the liquid of nitrogen stripping.Flash separation pressure is equal to or less than flashing pressure, and is suitably in the scope between 1 to 2 absolute pressure bar, is separated into liquid hydrocarbon product stream 90 and flashed vapour 64.In one embodiment, flash separation pressure is contemplated to 1.05bara.
Process steam 60 is compressed to at least stripping pressure, obtains thus compressed steam stream 70.Stripping steam flow 71 flows 70 available from compressed steam, and is passed to nitrogen stripping tower 20 via the second entrance system 23.Described stripping steam can be to contact adverse current with downward diafiltration by the liquid of stripping portion section 23 upwards diafiltration by stripping portion section 23.
If outside stripping steam supply pipeline 74 is communicated with setting with the second entrance system 23 fluids, outside stripping steam is optionally fed to nitrogen stripping tower 20 via the second entrance system 23.Can avoid thus the main destruction of nitrogen stripping tower 20, for example, not play in the situation of the effect that the compressed steam of q.s stream 70 is provided at process compressor 260.
Relate to compressed steam stream 70 is optionally split into stripping part and non-stripping part by compressed steam stream 70 acquisition stripping steam flows 71.The by-passing part that non-stripping part comprises compressed vapour, described by-passing part also can be at steam by-passing part hereinafter referred to as.It is not containing stripping part.Stripping steam flow 71 at least contains stripping part.
Useful steam bypass control valve (BCV) 77 is controlled Selective implantation.Suitably, steam bypass control valve (BCV) 77 is by the pressure controller control on compressed vapour pipeline 70, and described pressure controller is set to respond the pressure increasing in compressed steam pipeline 70 and increases the part of opening of steam bypass control valve (BCV) 77.Expection allows to flow through steam bypass line 76 and to enter the flow of the steam by-passing part in overhead vapor stream 30 high especially in so-called loading pattern process, and the amount of the Volatile Gas in the time of described loading pattern is conventionally than much higher in so-called Holdover mode process.Preferably, steam bypass control valve (BCV) 77 cuts out completely in course of normal operation under Holdover mode.
By intermediate vapor is passed through to condenser by the intermediate flow of intermediate vapor forming section condensation.At least non-stripping part that intermediate vapor comprises compressed vapour.In preferred embodiments, as shown in Figure 1, intermediate vapor also contains overhead vapor 30.This can realize by the non-stripping part of compressed vapour optionally being injected to overhead vapor stream 30, forms thus intermediate vapor.The formation of the intermediate vapor of partial condensation suitably relates to makes intermediate vapor and auxiliary refrigerant flow 132 indirect heat exchange, and partial condensation intermediate vapor, and heat is passed to auxiliary refrigerant stream 132 to select cooling load from intermediate vapor thus.The intermediate flow of gained partial condensation comprises containing the condensate fraction of excess liq and vapor fraction.Vapor fraction contains the by-passing part from compressed vapour, and described by-passing part remains in vapor phase in whole partial condensation.
Condensate fraction separates with vapor fraction under separating pressure in top separator 33, and described separating pressure can be lower than stripping pressure, and preferably in the scope between 2 to 15 absolute pressures bar.Vapor fraction is discharged via vapor fraction discharge pipe line 80 as waste gas.It contains available from the discharge cut of the overhead vapor of the headroom 26 of nitrogen stripping tower 20 and steam by-passing part at least.Condensate fraction is for example disposed to return-flow system from top separator 33 via condensate fraction discharge pipe line 37.
In this way, from compressed vapour selective divided-flow being become to stripping part and non-stripping part until the discharge of by-passing part the vapor fraction of waste gas, by-passing part is walked around at least one inner stripping portion section 24.In other words, by bypass diverter 79 to the path of overhead vapor discharge pipe line 30 and/or vapor fraction discharge pipe line 80, by-passing part is without at least one inner stripping portion section 24.What realize thus is, the any compressed vapour in compressed steam pipeline 70 that exceedes the amount of the stripping steam consuming in the course of normal operation of the nitrogen stripping tower 20 under balance turns to around stripping portion section 24, thus the stripping balance in not disturbance nitrogen stripping tower 20.In preferred embodiments, by-passing part is not only walked around stripping portion section 24, also walks around whole nitrogen stripping tower 20, as shown in the embodiment of Fig. 1.
By guiding at least partly liquid recirculation line 13 of the condensate fraction of discharging from top separator 33, to form liquid recycle sections.Can suitably control recycle valve 14 with the liquid-level controller that is arranged at the flow governor in condensate fraction discharge pipe line 37 and/or be arranged on top separator 33.Liquid recycle sections contain excess liq at least partly.The liquid hydrocarbon product that is back at least partly of liquid recycle sections is flowed, and make described remaining at least partly in liquid phase simultaneously.This can complete by liquid recycle sections being fed in following at least one: nitrogen stripping tower 20, low temperature hydrocarbon compositions 8, the first nitrogen stripping device feeding line 10, optional bypass feeding line 11, through the liquid 40 of nitrogen stripping, optional end flash separator 50 and liquid hydrocarbon product stream 90.
Therefore, condenser (it implements with form of evaporator overhead condenser 35 in the embodiment of Fig. 1) allows by any this steam is added into (compression) process vapor stream containing the stream of methane, thereby condensation forms the steam methane of the part of thick liquiefied product 1 (or low temperature hydrocarbon compositions 8) before again.Preferably, methane is condensed to the degree of the aim parameter that exceedes the methane in discharge vapor fraction 80.Once the part of forming process steam 60 or compression process steam 70, steam methane can be managed and auxiliary refrigerant 132 heat exchanges, thus, steam methane condenses from the overhead vapor 30 from nitrogen stripping tower 20, and allows the major part of nitrogen to discharge together with waste gas simultaneously.Therefore, likely from low temperature hydrocarbon compositions 8, remove enough nitrogen, to be created in the liquid hydrocarbon product stream 90 in the required Maximum Index of nitrogen content, and in waste gas, do not produce than required more thermal capacity simultaneously.
Vapor fraction 80 in waste gas has calorific value conventionally.Suitably regulate the calorific value of the vapor fraction 80 being discharged by regulating the cooling load in evaporator overhead condenser 35.This can complete by cooling load controller 34.By regulating heat to be passed to the cooling load that auxiliary refrigerant flows, the relative quantity of methane in adjustable waste gas from overhead vapor.As a result of, the calorific value of adjustable discharge vapor fraction with heating power specifically need mate.This makes waste gas be suitable as fuel gas stream, even in the variable situation of the needs of calorific value.
When vapor fraction 80 as delivery of fuel to burner 220, and while being consumed by burner 220, adjustable calorific value, to mate with the actual needs of the heating power of burner 220.
Can select regulated calorific value as the suitable situation of the desired use of fuel gas according to waste gas.Can be according to DIN 51857 standard calorific values.For many application, the calorific value regulating can with low heat value (LHV; Be sometimes referred to as net heating value) proportional, described low heat value may be defined as by burning specified amount (at first at 25 DEG C) and makes the temperature of combustion product be back to 150 DEG C of heats that discharge.This hypothesis does not reclaim the evaporation of water latent heat in product.
But, in order to regulate the object of calorific value in context of the present disclosure, without the actual calorific value of determining the vapor fraction being discharged on absolute value basis.Conventionally,, in order to make any shortage of sent heating power or excessively to reach minimum, regulate calorific value enough with respect to the actual needs of heating power.
In the context of the present specification, cooling load has reflected the speed that heat exchanges in condenser, and it can for example, represent with power unit (watt or megawatt).Cooling load is to stand flow with the auxiliary refrigerant of the heat exchange of overhead vapor relevant.
Preferably, respond therefore relevant to regulated calorific value signal and automatically regulate cooling load.Therein vapor fraction is passed in selectivity consume person's (example burner 220 as shown in Figure 1) the embodiment of one or more methane, can respond required heating power and complete control, the partial discharge of controlling thus methane mates to obtain the calorific value needing.
Suitably, auxiliary refrigerant stream flow control valve 135 can be controlled by pressure controller PC, to keep auxiliary refrigerant stream 132 by the predeterminated target flow of evaporator overhead condenser 35.Actual pressure in vapor fraction discharge pipe line 80 is therefore relevant to regulated calorific value.In the time that pressure drop is below horizontal to predeterminated target (it represents that the depletion rate of methane is higher than the delivery rate of vapor fraction 80), pressure controller PC is set as reducing the part of opening of auxiliary refrigerant stream flow control valve 135.On the contrary, in the time that pressure exceedes predeterminated target level, pressure controller PC is set as increasing the part of opening of auxiliary refrigerant stream flow control valve 135.
Expection vapor fraction 80 contains the nitrogen between 50mol% to 95mol%, the preferably nitrogen between 70mol% to 95mol% or the nitrogen between 50mol% to 90mol%, more preferably the nitrogen between 70mol% to 90mol%, the also more preferably nitrogen between 75mol% to 95mol%, the most preferably nitrogen between 75mol% to 90mol%.Expection condensate fraction 37 contains the nitrogen that is less than 35mol%.
Auxiliary refrigerant 132 flows under standard conditions and at the temperature of the bubbling point lower than overhead vapor stream 30, under standard conditions, preferably to have bubbling point (ISO13443 standard: under 1.0 atmospheric pressure 15 DEG C).This be conducive to condensation more relatively more a large amount be present in the methane in overhead vapor stream 30, thereby and then promote the controllability of the methane content in vapor fraction 80.For example, auxiliary refrigerant can contain the nitrogen between 5mol% to 75mol%.In a preferred embodiment, auxiliary refrigerant stream is formed by the slip-stream of main refrigerant flow, is more preferably formed by the slip-stream of light refrigerant fraction.A rear situation is shown in Fig. 2, but also applicable to the embodiment of Fig. 1.This slip-stream can be transmitted back in main refrigerant circuit expediently via the shell-side of low temperature heat exchanger 180 186, and wherein said slip-stream can still assist to extract heat in the stream from top and/or lower bundle.
In one embodiment, auxiliary refrigerant contemplated composition contains methane between nitrogen, the 30mol% to 60mol% between 25mol% to 40mol% and the C of 30mol% at the most 2(ethane and/or ethene), thus, auxiliary refrigerant contains these compositions of at least 95% and/or nitrogen and methane and is total up at least 65mol%.If use mix refrigerant for liquefying the excessively cold of hydrocarbon stream, the composition within the scope of these can be easy to derive from main refrigerant circuit.
Also may use kind of refrigeration cycle separately with the object for partial condensation overhead vapor stream 30.But, use and have the following advantages from the slip-stream tool of main refrigerant flow: the amount minimum of the other equipment of installation.For example, do not need other auxiliary refrigerant compressor and auxiliary refrigerant condenser.
If nitrogen stripping tower 20 is equipped with optional inside rectifying portion section 22 as above, the headroom of the preferred nitrogen stripping tower 20 available from rectifying portion section 22 tops of overhead vapor stream 30.
Originate in the level place above rectifying portion section 22, make the part 36 that at least refluxes of condensate fraction arrive the rectifying portion section 22 in nitrogen stripping tower 20.Described backflow part from here diafiltration downwards, by rectifying portion section 22, and contacts by the steam of rectifying portion section 22 with rising upwards.In the situation of the embodiment of Fig. 1, condensate fraction can pass through to nitrogen stripping tower 20 via reflux inlet system 25.Reflux part suitably available from condensate fraction, and pack in nitrogen stripping tower 20 via optional reflux pump 38 (and/or its can in gravity effect current downflow) and backflow part pipeline 36.In the situation of the embodiment of Fig. 2, condensate fraction is inner separation of headroom of nitrogen stripping tower 20, and therefore in rectifying portion section 22, can obtain.
The part that refluxes can contain whole condensate fraction, but optionally, condensate fraction is divided into liquid recycle sections and backflow part in the optional condensate fraction current divider 39 arranging, described liquid recycle sections is disposed in for example the first incoming flow 10 via liquid recirculation line 13, and described backflow part is disposed in nitrogen stripping tower 20 via reflux inlet system 25 and backflow part pipeline 36.
The ability that condensate fraction is divided into backflow part 36 and liquid recycle sections 13 is conducive to make any excess liq of condensate fraction to turn to as liquid recirculation around rectifying portion section 22, for example, not disturb the operation of rectifying portion section 22.Therein liquid recycle sections is recycled in the embodiment of nitrogen stripping tower 20, can liquid recycle sections be fed in nitrogen stripping tower 22 by the some place below rectifying portion section 22 gravity, walk around inner rectifying portion section 22 thereby complete.
Partial condensation also can relate to the direct and/or indirect heat exchange with other streams in other continuous top heat exchangers that arrange.For example, cold recovery heat exchanger 85 can be a kind of top heat exchanger, and by described top heat exchanger, the partial condensation of overhead stream also comprises and vapor fraction 80 indirect heat exchange.
Can suitably optionally use optional vapor line 87 by optionally opening steam recirculation control valve 88, to increase the nitrogen amount being held in liquid hydrocarbon product stream 90.This can be by completing as follows: from vapor fraction, extract steam recycle sections, steam recycle sections is decompressed to flashing pressure, and subsequently steam recycle sections is injected to the liquid 40 through nitrogen stripping.The remainder that is not passed to the vapor fraction 80 in vapor line 87 can form fuel meat, and described fuel meat can be sent to burner 220.
In some embodiments, the aim parameter that is dissolved in the nitrogen in liquid hydrocarbon product stream 90 is between 0.5 to 1mol%, preferably approaches 1.0mol%, but is no more than as far as possible 1.1mol%.Steam recirculation flow brake control valve 88 regulates charging to be back in end flash separator 50 for example and walks around the amount of the vapor fraction stream 80 of nitrogen stripping tower 20 simultaneously.Therefore, can affect the nitrogen amount in liquid hydrocarbon product stream 90.In order further to contribute to meet target nitrogen content, can respond from being optionally arranged at the signal of the mass measurer QMI in liquid hydrocarbon product pipeline 90 and control steam recirculation flow brake control valve 88.
The method and apparatus proposing is suitable for especially in conjunction with hydro carbons liquefaction system (as natural gas liquefaction system) application, to remove nitrogen from thick liquiefied product.Find, even when thick liquiefied product or low temperature hydrocarbon compositions contains 1mol% (or about 1mol%) until when the nitrogen of the quite high amount of 5mol% (or until about 5mol%), gained liquid hydrocarbon product can meet the nitrogen content in the index of the nitrogen between 0.5 to 1mol%.
The remainder of nitrogen discharges together with the part of the vapor fraction in waste gas and the methane of controlled quatity.
It is suggested, when thick liquiefied product or low temperature hydrocarbon compositions contain 1.5mol% (preferably 1.8mol%) until when the nitrogen of 5mol%, method and apparatus in this paper is the most favourable.When nitrogen content is during lower than about 1.8mol% and/or lower than about 1.5mol%, existing selectable method is also enough to work.
For Holdover mode (table 1) and loading pattern (table 2) both, carry out static simulation in the embodiment shown in Fig. 1.Supposing that low temperature hydrocarbon compositions 8 comprises exceedes the nitrogen of 90mol% and the mixture of methane (98.204mol%).In an embodiment, the amount of nitrogen (1.654mol%) and methane (98.204mol%) exceedes 99.8mol%, and the surplus of 0.142mol% is made up of carbon dioxide (0.005mol%).Carbon dioxide leaves described process via the liquid 40 through nitrogen stripping and liquid hydrocarbon product stream 90.In two kinds of situations, the split ratio of initial steam current divider 9 is approximately 75%.
Can find out, in Holdover mode and loading pattern, although the measurer of process steam has large difference, but the amount of the methane of discharge in vapor fraction 80 can be maintained at about under 80mol% and suitably in the scope between 10mol% to 25mol%, and the nitrogen content in liquid hydrocarbon product stream 90 remains in the target that approaches 1.0mol% and be no more than 1.1mol% simultaneously.
In Holdover mode, the Volatile Gas being made up of the nitrogen of about 17mol% and the methane of 83mol% of about 2.0kg/s is added into process via Volatile Gas supply line 230, and is about 4.4kg/s in Volatile Gas described in loading pattern.
In Holdover mode, steam is not guided through to steam bypass line 76, and in loading pattern, 30% in compressed vapour 70 is guided through to steam bypass line 76, to hold the other steam being brought by other Volatile Gas inflow.In loading pattern, liquid recirculation 13 is also increased to approximately 41% of described condensate fraction by approximately 8% of the condensate fraction in condensate fraction discharge pipe line 37.Flowing of other condensate fraction caused by the other methane of condensation again.
Liquefaction system 100 in calculating uses setting as shown in Figure 2, and the mix refrigerant in compressed refrigerant pipeline 120 has as being labeled as composition listed in the row of " 120 " in table 3.
Table 3: mix refrigerant composition
(in mol%)
In Holdover mode, the pressure in compressed refrigerant pipeline 120 is 58bara, higher at pressure described in loading pattern, is 61bara.In two kinds of situations, the total pressure drop in bottom and the top LMR tube bank (being respectively 183 and 184) of low temperature heat exchanger is 13bar.The pressure drop being applied by auxiliary refrigerant stream flow control valve 135 for 39bar, is 42bar in Holdover mode situation in loading pattern, thereby for Holdover mode and loading pattern, the shell in the shell-side 186 of low temperature heat exchanger 180 is pressed identical.
The relative discharge of auxiliary refrigerant stream 132 is 11% of total LMR flow in LMR pipeline 131.In loading pattern, the relative discharge of auxiliary refrigerant stream 132 is 18% of total LMR flow in LMR pipeline 131.And actual flow is 1.6 times in Holdover mode situation, but than in Holdover mode operation, in loading pattern operation, make MR separator 128 in slightly more preference HMR of separation between HMR and LMR.
In as above embodiment, suppose that low temperature hydrocarbon compositions is containing the hydro carbons (C heavier than methane 2+ hydro carbons), for example following situation: low temperature hydrocarbon compositions is derived from non-conventional gas body source, as coalbed methane, shale gas or some possible synthetic source.But the method and apparatus proposing also can be applicable to wherein low temperature hydrocarbon compositions and contains the C of about 15mol% at the most 2the situation of+hydro carbons (comprising one or more that are selected from ethane, propane, iso-butane, normal butane and pentane).In fact, do not expect the C that these are other 2+ hydro carbons changes the running of the method and apparatus proposing, because it is expected that this C 2+ hydro carbons is all present in the waste gas of overhead vapor 30 or vapor fraction discharge pipe line 80 unlike the carbon dioxide of embodiment.
It will be apparent to those skilled in the art that the scope in the case of not departing from appended claims, can carry out the present invention in many different modes.

Claims (17)

1. from low temperature hydrocarbon compositions, remove the method for nitrogen, described low temperature hydrocarbon compositions comprises the liquid phase containing nitrogen and methane, and described method comprises:
-the low temperature hydrocarbon compositions comprising containing the liquid phase of nitrogen and methane is provided;
-the first nitrogen stripping device incoming flow under stripping pressure is fed to nitrogen stripping tower, described nitrogen stripping tower comprises the inner stripping of at least one that be arranged in nitrogen stripping tower portion section, the Part I that described the first nitrogen stripping device incoming flow comprises low temperature hydrocarbon compositions;
-liquid from the liquid storage spatial extraction of the nitrogen stripping tower of described stripping portion section below through nitrogen stripping;
-prepare at least liquid hydrocarbon product stream and process steam by the described liquid through nitrogen stripping, at least comprise the step to flashing pressure by the described liquid pressure-reducing through nitrogen stripping;
-described process steam is compressed to at least stripping pressure, obtain thus compressed vapour;
-described compressed vapour is optionally divided into stripping part and does not comprise the non-stripping part of stripping part, the by-passing part that described non-stripping part comprises described compressed vapour;
-stripping steam flow being passed in the nitrogen stripping tower at the level place below described stripping portion section gravity, described stripping steam flow at least comprises the stripping part of described compressed vapour;
-intermediate vapor is passed through to condenser, thereby make described intermediate vapor and auxiliary refrigerant stream indirect heat exchange, and intermediate vapor described in partial condensation, wherein said intermediate vapor at least comprises the non-stripping part of described compressed vapour, and wherein said heat exchange comprises that heat is passed to auxiliary refrigerant with certain cooling load from described intermediate vapor to flow, excess liq is formed by described intermediate vapor thus, and remains in gas phase from least described by-passing part of described compressed vapour thus;
-discharge the vapor fraction as waste gas, described vapor fraction comprises the discharge cut available from the overhead vapor of the headroom of described nitrogen stripping tower, and at least comprises described by-passing part; And
-by described being back at least partly of liquid recycle sections liquid hydrocarbon product stream, wherein said liquid recycle sections comprises at least part of of described excess liq;
The wherein discharge from described Selective Separation to the by-passing part the vapor fraction of described waste gas, described by-passing part is walked around at least one inner stripping portion section.
2. method according to claim 1, the partial condensation of wherein said intermediate vapor produces the intermediate flow of the partial condensation that comprises condensate fraction and described vapor fraction, wherein said vapor fraction comprises described by-passing part, and wherein said condensate fraction comprises described excess liq, described method also comprises:
In-overhead vapor by the non-stripping part Selective implantation of described compressed vapour available from the headroom of described nitrogen stripping tower, form thus described intermediate vapor; And
-before described vapor fraction is discharged as waste gas, under separating pressure, from described vapor fraction, separate described condensate fraction.
3. method according to claim 1 and 2, wherein the vapor fraction in described waste gas has calorific value, and described method also comprises:
-regulate described cooling load to regulate the calorific value of the vapor fraction of being discharged.
4. according to the method in claim 2 or 3, wherein said nitrogen stripping tower also comprises at least one inner rectifying portion section, described at least one inner rectifying portion section gravity is arranged in described nitrogen stripping tower higher than the described stripping portion's section in described nitrogen stripping tower, and described method also comprises:
-make the part that at least refluxes of described condensate fraction enter the rectifying portion section in described nitrogen stripping tower from the level of described rectifying portion's section top.
5. method according to claim 4, it also comprises:
-described condensate fraction is divided into described backflow part and described liquid recycle sections, described liquid recycle sections does not comprise described backflow part thus; And the wherein said described liquid hydrocarbon product stream of being back at least partly of described liquid recycle sections that makes comprises:
-described liquid recycle sections is turned to around described rectifying portion section.
6. according to method in any one of the preceding claims wherein, wherein, after described selective divided-flow, described stripping part has composition and the phase identical with described non-stripping part.
7. according to method in any one of the preceding claims wherein, in the scope of wherein said stripping pressure between 2 to 15 absolute pressures bar and/or wherein said flashing pressure be between 1 to 2 absolute pressure bar.
8. according to method in any one of the preceding claims wherein, it also comprises at least fuel meat of described vapor fraction is passed to not higher than the burner under the fuel gas pressure of stripping pressure.
9. according to method in any one of the preceding claims wherein, wherein said process steam comprises by heat being added into described liquid hydrocarbon product and flows the Volatile Gas obtaining, thus the part evaporation of liquid hydrocarbon product stream and form described Volatile Gas.
10. according to method in any one of the preceding claims wherein, wherein described, the described liquid pressure-reducing through nitrogen stripping is produced to flashed vapour to the process of described flashing pressure, and wherein said process steam comprises described flashed vapour.
11. according to method in any one of the preceding claims wherein, and the wherein said described low temperature hydrocarbon compositions that provides comprises:
-make the charging steam that comprises hydrocarbon-containifirst incoming flow in low temperature heat exchanger with main refrigerant flow heat exchange, the charging steam of the described incoming flow of liquefying is thus to provide thick fluidized flow; And
-obtain described low temperature hydrocarbon compositions by described thick fluidized flow.
12. according to method in any one of the preceding claims wherein, and it also comprises:
-extract steam recycle sections from described vapor fraction;
-described steam recycle sections is decompressed to flashing pressure;
-described steam recycle sections is injected to following at least one: through liquid, liquid hydrocarbon product stream and the process steam of nitrogen stripping.
13. according to method in any one of the preceding claims wherein, and wherein said auxiliary refrigerant stream contains the nitrogen between 5mol% to 75mol%.
14. according to method in any one of the preceding claims wherein, and wherein said vapor fraction comprises the nitrogen between 50mol% to 95mol%.
15. 1 kinds for removing the method for nitrogen from low temperature hydrocarbon compositions, described low temperature hydrocarbon compositions comprises the liquid phase containing nitrogen and methane, and described device comprises:
-being connected to the low temperature feeding line in the source of low temperature hydrocarbon compositions, described low temperature hydrocarbon compositions comprises the liquid phase containing nitrogen and methane;
-nitrogen stripping the tower that is communicated with described low temperature feeding line fluid, the liquid storage space that described nitrogen stripping tower comprises at least one inner stripping portion's section of being arranged in nitrogen stripping tower and limits below described stripping portion section gravity;
-comprise the discharge pipe line of the liquid through nitrogen stripping of intermediate relief device, the discharge pipe line of the described liquid through nitrogen stripping is communicated with the liquid storage space fluid of described nitrogen stripping tower, and arrange in order to receive through the liquid of nitrogen stripping and by the liquid pressure-reducing through nitrogen stripping from described liquid storage space, described intermediate relief device is at the stripping that comprises nitrogen stripping tower on the interface on the pressure side and between flashing pressure side;
-be communicated with described intermediate relief device be arranged at the liquid hydrocarbon product pipeline in flashing pressure side, flow to discharge the liquid hydrocarbon product being produced by the described liquid through nitrogen stripping;
-be communicated with described intermediate relief device be arranged at the process steam pipeline in flashing pressure side, to receive the process steam being produced by the described liquid through nitrogen stripping;
-be arranged at the process compressor in described process steam pipeline, it arranges in order to receive described process steam and to compress described process steam, provide compressed vapour with the process compressor discharge place at described process compressor, described process compressor is at stripping on the described interface on the pressure side and between flashing pressure side;
-bypass diverter, its upstream side is communicated with to receive compressed vapour with the floss hole fluid of described process compressor thus, the first waste side of described bypass diverter is via stripping vapor line and the second entrance system and be communicated with described nitrogen stripping tower fluid, described the second entrance system is arranged at the level place of the gravity below of described stripping portion section, and arrange in order to receive at least stripping part from the described compressed vapour of described process compressor, the second waste side of described bypass diverter is communicated with the steam bypass line fluid of the non-stripping part that contains described compressed vapour,
-be communicated with the condenser arranging with described steam bypass line fluid to bring the intermediate vapor at least comprising from the non-stripping part of described steam bypass line, described condenser comprises heat exchange surface, and described heat exchange surface provides the indirect heat exchange between described intermediate vapor and auxiliary refrigerant stream to contact;
-the discharge pipe line that is communicated with the headroom of described condenser and described nitrogen stripping tower, it arranges the vapor fraction as waste gas in order to discharge, described vapor fraction comprises available from the overhead vapor of the headroom of described nitrogen stripping tower and the by-passing part that comprises non-condensing steam, and described non-condensing steam is controlled oneself by the intermediate vapor of described condenser; And
-liquid recirculation line, described liquid recirculation line at its upstream side is communicated with described condenser fluid, and is communicated with described liquid hydrocarbon product pipeline liquid in its downstream;
Wherein bypass path is extended between described bypass diverter and described discharge pipe line, and wherein said bypass path is walked around described at least one inner stripping portion section, and wherein said steam bypass line extends along described bypass path.
16. devices according to claim 15, wherein said condenser is also communicated with setting with the headroom fluid of described nitrogen stripping tower, and described intermediate vapor comprises from the non-stripping part of described steam bypass line with available from the overhead vapor of the headroom of described nitrogen stripping tower thus.
17. devices according to claim 16, wherein said nitrogen stripping tower also comprises at least one inner rectifying portion section, described at least one inner rectifying portion section gravity is arranged in described nitrogen stripping tower higher than the described stripping portion's section in described nitrogen stripping tower, described device also comprises return-flow system and condensate fraction current divider, described return-flow system arranges to be used so that partly enter the rectifying portion section in described nitrogen stripping tower from the level of described rectifying portion's section top from least the refluxing of condensate fraction of condenser, described condensate fraction current divider arranges in order to receive the condensate fraction from condenser, wherein said liquid recirculation line is communicated with condenser fluid via described condensate fraction current divider, and be communicated with described liquid hydrocarbon product pipeline liquid via the recirculation path of walking around described rectifying portion section.
CN201280061161.0A 2011-12-12 2012-12-10 Method and apparatus for removing nitrogen from cryogenic hydrocarbon composition Pending CN103988035A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110114627A (en) * 2016-10-28 2019-08-09 乔治洛德方法研究和开发液化空气有限公司 Method for cryogenic separation hydrogen and the mixture of carbon monoxide

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9816754B2 (en) * 2014-04-24 2017-11-14 Air Products And Chemicals, Inc. Integrated nitrogen removal in the production of liquefied natural gas using dedicated reinjection circuit
US9945604B2 (en) 2014-04-24 2018-04-17 Air Products And Chemicals, Inc. Integrated nitrogen removal in the production of liquefied natural gas using refrigerated heat pump
US20150308737A1 (en) * 2014-04-24 2015-10-29 Air Products And Chemicals, Inc. Integrated Nitrogen Removal in the Production of Liquefied Natural Gas Using Intermediate Feed Gas Separation
US11221176B2 (en) 2018-08-14 2022-01-11 Air Products And Chemicals, Inc. Natural gas liquefaction with integrated nitrogen removal
AU2021364547A1 (en) * 2020-10-19 2023-06-01 Conocophillips Company Process composition analysis via online mass spectrometry

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN86107895A (en) * 1983-03-18 1988-06-01 戴尔·戈登·琼斯 The method and apparatus of getting rid of nitrogen and sulfur oxide from combustion gases
US20080066493A1 (en) * 2004-07-12 2008-03-20 Cornelis Buijs Treating Liquefied Natural Gas
DE102007010032A1 (en) * 2007-03-01 2008-09-04 Linde Ag Procedure for separating a nitrogen-rich fraction from a liquefied natural gas, comprises supplying the natural gas after its liquefaction and super cooling, to a stripping column that serves the separation of the nitrogen-rich fraction
CN101631934A (en) * 2007-01-31 2010-01-20 尤米科尔股份公司及两合公司 Method for regenerating soot filters in the exhaust gas system of a lean mix engine, and exhaust gas system therefor
WO2011009832A2 (en) * 2009-07-21 2011-01-27 Shell Internationale Research Maatschappij B.V. Method for treating a multi-phase hydrocarbon stream and an apparatus therefor
US20110239701A1 (en) * 2008-11-03 2011-10-06 Sander Kaart Method of rejecting nitrogen from a hydrocarbon stream to provide a fuel gas stream and an apparatus therefor

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4404008A (en) 1982-02-18 1983-09-13 Air Products And Chemicals, Inc. Combined cascade and multicomponent refrigeration method with refrigerant intercooling
IT1176290B (en) 1984-06-12 1987-08-18 Snam Progetti LOW-BOILING GAS COOLING AND LIQUEFATION PROCESS
MY118329A (en) 1995-04-18 2004-10-30 Shell Int Research Cooling a fluid stream
US5657643A (en) 1996-02-28 1997-08-19 The Pritchard Corporation Closed loop single mixed refrigerant process
US5669234A (en) 1996-07-16 1997-09-23 Phillips Petroleum Company Efficiency improvement of open-cycle cascaded refrigeration process
DE19716415C1 (en) 1997-04-18 1998-10-22 Linde Ag Process for liquefying a hydrocarbon-rich stream
TW477890B (en) 1998-05-21 2002-03-01 Shell Int Research Method of liquefying a stream enriched in methane
US6308531B1 (en) 1999-10-12 2001-10-30 Air Products And Chemicals, Inc. Hybrid cycle for the production of liquefied natural gas
TW480325B (en) 1999-12-01 2002-03-21 Shell Int Research Plant for liquefying natural gas
US6295833B1 (en) 2000-06-09 2001-10-02 Shawn D. Hoffart Closed loop single mixed refrigerant process
EG24658A (en) 2002-09-30 2010-04-07 Bpcorporation North America In All electric lng system and process
US7127914B2 (en) 2003-09-17 2006-10-31 Air Products And Chemicals, Inc. Hybrid gas liquefaction cycle with multiple expanders
US6962060B2 (en) 2003-12-10 2005-11-08 Air Products And Chemicals, Inc. Refrigeration compression system with multiple inlet streams
WO2008020044A2 (en) 2006-08-17 2008-02-21 Shell Internationale Research Maatschappij B.V. Method and apparatus for liquefying a hydrocarbon-containing feed stream
US20080141711A1 (en) 2006-12-18 2008-06-19 Mark Julian Roberts Hybrid cycle liquefaction of natural gas with propane pre-cooling

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN86107895A (en) * 1983-03-18 1988-06-01 戴尔·戈登·琼斯 The method and apparatus of getting rid of nitrogen and sulfur oxide from combustion gases
US20080066493A1 (en) * 2004-07-12 2008-03-20 Cornelis Buijs Treating Liquefied Natural Gas
CN101631934A (en) * 2007-01-31 2010-01-20 尤米科尔股份公司及两合公司 Method for regenerating soot filters in the exhaust gas system of a lean mix engine, and exhaust gas system therefor
DE102007010032A1 (en) * 2007-03-01 2008-09-04 Linde Ag Procedure for separating a nitrogen-rich fraction from a liquefied natural gas, comprises supplying the natural gas after its liquefaction and super cooling, to a stripping column that serves the separation of the nitrogen-rich fraction
US20110239701A1 (en) * 2008-11-03 2011-10-06 Sander Kaart Method of rejecting nitrogen from a hydrocarbon stream to provide a fuel gas stream and an apparatus therefor
WO2011009832A2 (en) * 2009-07-21 2011-01-27 Shell Internationale Research Maatschappij B.V. Method for treating a multi-phase hydrocarbon stream and an apparatus therefor

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110114627A (en) * 2016-10-28 2019-08-09 乔治洛德方法研究和开发液化空气有限公司 Method for cryogenic separation hydrogen and the mixture of carbon monoxide
CN110114627B (en) * 2016-10-28 2022-02-25 乔治洛德方法研究和开发液化空气有限公司 Method for the cryogenic separation of a mixture of hydrogen and carbon monoxide

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