CN110066695A - Natural gas nitrogen rejection facility and method - Google Patents
Natural gas nitrogen rejection facility and method Download PDFInfo
- Publication number
- CN110066695A CN110066695A CN201910361735.XA CN201910361735A CN110066695A CN 110066695 A CN110066695 A CN 110066695A CN 201910361735 A CN201910361735 A CN 201910361735A CN 110066695 A CN110066695 A CN 110066695A
- Authority
- CN
- China
- Prior art keywords
- gas
- flash
- high pressure
- pressure flash
- natural gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
- B01D53/1425—Regeneration of liquid absorbents
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
- B01D53/18—Absorbing units; Liquid distributors therefor
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
- C10L3/00—Gaseous fuels; Natural gas; Synthetic natural gas obtained by processes not covered by subclass C10G, C10K; Liquefied petroleum gas
- C10L3/06—Natural gas; Synthetic natural gas obtained by processes not covered by C10G, C10K3/02 or C10K3/04
- C10L3/10—Working-up natural gas or synthetic natural gas
- C10L3/101—Removal of contaminants
- C10L3/105—Removal of contaminants of nitrogen
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2252/00—Absorbents, i.e. solvents and liquid materials for gas absorption
- B01D2252/50—Combinations of absorbents
- B01D2252/504—Mixtures of two or more absorbents
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2257/00—Components to be removed
- B01D2257/10—Single element gases other than halogens
- B01D2257/102—Nitrogen
Landscapes
- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Engineering & Computer Science (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Analytical Chemistry (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The present invention relates to a kind of natural gas denitrogenation methods, including the following steps: raw natural gas is pre-chilled first, is then freezed to -25 DEG C~-30 DEG C；N is carried out into absorption tower2Removing, the N of removing2Self-absorption tower top discharge by with go to be vented after raw natural gas re-heat；Absorption tower bottom rich solution carries out high pressure flash by recover energy laggard high pressure flash tower of hydraulic turbine machine；Middle pressure flashed gas with after raw natural gas re-heat by being used as purified gas to go outer defeated system；Normal pressure presses flashed gas by pressing flashed vapour booster compressor systems into frequent with after raw natural gas re-heat, goes outer defeated system as purified gas after pressurization.Present invention simultaneously provides a kind of devices for realizing the above method.
Description
Technical field
The invention belongs to natural gas processing fields, more particularly, to N in a kind of removing natural gas2Device.
Background technique
Natural gas is the gaseous hydrocarbons extraction substance of petroleum, is high-grade fuel and industrial chemicals.Methane accounts for absolutely in natural gas
It is most of, separately there are a small amount of ethane, propane and butane, furthermore generally also contains H2S、CO2、H2O etc. contains in some natural gases
N2, other also contain argon gas and neon etc..Containing N2Excessively high natural gas can also reduce the calorific value of natural gas, be allowed to not expire
The requirement of the technical indicator defined of sufficient Chinese commodity natural gas.Therefore, it is necessary to the N that will be rich in natural gas2It carries out effective
Removing.
Summary of the invention
The object of the present invention is to provide a kind of processes simply, low energy consumption, process is short, N2The high natural qi exhaustion N of removal efficiency2Dress
It sets, belongs to physical solvent process.Natural gas N is carried out using the present apparatus2, using propane refrigeration low temperature absorption, take off N2Before should carry out it is medium
The dehydration of degree, technique are not required to heat, and only need electric energy, and total energy consumption is low, and operating cost is low, can also remove the inertia such as Ne and Ar simultaneously
Gas.Technical solution is as follows:
A kind of natural gas denitrogenation method, including the following steps:
(1) contain N2Raw natural gas be pre-chilled first, then freeze to -25 DEG C~-30 DEG C；
(2) enter absorption tower at 3.0~12.0MPaG and carry out N2Removing, the N of removing2Self-absorption tower top discharge by with
It goes to be vented after raw natural gas re-heat, is vented N2Content≤5% of middle methane；
(3) absorption tower bottom rich solution carries out high pressure flash, high pressure by recover energy laggard high pressure flash tower of hydraulic turbine machine
Flashing pressure is 1.5~4.0MPaG, goes high pressure flash air compressor system after the gas of high pressure flash out and raw natural gas re-heat
Be recycled to absorb the bottom of the tower as bottom feed, high pressure flash go out liquid carry out again in press flash distillation；
(4) in pressure flashing pressure be 0.6~1.5MPaG, middle pressure flashed gas by with after raw natural gas re-heat
Outer defeated system is gone as purified gas, it is middle that the liquid flashed off is pressed to carry out low pressure flash again；Low pressure flash pressure be 0.3~
0.6MPaG, by being used as purified gas to go outer defeated system with after raw natural gas re-heat, low pressure flash goes out the gas that low pressure flash goes out
Liquid carry out atmospheric flashing again；
(5) atmospheric flashing pressure be 0.0MPaG, normal pressure press flashed gas by with enter after raw natural gas re-heat
Through normal pressure flashed vapour booster compressor systems, outer defeated system is gone as purified gas after pressurization, the liquid that atmospheric flashing goes out removes solvent
Circulating pump is pressurized to 3.4~12.4MPaG, then goes to absorb tower top recycling to -25 DEG C~-30 DEG C by refrigeration.
Preferably, the gas that high pressure flash goes out is compressed through high pressure compressor, is freezed again to after -25 DEG C~-30 DEG C after air-cooled
Be recycled to absorb the bottom of the tower, middle pressure flashed vapour, low pressure flash gas and atmospheric flashing gas be connected together gone as purified gas it is outer defeated
System.
Absorption tower bottom rich solution is depressured laggard horizontal high voltage flash distillation, the power of high pressure hydraulic turbine by high pressure hydraulic turbine
It is available to solvent circulating pump.
The liquid that high pressure flash goes out presses flash distillation in carrying out after the decompression of middle hydraulic fluid power turbine, middle hydraulic fluid power turbine
Power is supplied to solvent circulating pump.
The absorbent used for heptane (C7), octane (C8), nonane (C9) and decane (C10) mixture, quality proportioning
For (5-15): (45-55): (15-25): (15-25).
Present invention simultaneously provides a kind of natural gas nitrogen rejection facilitys, including raw natural gas, and ice chest (1), raw natural gas is pre-chilled
Evaporator (2), absorption tower (3), high pressure flash tower (4), middle pressure flash column (5), Low Pressure Flashing Column (6), atmospheric flash tower (7),
Solvent circulating pump (8), solvent evaporator (9), high pressure flash air compressor (10), high pressure flash gas evaporator (11), low pressure are dodged
Pistonless compressor (12), low pressure flash gas air cooler (13), which is characterized in that
Raw natural gas is after the preliminary pre-cooling of raw natural gas pre-cooling ice chest (1), by raw natural gas evaporator
(2) it is admitted in the middle part of absorption tower (3) after further cooling；N2Discharge line (S10) is located at the top of absorption tower (3) and and raw material
Natural gas is pre-chilled ice chest (1) and is connected, the N after re-heat2Discharge line (S10) interior gas is discharged；
The both ends of absorption tower bottom flash liquid discharge line (S3) are located at absorption tower (3) bottom and high pressure flash tower (4)
Top, the both ends of high pressure flash liquid discharge line (S4) are located at high pressure flash tower (4) bottom and middle pressure flash column (5) top
Portion, the both ends of high pressure flash gas discharge line (S11) are separately connected at the top of high pressure flash tower (4) and ice chest is pre-chilled in raw natural gas
(1) the high pressure flash air pipe S15 of cooling box is connected to the entrance of high pressure flash air compressor (10), after high pressure flash air pressure contracting
Discharge line (S20) is connected to high pressure flash gas evaporator (11), and discharge line (S21) connection absorbs after high pressure flash air cooling
The bottommost of tower (3)；The both ends of middle pressure flash liquid discharge line (S5) are located at middle pressure flash column (5) bottom and low pressure flash
At the top of tower (6), the both ends of middle pressure flashed vapour discharge line (S12) are separately connected at the top of middle pressure flash column (5) and raw natural gas
It is pre-chilled ice chest (1), the inner gas conduct of middle pressure flash distillation air pipe (S18) after ice chest (1) re-heat is pre-chilled in raw natural gas
Purified natural gas discharge；The both ends of low pressure flash liquid discharge line (S6) are located at Low Pressure Flashing Column (6) bottom and normal pressure dodges
The top of tower (7) is steamed, the both ends of low pressure flash gas discharge line (S13) are separately connected at the top of Low Pressure Flashing Column (6) and unstripped gas
It is pre-chilled ice chest (1), presses flash distillation in low pressure flash air pipe (S17) access after ice chest (1) re-heat is pre-chilled in raw natural gas
Air pipe (S18)；The both ends of atmospheric flashing liquid discharge line (S7) are located at atmospheric flash tower (7) bottom and solvent circulating pump
(8) entrance, the both ends of atmospheric flashing gas discharge line (S14) are separately connected at the top of atmospheric flash tower (7) and unstripped gas pre-cooling
Ice chest (1), the atmospheric flashing air pipe (S19) after ice chest (1) re-heat is pre-chilled in raw natural gas contract into low pressure flash air pressure
Machine (12), the gas pipeline (S22) being pressurized through low pressure flash air compressor (12) are connected to atmospheric flashing gas air cooler (13),
Pipeline (S23) after cooling is connected to middle pressure flash distillation air pipe (S18)；The export pipeline (S8) of solvent circulating pump (8) connects respectively
The outlet of interface solvent circulating pump (8) and the entrance of solvent evaporator (9), export pipeline (S9) connection of solvent evaporator (9)
To the top of absorption tower (3).
Preferably, device further includes high pressure hydraulic turbine (14), middle hydraulic fluid power turbine (15), and wherein high pressure hydraulic is saturating
Flat machine (14) is arranged on absorption tower bottom flash liquid discharge line (S3), and middle hydraulic fluid power turbine (15) is arranged in high pressure flash liquid
On discharge line (S4).
The advantages and positive effects of the present invention are:
1, low energy consumption, and the present invention only needs consuming electric power, and air cooler can be used in the natural Gas Cooler of compressor outlet, or using first
The method that propane refrigeration is used after air cooler, process energy consumption take off N far below pure LNG liquefying and rectifying2Process energy consumption；
2, absorbent is not required to heating regeneration only with flash regeneration；
3, product N is removed2Gas purity is higher, up to 95%, and can deviate from the helium (He) in natural gas, neon (Ne),
The inert gases such as argon (Ar), flammable gas component is few, N2The rate of recovery may be up to 99%；
4, the purified natural gas rate of recovery is high, and product loss is few, CH4The rate of recovery may be up to 99%.
Detailed description of the invention
Fig. 1 is the device of the invention schematic diagram
In figure:
Equipment:
1, ice chest is pre-chilled in raw natural gas；2, raw natural gas evaporator；3, absorption tower；4, high pressure flash tower；5, middle pressure
Flash column；6, Low Pressure Flashing Column；7, atmospheric flash tower；8, solvent circulating pump；9, solvent evaporator；10, high pressure flash air pressure is contracted
Machine；11, high pressure flash gas evaporator；12, low pressure flash air compressor；13, low pressure flash gas air cooler；14, high pressure hydraulic is saturating
Flat machine；15, low pressure hydraulic turbine.
Pipeline:
S0, raw natural gas air inlet pipeline
Export pipeline is pre-chilled in S1, raw natural gas
S2, propane refrigeration raw natural gas discharge line
S3, absorption tower bottom flash liquid discharge line
S4, high pressure flash liquid discharge line
S5, middle pressure flash liquid discharge line
S6, low pressure flash liquid discharge line
S7, atmospheric flashing liquid discharge line
S8, solvent circulating pump export discharge line
S9, evaporator lyosoption discharge line
S10, tower top N2 discharge line is absorbed
S11, high pressure flash gas discharge line
S12, middle pressure flashed vapour discharge line
S13, low pressure flash gas discharge line
S14, atmospheric flashing gas discharge line
S11, circulation compression set outlet pipe
Discharge line after S15, N2 re-heat
Discharge line after S16, high pressure flash gas re-heat
Discharge line after S17, low pressure flash gas re-heat
Discharge line after S18, middle pressure flashed vapour re-heat
Discharge line after S19, atmospheric flashing gas re-heat
Discharge line after S20, high pressure flash air pressure contracting
Discharge line after S21, high pressure flash air cooling
Discharge line after S22, atmospheric flashing air pressure contracting
Discharge line after S23, atmospheric flashing air cooling
Specific embodiment
The processing step of the device of the invention are as follows: contain N2Raw natural gas be pre-chilled first, then carry out propane system
It is cooled to -25 DEG C -- 30 DEG C, N is carried out at 3.0-12.0MPaG2Removing, the N of removing2The discharge of self-absorption tower top is passed through and raw material day
Emptying (or going to burn) is gone after right gas re-heat, is vented N2Content≤5% of middle methane.Absorption tower bottom rich solution passes through hydraulic turbine
Recover energy laggard high pressure flash tower of machine carries out high pressure flash, and high pressure flash pressure is 1.5-4.0MPaG, the gas that high pressure flash goes out
It is fed to absorb the bottom of the tower as bottom with high pressure flash gas recycle compressor system circulation is gone after raw natural gas re-heat, high pressure
The liquid flashed off presses flash distillation in carrying out again；Middle pressure flashing pressure is 0.6-1.5MPaG, and middle pressure flashed gas is passed through and original
Outer defeated system is gone as purified gas after material natural gas re-heat, it is middle that the liquid flashed off is pressed to carry out low pressure flash again；Low pressure flash pressure
Power is 0.3-0.6MPaG, and the gas that low pressure flash goes out is low by being used as purified gas to go outer defeated system with after raw natural gas re-heat
The liquid flashed off is pressed to carry out atmospheric flashing again；Atmospheric flashing pressure is 0.0MPaG, and normal pressure presses flashed gas to pass through and original
Enter often pressure flashed vapour booster compressor systems after expecting natural gas re-heat, removes outer defeated system, normal pressure as purified gas after pressurization
The liquid flashed off goes solvent circulating pump to be pressurized to 3.4-12.4MPaG, then goes to absorb tower top to -30 DEG C by propane refrigeration
It is recycled.
In above-mentioned technique, the gas that high pressure flash goes out can be compressed through high pressure compressor, and air-cooled plus propane refrigeration is to -30 DEG C
After be recycled to absorb the bottom of the tower, middle pressure flashed vapour, low pressure flash gas and atmospheric flashing gas be connected together gone as purified gas it is outer
Defeated system.The case where according to unstripped gas, can add in, low-pressure charging compressor assembly.
The device of the invention can deviate from the inert gases such as helium (He), neon (Ne), argon (Ar) in natural gas, these inertia
Gas is deviate from together with N2.
In order to make full use of system capacity, absorption tower bottom rich solution can be depressured laggard horizontal high voltage by high pressure hydraulic turbine and dodge
It steams, the power of high pressure hydraulic turbine is available to solvent circulating pump；Hydraulic fluid power turbine in the liquid process that high pressure flash goes out
Flash distillation is pressed in carrying out after decompression, the power of middle hydraulic fluid power turbine is supplied to solvent circulating pump.
The absorbent that the device of the invention uses for heptane C7, octane (C8), nonane (C9) and decane C10 mixture,
Quality proportioning is 10%, 50%, 20% and 20%.
Device of the invention, as shown in Figure 1, including raw natural gas pre-cooling ice chest 1, raw natural gas evaporator 2, inhaling
Receive tower 3, high pressure flash tower 4, middle pressure flash column 5, Low Pressure Flashing Column 6, atmospheric flash tower 7, solvent circulating pump 8, solvent evaporator
9, high pressure flash air compressor 10, high pressure flash gas evaporator 11, low pressure flash air compressor 12, low pressure flash gas air cooler
13。
Raw natural gas is after the preliminary pre-cooling of raw natural gas pre-cooling ice chest 1, by raw natural gas evaporator 2
3 middle part of absorption tower is further admitted to after cooling；N2Discharge line S10 is located at 3 top of absorption tower and is pre-chilled with raw natural gas
Ice chest 1 is connected, the N after re-heat2Gas is expelled to high altitude discharge in discharge line S10；
High pressure hydraulic turbine 14, absorption tower bottom flash liquid discharge line are set on the flash liquid discharge line S3 of absorption tower bottom
The both ends of S3 are located at 4 top of 3 bottom of absorption tower and high pressure flash tower, hydraulic fluid in setting on high pressure flash liquid discharge line S4
Power turbine 15, the both ends of high pressure flash liquid discharge line S4 are located at 4 bottom of high pressure flash tower and middle pressure flash column 5 top
Portion, the both ends of high pressure flash gas discharge line S11 are separately connected 4 top of high pressure flash tower and raw natural gas pre-cooling ice chest 1 goes out
The high pressure flash air pipe S15 of ice chest is connected to the entrance of high pressure flash air compressor 10, discharge pipe after high pressure flash air pressure contracting
Road S20 is connected to high pressure flash gas evaporator 11, the bottommost on discharge line S21 connection absorption tower 3 after high pressure flash air cooling；
The both ends of middle pressure flash liquid discharge line S5 are located at 6 top of middle 5 bottom of pressure flash column and Low Pressure Flashing Column, middle pressure flashed vapour
The both ends of discharge line S12 are separately connected middle 5 top of pressure flash column and ice chest 1 is pre-chilled in raw natural gas, by raw natural gas
The gas in middle pressure flash distillation air pipe S18 after 1 re-heat of ice chest is pre-chilled is discharged as purified natural gas；Low pressure flash liquid discharge pipe
The both ends of road S6 are located at the top of Low Pressure Flashing Column 6 bottom and atmospheric flash tower 7, low pressure flash gas discharge line S13's
Both ends are separately connected 6 top of Low Pressure Flashing Column and ice chest 1 is pre-chilled in unstripped gas, after 1 re-heat of ice chest is pre-chilled in raw natural gas
Pressure flash distillation air pipe (S18) in low pressure flash air pipe S17 access；The both ends of atmospheric flashing liquid discharge line S7 are located at often
The entrance of flash column 7 bottom and solvent circulating pump 8 is pressed, the both ends of atmospheric flashing gas discharge line S14 are separately connected atmospheric flashing
Ice chest 1 is pre-chilled in the top of tower 7 and unstripped gas, and the atmospheric flashing air pipe S19 after 1 re-heat of ice chest is pre-chilled in raw natural gas is into low
Flash gas compression machine 12 is pressed, it is air-cooled that the gas pipeline S22 being pressurized through low pressure flash air compressor 12 is connected to low pressure flash gas
Device 13, pipeline S23 after cooling are connected to middle pressure flash distillation air pipe S18；The export pipeline S8 of solvent circulating pump 8 is separately connected mouth
The outlet of solvent circulating pump 8 and the entrance of solvent evaporator 9, the export pipeline S9 of solvent evaporator 9 are connected to the top on absorption tower 3
Portion.
The following describes the present invention in detail with reference to examples.
Raw natural gas treating capacity: 85 × 104m3/ d (0 DEG C, 101.325kPaA)
Raw natural gas component:
Unstripped gas component --- content mol/%
C1:76.71
C2:8.05
C3:0.14
IC4:0.01
NC4:0.02
C5+:0.00
N2: 14.30
CO2: 0.77
H2S:0.00
Step as shown in Figure 1: 3.2MPaG, 56.7 DEG C contain N2Raw natural gas (being dehydrated in advance) initially enter original
Expect that ice chest 1 is pre-chilled in natural gas, is cooled to -22 DEG C in advance through ice chest, is then cooled further to -30 through evaporator (plate-fin ice chest)
DEG C, pipeline S1 enters 3 middle and lower part of absorption tower and the cold absorbent entered with absorption tower teeming contacts, and carries out under 3.0MPaG pressure
De- N2, hydro carbons, CO2It is absorbed, not by the N of solvent absorption2Equal inert gases self-absorption tower top pipeline S10 discharge, it is natural through raw material
Gas is pre-chilled after 1 re-heat of ice chest by pipeline S15 high altitude discharge；Absorption tower bottom rich solution is after the decompression of high pressure hydraulic turbine 14 through pipe
Road S3 enters high pressure flash tower 4 and carries out high pressure flash, and high pressure flash pressure is 1.68MPaG, and the gas that high pressure flash goes out is by the road
S11 enters after raw natural gas pre-cooling 1 re-heat of ice chest by pipeline S16 to high pressure flash gas compression machine 10, through air-cooled, propane refrigeration
It is recycled to 3 bottom of absorption tower to -30 DEG C, the liquid that high pressure flash goes out is after the decompression of middle hydraulic fluid power turbine 15 through pipeline S4
It is pressed in and presses flash distillation in the progress of flash column 5, middle pressure flashing pressure is pressure 0.6MPaG, and middle pressure flashed gas is by the road
S12 enters after raw natural gas pre-cooling 1 re-heat of ice chest by pipeline S18 discharge as purified gas, middle to press the liquid decompression flashed off
Enter Low Pressure Flashing Column 6 by pipeline S5 and carry out low pressure flash, low pressure flash pressure is 0.33MPaG, the gas that low pressure flash goes out
S13 enters after raw natural gas pre-cooling 1 re-heat of ice chest by the road is also used as purified gas to be discharged by pipeline S17 adapter tube road S18.Low pressure
S6 removes atmospheric flash tower 7 to the liquid flashed off by the road, and atmospheric flashing pressure is 0.0MPaG, and the gas that atmospheric flashing goes out is through pipe
Road S14 enters after raw natural gas pre-cooling 1 re-heat of ice chest by pipeline S19 to low pressure flash air compressor 12, is pressurized to 0.3MPaG
Purification air pipe S18 is accessed by pipeline 23 after being air-cooled to 45 DEG C.For solvent after low pressure flash as cyclic absorption agent, process is molten
Agent circulating pump 8 boosts to 3.4MPaG, and S9 goes at the top of absorption tower 1 to recycle by the road.
The C1 rate of recovery is that 99%, the C2 rate of recovery is 98.5%；
N in purified natural gas2Content 0.5%；
Discharge N2Middle N2The purity of gas is 94.3%, CH4Concentration be 4.7%；
Product N2Tolerance are as follows: 12.8 × 104m3/ d (0 DEG C, 101.325kPaA)；
Purified natural gas: 72.2 × 104m3/ d (0 DEG C, 101.325kPaA).
The refrigerant of each evaporator used by the present embodiment is propane, can be freezed to -30 DEG C.
Claims (8)
1. a kind of natural gas denitrogenation method, including the following steps:
(1) contain N2Raw natural gas be pre-chilled first, then freeze to -25 DEG C~-30 DEG C；
(2) enter absorption tower at 3.0~12.0MPaG and carry out N2Removing, the N of removing2The discharge of self-absorption tower top passes through and raw material
It goes to be vented after natural gas re-heat, is vented N2Content≤5% of middle methane；
(3) absorption tower bottom rich solution carries out high pressure flash, high pressure flash by recover energy laggard high pressure flash tower of hydraulic turbine machine
Pressure is 1.5~4.0MPaG, goes high pressure flash air compressor system circulation after the gas of high pressure flash out and raw natural gas re-heat
To absorb the bottom of the tower as bottom feed, high pressure flash go out liquid carry out again in press flash distillation；
(4) in pressure flashing pressure be 0.6~1.5MPaG, middle pressure flashed gas by with conduct after raw natural gas re-heat
Purified gas goes outer defeated system, middle that the liquid flashed off is pressed to carry out low pressure flash again；Low pressure flash pressure is 0.3~0.6MPaG, low
Pressure flashed gas by being used as purified gas to go outer defeated system with after raw natural gas re-heat, the liquid that low pressure flash goes out again into
Row atmospheric flashing；
(5) atmospheric flashing pressure is 0.0MPaG, and normal pressure presses flashed gas to enter often by with after raw natural gas re-heat
Flashed vapour booster compressor systems are pressed, go outer defeated system as purified gas after pressurization, the liquid that atmospheric flashing goes out goes solvent to recycle
Pump is pressurized to 3.4~12.4MPaG, then goes absorption tower top to be recycled by extremely -25 DEG C~-30 DEG C of refrigeration.
2. empty the method according to claim 1, wherein the gas that high pressure flash goes out is compressed through high pressure compressor
Freeze again after cold to being recycled to absorb the bottom of the tower, middle pressure flashed vapour, low pressure flash gas and atmospheric flashing gas after -25 DEG C~-30 DEG C
It is connected together and goes outer defeated system as purified gas.
3. the method according to claim 1, wherein absorption tower bottom rich solution is after the decompression of high pressure hydraulic turbine
High pressure flash is carried out, the power of high pressure hydraulic turbine is available to solvent circulating pump.
4. the method according to claim 1, wherein hydraulic fluid power turbine drop in the liquid process that high pressure flash goes out
Flash distillation is pressed in carrying out after pressure, the power of middle hydraulic fluid power turbine is supplied to solvent circulating pump.
5. the method according to claim 1, wherein the absorbent used is heptane (C7), octane (C8), nonane
(C9) and the mixture of decane (C10).
6. according to the method described in claim 5, it is characterized in that, heptane (C7), octane (C8), nonane (C9) and decane
(C10) quality proportioning is (5-15): (45-55): (15-25): (15-25).
7. ice chest (1), raw natural gas evaporator (2), absorption tower is pre-chilled in a kind of natural gas nitrogen rejection facility, including raw natural gas
(3), high pressure flash tower (4), middle pressure flash column (5), Low Pressure Flashing Column (6), atmospheric flash tower (7), solvent circulating pump (8), molten
Agent evaporator (9), high pressure flash air compressor (10), high pressure flash gas evaporator (11), low pressure flash air compressor (12) are low
It presses flashed vapour air cooler (13), which is characterized in that
Raw natural gas is after the preliminary pre-cooling of raw natural gas pre-cooling ice chest (1), by raw natural gas evaporator (2)
Further it is admitted in the middle part of absorption tower (3) after cooling；N2Discharge line (S10) is located at the top of absorption tower (3) and natural with raw material
Gas is pre-chilled ice chest (1) and is connected, the N after re-heat2Discharge line (S10) interior gas is discharged；
The both ends of absorption tower bottom flash liquid discharge line (S3) are located at the top of absorption tower (3) bottom and high pressure flash tower (4),
The both ends of high pressure flash liquid discharge line (S4) are located at the top of high pressure flash tower (4) bottom and middle pressure flash column (5), high pressure
The both ends of flashed vapour discharge line (S11) are separately connected at the top of high pressure flash tower (4) and raw natural gas pre-cooling ice chest (1) is cold out
The high pressure flash air pipe S15 of case is connected to the entrance of high pressure flash air compressor (10), discharge pipe after high pressure flash air pressure contracting
Road (S20) is connected to high pressure flash gas evaporator (11), discharge line (S21) connection absorption tower (3) after high pressure flash air cooling
Bottommost；The both ends of middle pressure flash liquid discharge line (S5) are located at middle pressure flash column (5) bottom and Low Pressure Flashing Column (6)
Top, the both ends of middle pressure flashed vapour discharge line (S12) are separately connected at the top of middle pressure flash column (5) and raw natural gas pre-cooling is cold
Case (1), the middle pressure after ice chest (1) re-heat is pre-chilled in raw natural gas flash air pipe (S18) inner gas as purification day
Right gas discharge；The both ends of low pressure flash liquid discharge line (S6) are located at Low Pressure Flashing Column (6) bottom and atmospheric flash tower (7)
Top, the both ends of low pressure flash gas discharge line (S13) are separately connected at the top of Low Pressure Flashing Column (6) and ice chest is pre-chilled in unstripped gas
(1), pressure flash distillation air pipe in low pressure flash air pipe (S17) access after ice chest (1) re-heat is pre-chilled in raw natural gas
(S18)；The both ends of atmospheric flashing liquid discharge line (S7) are located at atmospheric flash tower (7) bottom and solvent circulating pump (8)
Entrance, the both ends of atmospheric flashing gas discharge line (S14) are separately connected at the top of atmospheric flash tower (7) and ice chest is pre-chilled in unstripped gas
(1), the atmospheric flashing air pipe (S19) after ice chest (1) re-heat is pre-chilled in raw natural gas is into low pressure flash air compressor
(12), the gas pipeline (S22) being pressurized through low pressure flash air compressor (12) is connected to atmospheric flashing gas air cooler (13), cold
But the pipeline (S23) after is connected to middle pressure flash distillation air pipe (S18)；The export pipeline (S8) of solvent circulating pump (8) is separately connected
The outlet of mouth solvent circulating pump (8) and the entrance of solvent evaporator (9), the export pipeline (S9) of solvent evaporator (9) are connected to
The top on absorption tower (3).
8. device according to claim 7, which is characterized in that further include that high pressure hydraulic turbine (14), middle hydraulic fluid power are saturating
Flat machine (15), wherein high pressure hydraulic turbine (14) is arranged on absorption tower bottom flash liquid discharge line (S3), and middle hydraulic fluid power is saturating
Flat machine (15) is arranged on high pressure flash liquid discharge line (S4).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910361735.XA CN110066695A (en) | 2019-04-30 | 2019-04-30 | Natural gas nitrogen rejection facility and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910361735.XA CN110066695A (en) | 2019-04-30 | 2019-04-30 | Natural gas nitrogen rejection facility and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110066695A true CN110066695A (en) | 2019-07-30 |
Family
ID=67369754
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910361735.XA Pending CN110066695A (en) | 2019-04-30 | 2019-04-30 | Natural gas nitrogen rejection facility and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110066695A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114606033A (en) * | 2020-12-09 | 2022-06-10 | 中国石油化工股份有限公司 | Natural gas solvent absorption denitrification flash control system and parameter optimization method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004015346A1 (en) * | 2002-08-12 | 2004-02-19 | Conocophillips Company | Natural gas liquefaction with improved nitrogen removal |
| CN104263443A (en) * | 2014-09-19 | 2015-01-07 | 北京安珂罗工程技术有限公司 | Method and system for separating nitrogen from liquefied natural gas |
| CN106433832A (en) * | 2016-10-14 | 2017-02-22 | 帝仕达工程技术（北京）有限公司 | Process and device for removing CO2 in natural gas |
| CN206352930U (en) * | 2016-12-30 | 2017-07-25 | 四川杰瑞恒日天然气工程有限公司 | Flash the re-liquefied system of natural gas denitrogenation |
-
2019
- 2019-04-30 CN CN201910361735.XA patent/CN110066695A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004015346A1 (en) * | 2002-08-12 | 2004-02-19 | Conocophillips Company | Natural gas liquefaction with improved nitrogen removal |
| CN104263443A (en) * | 2014-09-19 | 2015-01-07 | 北京安珂罗工程技术有限公司 | Method and system for separating nitrogen from liquefied natural gas |
| CN106433832A (en) * | 2016-10-14 | 2017-02-22 | 帝仕达工程技术（北京）有限公司 | Process and device for removing CO2 in natural gas |
| CN206352930U (en) * | 2016-12-30 | 2017-07-25 | 四川杰瑞恒日天然气工程有限公司 | Flash the re-liquefied system of natural gas denitrogenation |
Non-Patent Citations (1)
| Title |
|---|
| ***等: "天然气脱氮工艺综述", 《石油规划设计》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114606033A (en) * | 2020-12-09 | 2022-06-10 | 中国石油化工股份有限公司 | Natural gas solvent absorption denitrification flash control system and parameter optimization method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10113127B2 (en) | Process for separating nitrogen from a natural gas stream with nitrogen stripping in the production of liquefied natural gas | |
| CN108458549B (en) | System and method for extracting helium from natural gas and liquefying same | |
| RU2014153653A (en) | The method of complex extraction of valuable impurities from natural helium-containing hydrocarbon gas with a high nitrogen content | |
| CN102564060A (en) | Method for separating off nitrogen and hydrogen from natural gas | |
| CN102764563B (en) | Adsorption compression formula oil gas recovery processing system and recovery processing technique thereof | |
| CN110093197B (en) | Denitrification method and denitrification system for oilfield associated gas | |
| CN104941383A (en) | Method and device for recycling methane chloride tail gas in depth | |
| CN105038882B (en) | A kind of saturated aqueous oil field gas reclaims the comprehensive smart dewatering process of LNG/LPG/NGL products | |
| CN204987654U (en) | Device is used multipurposely to synthetic ammonia tail gas | |
| CN104061755B (en) | A kind of nitrogen rejection facility for natural gas and denitrification process thereof | |
| CN104513680A (en) | Technology and device for removing hydrogen and nitrogen from methane-rich gas through rectification and producing liquefied natural gas | |
| CN114017994B (en) | Process for purifying carbon dioxide from alcohol tail gas | |
| CN110066695A (en) | Natural gas nitrogen rejection facility and method | |
| CN214371298U (en) | Carbon dioxide gathering liquefaction recovery device | |
| CN206244740U (en) | Pipe natural gas heavy hydrocarbon removal unit | |
| CN111320524A (en) | Method and device for separating ethylene and propylene from pyrolysis gas and/or dry gas | |
| CN103267402B (en) | Method for extracting methane in low-concentration oxygen-containing coal bed gas | |
| US9511323B2 (en) | Dehydration of gases with liquid desiccant | |
| CA2998529C (en) | A method of preparing natural gas to produce liquid natural gas (lng) | |
| CN114518016A (en) | Carbon dioxide capturing, liquefying and recycling device and method | |
| CN210133884U (en) | Electronic grade high-purity hydrogen chloride preparation system | |
| CN210065692U (en) | A denitrogenation system for oil field associated gas | |
| CN104893773A (en) | Heavy hydrocarbon removal unit for pipeline natural gas and heavy hydrocarbon removal method | |
| US3026683A (en) | Separation of hydrogen and methane | |
| CN103361138B (en) | Method for preparing liquefied natural gas and synthesis ammonia raw material gases by use of hydrogen extraction desorption gas |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20190730 |
|
| WD01 | Invention patent application deemed withdrawn after publication |