CN205821275U - A kind of system separating heavy hydrocarbon lime set from gas deliquescence process - Google Patents

Abstract

This utility model relates to a kind of system separating heavy hydrocarbon lime set from gas deliquescence process.Heavy hydrocarbon in natural gas is separated and further process of refinement by this utility model by arranging domethanizing column 2, dethanizer 3 and stabilizer 4 after natural gas precooling zone, thus produces commerical grade butane product and C5+ lime set heavier hydrocarbon products.Ice chest 1 is exported LNG product and extracts one out and provide cold for de-heavy hydrocarbon process by system of the present utility model, and makes de-heavy hydrocarbon technique be coupling in gas deliquescence process, and process integration is high.System stability of the present utility model is good, and the suitability is extensive, has the strongest operability.

Description

A kind of system separating heavy hydrocarbon lime set from gas deliquescence process

Technical field

This utility model relates to liquefied natural gas (LNG) production field, particularly to one separating heavy from gas deliquescence process The system of hydrocarbon lime set.

Background technology

In liquefied natural gas field, heavy hydrocarbon typically refers to C5 and above hydro carbons.Owing to these hydro carbons freezing pointes are of a relatively high, If heavy hydrocarbon not being previously isolated from out, then freeze there is heavy hydrocarbon and the risk of occluding device during natural gas deep cooling.For Ensure the normal work of natural gas liquefaction system, it is necessary to take measures to be taken off by heavy hydrocarbon therein before natural gas enters deep cooling workshop section Remove.

At present, the method for natural QI prostration heavy hydrocarbon has solid absorption method, solvent absorption, condensation separation method and membrane separation process. Solid absorption method utilizes the solid absorbent with loose structure to make hydrocarbon gas be able to the difference of hydrocarbon component absorbability The method separated, the method flow process is simple, has certain selectivity, but the method is not suitable for heavy hydrocarbons content height and processes Measure big operating mode, especially contain the operating mode of neopentane.And adsorbent need to be regularly replaced, power consumption height during regeneration.Solvent absorption Method process program strong adaptability, does not limit the heavy hydrocarbons content in natural gas, but the method flow process is complicated, absorbent regeneration Time also consume big energy, the heavy hydrocarbon being removed also to enter follow-up dethanizer to reclaim lighter hydrocarbons, it is impossible to adapt to source of the gas group Divide the situation of rapid fluctuations.Membrane separation process use in natural gas lighter hydrocarbons separate utilizes the non-porous matter dissolving diffusion mechanism more Film, gas membrane Seperation Technology has technique and is simple and convenient to operate, keeps in repair the advantage such as simplicity and plant investment province, and make amends for one's faults the party Division A League Matches of French Football alkane loss rate is too high, reaches 30% ~ 40%, can not accept for liquefied natural gas (LNG) plant.Condensation separation method is also known as cryogenic rectification Method, utilizes the difference of molten boiling point, carries out gas-liquid separation.It is that natural gas is cooled to the required low temperature of below hydrocarbon dew point temperature, To part rich in the lime set of heavier hydro carbons, essence is exactly gas liquid technology.And right current this method is used for natural more Gas dew point controls, and to natural QI prostration lacking of property of heavy hydrocarbon, causes this method in area of natural gas liquefaction application by the biggest Restriction.Based on this, this utility model provides a kind of system separating heavy hydrocarbon lime set from gas deliquescence process.

Utility model content

The purpose of this utility model is to overcome the deficiencies in the prior art, reduces liquefaction natural gas and (has taken off sour gas, taken off Water, the natural gas of demercuration) energy consumption of de-heavy hydrocarbon process, simplify natural QI prostration heavy hydrocarbon technique, and will be enriched in the de-heavy hydrocarbon mistake of heavy hydrocarbon Journey couples with gas deliquescence process；Thus a kind of system separating heavy hydrocarbon lime set from gas deliquescence process is provided, this is System, not only from rich in having reclaimed heavier hydrocarbon products the natural gas of heavy hydrocarbon, increases technique added value, and meet heavy hydrocarbon component and The demand that heavy hydrocarbon is removed by the natural gas that changes of contents is big, enhances the adaptability of technique.

System of the present utility model by arrange three cryogenic rectification towers will be enriched in the de-heavy hydrocarbon process of heavy hydrocarbon natural gas with Liquefaction process couples thus is removed by the heavy hydrocarbon in natural gas, thus provides a kind of heavy hydrocarbon that separates from gas deliquescence process to coagulate The system of liquid, this system includes: the first flow A1 of ice chest 1, the second runner A2, the 3rd runner A3, domethanizing column 2, deethanization Tower 3, stabilizer 4, domethanizing column condenser 5, deethanizer reboiler 6, stabilizer condenser 7, heavy hydrocarbon return tank 8, heavy hydrocarbon return Flow pump 9, stabilizer reboiler 10, heavy hydrocarbon cooler the 11, first valve V1 to the 7th valve V7 and connect pipeline accordingly, its In, the first flow A1 entrance of ice chest 1 is connected with unstripped gas natural gas line, exports through the first valve V1 and domethanizing column 2 Bottom feed mouth connects；Second runner A2 entrance of ice chest 1 is connected with the shell-side gaseous phase outlet of domethanizing column condenser 5, exports It is connected with LNG product pipeline；3rd runner A3 entrance of ice chest 1 is connected with the gaseous phase outlet of dethanizer 3, exports and produce with LNG QC line connects；The tube-side inlet of domethanizing column condenser 5 is through the LNG of the second valve V2 with the second runner A2 outlet of ice chest 1 Product pipeline connects, tube side outlet is connected with the second charging aperture of dethanizer 3；Domethanizing column 2 tower bottom liquid exports mutually through the 3rd Valve V3 is connected with dethanizer 3 first charging aperture；Deethanizer reboiler 6 liquid-phase outlet is through the 4th valve V4 and stabilizer 4 First charging aperture is connected；Stabilizer condenser 7 import is connected with stabilizer 4 gaseous phase outlet, exports and heavy hydrocarbon return tank 8 import phase Even；Heavy hydrocarbon return tank 8 gaseous phase outlet is connected with fuelgas pipeline through the 5th valve V5, liquid-phase outlet and heavy hydrocarbon reflux pump 9 import It is connected；Heavy hydrocarbon reflux pump 9 exports and is connected with stabilizer 4 second charging aperture and butane product line through the 7th valve V7；Stabilizer is again Boiling device 10 liquid-phase outlet is connected with heavy hydrocarbon cooler 11 entrance；Heavy hydrocarbon cooler 11 exports through the 6th valve V6 and C5+ lime set weight Hydrocarbon product pipeline connects.

Above-mentioned domethanizing column condenser 5 is arranged on domethanizing column 2, and both are directly connected to by flange.

Above-mentioned domethanizing column 2, dethanizer 3 and stabilizer 4 are packed tower or plate column.

Above-mentioned domethanizing column 2, dethanizer 3 and stabilizer 4 is provided with demister.

Above-mentioned stabilizer condenser 7 is air cooler or shell-and-tube heat exchanger.

The technical solution of the utility model is by arranging domethanizing column, dethanizer after the one-step cooling of ice chest natural gas side And stabilizer, utilize the principle that natural gas liquefaction condensation process heavy hydrocarbon condensation point first liquefies than natural upward adverse flow of QI, thus realize weight The separation of hydrocarbon, makes heavy hydrocarbon contained by natural gas be able to the degree of depth in liquefaction process and separates and purify, and processing performance is stable；This reality simultaneously By novel technical scheme, natural QI prostration heavy hydrocarbon process is coupled with liquefaction process, simple process, workable.

Advantage of the present utility model and positive role are:

(1) separating technology arranging domethanizing column, dethanizer and stabilizer after using natural gas one-step cooling realizes weight The separation of hydrocarbon, it is possible to meeting heavy hydrocarbon component and the big natural QI prostration heavy hydrocarbon demand of changes of contents, processing performance is stable.

(2) achieve natural QI prostration heavy hydrocarbon process to couple with liquefaction process, simplify natural gas liquefaction process flow process, investment Saving, de-heavy hydrocarbon specific energy consumption is less than 0.018 kW/ (h NM³Raw natural gas), operating cost is low, cost-effective, thus produces Raw obvious economic benefit.

(3) heavy hydrocarbon in natural gas all reclaimed and obtain qualified heavier hydrocarbon products, meeting commercial butane and C5+ lime set Product specification requirement, improves the level of resources utilization, adds technique added value.

Accompanying drawing explanation

Fig. 1 is process flow diagram of the present utility model.

De-heavy hydrocarbon system the most of the present utility model；B. refrigeration system.

In figure, code name implication is as follows:

1. ice chest

2. domethanizing column

3. dethanizer

4. stabilizer

5. domethanizing column condenser

6. deethanizer reboiler

7. stabilizer condenser

8. heavy hydrocarbon return tank

9. heavy hydrocarbon reflux pump

10. stabilizer reboiler

11. heavy hydrocarbon coolers.

Detailed description of the invention

Below in conjunction with embodiment and accompanying drawing, this utility model is explained

Embodiment 1

The concrete technology flow process of the present embodiment refers to Fig. 1.

A kind of system separating heavy hydrocarbon lime set from gas deliquescence process, including: the first flow A1 of ice chest 1, second Runner A2, the 3rd runner A3, domethanizing column 2, dethanizer 3, stabilizer 4, domethanizing column condenser 5, deethanizer reboiler 6, stabilizer condenser 7, heavy hydrocarbon return tank 8, heavy hydrocarbon reflux pump 9, stabilizer reboiler 10, heavy hydrocarbon cooler the 11, first valve V1 to the 7th valve V7 and connect pipeline accordingly, wherein, the first flow A1 entrance of ice chest 1 is with unstripped gas natural gas line even Connect, export and be connected with the bottom feed mouth of domethanizing column 2 through the first valve V1；Second runner A2 entrance and demethanation of ice chest 1 The shell-side gaseous phase outlet of tower condenser 5 connects, outlet is connected with LNG product pipeline；3rd runner A3 entrance of ice chest 1 and de-second The gaseous phase outlet of alkane tower 3 connects, outlet is connected with LNG product pipeline；The tube-side inlet of domethanizing column condenser 5 is through the second valve V2 is connected with the LNG product pipeline of the second runner A2 outlet of ice chest 1, tube side exports the second charging aperture phase with dethanizer 3 Even；Domethanizing column 2 tower bottom liquid exports mutually and is connected with dethanizer 3 first charging aperture through the 3rd valve V3；Deethanizer reboiler 6 Liquid-phase outlet is connected with stabilizer 4 first charging aperture through the 4th valve V4；Stabilizer condenser 7 import goes out with stabilizer 4 gas phase Mouth is connected, and outlet is connected with heavy hydrocarbon return tank 8 import；Heavy hydrocarbon return tank 8 gaseous phase outlet is through the 5th valve V5 and fuelgas pipeline Being connected, liquid-phase outlet is connected with heavy hydrocarbon reflux pump 9 import；Heavy hydrocarbon reflux pump 9 exports and enters with stabilizer 4 second through the 7th valve V7 Material mouth is connected with butane product line；Stabilizer reboiler 10 liquid-phase outlet is connected with heavy hydrocarbon cooler 11 entrance；Heavy hydrocarbon cooler 11 outlets are connected through the 6th valve V6 and C5+ lime set heavier hydrocarbon products pipeline.More than constitute separating heavy from gas deliquescence process The system of hydrocarbon lime set.

To be passed through the first flow A1 entrance of ice chest 1 from outside raw natural gas I, this raw natural gas is deacidification Property gas, dehydration, demercuration, natural gas rich in heavy hydrocarbon, flow is 60236 kg/h, and pressure is 4.9 MPa, and temperature is 45 C, weight Hydrocarbon total content is 4390 ppmv, and wherein neopentane content is 140ppmv, and benzene content is 200 ppmv, C6 and above hydrocarbon content Being 4050 ppmv, after ice chest 1 first flow A1 cools down, temperature is down to-66 C and is obtained the natural gas II of gas-liquid two-phase state, Natural gas II enters the bottom feed mouth of domethanizing column 2 after the first valve V1 is decompressed to 4.55 MPa, carries through de-heavy hydrocarbon rectification Pure, obtain at the bottom of tower temperature be-69 C, flow be liquid phase I of 5559kg/h, tower top obtains the natural gas that temperature is-75 C III, wherein neopentane content is 3 ppmv, and benzene content is 0.1 ppmv, and C6 and above hydrocarbon content are 6 ppmv, meet deep cooling Requirement.Natural gas III continues cool to-161 C through the second runner A2 entrance entrance ice chest 1 and i.e. obtains qualified LNG product I. Domethanizing column 2 top arranges domethanizing column condenser 5, extracts 5.5% out and be decompressed to 1.36 through the second valve V2 from LNG product I The tube-side inlet of domethanizing column condenser 5 is entered after MPa.The tube side outlet of domethanizing column condenser 5 is the natural of gas-liquid two-phase Gas IV, its temperature is-107.6 C, enters the second charging aperture of dethanizer 3 afterwards.Liquid phase I is decompressed to through the 3rd valve V3 The first charging aperture of dethanizer 3 is entered after 1.34 MPa.It is 1.33 MPa that dethanizer 3 operates pressure, through de-heavy hydrocarbon rectification Purify, obtain at the bottom of tower temperature be 150 C, flow be the heavy hydrocarbon I of 2083 kg/h, it is the natural of-43.81 C that tower top obtains temperature Gas V, wherein neopentane content is 4 ppmv, and benzene content is 2 ppmv, and C6 and above hydrocarbon content are 8 ppmv, meets deep cooling and wants Ask.Natural gas V continues cool to-161 C through the 3rd runner A3 entrance entrance ice chest 1 and i.e. obtains qualified LNG product II.Weight Hydrocarbon I enters stabilizer 4 after the 4th valve V4 is decompressed to 0.53 MPa, and through de-heavy hydrocarbon rectification and purification, obtaining temperature at the bottom of tower is 121.4 DEG C, flow be the heavy hydrocarbon II of 1775 kg/h, it is 48.1 DEG C that tower top obtains temperature, and flow is the butane of 1335 kg, through steady After determining tower condenser 7 condensation, obtaining the liquid phase butane that temperature is 47 DEG C, wherein the liquid phase butane of 1027kg is steady as being recirculated back to Determining tower 4, the liquid phase butane of 308kg sends into fuel gas system as butane product, the fixed gas of trace by the 5th valve V5.Weight Hydrocarbon II cools down through heavy hydrocarbon cooler 11, then obtains C5+ lime set heavier hydrocarbon products after the 6th valve V6 is decompressed to 0.09 MPa. In C5+ lime set heavier hydrocarbon products, the content of methane is 0.001%, and the content of ethane is 0.02%, and natural gas yield is 99.8%, heavy hydrocarbon The response rate is 99.9%, and de-heavy hydrocarbon specific energy consumption is 0.012 kW/ (h NM³Raw natural gas).

Claims (2)

1. the system separating heavy hydrocarbon lime set from gas deliquescence process, it is characterised in that this system includes: ice chest (1) First flow (A1), the second runner (A2), the 3rd runner (A3), domethanizing column (2), dethanizer (3), stabilizer (4), de- Methane tower condenser (5), deethanizer reboiler (6), stabilizer condenser (7), heavy hydrocarbon return tank (8), heavy hydrocarbon reflux pump (9), stabilizer reboiler (10), heavy hydrocarbon cooler (11), the first valve (V1) to the 7th valve (V7) and corresponding connecting tube Road, wherein, first flow (A1) entrance of ice chest (1) is connected with unstripped gas natural gas line, export through the first valve (V1) with The bottom feed mouth of domethanizing column (2) connects；Second runner (A2) entrance of ice chest (1) and the shell of domethanizing column condenser (5) Side gaseous phase outlet connects, outlet is connected with LNG product pipeline；3rd runner (A3) entrance of ice chest (1) and dethanizer (3) Gaseous phase outlet connects, outlet is connected with LNG product pipeline；The tube-side inlet of domethanizing column condenser (5) is through the second valve (V2) The LNG product pipeline exported with second runner (A2) of ice chest (1) is connected, tube side outlet feeds with the second of dethanizer (3) Mouth is connected；Domethanizing column (2) tower bottom liquid exports mutually and is connected with dethanizer (3) first charging aperture through the 3rd valve (V3)；De-second Alkane tower reboiler (6) liquid-phase outlet is connected with stabilizer (4) first charging aperture through the 4th valve (V4)；Stabilizer condenser (7) Import is connected with stabilizer (4) gaseous phase outlet, and outlet is connected with heavy hydrocarbon return tank (8) import；Heavy hydrocarbon return tank (8) gaseous phase outlet Being connected with fuelgas pipeline through the 5th valve (V5), liquid-phase outlet is connected with heavy hydrocarbon reflux pump (9) import；Heavy hydrocarbon reflux pump (9) Outlet is connected with stabilizer (4) second charging aperture and butane product line respectively through the 7th valve (V7)；Stabilizer reboiler (10) Liquid-phase outlet is connected with heavy hydrocarbon cooler (11) entrance；Heavy hydrocarbon cooler (11) outlet is through the 6th valve (V6) and C5+ lime set weight Hydrocarbon product pipeline connects.

The system separating heavy hydrocarbon lime set from gas deliquescence process the most according to claim 1, it is characterised in that stable Tower condenser (7) is air cooler or shell-and-tube heat exchanger.