CN1115187C - Process for shut-down of membrane operation - Google Patents
Process for shut-down of membrane operation Download PDFInfo
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- CN1115187C CN1115187C CN97121419A CN97121419A CN1115187C CN 1115187 C CN1115187 C CN 1115187C CN 97121419 A CN97121419 A CN 97121419A CN 97121419 A CN97121419 A CN 97121419A CN 1115187 C CN1115187 C CN 1115187C
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- 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
- B01D53/22—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 diffusion
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- 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
- B01D53/22—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 diffusion
- B01D53/229—Integrated processes (Diffusion and at least one other process, e.g. adsorption, absorption)
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
- Y02C20/00—Capture or disposal of greenhouse gases
- Y02C20/40—Capture or disposal of greenhouse gases of CO2
Abstract
The present invention relates to a technology process which comprises a non-permeation side and a permeation side and processes the shutdown of a membrane separation region for supplying airflow. The supplied airflow comprises a non-permeation component, a condensable component not easily permeated, and a component easily permeated. When no airflow is supplied to pass through the membrane separation region, the airflow is blown and swept at high pressure to pass through the non-permeation side of the membrane separation region; thus, the residual airflow is eliminated, and the condensation of the condensable component not easily permeated can be prevented during the pressure reduction and/or temperature reduction of the membrane separation region. The present invention has the advantages of requirement reduction of an oversized membrane system, reduction of production cost and prevention of the permeation damage generated by the condensation of the condensable component not easily permeated, such as C6<+> hydrocarbon to the surface of the membrane.
Description
The present invention relates to a kind of method that is used to operate continuous film separation process, wherein, when film is stopped work (shut-down), particularly when membrane separation zone shut-down unexpected or that do not expect, this method can prevent the damage of film, The present invention be more particularly directed to a kind of from light hydrocarbon gas in the process of separating carbon dioxide, the method that membrane safety is stopped work.
Permeable membrane is handled and have been known in the prior art with system and be used for or manage to be used for separating of all gases and liquid.In such process, supply with air-flow and contact, and the easy infiltration component of supply air-flow is separated as permeating airflow, is difficult for infiltration component and extracts from the film system as non-permeating airflow with the surface of film.Membrane separation assemblies remains under the duty, promptly imports supply gas down and extracts non-permeating airflow in non-osmotic lateral pressure, extracts permeating airflow down in osmotic lateral pressure.The pressure of the non-per-meate side of film is higher than the pressure of per-meate side, and the pressure reduction between them has been determined to separate the separation that is obtained by film.
Film is widely used in supplying with the easy infiltration component of separation the air-flow from gaseous state.For example, the application of such process can comprise and separates gaseous acid from natural gas flow, separation of water vapor from air and lighter hydrocarbons air-flow, separation of hydrogen from the heavy hydrocarbon air-flow.Film also is used to handle gas, separates easy infiltration component from flow of process air.Extensive processing method as natural gas adopts the film system usually.
In the prior art, so intrinsic simplicity of fluid separation process has promoted that the film system is developed in the application of the commercialization process of reality.All production requirements that the selectivity of this film system and permeability must be able to be adapted to given purposes.Also need film to demonstrate satisfied stability in addition and in the course of industrialization of reality, do not suffer the characteristic of undue damage.
The film that is used for gas treatment is generally worked in a continuous manner, supplies with air-flow and is input to the film gas separation component in the non-per-meate side of film.Supply gas is to import under the condition with such separating pressure and temperature: promptly such separating pressure and temperature can make the component of supplying with air-flow keep steam state, substantially exceed the dew point of air-flow, and perhaps this temperature and pressure can make one of component produce condensation.Yet if supply with the flow disruption of air-flow, perhaps supply pressure reduces suddenly, and the residual substance in the membrane separation zone can reach its dew point and produce condensation.Therefore the supply air-flow that is provided to gas separation membrane can contain a certain amount of moisture, can produce in instrument, pipeline, pneumatic tool, the ventilation blower equipment relevant with other films separated from the gas and corrode and condensation.In some cases, it also can cause gas separation membrane and/or other equipment, for example the bad operation of adsorption trap.When estimating suitable condensation number, usually film is done too muchly, compensate loss with this above the film surface of the useful life of film.With regard to large-scale gas treatment was used, the excessive design of this membrane capacity can make the cost costliness.
Application about the gas drying discloses in the certain methods: available purge gas is removed moisture from film before its condensation.For example, in using the comparatively desirable air separation application of permeable membrane, for specific film, oxygen generally is to supply with the component of easily permeating in the air-flow, and is extracted as infiltration gas.Among such embodiment, nitrogen is the component that is difficult for infiltration, reclaims as non-infiltration gas.Liquid water is usually by conventional equipment, and for example knockout drum is isolated from the upstream of the supply air-flow of film.The water vapour that exists in the supply air-flow produces dry non-infiltration gas with the infiltrate film.In the application of air separation, some impurity of existence is responsive to the performance of film in the air-flow to supplying with.Being exposed to such impurity in use can cause permeability of the membrane obviously to descend.Luckily, have been found that the most of impurity that generally are present in the surrounding air at most only make permeability of the membrane slightly descend, these impurity are if any lighter hydrocarbons, H
2O and CO
2The appearance of heavy-hydrocarbon oil steam, even concentration is lower, for example perhaps this heavy-hydrocarbon oil steam be that air compressor machine from oil lubrication enters the supply air-flow, by volume calculates to be lower than 1ppm, also can accelerate, aggravate permeability of the membrane decline.
Descending in order to respond this unfavorable permeability of the membrane, generally is the effective area size of setting film with an enough big safety coefficient at present, so that compensation infiltrative decline that estimated, that a variety of causes causes.At first, for required product air-flow, the size of film system is obviously excessive, and the state work to regulate usually of supply gas compressor.When permeability reduces, can be by improving operating temperature or pressure or both compensate infiltrative decline.Under some situation, walk around some assemblies in the film system at first and be necessary or say comparatively desirable, when film has its whole penetrating power, do the area that can reduce employed excessive film like this, when the assembly of initial use begins to decay, can the assembly of walking around like this be connected air-flow thereupon.Except the considerable cost of investment relevant with excessive membrane area is provided, this film system entails was worked under off-design conditions in the quite long period of its working life, and compare with a kind of system near its optimal design condition work, the control of this film system is more complicated.
For compensate film damage in use, replacement scheme as the film system of the so excessive design of another kind, the performance of having made an effort and having recovered to lose, but at the aspect of performance that a kind of economically viable device of exploitation is lost with the film that recovers to damage, be unsuccessful at first.Any part of repairing the film that has damaged all needs to interrupt the course of work of gas treatment, replaces a large amount of gases.No matter make the excessive design of film system, the course of work of still interrupting gas treatment is to carry out repair process to film, perhaps the combination of the two descends for overcome permeability in the industrialization gas of reality or other gas separation process, is not entirely satisfactory.In existing membrane technology, expect very much to make further improvement at the damage problem of film.
US-A-4,881,953 disclose and have a kind ofly for example used active carbon adsorption impurity by making the supply gas mixture prevent the method that permeability of the membrane descends through an adsorbent bed, as heavy hydrocarbon, and lighter hydrocarbons are isolated.This method need provide a kind of dried up device that divides from supply gas, reason is that higher water content is generally understood the adsorption capacity of restricted activity carbon adsorbent to heavy hydrocarbon.
US-A-5,030,251 relates to isolate the technical process of water vapour with the membrane separator for preparing dry air products from humid air.Interrupt when a kind of like this technical process of film, some remaining water vapours will remain in the membrane separator, and when supplying with the air-flow recovery, remaining water vapour just flows out with non-permeating airflow.Therefore, membrane separator resets gas products made in the process not as the drying of steady state process process.In order to correct this problem, the non-infiltration gas product of part is stored in the storage tank, when not supplying with air-flow and offer separator with its delivery film separator, so that between circulation, eliminate remaining water vapour.Supply with and circulate when stopping, the air pressure of the non-per-meate side of separator is reduced to atmospheric pressure.Because the pressure in the storage tank is higher than atmospheric pressure,, the non-infiltration gas of some storages purges air-flow so overflowing to form.
US-A-5,383,956 relate to the technical process and the device of the membrane gas separation system that starts and stop to handle wet gas supply air-flow.This process is used film dry component and gas separating film module according to dry with separating the different setting up procedure of supplying with air-flow and stopping step.When a kind of like this technical process that includes at least one gas separation component and at least one film drier was interrupted, the flow disruption of supply gas can not arrive two membrane modules, and membrane module is just by reducing pressure from the isolated gas-pressurized of the non-per-meate side of membrane module.The gas of pressurization can pass corresponding membrane module and be penetrated into per-meate side, is just purged the per-meate side and the non-per-meate side of membrane module subsequently by a dry gas stream.
When membrane separation zone is handled natural gas, for example reducing heavy hydrocarbon, for example C under certain condition of temperature and pressure
+ 6Hydrocarbon, particularly C
+ 10The appearance of hydrocarbon, the perhaps variation on the component all can cause membrane capacity to descend, and normally nonvolatil damage.So managing to seek the processing method that makes film separation unit avoid such damage always.
Therefore, an object of the present invention is to provide the technical process of the improved shut-down of a kind of film system, this process can for example overcome the problem that permeability descends in appropriate hydrocarbon gas production in the gas production.
Another object of the present invention provides the technical process of a kind of film system and shut-down, wherein can avoid excessive design requirement or change the membrane module of performance degradation too early, and can reduce the demand of interrupting the gas generation process for the permeability of repair membrane is handled by membrane module to greatest extent.
The invention provides the out-of-work technical process of a kind of film separation system safety, this process has reduced the danger that film damages to greatest extent.Found to be difficult for infiltration, condensable components, for example C when the film flow of process air comprises
+ 6During hydrocarbon, if may take place at this hydrocarbon to work under the environment of condensation, when shut-down step and then common after this hydrocarbon condensation, for example non-osmotic lateral pressure reduces, and film will be damaged.When find stopping work again the decompression of film only with the non-infiltration area that purges film unit in or produce afterwards be only desirable.According to the present invention, to find to carry out drying after the condensation, the non-per-meate side of preferred film and per-meate side do not have relative pressure and change, and just can avoid infiltrative decline also to keep unexpectedly or the raising selectivity.
Generally speaking, the present invention relates to a kind of out-of-work technical process of membrane separation zone safety of separating easy infiltration component from the supply gas mixture that is used in, wherein the supply gas mixture comprises easy infiltration component, non-infiltration component and is difficult for infiltration, condensable components.This process comprises the supply gas mixture is exhausted delivery film Disengagement zone, ground between under the separation condition, thereby non-permeating airflow and permeating airflow are provided.Membrane separation zone has a non-per-meate side and a per-meate side.Non-permeating airflow extracts from the non-per-meate side of membrane separation zone, and permeating airflow per-meate side from membrane separation zone under an osmotic pressure is extracted.When not having the supply gas mixture by membrane separation zone, the purging air-flow that has reduced difficult infiltration, condensable components leads to the non-per-meate side of membrane separation zone under a pressure of the osmotic pressure that is higher than separating step, so that before the membrane separation zone condensation, dispose this residual gas that part remains in the non-per-meate side of membrane separation zone at least at residual gas.Subsequently, finished the shut-down step by the pressure that reduces the Disengagement zone.
In a specific embodiment of the present invention, supply with the air-flow separating carbon dioxide to make the technical process of selling air-flow from hydrocarbon with the present invention relates to exhaust between a kind of being used for.This appropriate hydrocarbon gas is supplied with mixture and is comprised C
1To C
6Hydrocarbon, carbon dioxide and C
+ 6Hydrocarbon.C
+ 6Hydrocarbon is not easily infiltration and condensable.Appropriate hydrocarbon gas supply with mixture can be under separation condition by having the membrane separation zone of a non-infiltration area and an infiltration area, thereby non-permeating airflow that can extract from non-infiltration area and the permeating airflow that can extract from the infiltration area under an osmotic pressure are provided.Non-permeating airflow comprises C
+ 6The carbon dioxide of hydrocarbon and relative appropriate hydrocarbon gas supply mixture decrement.The relative appropriate hydrocarbon gas of permeating airflow has been supplied with mixture enrichment carbon dioxide.Between exhausting property ground, when not having hydrocarbon to supply with mixture by membrane separation zone, the C in the non-relatively permeating airflow
+ 6Hydrocarbon has reduced C
+ 6The purging air-flow of hydrocarbon amount between being higher than under the pressure of osmotic pressure exhausting property ground by non-infiltration area, thereby prevented to remain in C in the non-permeating airflow of non-infiltration area
+ 6The condensation of hydrocarbon.
Fig. 1 is the separation process flow chart that carries out shut-down technical process of the present invention.
The present invention is used at a membrane separation zone carbon dioxide being isolated from a kind of hydrocarbon or gas flow, thereby the pure natural entraining air stream is provided, and this air-flow is through the subsequent treatment of natural gas processing plant and further remove heavy hydrocarbon, as C
+ 6Hydrocarbon, thus a kind of sale air-flow or pure natural entraining air stream are provided.Gas is supplied with air-flow can pass through a film separation unit, so that permeating airflow that comprises carbon dioxide and the non-permeating airflow that comprises lighter hydrocarbons are provided.Natural gas supply air-flow preferably comprises the heavy hydrocarbon above 500ppm, more preferably comprises 500ppm to 2mol% heavy hydrocarbon.
Term " enrichment " is meant that a kind of component of product air-flow supplies with in the air-flow this concentration of component relatively and produce and concentrate as used herein.For example, the easy infiltration component of supplying with air-flow relatively from the easy infiltration component of the permeating airflow of membrane separation zone produces enrichment.Term " membrane separation zone " is meant to have one or more device that at least one is used for permeating or separating from the supply gas mixture film of easy infiltration component.Term " dew point " is meant the temperature under a setting pressure, steam wherein, and for example hydrocarbon or water begin condensation under this condition.
In the prior art,, can from fluid mixture (gas or liquid), be considered to convenient, efficient favourable means by the permeable membrane of the component of separating at least one selection for obtaining the perfect fluid separation and/or concentrating.Being applicable to that film of the present invention comprises for example is disclosed in US-A-4, those composite membranes in 822,382.
Term " exhausting a property ground " is meant to have interrupt cycle, particularly unplanned property or unexpected interruption, or the interruption of normal supply air-flow.In interrupt cycle, film must quit work safely, otherwise will produce damage, the invention provides a kind of technical process that is used to make the membrane safety shut-down, be specially adapted to shut-down this unplanned property or an exhausting property, wherein can alleviate the infringement that this determined condition of stopping work produces film.
When stopping work, the condensation in the film may be by due to the phenomenon of a kind of being called " anti-condensation ".Anti-condensation is meant the condensation that produces in the mode that againsts one's expectation.For example, occur admixture of gas in the film, condensation just can produce when pressure reduced.According to the present invention, the supply air communication that contains easy infiltration, non-condensable components and difficult infiltration, condensable components mixture is crossed film device.Film comprises a non-infiltration area and the infiltration area that can therefrom extract permeating airflow that can therefrom extract non-permeating airflow.When film is subjected to unexpected interruption and supply with the supply air-flow interruption of this film, might on film, produce condensation.Stop although supplying with flowing of air-flow, easily infiltration, the infiltration of condensable components does not still continue.This continuous process of osmosis causes the pressure of the non-infiltration area of film to reduce usually.After the Joule-Thompson cooling effect combined, the temperature and pressure of non-per-meate side all reduced.When the pressure of non-infiltration area reduced, the dividing potential drop that is difficult for infiltration, condensable components raise.Change if some are not introduced in non-infiltration area, the dividing potential drop that is difficult for infiltration, condensable components can reach a point, at this some place, will have liquid to form and the generation condensation.Effect of the present invention is exactly with the non-infiltration area that purges the gas flow purging film unit, alleviates this anti-condensation, and wherein this purging air-flow can make the dividing potential drop that is difficult for condensed components of non-infiltration area remain on more than the dew point, or more than the point of meeting generation condensation.For example, in the process of handling gas flow, present invention resides under the operating pressure, make easy infiltration, uncondensable lighter hydrocarbons, for example C
1To C
6Hydrocarbon and carbon dioxide and difficult infiltration, condensable components, for example C
+ 6Or C
+ 10The mixture of hydrocarbon is by having the film unit of a non-infiltration area and an infiltration area.The non-permeating airflow that has reduced carbon dioxide content extracts from non-infiltration area being substantially equal under the pressure of operating pressure, supply with the air-flow enrichment relatively the permeating airflow of carbon dioxide under a lower pressure, extract from the infiltration area.Because carbon dioxide is by the continuation infiltration of film, so interrupt suddenly to the supply air-flow of film and the blocking-up of non-infiltration and permeating airflow the pressure of non-infiltration area being reduced.Carbon dioxide is isolated from non-infiltration area by infiltration, makes C
+ 6Or C
+ 10Difficult infiltration like this, the dividing potential drop of condensable components raise, and if do not go to stop, will produce condensation and damage film.According to the present invention, when supplying with the air-flow interruption, the non-infiltration area of available purging gas flow purging, thus the dividing potential drop that is difficult for infiltration, condensable components is remained on more than the condensation point.Therefore just need to purge difficult infiltration, the condensable components that air-flow comprised and to be lower than this components contents of non-infiltration area.The purging air-flow has reduced the content of difficult infiltration, condensable components, preferred purging air-flow contains difficult infiltration, the condensable components of the non-permeating airflow that is lower than 90mol-%, more preferably purge air-flow and contain difficult infiltration, the condensable components of the non-permeating airflow that is lower than 10mol-%, most preferably purge difficult infiltration, condensable components that air-flow contains the non-permeating airflow that is lower than 0.1mol-%.
Can measure the duty of film by permeability of the membrane by selectivity and a kind of component of film.For every kind of component, these parameters depend on the dividing potential drop driving force between non-infiltration area and the infiltration area.When osmotic flow is relatively lower to the molar flow of supply flow, in film unit, separate under the situation of two kinds of components, selectivity (" S ") is to supply with the product of the inverse ratio of the molar fraction ratio of component in the air-flow and the dividing potential drop driving force between non-infiltration area and the infiltration area, and wherein the dividing potential drop driving force of the given component of a mixture is poor between the dividing potential drop of the dividing potential drop of this component in the feed and this component in the osmotic flow.Can be formulated as:
S=X
1 *(PP
F2-PP
P2)/X
2 *(PP
F1-PP
P1) X wherein
1And X
2It is the supply molar fraction of component 1 and 2; PP
F1And PP
F2It is the dividing potential drop of supplying with component 1 in the air-flow and 2; PP
P1And PP
P2Be component 1 and 2 dividing potential drop in the permeating airflow.Osmotic flow is represented according to every kind of composition the permeability (" PM ") under the low molar flow ratio of supply flow, is exactly the product that this component is supplied with the dividing potential drop driving force between air-flow and permeating airflow dividing potential drop by the flow of film divided by surface area and this component of film.The permeability of component 1 can be formulated as:
PM=F
P *X
F1/ A
*(P
h *X
F1-P
1 *X
P1) F wherein
PIt is the seepage discharge that flows out diaphragm area; A is the surface area of film; P
hAnd P
1It is the gross pressure of supplying with air-flow and permeating airflow; X
P1And X
F1Be in the permeate end of film and the molar fraction of supply air-flow end composition 1.
In one embodiment, purge gas contains the sale gas of the gas treatment factory that derives from the membrane separation zone downstream.In another embodiment, purge gas contains from part and supplies with the absorption effluent air-flow that is obtained the absorption of heavy hydrocarbon of air-flow.In another embodiment, purge in the group that air-flow is made of nitrogen, methane, ethane, propane, butane and composition thereof and select.According to the present invention, part is supplied with air-flow can be by an adsorbent bed of selective adsorbent, and this adsorbents adsorb hydrocarbon also produces the absorption effluent of having removed hydrocarbon basically.When to film once again during feed, adsorbent bed can be regenerated in habitual mode by the regeneration air stream of heating.Although can use any suitable air-flow for this reason, regeneration air stream should be preferably sold the group that gas, infiltration gas, non-infiltration gas and composition thereof constituted from nitrogen, fuel gas stream, part and is selected.Because infiltration gas has been removed heavy hydrocarbon, for example C basically
+ 6Or C
+ 10So hydrocarbon is more preferably infiltration gas.Can be used as fuel with the regeneration gas of crossing.
Adsorption zone of the present invention relates to habitual temperature transition process, in this process, adsorbent bed in each adsorption zone adsorbs circularly at adsorption temp, optionally the easy absorbed component in the air-flow is supplied with in absorption, enrichment is provided has been difficult for the absorption effluent air-flow of absorbed component, regenerative process is to carry out by means of the purging air-flow that feeds under the high temperature at the desorption temperature that is higher than adsorption temp, that is: be to make adsorbent bed be cooled to adsorption temp to be equal to or higher than needed desorption temperature by adsorbent bed, to pass therefrom by means of purge gas.Such processing step is disclosed, for example at above-mentioned US-A-4, in 484,933.
Be construed as: adsorption zone of the present invention comprises an adsorbent bed that contains adsorbent, and this adsorbent is applicable to the absorption specific components.Should also be appreciated that the direction that flows through adsorbent bed for: term " adverse current " expression gas, is the adverse current of supplying with the air current flow direction relatively.Similarly, term " following current " expression is flowed with the supply air-flow is equidirectional.If not other note, term " enrichment " expression is with respect to supplying with the air-flow component.
Should also be appreciated that for: adopt the sorbent material that is fit in the adsorbent bed can realize the present invention, this adsorbent bed has selectivity to the different component of supplying with air-flow with respect to other such component.Provide and be difficult for absorbed component and easy absorbed component.Among the present invention, easily absorbed component is a heavy hydrocarbon, for example C
+ 6Hydrocarbon and water, being difficult for absorbed component is C
1-C
6Hydrocarbon.Well known in the prior art, commercially available suitable adsorbent comprises crystalline molecular sieve, activated carbon, activated clay, silica gel, active sulfone soil and composition thereof.Crystalline molecular sieve comprises zeolite molecular sieve.
The zeolite molecular sieve of calcinated form can be expressed as with chemical structural formula:
Me
Z/nO:Al
2O
3: XSiO
2Wherein Me is a cation, and X is from 2 to an infinitely-great numerical value, and n is the cation valency.Generally the used zeolite of knowing comprises: chabasie one also is called zeolite D, clinoptilolite, EMC-2, zeolite L, ZSM-5, ZSM-11, ZSM-18, ZSM-57, EU-1, offretite, faujasite, U.S. alkali zeolite (ferrierite), modenite, zeolite A, ZK-5, zeolite P (zeolite rho), zeolite beta, boggsite and silicalite.Adsorbent of the present invention can be chosen from these zeolite adsorbents and composition thereof.The visible D.W.Breck of detailed argumentation of relevant above-mentioned zeolite, " zeolite molecular sieve ", John Wiley and Sons, New York, 1974, be incorporated herein with for referencial use.
When using crystalline molecular sieve, suitable particle size is arranged, often need make molecular sieve and binding agent coalescent for guaranteeing adsorbent.Although various obtainable synthetic and natural adhesives are arranged, for example metal oxide, clay, silica, aluminium oxide, silicon-aluminum oxide, silicon-Zirconium oxide, silicon-thorium oxide, silicon-beryllium oxide, silicon-titanium oxide, silicon-aluminium-thorium oxide, silicon-aluminum-zirconium oxide, their mixture and analog thereof, but preferred silica binder.Preferred silica be since it can be under the situation of the adsorption property that does not change zeolite substantially the agglomeration molecular sieve.The selection of binder that is fit to and the method for agglomeration molecular sieve are understood by those skilled in the art, then need not do further argumentation at this.
Operating under preferred 5 ℃ to the 80 ℃ adsorption temp of adsorption process is the most effective.The desorb effluent reclaims at desorption temperature, preferably 120 ℃ to 315 ℃ of the scopes of desorption temperature.
Experimental result hereinafter shows: handle the admixture of gas contain condensable components when membrane separation device and run into when supplying with air-flow and interrupting suddenly, supplying with the air-flow intercourse, the non-infiltration area of separative element is purged by purge gas, compare with non-infiltration area, purge gas contains less condensable components, can successfully prevent and even improves infringement to film.Decompression or cause condensation or when appointing an infiltration area pressure rising to produce condensation, the infringement of making pair of films after the condensation by decompression.
Supplying with the air-flow intercourse, a separation adsorption zone can be film provides purge gas, normal work period at film, then available permeating airflow regeneration adsorption zone, with this two aspect in conjunction with just preventing infringement with a kind of capacity of method maintenance film of novelty and in large-scale industrialization treatment plant to the film system.
In the accompanying drawing, technical process of the present invention is by a flowcharting of simplifying, in the drawings slightly in such as pump, and instrument, heat exchange and recuperation of heat circulation, compressor and similar hardware, they are not vital to understanding related technical process.Adopt such diversification setting to belong in the general knowledge scope of those skilled in the art.
Referring now to Fig. 1,, it is (100 pounds/inch of 700KPa in the separating pressure scope that hydrocarbon is supplied with air-flow 200
2) to (1500 pounds/inch of 10.5MPa
2), the separation temperature scope is that 200 and 210 exhausting property ground are by membrane separation zone 400 by the road under the condition of a separating pressure of 25-60 ℃ and a separation temperature.Hydrocarbon is supplied with air-flow and is comprised C
1-C
6Hydrocarbon, carbon dioxide and heavy hydrocarbon, for example C
+ 6Or C
+ 10Hydrocarbon.Membrane separation zone 400 comprises a non-infiltration area 400a and an infiltration area 400b.Containing heavy hydrocarbon and relatively supplying with air-flow has the non-permeating airflow of the carbon dioxide of decrement 220 can extract from non-infiltration area 400a by the road under a non-osmotic pressure that equals separating pressure substantially, enrichment the permeating airflow of carbon dioxide be (15 pounds/inch of 100KPa in the osmotic pressure scope
2) to (150 pounds/inch of 1050KPa
2) an osmotic pressure under 260 and 280 can extract by the road from the infiltration area.Non-permeating airflow 220 passes through Disengagement zone 465, at this, and hydrocarbon, for example C
+ 6Hydrocarbon is separated, thereby has produced the sale air-flow along pipeline 230, can extract this air-flow along selling gas generation pipeline 250.
This technical process is worked in the mode of an exhausting property, so that when supplying with the air-flow interruption, membrane separation zone 400 quits work.According to technical process of the present invention, when the flow disruption of supplying with air-flow 200, part supply with air-flow 200 by the road 310, valve 450, pipeline 320 and 330 arrive adsorption zones 460.Adsorption zone 460 comprises the adsorbent that is selected from by activated carbon, silica gel, alumina molecular sieve and the group that constitutes thereof, can optionally supply with the air-flow from gas and remove portion C at least
+ 6Hydrocarbon, and 360 generations contain than non-permeating airflow C still less by the road
+ 6The purging air-flow of hydrocarbon.When not supplying with air-flow when the membrane separation zone, sweep gas is flowed through pipeline 360,380, valve 430 and pipeline 390 by non-infiltration area, thereby disposes the condensable C that contains of any remnants of remaining in non-infiltration area before the pressure that reduces non-infiltration area
+ 6The non-infiltration gas of hydrocarbon.
Adsorption zone provides the purging air-flow in the time of can stopping to supply with at the supply air-flow of an exhausting property.The preferred air-flow that purges comprises the non-permeating airflow that part has reduced difficult infiltration, condensable components, more preferably purges air-flow and comprises part and compare the supply gas mixture that has reduced difficult infiltration, condensable components with non-permeating airflow.When this purging air-flow is used for removing in the infiltration area remaining, non-infiltration gas, has just prevented the condensation of heavy hydrocarbon and therefore avoided the damage of membrane separation zone.Cross in the cycle of membrane separation zone in the supply air communication, adsorption zone is regenerated by one of the following step: second purges air-flow, and for example the part in the pipeline 240 is sold gas; Fuel gas stream in the pipeline 500; Or the part permeating airflow in the pipeline 270 240,290 and 290 ' arrives heater 410 by the road, heater purges air-flow with second and is heated to a regeneration temperature of 30-300 ℃, and the regeneration air stream of heating by the road 300, valve 420 and pipeline 360 arrive adsorption zones 460.Adsorption zone can purge air-flow regeneration by second like this, and second purges air-flow can select from sold the group that gas, fuel gas stream, part permeating airflow, nitrogen, the non-permeating airflow of part and composition thereof constituted by part.In the operate as normal cycle of film unit, preferably permeating airflow is used as regenerative agent.Permeating airflow has been removed heavy hydrocarbon substantially, and does not need special storage just can obtain all the time to be used for regeneration.The regeneration gas of having used can from adsorption zone flow out and by the road 330,340, valve 440 and pipeline 350 extract from this system.The regeneration gas of having used 350 can be used to provide fuel gas in Disengagement zone 465.
Film carries out the performance of the following example of work based on the film micromodule under the condition of potential condensation, as US-A-4, disclosed in 822,382, each all includes 2800mm
2The composite membrane surface, this film surface has a separating layer, and this separating layer is made up of at least a poly-(tetramethyl) bisphenol-A phthalic acid ester.Under the situation of not extracting non-permeating airflow, micromodule is forced into (515 pounds/inch of 3.6MPa by ready supply air-flow
2) separating pressure.The preparation that condensable supporting gas is supplied with air-flow is to spray the liquid hydrocarbon mixture that passes through 10Vol-% benzene and 90Vol-% hexane by means of the hydrogen stream with 99.9% purity under the temperature of 24 ℃ (75), carries out with the saturated hydrogen stream of hydrocarbon mixture.As the part of each experiment, the selectivity of film can be before film be exposed to saturated hydrogen stream and by the admixture of gas by 10Vol-% carbon dioxide and 90Vol-% methane the film micromodule be pressurizeed afterwards and measure.For these examples, permeating airflow is lower than 3% to the mol ratio of supplying with air-flow.
Comparison example I
Reduce pressure after the condensation
Remain on 37 ℃ (100 °F) in the temperature of membrane module, permeating airflow flows out under the situation of micromodule nothing but, under the temperature of sprayer survey into the pressure of 3.6MPa and 24 ℃, sprays hydrogen stream and by lasting 6 hours of micromodule as indicated abovely.Make micromodule be reduced to atmospheric pressure then.After the step-down, the admixture of gas that contains 10Vol-% carbon dioxide and 90Vol-% methane is by the film micromodule, in the temperature of 49 ℃ (120) micromodule is forced into (515 pounds/inch of 3.6MPa again
2) and determine the selectivity of film.The result is as shown in table 1.Before the experiment, the selectivity of four test specimens is 6, and permeability is 4.Shown in hurdle 0, condensation and reduce pressure at once after, average permeability reaches 46, selectivity reduces to 1.Clearly, the pressure lowering effect that produces after the condensation can seriously damage film.And then, even micromodule test specimen CO
2/ CH
4Admixture of gas is after dry a couple of days, (515 pounds/inch of the temperature of 37 ℃ (100) and 3.6MPa
2) pressure under, as from condensation with reduce shown in 4,11,18 days that pressure spot begins CO
2/ CH
4Selectivity and CO
2Permeability can not turn back to initial level yet.Therefore, the pressure reduction that occurs after the condensation has seriously damaged film, in some sense, even dry this membrane module of this infringement is also irreparable.
Table 1
Reduce pressure after the condensation
Fate after the condensation before the condensation
04 1118CO
2Permeability 4 46 6 55CO
2/ CH
4Selectivity 612 22
Invention example II
Do not reduce pressure after the condensation
Under the situation of not extracting non-permeating airflow, the hydrogen of the spraying of comparison example I is continued the film micromodule to be supplied with in 6 hours 3.6MPa and 37 ℃.When 6 hours end cycle, extracted non-permeating airflow 30 minutes with a flow rate that equals to supply with flow rate, simultaneously the hydrogen of input spraying still.At 30 minutes end cycles and when not reducing pressure, introduce CO again
2/ CH
4Supply and measure permeability and selectivity.The result 3 and 4 days the time is as shown in table 2 before the time cycle is condensation and after the condensation.The result shows, is being exposed to when film after the hydrocarbon of condensation, uses under the situation of non-per-meate side that keeps film and the pressure reduction between the per-meate side when removing the purge gas desciccator diaphragm of condensable components basically, and the performance of film is kept even slightly improves surprisingly.
Table 2
Do not reduce pressure after the condensation
3 days 4 days before
CO
2Permeability 46 3.5
CO
2/ CH
4Selectivity 6 7.5 9
Comparison example II
Improve osmotic pressure after the condensation
In this example, under the condition of invention example I, continue the film micromodule to be sprayed in 6 hours with the saturated hydrogen of hydrocarbon of example I.Blocking-up is brought up to feed pressure from the permeating airflow that membrane module flows out with the pressure of film per-meate side, continues a cycle of 10 minutes.Spray the CO of the input of hydrogen by example I
2/ CH
4Replace, infiltration and non-permeating airflow are set up under the temperature of the operating pressure of 3.6MPa and 49 ℃ (120).1 day measured permeability and selectivity are as shown in table 3 after the condensation.Make osmotic pressure be elevated to feed pressure after the condensation, can cause the selectivity of film to reduce.
Table 3
The blocking-up of permeating when not reducing pressure
After 1 day before
CO
2Permeability 5 13
CO
2/ CH
4Selectivity 7 1.5
Claims (10)
1, a kind of technical process that is used for separating the membrane separation zone shut-down of easy infiltration component from the supply gas mixture, wherein the supply gas mixture contains described easy infiltration component, non-infiltration component and is difficult for infiltration, condensable components, and the described course of work may further comprise the steps:
A). under separation condition, make described supply gas mixture by the described membrane separation zone of a non-per-meate side and a per-meate side is arranged, thereby non-permeating airflow that extracts from non-per-meate side and the permeating airflow that extracts from per-meate side under an osmotic pressure are provided;
B). when not having described supply gas mixture by membrane separation zone, between exhausting property ground by purging air-flow, the pressure of this purging air-flow is higher than the osmotic pressure that is used in step (a), difficult infiltration, condensable components have reduced described in this purging air-flow of the described non-per-meate side of described relatively membrane separation zone, so that removed the described residual gas of at least a portion at the residual gas that residues in non-per-meate side before described membrane separation zone condensation; With
C). finish operation downtime by the pressure that reduces described Disengagement zone.
2, according to the described a kind of technical process of claim 1, it is characterized in that, carry out step (c) and (b) simultaneously.
3, according to claim 1 or 2 described a kind of technical process, it is characterized in that described difficult infiltration, condensable components comprise C
+ 6Hydrocarbon, described easy infiltration component comprises carbon dioxide.
4, according to claim 1 or 2 described a kind of technical process, it is characterized in that described easy infiltration component comprises carbon dioxide.
According to the described a kind of technical process of arbitrary claim in the claim 1 to 4, it is characterized in that 5, described purging air-flow is selected from the group that is made of nitrogen, methane, ethane, propane, butane itself and mixture.
According to the described a kind of technical process of arbitrary claim in the claim 1 to 4, it is characterized in that 6, described purging air-flow comprises the described non-permeating airflow that a part has wherein reduced described difficult infiltration, condensable components.
According to the described a kind of technical process of arbitrary claim in the claim 1 to 4, it is characterized in that 7, described purging air-flow comprises the described supply gas mixture that non-relatively permeating airflow has reduced described difficult infiltration, condensable components.
8, according to claim 1 or 2 described a kind of technical process, it is characterized in that the supply gas mixture is a kind of C of containing
1To C
6Hydrocarbon, C
+ 6The hydrocarbon supply gas mixture of hydrocarbon and carbon dioxide.
9, according to the described a kind of technical process of claim 8, it is characterized in that, purge C in the air-flow
+ 6The hydrocarbon amount reduces and contains C in the non-permeating airflow that is less than 90mol-%
+ 6Hydrocarbon.
10, according to claim 8 or 9 described a kind of technical process, it is characterized in that separation condition comprises (100 pounds/inch of 700KPa
2(1500 pounds/inch of)-7.5MPa
2) separating pressure and 25 ℃-60 ℃ separation temperature.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/648,785 US5669959A (en) | 1996-05-16 | 1996-05-16 | Process for safe membrane operation |
| CA002215777A CA2215777C (en) | 1996-05-16 | 1997-09-18 | Process for shut-down of a membrane operation |
| NO974330A NO307036B1 (en) | 1996-05-16 | 1997-09-19 | Method of stopping a membrane separation zone |
| CN97121419A CN1115187C (en) | 1996-05-16 | 1997-09-22 | Process for shut-down of membrane operation |
| EP97307345A EP0903172B1 (en) | 1996-05-16 | 1997-09-22 | Process for shut-down of a membrane operation |
| AU39194/97A AU737647B2 (en) | 1996-05-16 | 1997-09-23 | Process for shut-down of a membrane operation |
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/648,785 US5669959A (en) | 1996-05-16 | 1996-05-16 | Process for safe membrane operation |
| CA002215777A CA2215777C (en) | 1996-05-16 | 1997-09-18 | Process for shut-down of a membrane operation |
| NO974330A NO307036B1 (en) | 1996-05-16 | 1997-09-19 | Method of stopping a membrane separation zone |
| CN97121419A CN1115187C (en) | 1996-05-16 | 1997-09-22 | Process for shut-down of membrane operation |
| AU39194/97A AU737647B2 (en) | 1996-05-16 | 1997-09-23 | Process for shut-down of a membrane operation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1212175A CN1212175A (en) | 1999-03-31 |
| CN1115187C true CN1115187C (en) | 2003-07-23 |
Family
ID=31721749
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN97121419A Expired - Fee Related CN1115187C (en) | 1996-05-16 | 1997-09-22 | Process for shut-down of membrane operation |
Country Status (4)
| Country | Link |
|---|---|
| CN (1) | CN1115187C (en) |
| AU (1) | AU737647B2 (en) |
| CA (1) | CA2215777C (en) |
| NO (1) | NO307036B1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3141295A1 (en) * | 2015-09-10 | 2017-03-15 | Axiom Angewandte Prozeßtechnik Ges. m.b.H. | Device and method of separating a gas mixture in a membrane unit |
| FR3052684A1 (en) * | 2016-06-16 | 2017-12-22 | L'air Liquide Sa Pour L'etude Et L'exploitation Des Procedes Georges Claude | APPARATUS AND METHOD FOR LOW TEMPERATURE CO2 SEPARATION COMPRISING A PERMEATION SEPARATION STEP |
| US11725153B2 (en) * | 2020-04-17 | 2023-08-15 | Uop Llc | Process and apparatus for recovering catalyst from a product stream |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4944776A (en) * | 1989-10-05 | 1990-07-31 | Andrew Corporation | Dehumidifier for waveguide system |
| US5030251A (en) * | 1989-10-30 | 1991-07-09 | Permea, Inc. | System and method for separating a portion of a gas from a mixture of gases |
| US5383956A (en) * | 1993-10-12 | 1995-01-24 | Praxair Technology, Inc. | Start-up and shut down processes for membrane systems and membrane systems useful for the same |
| US5411721A (en) * | 1992-12-29 | 1995-05-02 | Uop | Process for the rejection of CO2 from natural gas |
| US5435836A (en) * | 1993-12-23 | 1995-07-25 | Air Products And Chemicals, Inc. | Hydrogen recovery by adsorbent membranes |
-
1997
- 1997-09-18 CA CA002215777A patent/CA2215777C/en not_active Expired - Fee Related
- 1997-09-19 NO NO974330A patent/NO307036B1/en unknown
- 1997-09-22 CN CN97121419A patent/CN1115187C/en not_active Expired - Fee Related
- 1997-09-23 AU AU39194/97A patent/AU737647B2/en not_active Ceased
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4944776A (en) * | 1989-10-05 | 1990-07-31 | Andrew Corporation | Dehumidifier for waveguide system |
| US5030251A (en) * | 1989-10-30 | 1991-07-09 | Permea, Inc. | System and method for separating a portion of a gas from a mixture of gases |
| US5411721A (en) * | 1992-12-29 | 1995-05-02 | Uop | Process for the rejection of CO2 from natural gas |
| US5383956A (en) * | 1993-10-12 | 1995-01-24 | Praxair Technology, Inc. | Start-up and shut down processes for membrane systems and membrane systems useful for the same |
| US5435836A (en) * | 1993-12-23 | 1995-07-25 | Air Products And Chemicals, Inc. | Hydrogen recovery by adsorbent membranes |
Also Published As
| Publication number | Publication date |
|---|---|
| NO974330D0 (en) | 1997-09-19 |
| CA2215777C (en) | 2006-01-03 |
| NO974330L (en) | 1999-03-22 |
| AU737647B2 (en) | 2001-08-23 |
| AU3919497A (en) | 1999-04-15 |
| NO307036B1 (en) | 2000-01-31 |
| CA2215777A1 (en) | 1999-03-18 |
| CN1212175A (en) | 1999-03-31 |
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