CA1211662A - Apparatus for the separation of hydrogen sulfide from a gas mixture - Google Patents
Apparatus for the separation of hydrogen sulfide from a gas mixtureInfo
- Publication number
- CA1211662A CA1211662A CA000438767A CA438767A CA1211662A CA 1211662 A CA1211662 A CA 1211662A CA 000438767 A CA000438767 A CA 000438767A CA 438767 A CA438767 A CA 438767A CA 1211662 A CA1211662 A CA 1211662A
- Authority
- CA
- Canada
- Prior art keywords
- membrane
- recited
- polymer
- hydrogen sulfide
- support layer
- 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.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/66—Polymers having sulfur in the main chain, with or without nitrogen, oxygen or carbon only
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form
- B32B3/26—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar form; Layered products having particular features of form characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids ; characterised by an apertured layer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/18—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by features of a layer of foamed material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2266/00—Composition of foam
- B32B2266/02—Organic
- B32B2266/0214—Materials belonging to B32B27/00
- B32B2266/025—Polyolefin
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2307/00—Properties of the layers or laminate
- B32B2307/70—Other properties
- B32B2307/724—Permeability to gases, adsorption
Abstract
ABSTRACT OF THE INVENTION
A flexible layered membrane comprising a chemically inert microporous support layer coated on one surface with a thin con-tinuous selective permeability pellicle of cured polysulfide polymer having a separation factor favoring hydrogen sulfide.
The resulting article is suitable for removing hydrogen sulfide from a mixture of gases.
A flexible layered membrane comprising a chemically inert microporous support layer coated on one surface with a thin con-tinuous selective permeability pellicle of cured polysulfide polymer having a separation factor favoring hydrogen sulfide.
The resulting article is suitable for removing hydrogen sulfide from a mixture of gases.
Description
BACKGROUND OF THE INVEN'rION
A. Field of the Invention This invention relates to the separation o~ hydrogen sulfide from a mixture of gases which could include methane, and, more ¦particularly, to multi-component membranes for separating hydro-¦gen sulfide from gaseous mixtures, and to processes and apparatus ¦for separating hydrogen sulfide from gaseous mixtures by perme-ation utilizing such multi-component membranes.
,B. Background Art ,~ The use of semi-permeable membranes for reverse osmosis or ultra filtration processes is well known. For example, in a llreverse osmosis process, high pressure saline water is placed in ¦¦contact with a semi-permeable membrane permeable to water but llrelatively impermeable to salt in order to separate concentrated ~¦brine and relatively pure water, the water then being available ¦for personal use such as drinking, cooking, and cleaning.
It has now been discovered that certain membranes may also be employed for the separation of various specific gases. The i,separation of a gas mixture utilizing a membrane is effected by 20 1l passing a feed stream of a gas mixture across a surface of the ¦Imembrane at an elevated pressure relative to an effluent stream lemerging from ~he other surface thereof. Any component of the mixture which is more permeable than the other gases thereof will ! pass through the membrane at a more rapid rate than the less per-~meable components. Therefore, the permeate stream which emerges ! from ~he membrane is enriched in the more permeable component I while, conversely, the residue stream is enriched in the less permeable components of the feed gas mixture. Thus, selective separation can provide preferential depletion or concentration of one or more desired gases in a mixture.
Ii .~` , ~ r- ¦
12~ 62 This invention is particularly concerned with a membrane which is more permeable to hydrogen sulfide than to other gase~
with Which it might normally be mixed. Through the use of the membrane of the present invention, the permeate stream passing through the membrane exhibits an enriched concentration of hydro-gen sul~ide in relation to the feed stream of gases, while the Iresidue o~ the feed stream exhibits a decreased concentration of !I hydrogen sulfide gas.
I Many possible uses oi such a membrane are conceivable.
I Reduction of air pollution makes it essential to minimize the " release of sulphur dioxide~ into the atmosphere. By removing ,jhydrogen sulfide from coaL gas utilized in combustion processes, ,¦oxidation of thç hydrogen sulfide into sulphur dioxide is llavoided. Moreover, in many commercial enterprises, the waste Igas from hydrogen sulfide removal is converted into sulphur in a process the cost of which is inversely dependent upon the concen-tration of hydrogen sulfide supplied. As an overall effect, therefore, removing hydrogen sulfide prior to combustion of coal ; gas not only will reduce air pollution resulting from that com-,,bustion, but can, through concentration of the hydrogen sulfide~stream, result in lowering the cost of processing waste gases.
Il Furthermore, natural gas contains various percentages of ¦~hydrogen sulfide. To be commercially acceptable, however, the ,jhydrogen sulfide content of natural gas must be reduced to con-~centrations of no more than one quarter to one half grain per one,hundred standard cubic feet, so as to minimize the risk of hydro-gen sulfide corrosion of valves and fittings in natural gas dis-~tribution systems.
, Hydrogen sulfide may be removed from hydrocarbon gas streams 30 1l such as natural gas by many methods. These methods may be i!
A. Field of the Invention This invention relates to the separation o~ hydrogen sulfide from a mixture of gases which could include methane, and, more ¦particularly, to multi-component membranes for separating hydro-¦gen sulfide from gaseous mixtures, and to processes and apparatus ¦for separating hydrogen sulfide from gaseous mixtures by perme-ation utilizing such multi-component membranes.
,B. Background Art ,~ The use of semi-permeable membranes for reverse osmosis or ultra filtration processes is well known. For example, in a llreverse osmosis process, high pressure saline water is placed in ¦¦contact with a semi-permeable membrane permeable to water but llrelatively impermeable to salt in order to separate concentrated ~¦brine and relatively pure water, the water then being available ¦for personal use such as drinking, cooking, and cleaning.
It has now been discovered that certain membranes may also be employed for the separation of various specific gases. The i,separation of a gas mixture utilizing a membrane is effected by 20 1l passing a feed stream of a gas mixture across a surface of the ¦Imembrane at an elevated pressure relative to an effluent stream lemerging from ~he other surface thereof. Any component of the mixture which is more permeable than the other gases thereof will ! pass through the membrane at a more rapid rate than the less per-~meable components. Therefore, the permeate stream which emerges ! from ~he membrane is enriched in the more permeable component I while, conversely, the residue stream is enriched in the less permeable components of the feed gas mixture. Thus, selective separation can provide preferential depletion or concentration of one or more desired gases in a mixture.
Ii .~` , ~ r- ¦
12~ 62 This invention is particularly concerned with a membrane which is more permeable to hydrogen sulfide than to other gase~
with Which it might normally be mixed. Through the use of the membrane of the present invention, the permeate stream passing through the membrane exhibits an enriched concentration of hydro-gen sul~ide in relation to the feed stream of gases, while the Iresidue o~ the feed stream exhibits a decreased concentration of !I hydrogen sulfide gas.
I Many possible uses oi such a membrane are conceivable.
I Reduction of air pollution makes it essential to minimize the " release of sulphur dioxide~ into the atmosphere. By removing ,jhydrogen sulfide from coaL gas utilized in combustion processes, ,¦oxidation of thç hydrogen sulfide into sulphur dioxide is llavoided. Moreover, in many commercial enterprises, the waste Igas from hydrogen sulfide removal is converted into sulphur in a process the cost of which is inversely dependent upon the concen-tration of hydrogen sulfide supplied. As an overall effect, therefore, removing hydrogen sulfide prior to combustion of coal ; gas not only will reduce air pollution resulting from that com-,,bustion, but can, through concentration of the hydrogen sulfide~stream, result in lowering the cost of processing waste gases.
Il Furthermore, natural gas contains various percentages of ¦~hydrogen sulfide. To be commercially acceptable, however, the ,jhydrogen sulfide content of natural gas must be reduced to con-~centrations of no more than one quarter to one half grain per one,hundred standard cubic feet, so as to minimize the risk of hydro-gen sulfide corrosion of valves and fittings in natural gas dis-~tribution systems.
, Hydrogen sulfide may be removed from hydrocarbon gas streams 30 1l such as natural gas by many methods. These methods may be i!
2~
broadly classified as chemical reaCtion~ physical ab~orption~ and adsorption. Chemical reaction pro~esses rely on reversible ~hem-ical reactions and use an absorbant which reacts with hydrogen sulfide in a contactor. The absorbant can be regenerated by use of a high temperature stripper. The reversal of some chemical reaction processe!s iS SO diffiCUlt that coSt prohibits regenera-,j tion, and hydrogen sulfide is removed in a precipation process which consumes the absorbant, usuall~ a heavy metal chloride or I nitrate. The physical absorption processes utilize the affinity ,of certain chemicals for h~ydrogen sulfide and basically employ a l'contactor to remove acid g,~s from the feedstream. Also, a !l stripper is used to separate the acid gas from the absorbent.
IIThe adsorption processes are based on the unique adsorbant quali llties of certain minerals such as zeolites. 5enerally, these l¦ adsorption processes are of a batch-type employing a molecular 'sieve. In operation the acid gas components of the feed gas stream are adsorbed on the surface of the mineral used and are subsequently removed therefrom during a high temperature regener-' ation cycle.
I.l All of the above-mentioned processes are not particularly !l attractive when evaluated using commercial parameters such as ¦cost, energy consumption, plant area requirements, operation man- ;
,¦power requirements, and maintenance costs. These processes become more uneconomical for treating sour natural gas as th~
~5 I;cost of the processes, evaluated with the above paramaters con-litinue to increase. For example, on the north slope of Alaska and i;on offshore platforms, the area available for process systems is extremely expensive and, hence, it follows that systems used at these locations mus~ have small area requirements.
Furthermore, it is well-know~ by those in the art that these ¦¦processes are energy-intensive. Molecular sieves, for example, ¦¦ must be heated to and held at approximately 600 Fahrenheit l¦during regeneration in order to remove all of the adsorbed mate-S ilrials from the mineral surfaces. High energy input is required to achieve such ~emperatures. An additional disadvantage of the above-mentioned rnethods is that they quite frequently require interruption of t:he separation process to p~rmit regeneration and/or replacement of the chemicals involved; therefore, truly continuous flow-through separation processes are not available.
However, other processes have been used to separate one or more gaseous components from a gaseous mixture. In particular, membranes have been used for many years in gas permeation sepàra-I~tion methods. Gas permeation may be defined as a physical phe-i nomenon in which certain components selectively pass through a ! substance such as a membrane. Basically, a gas permeation pro-cess involves introducing a gas into one side of a chamber w~ich is separated into two compartments by a permeable membrane. 'I'he feed gas s~ream flows along the surface of the membrane and its more permeable components pass through the membrane barrier at a highsr rate than those of lower permeability. After contacting 'the membrane, the depleted feed gas residue stream is removed through a suitable outlet on the feed compartment side of the llvessel. The other side of the membrane, the permeate side, is 'provided with a suitable outlet through which the permeate gaseous components can be removed.
The purpose of a membrane in a gas permeation process is to act as a selective barrier, that is, to permit passage of some but not all components of the gaseous feed stream. Generally, in 30 1l gaseous membrane separatlon processes, the separation is due to ~, lZ~l~.66i~
molecular interaction between gaseous components of the feed stream and the membrane. Because diff~r~nt gaseous components react differently with the membrane, the transmission rates are l different for each gas. Hence, separation of different compo-5 ¦¦ nents can be effected by !~ingle or repeated diffusions through a given selective membrane.
To date thel selection of suitable components for use in a ~gas separation membrane is largely a matter of intuition~
,i Accordingly, one object of the present invention i~ the pro-duction of a membrane suit:able for use in a continuous flow-through process for extracting hydrogen sulfide from a mixture of gases.
!l Another object of the present invention is a selective gas Ipermeation membrane which favors hydrogen sulfide diffusion and 15 ll is possessed of durable construction and capable of being manu-factured with ease from readily available components.
Additional objects and advantages of the invention will be set forth in a description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objects and advantages of the invention may be r~ali7ed and obtained by means of the instruments and com-binations particularly pointed out in the appended claims.
SUMMA~Y OF THE INVENTION
, To achieve the foregoing objects, and in accordance with the invention as embodied and broadly described herein, a flexible layered membrane for use in separating hydrogen ~ulfide from a mixture of gases in a con~inuou~ flow-through process is provided comprising a fine-textured support layer permeable at least to hydrogen sulfide and having pores occludable by a very thin Icoating; and a selective permeability pellicle of cured ~ .
'l r i lZ~6~Z
.
I polysul~ide polymer having a separation factor favoring hydrogen ¦¦ sulfide adhered to a surface of said support layer and occluding ¦ the pores thereof. The selective permeability pellicle prefer-l¦ ably comprises a polymer of bis-(ethylene oxy) methane containing 5 '1¦ disulfide linkages, and the support layer comprises a microporous ,I substance.
In another preferred embodiment of the present invention, apparatus for removing hydrogen sulfide from a mixture of gases comprises a flexible layered membrane including a fine-textured 9upport layer permeable at least to hydrogen sulfide gas and having pores occludable by a very thin coating, and a selective permeability pellicle of cured polysulfide polymer having a sepa-ration factor favoring hydrogen sulfide adhered to a surface of the support layer occluding the pores thereof; means for conduct-~ing the mixture of gases under pressure along one surface of the ;layered membrane; and means for removing gases emerging from the `;surface of the layered membrane opposite the one surface thereof.Preferably the conducting means introduces tha mixture of gases along a surface of the selective permeability pellicle and the removing means draws off gases emerging from the fine-textured support layer.
, The membrane and apparatus of the present invention are par~
~ticularly directed to removing hydrogen sulfide from a mixture of ''gas which includes methane by the means and structure described 'herein.
~' BRIEF DESCRIPTIO~ OF THE DRAWINGS
The invention will be described with additional specificity and detail through the use of the accompanying diagrams in which:
Fig. 1 is a perspective view of a flexible memb~ane incor-iporating the teaching of the the present invention; and "
12116t;~
.
E'ig. 2 is a schematic diagram of equipment arranged to test ! the permeability of various gases in relation to the membxane of Fig. 1.
il DESC IPTION OF THE PREFERRED EMBODIMENTS
~I Referring to Fig. 1, a two-layered flexible membrane 10 used in separating hydrogen sulfide from a mixture of gases comprises a support layer 12 and a selective permeability pellicle 14 adhered to a surface thereof. Support layer 12 is composed of a ~ fine-textured, mechanically and chemically stable material perme-able at least to hydrogen sulfide and should be of such porosity as to be capable of accepting continuous coatings of other mate-rials that are very thin but nonetheless occlude the pores thereof. The more microporous the material of suppoxt layer 12, ' lthe thinner may be the coating received thereon for functioning ll as selective permeability pellicle 14. A very thin coating upon support layer 12 is desirable in that the thinner composite flex-ible membrane 10, the more permeable it will be to any gas, but particularly to hydrogen sulfide. In turn, increased permeabil ity will result in a reduced membrane area or pressure differ-~ ential required for permeation of a given quantity of gas.
It has heen found advantageous in the context of the present invention t~ employ as support layer 12 highly crystalline films ,of expanded polytetrafluoro~thylene such as that marketed by W.L.
Gore and Associates Inc. under the trade name GORE-TEX~. These Ifilms consist of shee~s of fibers in two-dimensional orthogonal arrays connected at nodes of the same material, which nodes are not apparently fibrous. GORE-TEX~ film is readily permeable to all gases because of its open structure, and is capable of occlu-,ded coating by a thin layer of another substance as has been dem-ionstrated in U.S. Patent No. 4,194,041 wherein it is disclosed to il ~
ll r i ~oat QO~E~IEX ~ e~ded PE~ film W.Lth polyure~ne to pn~oe a wa~proof but ¦breathable laminat~. Additionally, it i~ propo~ed that a micro-porous polypropylene film ~uch as that ~old by Celanese Plastics l Co. under the trade nEme Celgar~ could suitably function as sup-1 por~ layer 12.
!! A3 substances frc~m which to form selective permeability pellicle 14, materials; which seadily ab60rb hydrogen sulfide were investigated. Materials suita~le to the aims o~ the present invention have been lo~a$ed in the ~eries of polysulfi~e polymers marXeted by Thiokol Corporation under the trade name LP~. Dif-ferent polymers in the ~eries are designated by a number follow-,~ing the trade designation, such as LP~-2. Such polymers can b~
~ cured from liquid form at room temperature to solid rubber with-; out shrinkage by use of a suitable curing agent, mo~t commonly i¦oxygen donating materials such as lead dioxide, calcium peroxid~, cumene hydroperoxide, and p-quinone dioxime. Lower valence metallic oxides, other organic peroxides, metallic paint driers and aldehydes can also function as curatives. Chemically, the LP~ series of polysulfides are polymers of bis-[ethylene oxy) `;methane con~aining disulfide linkages. m e polymer segm0nts are ,~lterminated with reactive mercaptan (-SH) groups, and branched ~mercaptan groups are built into the polymer chains to control modulus and elongation. The general struc~ure i8:
`~ HS(C2H~-0-cH2-o-c2H4ss)xc2~4 CH2 2 4 `i where x is ~n integer.
~¦Each polymer is supplied with a specific proportion of branch cha~ns whi~h contribute to the production of crosslinking when ~cured. Prior to ~uring, LP~-2, LP12, and LP~-32 have average !~ molecular weights in the range of 3~000 to 5,000. On the other 'li hand LP~-31 in the same series has d corresponding weight of I .1 ~ . P
. .
1.21~ Z
'` 7, 000 to 9, 000, while for LP~ 3 and LP~-33 the figure iS about 000 .
In a gas separation process employing a permeable membrane I of the present invention, a mixture of gases is brought into con-5 1l tact with one side of flexible membrane 10 and a sufficient posi-1l tive pressure differential is maintained across membrane 10 such ' that the more pelrmeable gas, hydrogen sulfide, is driven from thefeed side of membrane 10 1:o the permeate side. The more perme-able hydrogen sulfide pass;es through the membrane at a higher rat~ than do the other components of the feed mix which have lower permeabilities. The partial pressure of the hydrogen sul-fide is maintained at a hiLgher level on the feed side of membrane 10 than on the permeate side by separately removing the residue ; of the feed stream and the permeate stream from contact with mem-'I brane 10. Although in theory the desired effect may be obtained by supplying the feed stream gas to either side of the flexible membrane, it is likely that the mechanical integrity of the mem-brane will be enhanced throughout its operation if the positive feed stream is supplied to permeability pellicle side 14 of com-poRite membrane 10, permitting the permeate hydrogen sulfide toemerge from fine-textured support layer side 12.
` In order for a separation membrane to function economically ;l it is necessary that the permeability of the gas to be removed , from a mixture of gases be several times greater than that of the other gases in the mixture. In order to measure the permeability i, of various gases in relation to membranes embodying the present invention, the apparatus as shown in Fig. 2, was employed.
Flexible membrane 10 composed of fine-textured support layer 12 and selective permeability pellicle 14 attached to a.surface thereo was secured in compression between steel flanges 16, 18 _g_ ,1 . r by cooperating nut and bolt assemblies 20. Gaskets 22 interposed between flanges 16, 18 and membrane lO served to seal membrane lO
llbetween flanges 16, 18 separating a void 24 between flanges 16, !l 18 into a feed chamber 26 and a permeate chamber 28. The lower l¦portion of permeate chamber 28 was provided with a porous member ,38 for mechanically supporting membrane 10 when gases under pres-sure were contained in receiving chamber 26.
Means were provided for conducting selected gases or mix-'tures of gases under pressure to one surface of membrane 10.
Feed chamber 26 was connectsd by suitable piping 30 through a pressure gauge 32, a pressure regulator 34, and a valve 38 to a source of pressurized gas 36. In addition, means were provided for removing gas emerging from the side of membrane 10 opposite ~jfrom the conducting means. Permeate chamber 28 was connected by llsuitable piping 40 to an inverted burette 42 containing a column of liquid 44 and standing in a reservoir 4~. For a number of gases supplied for specified durations and pressures to receiving `chamber 26, the displacement of water column 44 in burette 42 was ,measured and taken as an indication of the volume of the gas sup-2Q plied to receiving chamber 26 which had permeated through mem-~brane 10. From this information the permeability of the membrane being utilized was calculated by known means.
~i A number of examples employing different LP~ polymers were 'fabricated and tested. For a support layer, a piece of GORE-TEX~
~lexpanded polytetrafluoroethylene film, about 8 inches square, was secured about the periphery thereof to a flat surface. A small quantity of the apprepriate viscous liquid LP~ polymer was poured ~into a line on the support layer and drawn into a thin film using la film applicator. The applicator consisted of a knife edge sup-~ported by blocks at the ends thereof, in such a manner that the :1 . ,.
;Z
"
'I .
¦ knife edge was 0. 001 inc~es above the surface of the support ¦!layer. The polymer was allowed to cure into a thin selective ~ permeability pellicle which measured 20-5~m (0-00081 in-) in - llthickness.
,I The resulting flexible layered membrane was bolted in the ,test apparatus of Fig. 2 SO as to preclude gas leakage out of chambers 26, 28 1:o the surrounding atmosphere. Through the use of nitrogen as tes~ gas 36, it was verified that selective perme-ability pellicle 1~ was free of pinholes. Nitrogen was used because it is considered to have a very low permeability and any ~permeation apparent could be considered to represent leakage.
~Pellicles exhibiting leakage were accordingly discared. There-after application of various test gases yielded the specific ii ~,individual permeabilities below for a membrane, such as membrane jlO, constructed using different LP~ polymers.
EXAMPLE 1: A membrane 10 was constructed using LP~-31, which has a molecular weight before curing in the range of 7,000 to 9,000.
broadly classified as chemical reaCtion~ physical ab~orption~ and adsorption. Chemical reaction pro~esses rely on reversible ~hem-ical reactions and use an absorbant which reacts with hydrogen sulfide in a contactor. The absorbant can be regenerated by use of a high temperature stripper. The reversal of some chemical reaction processe!s iS SO diffiCUlt that coSt prohibits regenera-,j tion, and hydrogen sulfide is removed in a precipation process which consumes the absorbant, usuall~ a heavy metal chloride or I nitrate. The physical absorption processes utilize the affinity ,of certain chemicals for h~ydrogen sulfide and basically employ a l'contactor to remove acid g,~s from the feedstream. Also, a !l stripper is used to separate the acid gas from the absorbent.
IIThe adsorption processes are based on the unique adsorbant quali llties of certain minerals such as zeolites. 5enerally, these l¦ adsorption processes are of a batch-type employing a molecular 'sieve. In operation the acid gas components of the feed gas stream are adsorbed on the surface of the mineral used and are subsequently removed therefrom during a high temperature regener-' ation cycle.
I.l All of the above-mentioned processes are not particularly !l attractive when evaluated using commercial parameters such as ¦cost, energy consumption, plant area requirements, operation man- ;
,¦power requirements, and maintenance costs. These processes become more uneconomical for treating sour natural gas as th~
~5 I;cost of the processes, evaluated with the above paramaters con-litinue to increase. For example, on the north slope of Alaska and i;on offshore platforms, the area available for process systems is extremely expensive and, hence, it follows that systems used at these locations mus~ have small area requirements.
Furthermore, it is well-know~ by those in the art that these ¦¦processes are energy-intensive. Molecular sieves, for example, ¦¦ must be heated to and held at approximately 600 Fahrenheit l¦during regeneration in order to remove all of the adsorbed mate-S ilrials from the mineral surfaces. High energy input is required to achieve such ~emperatures. An additional disadvantage of the above-mentioned rnethods is that they quite frequently require interruption of t:he separation process to p~rmit regeneration and/or replacement of the chemicals involved; therefore, truly continuous flow-through separation processes are not available.
However, other processes have been used to separate one or more gaseous components from a gaseous mixture. In particular, membranes have been used for many years in gas permeation sepàra-I~tion methods. Gas permeation may be defined as a physical phe-i nomenon in which certain components selectively pass through a ! substance such as a membrane. Basically, a gas permeation pro-cess involves introducing a gas into one side of a chamber w~ich is separated into two compartments by a permeable membrane. 'I'he feed gas s~ream flows along the surface of the membrane and its more permeable components pass through the membrane barrier at a highsr rate than those of lower permeability. After contacting 'the membrane, the depleted feed gas residue stream is removed through a suitable outlet on the feed compartment side of the llvessel. The other side of the membrane, the permeate side, is 'provided with a suitable outlet through which the permeate gaseous components can be removed.
The purpose of a membrane in a gas permeation process is to act as a selective barrier, that is, to permit passage of some but not all components of the gaseous feed stream. Generally, in 30 1l gaseous membrane separatlon processes, the separation is due to ~, lZ~l~.66i~
molecular interaction between gaseous components of the feed stream and the membrane. Because diff~r~nt gaseous components react differently with the membrane, the transmission rates are l different for each gas. Hence, separation of different compo-5 ¦¦ nents can be effected by !~ingle or repeated diffusions through a given selective membrane.
To date thel selection of suitable components for use in a ~gas separation membrane is largely a matter of intuition~
,i Accordingly, one object of the present invention i~ the pro-duction of a membrane suit:able for use in a continuous flow-through process for extracting hydrogen sulfide from a mixture of gases.
!l Another object of the present invention is a selective gas Ipermeation membrane which favors hydrogen sulfide diffusion and 15 ll is possessed of durable construction and capable of being manu-factured with ease from readily available components.
Additional objects and advantages of the invention will be set forth in a description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objects and advantages of the invention may be r~ali7ed and obtained by means of the instruments and com-binations particularly pointed out in the appended claims.
SUMMA~Y OF THE INVENTION
, To achieve the foregoing objects, and in accordance with the invention as embodied and broadly described herein, a flexible layered membrane for use in separating hydrogen ~ulfide from a mixture of gases in a con~inuou~ flow-through process is provided comprising a fine-textured support layer permeable at least to hydrogen sulfide and having pores occludable by a very thin Icoating; and a selective permeability pellicle of cured ~ .
'l r i lZ~6~Z
.
I polysul~ide polymer having a separation factor favoring hydrogen ¦¦ sulfide adhered to a surface of said support layer and occluding ¦ the pores thereof. The selective permeability pellicle prefer-l¦ ably comprises a polymer of bis-(ethylene oxy) methane containing 5 '1¦ disulfide linkages, and the support layer comprises a microporous ,I substance.
In another preferred embodiment of the present invention, apparatus for removing hydrogen sulfide from a mixture of gases comprises a flexible layered membrane including a fine-textured 9upport layer permeable at least to hydrogen sulfide gas and having pores occludable by a very thin coating, and a selective permeability pellicle of cured polysulfide polymer having a sepa-ration factor favoring hydrogen sulfide adhered to a surface of the support layer occluding the pores thereof; means for conduct-~ing the mixture of gases under pressure along one surface of the ;layered membrane; and means for removing gases emerging from the `;surface of the layered membrane opposite the one surface thereof.Preferably the conducting means introduces tha mixture of gases along a surface of the selective permeability pellicle and the removing means draws off gases emerging from the fine-textured support layer.
, The membrane and apparatus of the present invention are par~
~ticularly directed to removing hydrogen sulfide from a mixture of ''gas which includes methane by the means and structure described 'herein.
~' BRIEF DESCRIPTIO~ OF THE DRAWINGS
The invention will be described with additional specificity and detail through the use of the accompanying diagrams in which:
Fig. 1 is a perspective view of a flexible memb~ane incor-iporating the teaching of the the present invention; and "
12116t;~
.
E'ig. 2 is a schematic diagram of equipment arranged to test ! the permeability of various gases in relation to the membxane of Fig. 1.
il DESC IPTION OF THE PREFERRED EMBODIMENTS
~I Referring to Fig. 1, a two-layered flexible membrane 10 used in separating hydrogen sulfide from a mixture of gases comprises a support layer 12 and a selective permeability pellicle 14 adhered to a surface thereof. Support layer 12 is composed of a ~ fine-textured, mechanically and chemically stable material perme-able at least to hydrogen sulfide and should be of such porosity as to be capable of accepting continuous coatings of other mate-rials that are very thin but nonetheless occlude the pores thereof. The more microporous the material of suppoxt layer 12, ' lthe thinner may be the coating received thereon for functioning ll as selective permeability pellicle 14. A very thin coating upon support layer 12 is desirable in that the thinner composite flex-ible membrane 10, the more permeable it will be to any gas, but particularly to hydrogen sulfide. In turn, increased permeabil ity will result in a reduced membrane area or pressure differ-~ ential required for permeation of a given quantity of gas.
It has heen found advantageous in the context of the present invention t~ employ as support layer 12 highly crystalline films ,of expanded polytetrafluoro~thylene such as that marketed by W.L.
Gore and Associates Inc. under the trade name GORE-TEX~. These Ifilms consist of shee~s of fibers in two-dimensional orthogonal arrays connected at nodes of the same material, which nodes are not apparently fibrous. GORE-TEX~ film is readily permeable to all gases because of its open structure, and is capable of occlu-,ded coating by a thin layer of another substance as has been dem-ionstrated in U.S. Patent No. 4,194,041 wherein it is disclosed to il ~
ll r i ~oat QO~E~IEX ~ e~ded PE~ film W.Lth polyure~ne to pn~oe a wa~proof but ¦breathable laminat~. Additionally, it i~ propo~ed that a micro-porous polypropylene film ~uch as that ~old by Celanese Plastics l Co. under the trade nEme Celgar~ could suitably function as sup-1 por~ layer 12.
!! A3 substances frc~m which to form selective permeability pellicle 14, materials; which seadily ab60rb hydrogen sulfide were investigated. Materials suita~le to the aims o~ the present invention have been lo~a$ed in the ~eries of polysulfi~e polymers marXeted by Thiokol Corporation under the trade name LP~. Dif-ferent polymers in the ~eries are designated by a number follow-,~ing the trade designation, such as LP~-2. Such polymers can b~
~ cured from liquid form at room temperature to solid rubber with-; out shrinkage by use of a suitable curing agent, mo~t commonly i¦oxygen donating materials such as lead dioxide, calcium peroxid~, cumene hydroperoxide, and p-quinone dioxime. Lower valence metallic oxides, other organic peroxides, metallic paint driers and aldehydes can also function as curatives. Chemically, the LP~ series of polysulfides are polymers of bis-[ethylene oxy) `;methane con~aining disulfide linkages. m e polymer segm0nts are ,~lterminated with reactive mercaptan (-SH) groups, and branched ~mercaptan groups are built into the polymer chains to control modulus and elongation. The general struc~ure i8:
`~ HS(C2H~-0-cH2-o-c2H4ss)xc2~4 CH2 2 4 `i where x is ~n integer.
~¦Each polymer is supplied with a specific proportion of branch cha~ns whi~h contribute to the production of crosslinking when ~cured. Prior to ~uring, LP~-2, LP12, and LP~-32 have average !~ molecular weights in the range of 3~000 to 5,000. On the other 'li hand LP~-31 in the same series has d corresponding weight of I .1 ~ . P
. .
1.21~ Z
'` 7, 000 to 9, 000, while for LP~ 3 and LP~-33 the figure iS about 000 .
In a gas separation process employing a permeable membrane I of the present invention, a mixture of gases is brought into con-5 1l tact with one side of flexible membrane 10 and a sufficient posi-1l tive pressure differential is maintained across membrane 10 such ' that the more pelrmeable gas, hydrogen sulfide, is driven from thefeed side of membrane 10 1:o the permeate side. The more perme-able hydrogen sulfide pass;es through the membrane at a higher rat~ than do the other components of the feed mix which have lower permeabilities. The partial pressure of the hydrogen sul-fide is maintained at a hiLgher level on the feed side of membrane 10 than on the permeate side by separately removing the residue ; of the feed stream and the permeate stream from contact with mem-'I brane 10. Although in theory the desired effect may be obtained by supplying the feed stream gas to either side of the flexible membrane, it is likely that the mechanical integrity of the mem-brane will be enhanced throughout its operation if the positive feed stream is supplied to permeability pellicle side 14 of com-poRite membrane 10, permitting the permeate hydrogen sulfide toemerge from fine-textured support layer side 12.
` In order for a separation membrane to function economically ;l it is necessary that the permeability of the gas to be removed , from a mixture of gases be several times greater than that of the other gases in the mixture. In order to measure the permeability i, of various gases in relation to membranes embodying the present invention, the apparatus as shown in Fig. 2, was employed.
Flexible membrane 10 composed of fine-textured support layer 12 and selective permeability pellicle 14 attached to a.surface thereo was secured in compression between steel flanges 16, 18 _g_ ,1 . r by cooperating nut and bolt assemblies 20. Gaskets 22 interposed between flanges 16, 18 and membrane lO served to seal membrane lO
llbetween flanges 16, 18 separating a void 24 between flanges 16, !l 18 into a feed chamber 26 and a permeate chamber 28. The lower l¦portion of permeate chamber 28 was provided with a porous member ,38 for mechanically supporting membrane 10 when gases under pres-sure were contained in receiving chamber 26.
Means were provided for conducting selected gases or mix-'tures of gases under pressure to one surface of membrane 10.
Feed chamber 26 was connectsd by suitable piping 30 through a pressure gauge 32, a pressure regulator 34, and a valve 38 to a source of pressurized gas 36. In addition, means were provided for removing gas emerging from the side of membrane 10 opposite ~jfrom the conducting means. Permeate chamber 28 was connected by llsuitable piping 40 to an inverted burette 42 containing a column of liquid 44 and standing in a reservoir 4~. For a number of gases supplied for specified durations and pressures to receiving `chamber 26, the displacement of water column 44 in burette 42 was ,measured and taken as an indication of the volume of the gas sup-2Q plied to receiving chamber 26 which had permeated through mem-~brane 10. From this information the permeability of the membrane being utilized was calculated by known means.
~i A number of examples employing different LP~ polymers were 'fabricated and tested. For a support layer, a piece of GORE-TEX~
~lexpanded polytetrafluoroethylene film, about 8 inches square, was secured about the periphery thereof to a flat surface. A small quantity of the apprepriate viscous liquid LP~ polymer was poured ~into a line on the support layer and drawn into a thin film using la film applicator. The applicator consisted of a knife edge sup-~ported by blocks at the ends thereof, in such a manner that the :1 . ,.
;Z
"
'I .
¦ knife edge was 0. 001 inc~es above the surface of the support ¦!layer. The polymer was allowed to cure into a thin selective ~ permeability pellicle which measured 20-5~m (0-00081 in-) in - llthickness.
,I The resulting flexible layered membrane was bolted in the ,test apparatus of Fig. 2 SO as to preclude gas leakage out of chambers 26, 28 1:o the surrounding atmosphere. Through the use of nitrogen as tes~ gas 36, it was verified that selective perme-ability pellicle 1~ was free of pinholes. Nitrogen was used because it is considered to have a very low permeability and any ~permeation apparent could be considered to represent leakage.
~Pellicles exhibiting leakage were accordingly discared. There-after application of various test gases yielded the specific ii ~,individual permeabilities below for a membrane, such as membrane jlO, constructed using different LP~ polymers.
EXAMPLE 1: A membrane 10 was constructed using LP~-31, which has a molecular weight before curing in the range of 7,000 to 9,000.
- 3 GAS PERMEABILITY _ cm mm 20 ` cm2~ sec cmH~
' Hydrogen Sulfide ~H2S) 1.08 x 10 7 Carbon Dioxide (C02) 0.17 x 10 7 Methane (CH4) <0 1 10-7 .
--11-- .
1~ .'i p 2 ~ 2 i EXAMPLE 2: A membrane 10 was constructed using LP~-2, which has a ¦ molecular weight before curing in the range of 3,000 to 5,000.
_ _ 3 j GAS PERMEABILITY cm . mm I cm ~ sec cmH~
,I Hydrogen Sulfide (H25) 4.21 x 10 j Carbon Dioxide ~C02) before 2 Q.24 x 10 ~ contact of membrane with H S
Carbon Dioxide (Co23 after 2 0.64 x 10 7 contact of membrane with H S
Methane (CH4) ~0.1 x 10 .
10 It should be noted that the figures above indicate that the permeability of carbon dioxide through a membrane 10 made with 1~ LP~-2 increases after the membrane is exposed to hydrogen sul-fide. It is not unexpected that any material dissolved in a mem-Il brane could change the permeability of that membrane in relation to a given gas, but the increased permeability of the membrane 10of Example 2 above to carbon dioxide in the presence of a hydro-` gen sulfide permeate may have particular significance in sweeten-ing natural gas. While hydrogen sulfide is one impurity which ; must oe removed from natural gas before its transport through a pipeline, carbon dioxide levels therein must also be reduced, for example to less than 2% from levels of perhaps 10~. A membrane ! which is permeable to hydrogen sulfide and when once exposed , thereto is increasingly permeable to carbon dioxide could prove especially valuable in the processing of natural gas.
. .
1 ~2~66;~
, EXAMPLE 3: A membrane 10 was constructed using LP~-3, which has Il .
Ila molecular weight before curing of approximately 1,000.
l. ~
GAS PERMEABILITY 2 cm mm , cm ~ sec cmHg I ~
1 Hydrogen Sulfide (H2S) 1.92 x 10 Carbon Dioxide (C02) 0.51 x 10 7 Methane (CH4) ~0.1 x 10 7 !
.
Of striking significance in these tests was the discovery ;that the permeability of the membranes tested to hydrogen sulfide was at least ten times, and in the case of LP~-2 more than th~rty times, the permeability in relation to methane, indicating the test membrane involved to be imminently suitable in a continuous ~ flow-through process for sweetening methane of sour gases.
While these initial results might lead to the hasty conclu-sion that LP~-2 is preferred for the purposes of the present invention, th~ inventor wishes to point out that pellicle fabri-cation is yet a relatively new tecllnology about which much remains to be understood. It is entirely possible that under more advanced manufacturing techniques a different, or an as yet untested, LP~ polymer will produce superior results to those ,shown above for LP~-2. Although the theoretical mechanism of pellicle functioning is also as yet uncertain, the inventor spe-ljculates that the crosslinking in the LP~ polymers arising upon 'cure accounts for their effectiveness as coatings in hydrogen ; sulfide separation membranes. If this theory proves accurate, it is then projected that LP~ polymers of low molecular weight, such as LP~-3, might ultimately produce the best results.
~i i ` - P
Z
t will be apparent to those skilled in the art that modifi-¦cations and variations can be made in the apparatus of this invention. The invention in its broader aspects i5, therefore, ~not limited to the specific details, representative methods and I,apparatuses, and illustrative example shown and described.
~'Accordingly, alterations may be made from such details without departing from t~he spirit or scope of Applicant's general inven-tive concept.
. ~ , 'i
' Hydrogen Sulfide ~H2S) 1.08 x 10 7 Carbon Dioxide (C02) 0.17 x 10 7 Methane (CH4) <0 1 10-7 .
--11-- .
1~ .'i p 2 ~ 2 i EXAMPLE 2: A membrane 10 was constructed using LP~-2, which has a ¦ molecular weight before curing in the range of 3,000 to 5,000.
_ _ 3 j GAS PERMEABILITY cm . mm I cm ~ sec cmH~
,I Hydrogen Sulfide (H25) 4.21 x 10 j Carbon Dioxide ~C02) before 2 Q.24 x 10 ~ contact of membrane with H S
Carbon Dioxide (Co23 after 2 0.64 x 10 7 contact of membrane with H S
Methane (CH4) ~0.1 x 10 .
10 It should be noted that the figures above indicate that the permeability of carbon dioxide through a membrane 10 made with 1~ LP~-2 increases after the membrane is exposed to hydrogen sul-fide. It is not unexpected that any material dissolved in a mem-Il brane could change the permeability of that membrane in relation to a given gas, but the increased permeability of the membrane 10of Example 2 above to carbon dioxide in the presence of a hydro-` gen sulfide permeate may have particular significance in sweeten-ing natural gas. While hydrogen sulfide is one impurity which ; must oe removed from natural gas before its transport through a pipeline, carbon dioxide levels therein must also be reduced, for example to less than 2% from levels of perhaps 10~. A membrane ! which is permeable to hydrogen sulfide and when once exposed , thereto is increasingly permeable to carbon dioxide could prove especially valuable in the processing of natural gas.
. .
1 ~2~66;~
, EXAMPLE 3: A membrane 10 was constructed using LP~-3, which has Il .
Ila molecular weight before curing of approximately 1,000.
l. ~
GAS PERMEABILITY 2 cm mm , cm ~ sec cmHg I ~
1 Hydrogen Sulfide (H2S) 1.92 x 10 Carbon Dioxide (C02) 0.51 x 10 7 Methane (CH4) ~0.1 x 10 7 !
.
Of striking significance in these tests was the discovery ;that the permeability of the membranes tested to hydrogen sulfide was at least ten times, and in the case of LP~-2 more than th~rty times, the permeability in relation to methane, indicating the test membrane involved to be imminently suitable in a continuous ~ flow-through process for sweetening methane of sour gases.
While these initial results might lead to the hasty conclu-sion that LP~-2 is preferred for the purposes of the present invention, th~ inventor wishes to point out that pellicle fabri-cation is yet a relatively new tecllnology about which much remains to be understood. It is entirely possible that under more advanced manufacturing techniques a different, or an as yet untested, LP~ polymer will produce superior results to those ,shown above for LP~-2. Although the theoretical mechanism of pellicle functioning is also as yet uncertain, the inventor spe-ljculates that the crosslinking in the LP~ polymers arising upon 'cure accounts for their effectiveness as coatings in hydrogen ; sulfide separation membranes. If this theory proves accurate, it is then projected that LP~ polymers of low molecular weight, such as LP~-3, might ultimately produce the best results.
~i i ` - P
Z
t will be apparent to those skilled in the art that modifi-¦cations and variations can be made in the apparatus of this invention. The invention in its broader aspects i5, therefore, ~not limited to the specific details, representative methods and I,apparatuses, and illustrative example shown and described.
~'Accordingly, alterations may be made from such details without departing from t~he spirit or scope of Applicant's general inven-tive concept.
. ~ , 'i
Claims (16)
1. A flexible layered membrane for use in separating hydrogen sulfide from a mixture of gases in a continuous flow-through process, said membrane comprising:
a. a fine textured support layer permeable at least to hydrogen sulfide and having pores occludable by a very thin coating; and b. a selective permeability pellicle of cured poly-sulfide polymer having a separation factor favoring hydrogen sulfide adhered to a surface of said support layer and occluding the pores thereof.
a. a fine textured support layer permeable at least to hydrogen sulfide and having pores occludable by a very thin coating; and b. a selective permeability pellicle of cured poly-sulfide polymer having a separation factor favoring hydrogen sulfide adhered to a surface of said support layer and occluding the pores thereof.
2. A membrane as recited in Claim 1, wherein said selec-tive permeability pellicle comprises a polymer of bis-(ethylene oxy) methane containing disulfide linkages.
3. A membrane as recited in Claim 2, wherein said selective permeability membrane contains polymer segments termi-nated with reactive mercaptan (-SH) groups.
4. A membrane as recited in Claim 1, wherein said polymer contains branched mercaptan groups to control modulus and elongation.
5. A membrane as recited in Claim 1, wherein prior to cur-ing said polymer has a predetermined proportion of branched chains for producing crosslinking.
6. A membrane as recited in Claim 1, wherein prior to cur-ing said polymer has an average molecular weight in a range of 8000 to 9000.
7. A membrane as recited in Claim 3, wherein said polymer contains branched mercaptan groups to control modulus and elongation.
8. A membrane as recited in Claim 3, wherein prior to cur-ing said polymer has a predetermined proportion of branched chains for producing crossllnking.
9. A membrane as recited in Claim 3, wherein prior to cur-ing said polymer has an average molecular weight in a range 1000 to 9000.
10. A membrane as recited in Claim 1, wherein said support layer is microporous.
11. A membrane as recited in Claim 1, wherein said support layer comprises expanded polytetrafluoroethylene.
12. A membrane as recited in Claim 1, wherein said support layer comprises microporous polypropylene.
13. A membrane as recited in Claim 1, wherein said selective permeability membrane contains polymer segments termi-nated with reactive mercaptan (-SH) groups.
14. a membrane as recited in Claim 13, wherein said polymer contains branched mercaptan groups to control modulus and elongation.
15. A membrane as recited in Claim 13, wherein prior to cur-ing said polymer has a predetermined proportion of branched chains for producing crosslinking.
16. A membrane as recited in Claim 13, wherein prior to cur-ing said polymer has an average molecular weight in a range 1000 to 9000.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US433,889 | 1982-10-12 | ||
| US06/433,889 US4493716A (en) | 1982-10-12 | 1982-10-12 | Apparatus for the separation of hydrogen sulfide from a gas mixture |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1211662A true CA1211662A (en) | 1986-09-23 |
Family
ID=23721945
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000438767A Expired CA1211662A (en) | 1982-10-12 | 1983-10-11 | Apparatus for the separation of hydrogen sulfide from a gas mixture |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US4493716A (en) |
| EP (1) | EP0108499B1 (en) |
| JP (1) | JPS59102402A (en) |
| AT (1) | ATE24846T1 (en) |
| CA (1) | CA1211662A (en) |
| DE (1) | DE3369077D1 (en) |
| DK (1) | DK470283A (en) |
| GR (1) | GR78389B (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4969998A (en) * | 1984-04-23 | 1990-11-13 | W. L. Gore & Associates, Inc. | Composite semipermeable membrane |
| DE3507617A1 (en) * | 1985-03-04 | 1986-09-04 | Salzgitter Lummus GmbH, 6200 Wiesbaden | METHOD FOR PURIFYING THE EXHAUST GAS FROM CLAUS PLANTS AND RECOVERING THE SULFUR COMPOUNDS CONTAINED IN THESE EXHAUST GAS |
| JP2534050B2 (en) * | 1987-01-19 | 1996-09-11 | 日東電工株式会社 | Sheet-like composite membrane |
| US4941897A (en) * | 1987-11-05 | 1990-07-17 | L & H Technologies, Inc. | Microporous filter and method |
| US4818258A (en) * | 1987-11-05 | 1989-04-04 | L&H Technologies, Inc. | Filter module |
| US4889541A (en) * | 1988-07-05 | 1989-12-26 | Texaco Inc. | Separation of gases |
| US5556449A (en) * | 1993-10-25 | 1996-09-17 | Membrane Technology And Research, Inc. | Acid gas fractionation process for fossil fuel gasifiers |
| US5401300A (en) * | 1993-10-25 | 1995-03-28 | Membrane Technology And Research, Inc. | Sour gas treatment process including dehydration of the gas stream |
| US5407466A (en) * | 1993-10-25 | 1995-04-18 | Membrane Technology And Research, Inc. | Sour gas treatment process including membrane and non-membrane treatment steps |
| US5558698A (en) * | 1993-10-25 | 1996-09-24 | Membrane Technology And Research, Inc. | Acid gas fractionation process |
| US5407467A (en) * | 1993-10-25 | 1995-04-18 | Membrane Technology And Research, Inc. | Sour gas treatment process |
| US20100024651A1 (en) * | 2008-07-30 | 2010-02-04 | General Electric Company | Membrane contactor systems for gas-liquid contact |
| JP5080601B2 (en) * | 2010-03-02 | 2012-11-21 | 一般財団法人国際石油交流センター | Apparatus for measuring hydrogen sulfide concentration in gas flow and method for determining sulfide ion |
| US8512442B2 (en) | 2011-05-23 | 2013-08-20 | Aaron Oken | Selective polysulfide composite membrane |
Family Cites Families (24)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1560793B2 (en) * | 1965-08-24 | 1974-10-10 | Flexa Industria Materie Plastiche S.P.A., Gallarate (Italien) | Process for the production of a lightweight, waterproof, pliable sheet material |
| DE1925582C3 (en) * | 1969-05-20 | 1974-07-04 | Linde Ag, 6200 Wiesbaden | Method and device for separating mixtures of substances by means of diffusion |
| US3534528A (en) * | 1969-05-26 | 1970-10-20 | Abcor Inc | Gas well sulfur removal by diffusion through polymeric membranes |
| US3735559A (en) * | 1972-02-02 | 1973-05-29 | Gen Electric | Sulfonated polyxylylene oxide as a permselective membrane for water vapor transport |
| US3770842A (en) * | 1972-06-29 | 1973-11-06 | Standard Oil Co | Method of separating aliphatically unsaturated hydrocarbons by contacting said hydrocarbons with a solid water-insoluble, semi-permeable film membrane |
| US3780496A (en) * | 1972-07-31 | 1973-12-25 | Gen Electric | Sulfonated polyxylene oxide as a permselective membrane for gas separations |
| US3865890A (en) * | 1973-02-23 | 1975-02-11 | Standard Oil Co | Process for separating a material from a mixture of mixture which comprises employing a solid water-insoluble, hydrophilic, semi permeable membrane |
| CA1062176A (en) * | 1974-03-21 | 1979-09-11 | Institute Of Gas Techonology | Gas sweetening by membrane permeation |
| US3980456A (en) * | 1975-03-31 | 1976-09-14 | General Electric Company | Method for sealing breaches in multi-layer ultrathin membrane composites |
| GB1478083A (en) * | 1975-04-29 | 1977-06-29 | Inst Of Gas Tech | Gas separation method |
| US4089653A (en) * | 1975-07-28 | 1978-05-16 | General Electric Company | Apparatus for the separation of hydrogen sulfide from gas mixture including carbon dioxide |
| US4060566A (en) * | 1975-11-19 | 1977-11-29 | Standard Oil Company (Indiana) | Membrane process for separating materials |
| US4230463A (en) * | 1977-09-13 | 1980-10-28 | Monsanto Company | Multicomponent membranes for gas separations |
| US4134742A (en) * | 1977-06-06 | 1979-01-16 | Envirogenic Systems Company | Gas separation membranes |
| US4130403A (en) * | 1977-08-03 | 1978-12-19 | Cooley T E | Removal of H2 S and/or CO2 from a light hydrocarbon stream by use of gas permeable membrane |
| US4208194A (en) * | 1977-09-26 | 1980-06-17 | Minnesota Mining And Manufacturing Company | Monitoring device |
| JPS5456985A (en) * | 1977-10-14 | 1979-05-08 | Mitsubishi Chem Ind Ltd | Gas-separaing membrane |
| US4194041A (en) * | 1978-06-29 | 1980-03-18 | W. L. Gore & Associates, Inc. | Waterproof laminate |
| US4181675A (en) * | 1978-09-19 | 1980-01-01 | Monsanto Company | Process for methanol production |
| US4255591A (en) * | 1978-11-20 | 1981-03-10 | Monsanto Company | Carbonylation process |
| US4243701A (en) * | 1979-11-08 | 1981-01-06 | Uop Inc. | Preparation of gas separation membranes |
| US4397661A (en) * | 1980-06-27 | 1983-08-09 | Monsanto Company | Gas permeation apparatus having permeate rate controlled valving |
| CA1173763A (en) * | 1980-08-21 | 1984-09-04 | Roger W. Fenstermaker | Engine performance operating on field gas as engine fuel |
| US4367135A (en) * | 1981-03-12 | 1983-01-04 | Monsanto Company | Processes |
-
1982
- 1982-10-12 US US06/433,889 patent/US4493716A/en not_active Expired - Lifetime
-
1983
- 1983-10-04 EP EP83306025A patent/EP0108499B1/en not_active Expired
- 1983-10-04 DE DE8383306025T patent/DE3369077D1/en not_active Expired
- 1983-10-04 AT AT83306025T patent/ATE24846T1/en not_active IP Right Cessation
- 1983-10-11 CA CA000438767A patent/CA1211662A/en not_active Expired
- 1983-10-11 GR GR72655A patent/GR78389B/el unknown
- 1983-10-11 JP JP58188545A patent/JPS59102402A/en active Granted
- 1983-10-12 DK DK470283A patent/DK470283A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| DK470283A (en) | 1984-04-13 |
| ATE24846T1 (en) | 1987-01-15 |
| GR78389B (en) | 1984-09-26 |
| JPS59102402A (en) | 1984-06-13 |
| EP0108499A1 (en) | 1984-05-16 |
| EP0108499B1 (en) | 1987-01-14 |
| DK470283D0 (en) | 1983-10-12 |
| JPH0420650B2 (en) | 1992-04-06 |
| US4493716A (en) | 1985-01-15 |
| DE3369077D1 (en) | 1987-02-19 |
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