CN1019475B - Pressure-gradient adsorption method for extracting of carbon dioxide from gaseous mixture - Google Patents
Pressure-gradient adsorption method for extracting of carbon dioxide from gaseous mixtureInfo
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- CN1019475B CN1019475B CN88105938A CN88105938A CN1019475B CN 1019475 B CN1019475 B CN 1019475B CN 88105938 A CN88105938 A CN 88105938A CN 88105938 A CN88105938 A CN 88105938A CN 1019475 B CN1019475 B CN 1019475B
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/50—Carbon dioxide
Abstract
The present invention provides a pressure swing adsorption method of extracting CO2 from different mixed gas containing rich CO2. CO2 used as a product is obtained at a desorption stage. In order to produce high-purity CO2 products, partial product gas is utilized in the process to replace by back flowing into a tower so as to further increase the concentration of the CO2 in the tower. In order to increase the extraction rate of CO2, the process of recovering the discharged gas used as raw material after forward pressure reduction and replacement is necessary. The CO2 extracted from mixed gas containing rich CO2 by the pressure swing adsorption method can be used as industrial chemicals, and can also be applied to fields of metallurgy, welding, drinks, scientific research, etc.
Description
The present invention utilizes pressure swing adsorption will be rich in carbon dioxide mix gas to separate, and extracts wherein carbonic acid gas component.
Be rich in carbonated 15～90%(volume in the carbon dioxide mix gas), all the other components are nitrogen, hydrogen, oxygen, carbon monoxide, methane etc.Different sources of the gas, the content range of each component are also different.The gas mixture that is rich in carbonic acid gas comprises: lime-kiln gas, conversion gas and other industrial gas etc.
Lime-kiln gas is limestone kiln calcined limestone and the gas that decomposes out, its compositing range following (representing with percent by volume):
O
20.5～1.8%
CO 0.5～1.5%
Adopt different methods and different material gas making in the synthesis ammonia plant, after conversion, all contain a large amount of CO
2, its compositing range (% represents with volume) is:
CO
215～30%
H
230～65%
N
215～35%
CH
40.5～4.5%
O
2+Ar 0.5～1%
With pressure swing adsorption process from the above-mentioned CO that is rich in
2Mixed gas in the carbonic acid gas that extracts, can be used as industrial chemicals, also can be used for industry such as metallurgy, welding, beverage, scientific research.
The object of the present invention is to provide that a kind of to extract concentration from the mixed gas that is rich in carbon dioxide gas be 99～99.9%(volume) the pressure swing absorption process of industrial carbon dioxide.
Another object of the present invention is to provide a kind of pressure swing absorption process that can obtain high carbon dioxide extraction rate.
Other purpose of the present invention will illustrate below:
Transformation absorption is exactly to utilize sorbent material that the loading capacity of each component in the gas is presented the characteristic of difference along with pressure change, alternately switches circulation technology by what select that absorption and two processes of desorption and regeneration form.The pressure swing adsorption technique of previous development, more representative is even pressure type pressure swing adsorption technique of four towers that United States Patent (USP) 3430418 is introduced.Its feature be each tower all must experience absorption, pressure equalization, seven steps such as decompression, reverse decompression, flushing, a pressurising, secondary pressurising forward.In the process implementing process, the impurity component is attracted on the sorbent material, and the product component is difficult for adsorbing on sorbent material, thereby obtains product free from foreign meter in gas phase.
And the used usually several sorbent materials of pressure swing adsorption process are strong than other component all to the adsorptive power that is rich in carbonic acid gas in the carbon dioxide mix gas, therefore extract with pressure swing adsorption process and are rich in CO in the carbon dioxide mix gas
2, as the product component is easy adsorbent component CO
2The impurity component is the component that is difficult for absorption, this effect and implication with typical pressure swing adsorption technique each process in implementation process is opposite fully, promptly select under the adsorption conditions at sorbent material, carbonic acid gas component during pressurization in the absorption unstripped gas, difficult adsorbent component hydrogen, oxygen, nitrogen, carbon monoxide, methane, argon etc. are discharged from the adsorption tower exit end, the carbonic acid gas desorption that adsorbs during decompression, and sorbent material obtains regeneration simultaneously.Another purpose of the present invention provides a kind of at desorption and regeneration stage acquisition CO
2The pressure swing absorption process of product.
Pressure swing adsorption process extracts carbonic acid gas from be rich in carbon dioxide mix gas usual procedure comprises following primary process: when envrionment temperature, absorption phase utilize sorbent material under adsorptive pressure to unstripped gas in carbonic acid gas different with the adsorptive power of other component, to absorb by the carbonic acid gas in the unstripped gas of bed, all the other components are (as H
2, O
2, CO, CH
4, N
2With Ar etc.) discharge from the bed exit end as waste gas.Adsorptive pressure preferably is controlled at 0.3～1.5MPa(gauge pressure) in the scope, when the absorb leading-edge of carbonic acid gas moves to a certain position of bed, just stop absorption.It then is desorption phase, it at first is pressure equalization step, promptly reduce pressure from the tower Way out, its objective is further with in the bed absorption mutually also components such as the hydrogen of occlusion, oxygen, nitrogen, methane, carbon monoxide discharge, to improve gas concentration lwevel in the bed, to utilize simultaneously the waste gas that discharges in the decompression process pressurising gas as another tower.During pressure equalization, its pressure is in 0.15～0.35MPa(gauge pressure) scope.Be depressurization steps forward then, in the waste gas that this step discharged because of carbonated concentration in 55～60% scopes, in order to reduce the loss, thus this strand gas is returned the unstripped gas system recoveries, to improve the extraction yield of carbonic acid gas.The end pressure that forward reduces pressure generally is controlled at 0.02～0.04MPa(gauge pressure).Behind depressurization steps forward, then utilize a part of carbon dioxide product gas, under the pressure of depressurization steps terminal hour forward, pass through bed from the tower entrance end, and from the outflow of tower exit end, this is called displacement step, also can be described as the product reflux step, the carbon dioxide replacement that its objective is high adsorption capacity remains in components such as the interior oxygen of bed, nitrogen, carbon monoxide, methane, and the gas concentration lwevel in the bed is increased substantially.Be air flow line decompression then against when absorption, promptly from the bed importer to reduce pressure-0.02～-the 0.01MPa(gauge pressure).This partly discharges the some that gas is carbon dioxide product gas.But this moment is still residual in the bed some carbonic acid gas component, must it be extracted out with vacuum pump, gas concentration lwevel height in the gas that one side is extracted out, to improve the finished product carbonic acid gas mean concns, also improved simultaneously the extraction yield of carbonic acid gas, be to make bed obtain desorb more completely on the other hand, improved the utilization ratio of bed.Reach desorption effect preferably, the negative pressure desorb resulting pressure of tower should not be higher than-the 0.07MPa(gauge pressure), in time forward absorption phase to for the tower that desorb is finished at last, also need to make adsorption tower rise to adsorptive pressure from negative pressure, the gas some of pressurising is in the waste gas that discharges in the tower of pressure equalization step from another, another partly is in the waste gas that discharges in the tower of adsorption step from another, pressurising finishes also to indicate the end in desorption and regeneration stage, and above-mentioned whole process all is under the envrionment temperature carries out.
Pressure swing adsorption process extracts carbonic acid gas " along falling the program of putting " and is that with the difference of " usual procedure " sequencing of " pressure equalization " and " forward decompression " two steps is different from be rich in carbon dioxide mix gas.Usual procedure carries out " pressure equalization " and then " forward decompression " earlier, and " along falling the program of putting " is then opposite.All the other steps are identical.
The present invention needs two adsorption towers that are filled with selective adsorbent at least, also can be three towers or four towers.The pressure swing adsorption system of forming by the tower more than two, wherein must there be a tower to be in the selection absorption phase, other tower then is in the different step in desorption and regeneration stage, they are according to the primary process of transformation absorption, carry out different steps at one time respectively, realize the circulation of absorption and desorb, reach the purpose of continuous extraction pure carbon dioxide.
The used sorbent material of the present invention can be silica gel, A type or X type molecular sieve, gac or carbonaceous molecular sieve, to be this sorbent material want big to the separation factor of carbonic acid gas to the key issue of selected adsorbent, simultaneously carbonic acid gas again can be at an easy rate from sorbent material desorption come out.In the sorbent material that transformation absorption is used always, Kiselgel A can satisfy above-mentioned requirements preferably.
Particular content of the present invention is with explanation in more detail below.
Referring to accompanying drawing.Fig. 1 is the synoptic diagram of the whole flow process of the present invention.Be rich in carbon dioxide mix gas by introducing outside the system, enter pressure in 0～0.04MPa(gauge pressure by pipeline 10) unstripped gas surge tank 11 in the scope, with from the gas that backflows of pipeline 27 through pipeline 12, feed gas compressor 13, be compressed to 0.3～1.5MPa(gauge pressure), through pipeline 14 to water separator 15.Flow of feed gas after separating moisture content enters dryer group 18 through pipeline 17, and dryer group 18 can adopt conventional alternating temperature moisture eliminator.Dryer group can be made up of two moisture eliminators, the inside filling siccative, for example silica gel.The source of the gas of regeneration siccative can adopt the dry waste gas of pressure swing adsorption system output, after this drying waste gas goes out pressure-swing absorption apparatus, from pipeline 29 steam heater 30 of flowing through, is heated to about 150 ℃, and going to regenerate has been adsorbed with water saturated siccative.The regeneration off gases of carrying moisture content is put to atmosphere through pipeline 33.
The dried carbon dioxide mix gas that is rich in enters pressure swing adsorption system 20 through pipeline 19, the pure carbon dioxide that extracts enters product compressor 22 by pipeline 21, be compressed to 7～8MPa, to product drying group 24, dried carbonic acid gas is sent to the user or charges into steel cylinder through pipeline 25 through pipeline 23.The principle of work of dryer group 24 is the same with dryer group 18, is filled with identical silica gel in the moisture eliminator, and the source of the gas of regeneration siccative is also identical.In pressure swing adsorption system, gas concentration lwevel height in decompression and the gas that discharges of displacement step forward backflows in the unstripped gas surge tank 11 by pipeline 27 so can be used as raw material.This is one of characteristics of the present invention, is intended to improve the extraction yield of carbonic acid gas.Feed gas compressor 13 preferably adopts oil free compressor, in order to avoid the oil vapour in the gas pollutes the sorbent material in the pressure-swing absorber.
Fig. 2 is the pressure swing adsorption technique schema that is used to implement process of the present invention.Here be illustrated as an example with three-column process flow.This technical process can be applicable to the pressure swing adsorption system 20 among above-mentioned Fig. 1.By Fig. 2 three adsorption tower A, B and C that are filled with Kiselgel A are shown, they are connected in parallel between dried raw material gas house steward 19 and the waste gas header 42.Self-acting valve 36A, 36B and 36C control the unstripped gas charging (unstripped gas of indication is also for being rich in carbon dioxide mix gas among the present invention) of adsorption tower A, B and C respectively.The not carbonated waste gas of self-acting valve 37 controls enters waste gas header 42 from above-mentioned corresponding adsorption tower.
Be adsorbed component and be carbonic acid gas by reverse decompression with vacuumize two steps and discharge from the product gas house steward 49 of each adsorption tower entrance end.Self-acting valve 41A, 41B and 41C will control respectively from corresponding column entrance end expellant gas.The vent gas of reverse decompression is discharged after self-acting valve 52 enters vacuum tank 53 from house steward 49.Vacuumize vent gas and enter product surge tank 57 through product house steward 49, self-acting valve 50, vacuum pump 55.Vacuum tank 53 plays the prime vacuum action of vacuum pump 55, and it has made full use of the pumpage of vacuum pump 55 outside vacuumizing step.Most of carbonic acid gas is guided to product compressor 22 shown in Figure 1 through pipeline 21 in the product surge tank 57, the small portion carbonic acid gas enters displacement gas dryer group 61 through pipeline 58, displacement gas compressor 59, pipeline 60, the principle of work of dryer group 61 is the same with dryer group 18, be filled with identical silica-gel drier in the moisture eliminator, the source of the gas of regeneration siccative is also identical.The carbonic acid gas that tower is advanced in the backflow of dry back enters displacement gas surge tank 63 through pipeline 62, again after pipeline 64, variable valve 65, self-acting valve 66 are flowed through pipeline 49 respectively one of in self-acting valve 41A, 41B and 41C, enter and go displacement in the corresponding adsorption tower, the adsorption column pressure during displacement is by variable valve 65 controls.After gas after the displacement flows out, enter pipeline 44 respectively one of in self-acting valve 39A, 39B and 39C from the exit end of corresponding column, and then through variable valve 45 feed channel 27 of backflowing shown in Figure 1 of backflowing.
Self-acting valve 38A, 38B and 38C are used for the pressure equalization between each tower, and self-acting valve 39A, 39B and 39C also are used for each tower and forward reduce pressure.Forward the vent gas during depressurization steps is through pipeline 44, variable valve 45 pipeline 27 that backflows.Valve 45 is used for controlling the vent gas flow velocity that forward reduces pressure.
Waste gas during absorption is outflow system behind waste gas header 42, variable valve 43 and pipeline 29.The some of effluent gases is as the regeneration source of the gas of moisture eliminator, rest part emptying.The pressure of adsorption tower when variable valve 43 is mainly used in control and keeps absorption.
Self-acting valve 40A, 40B and 40C are used for the secondary pressurising process of each tower, and the gas of pressurising is the waste gas from waste gas header 42, through valve 47 and fill house steward 46 by two and flow to corresponding adsorption tower.Valve 47 is used for control inflation flow velocity.
The circulation and the time-program(me) of giving an example referring to table 1 and table 2 just are easier to understand implementation process of the present invention.
By table 1 as seen, each tower is all being carried out mutually different step at one time, at any time, always has an adsorption tower to be in adsorption step, and waste gas is expelled to waste gas header 42 under the situation of pressure substantially constant.Meanwhile an adsorption tower being arranged all the time in other two towers is to use the waste gas pressurising, and the adsorption step that is is subsequently done last preparation, so unstripped gas can successively supply with, rather than intermittently.Meanwhile another tower is experiencing from pressure equalization to vacuumizing five steps, so the carbon dioxide product gas of output is to arrange intermittently through product house steward 49, but, just can guarantee that product gas steady and continuous ground is from pipeline 25 outputs by surge tank and automatic control and adjustment system.
Be that example illustrates each step that each tower is experienced in once circulating with the A tower now, and participate in the valve that circulation is switched among narration Fig. 2.Also list the residing pressure of adsorption tower in each step.Certainly, in the following description, force value and step time all are to belong to illustrative, for can adopt optimal pressure and each step time, any restriction never in addition in the invention process.All valves all are in closing condition before device turns round.
0～7 minute: adsorption step.The A tower is in the 0.8MPa(gauge pressure) absorption under the pressure.Valve 36A and valve 37 are opened, the exsiccant unstripped gas flows into A tower inlet ends and by this tower from unstripped gas house steward 19 under 0.8MPa pressure, and the waste gas of being made up of the hydrogen that is not adsorbed, oxygen, argon, nitrogen, methane and carbon monoxide etc. is from this tower exit end inflow exhaust gas house steward 42.A part of waste gas carries out second time pressurising by pipeline 46 and valve 40B to the B tower through valve 47 simultaneously.In adsorption step, carbonic acid gas is made this tower inlet end form the carbonic acid gas absorb leading-edge by selectivity absorption (also having adsorbed other component simultaneously on a small quantity), and moves to its exit end gradually.Adsorption step finishes when the carbonic acid gas absorb leading-edge moves in the tower certain certain position.
7～7.5 minutes: pressure equalization step.After adsorption step finishes valve 36A and 37 is closed, open valve 38A makes between A tower and the C tower and carries out pressure equalization simultaneously, so A tower dead space gas discharges from this tower exit end, and flows to the C tower bottom of just having taken out vacuum and all presses.All press when finishing, A, C two pressure towers are the 0.27MPa(gauge pressure substantially) about.At this moment, existing carbonic acid gas flows out in the A tower.This step 1 aspect utilizes the interior dead space gas of A tower that the C tower is carried out a pressurising, and the gas concentration lwevel in the A tower is improved.
7.5～8.0 minutes: depressurization steps forward.After the A tower is finished pressure equalization, shut-off valve 38A, open valve 39A simultaneously.Dead space gas continues to discharge towards exit end in the A tower.Discharge behind valve 39A, pipeline 44 and valve 45 along letting slip the journey effluent air.Because of carbon dioxide content height (being about 60%) in the suitable venting, for
Table 1 is applicable to each step of working cycle and the time program (" usual procedure ") of Fig. 2 flow process
Adsorption tower
Table 2 is applicable to each step of working cycle and the time program (" along falling the program of putting ") of Fig. 2 flow process
Reduce the loss, so this strand gas is returned unstripped gas surge tank 11 by pipeline 27, valve 45 is used for controlling along venting along putting speed.A Tata internal pressure further drops to the 0.03MPa(gauge pressure in this step) about, gas concentration lwevel further improves in the tower.
8.0～9.5 minutes: displacement step.When along after putting end, open valve 41A, valve 66 immediately.Portioned product (being carbonic acid gas) from product displacement gas surge tank 63 flows into the A bed through valve 65, valve 66 and valve 41A, removes to replace the impurity that still remains in the tower, to reach the purpose of gas concentration lwevel in the further raising tower.The substitution gas of discharging from the A tower returns unstripped gas surge tank 11 by the exit end of tower through valve 39A, pipeline 44, valve 45 and pipeline 27.In the replacement process, the tower internal pressure remains at 0.03MPa～0MPa(gauge pressure) between, displacement tolerance is by valve 65 control, and displacement whole moment is backflowed in the gas gas concentration lwevel in 70～82% scopes, replacement process finishes, and the gas concentration lwevel of occlusion further improves in the tower.
9.5～10.5 minutes: reverse depressurization steps.After displacement step finishes, shut-off valve 39A and valve 66, open valve 52 simultaneously.The vacuum tank 53 that this moment, the A tower was vacuumized is pumped into negative pressure, and the carbonic acid gas that is adsorbed in the A tower discharges from the tower entrance end, and this step is the reverse decompression of A tower, the decompression terminal hour, the tower internal pressure-0.01～-the 0.02MPa(gauge pressure) scope.Carbonic acid gas in the vacuum tank 53 is sent into product surge tank 57 by vacuum pump 55 through valve 54 and pipeline 56 extractions.In the reverse decompression process, the desorb carbonic acid gas time, also make sorbent material itself obtain partial regeneration from the sorbent material.
10.5～14.0 minutes: vacuumize step.When A tower internal pressure and vacuum tank 53 pressure reached balance substantially, reverse depressurization steps finished.This moment shut-off valve 52, valve 54, open valve 50.By vacuum pump 55 the A tower is directly vacuumized, the remainder carbonic acid gas is extracted out through valve 41A and valve 50 in the agent of tower internal adsorption, and this step is for vacuumizing.The gas of extracting out in the tower is product gas, directly is sent to product surge tank 57.Carbon dioxide purity 99.5% in the product surge tank 57.The agent of A tower internal adsorption is behind vacuum desorption, and most carbonic acid gas are drawn out of in the tower, and think that the agent of tower internal adsorption regenerates substantially fully this moment.
14.0～14.5 minutes: a pressurising.The A tower is prepared the beginning supercharging after having finished absorption, waste gas release, product desorb removal process.Shut-off valve 41A, valve 50, open valve 38B, valve 54, at this moment just finish the B tower of adsorption step and carried out equalization step, the dead space gas that it forward discharges flows to A tower inlet end through valve 38B, the A tower is carried out a pressurising, pressure until two towers equates that the pressure of this moment is about the 0.27MPa(gauge pressure) about.
14.5～21.0 minutes: secondary pressurising step.After the pressurising of A tower, the tower internal pressure does not also reach the operating pressure of adsorption step.This moment shut-off valve 38B, open valve 40A.Utilization is in the absorption waste gas that the C tower of adsorption step discharged and through pipeline 48, valve 47 and valve 40A the A tower is carried out the secondary pressurising, till the A tower reaches adsorptive pressure basically.Valve 47 is used for regulating two inflation body flows.
In pressure equalization, forward reduce pressure, when displacement, this four step of reverse decompression, valve 54 is opened, 55 pairs of vacuum tanks 53 of vacuum pump vacuumize, the product gas (carbonic acid gas) of extraction is sent to product surge tank 57.
So far, the A tower has been finished 21 minutes eight steps in the circulation successively, prepares shut-off valve 40A, open valve 36A and valve 37, circulates to import unstripped gas more next time.
The circulation step of B tower and C tower is identical with the A tower, and carries out adsorption process in succession with 1/3rd recurrence relation, so that the constantly stable input of unstripped gas.
Three above-mentioned tower pressure swing adsorption technique flow processs are that the working cycle according to table 1 is that usual procedure step and timetable thereof are implemented, also can promptly " along falling the program of putting " step and timetable thereof are implemented according to the working cycle of table 2.Table 2 is that with table 1 difference forward depressurization steps was finished before pressure equalization.Adopt along falling when putting program, forward depressurization steps adsorption column pressure at the end is controlled at the 0.1MPa(gauge pressure) about.Two tower equilibrium pressures of pressure equalization step are controlled at the 0.03MPa(gauge pressure) below.Isolation step vacuumize and a pressurising between carry out.
Though usual procedure and the suitable program of putting of falling are when carrying out " forward putting pressure " and " pressure equalization " step, its time program is put upside down each other, but its essence is equally, promptly all be to utilize these means of step-down, be implemented in and make the sorbent material depressurization desorption regenerated while, improve concentration of carbon dioxide in the adsorption tower.In addition, when carrying out " along falling the program of putting ", if will forward reduce pressure whole pressure-controlling in the 0.05MPa(gauge pressure) below, then the pressure at pressure equalization end can drop to negative pressure, in this course, because the CO that desorbs in the tower
2Can take residual impurities such as the oxygen in the sorbent material dead space, nitrogen, carbon monoxide and methane out of adsorption tower, thereby play the effect of displacement step, thereby can remove " displacement " step in the program, play the more effect of new technological flow.
Pressure swing adsorption technique flow process of the present invention also can adopt the array configuration of two towers or four towers, as shown in Figure 3, Figure 4.Each step of the working cycle of corresponding flow process and time-program(me) table thereof are shown in table 3, table 4.
The flow process of two towers or four tower array configurations is the same with the flow process of three tower array configurations, all can use " along falling the program of putting ", thereby suitably reducing along putting under the situation of end pressure, can remove " displacement " step, and whole process flow is simplified.
The present invention can also and vacuumize vent gas with reverse decompression vent gas and collect respectively, and the former is back in the tower as displacement, and the latter under same operational condition, can obtain better effect like this for product output, but flow process is complicated.
In order to make the present invention's air-flow in implementation process more stable and set up some buffer containers or improve necessary automatic control level and all be fine, do not make generation substantial variation of the present invention.
The three tower pressure swing adsorption technique flow processs of application drawing 2 and each step of working cycle and the time-program(me) table thereof of table 1 and table 2, the following test of carrying out can further specify and understand characteristics of the present invention:
Test 1(utilizes usual procedure)
Use three adsorption towers, the internal diameter of each tower is 1000mm, sorbent material floor height 5000mm, and about 3 tons of the Kiselgel A of interior dress Φ 3～Φ 5 is to select absorbing carbon dioxide.
Being rich in carbon dioxide mix gas test carbonated 32%(volume) is compressed to the 0.75MPa(gauge pressure with lime-kiln gas), temperature is a normal temperature, advances before the pressure swing adsorption system through pre-treatment to remove wherein saturated
Table 3 is applicable to each step of working cycle and the time-program(me) thereof of Fig. 3 flow process
Adsorption tower
Table 4 is applicable to the working cycle step and the time-program(me) thereof of Fig. 4 flow process
Adsorption tower
Water.Unstripped gas is 900Nm
3/ h, adsorptive pressure are the 0.75MPa(gauge pressure), total cycle time 10 ' 25 ", test-results is as shown in table 5.
Table 5 production by pressure swing adsorption carbon dioxide product test-results
Raw gas flow (Nm
3/ hr) 900
Working pressure [the MPa(gauge pressure)]
Absorption 0.75
Pressure equalization whole 0.27
Forward decompression whole 0.04
Displacement 0.04
Reverse decompression whole-0.01
Vacuumize end-0.09
A pressurising whole 0.27
Secondary pressurising whole 0.74
Product carbonic acid gas output pressure 7.6
Carbon dioxide purity (volume %) 〉=99.5
Carbon dioxide extraction rate (%) 86
Test 2(utilizes along falling the program of putting)
Utilize and test 1 identical system and identical unstripped gas, pressure swing adsorption system adopts along falling the program of putting, and its test-results is as shown in table 6.
Table 6 production by pressure swing adsorption carbon dioxide product test-results:
Lime-kiln gas flow (Nm
3/ hr) 900
Working pressure [the MPa(gauge pressure)]
Adsorptive pressure 0.75
Forward decompression whole 0.08
Pressure equalization whole 0.01
Displacement 0.01
Reverse decompression whole-0.01
Vacuumize-0.09
A pressurising whole 0.01
Secondary pressurising whole 0.74
Product carbonic acid gas output pressure 7.6
Carbon dioxide purity (volume %) 〉=99.5
Carbon dioxide extraction rate (%) 89
Claims (17)
1, a kind of from the various pressure swing adsorption techniques that extract pure carbon dioxide the carbon dioxide mix gas that are rich in, this technology comprises the following steps:
A, adsorption step: be rich in carbon dioxide mix gas and in pressure swing adsorption system, obtain separating in the tower in several adsorption towers that sorbent material is housed, the component that is difficult for absorption is hydrogen, oxygen, argon, nitrogen, carbon monoxide and methane, they discharge from the tower exit end, easily are adsorbed the component carbonic acid gas and stay in the tower;
B, pressure equalization step: after step (a) finished, this tower communicated with a certain adsorption tower entrance end that has finished evacuation step, made the interior gas of the tower that has adsorbed transport to another tower, and is equal substantially until two pressure towers;
C, depressurization steps forward: in step (b) afterwards, the tower that has adsorbed further along the decompression of exit end direction, is reduced to 0.02～0.04MPa (gauge pressure) until the tower internal pressure;
D, displacement step: allow the some of product gas, under the whole pressure of decompression forward, to the displacement that refluxes of the tower of firm end step (c), to exit end square tube mistake, displacement still remains in other interior component of tower to displacement gas from entrance end;
E, reverse depressurization steps: in step (d) afterwards, make the reverse entrance end discharge of carbonic acid gas in the tower, till a certain negative pressure is arrived in the tower pressure drop from tower;
F, vacuumize step: in step (e) afterwards, the tower internal pressure has been negative pressure, but some carbonic acid gas component of occlusion also, partly gas will be by continuing to vacuumize extraction for this;
G, a pressurising step: utilize another cat head that just has been in pressure equalization step to discharge gas,, carry out pressurising toward the exit end direction, till the pressure that makes the pressure of tower rise to the air supply source tower equates substantially from the entrance end of tower to the tower of completing steps (f);
H, secondary pressurising step: utilize another cat head that is in adsorption step to discharge gas,, carry out pressurising once more, the tower internal pressure is raised to is substantially equal to till the adsorptive pressure from the past entrance end direction of the exit end of tower to the tower of completing steps (g).
2, a kind of pressure swing adsorption technique (along falling the program of putting) that extracts pure carbon dioxide from be rich in carbon dioxide mix gas, this technology comprises the following steps:
A, adsorption step: be rich in carbon dioxide mix gas and in pressure swing adsorption system, obtain separating in the tower in several adsorption towers that sorbent material is housed, the component that is difficult for absorption is hydrogen, oxygen, argon, nitrogen, carbon monoxide and methane, they discharge from the tower exit end, easily are adsorbed the component carbonic acid gas and stay in the tower;
B, depressurization steps forward: after step (a) finished, the tower that has adsorbed was reduced to the 0.1MPa(gauge pressure along the decompression of exit end direction until the tower internal pressure);
C, pressure equalization step: in step (b) afterwards, this tower communicates with a certain adsorption tower entrance end of having finished evacuation step, makes the interior gas of tower that finishes forward to reduce pressure transport to another tower, and is equal substantially until two pressure towers;
D, displacement step: allow the some of product gas under the pressure equalization pressure at end, to the displacement that refluxes of the tower of firm end step (c), displacement gas passes through to the exit end direction from entrance end, and displacement still remains in other component in the tower;
E, reverse depressurization steps: in step (d) afterwards, make the reverse entrance end discharge of carbonic acid gas in the tower, till a certain negative pressure is arrived in the tower pressure drop from tower.
F, vacuumize step: in step (e) afterwards, the tower internal pressure has been negative pressure, but some carbonic acid gas component of occlusion also, partly gas will be by continuing to vacuumize extraction for this;
G, a pressurising step: utilize another cat head that just has been in pressure equalization step to discharge gas,, carry out pressurising toward the exit end direction, till the pressure that makes the pressure of tower rise to the air supply source tower equates substantially from the entrance end of tower to the tower of completing steps (f);
H, secondary pressurising step: utilize another cat head that is in adsorption step to discharge gas,, carry out pressurising once more, the tower internal pressure is raised to is substantially equal to till the adsorptive pressure from the past entrance end direction of the exit end of tower to the tower of completing steps (g).
3, according to the pressure swing adsorption process of claim 1 or 2, it is characterized in that: the adsorption tower that needs two filled with adsorbent at least.
4, according to the pressure swing adsorption process of claim 3, it is characterized in that: being filled with in the adsorption tower has the Kiselgel A of better selection absorption as sorbent material to carbonic acid gas.
5, according to the pressure swing adsorption process of claim 1 or 2, it is characterized in that: the adsorptive pressure when adsorption step is controlled at 0.3～1.5MPa(gauge pressure) in the scope.
6, according to the pressure swing adsorption process of claim 1 or 2, it is characterized in that: the working pressure when vacuumizing step is not higher than-the 0.07MPa(gauge pressure).
7, according to the pressure swing adsorption process of claim 1 or 2, it is characterized in that: when displacement step finished, gas concentration lwevel was controlled in 70～82% scopes during transient flow was given vent to anger.
8, according to the pressure swing adsorption process of claim 1 or 2, it is characterized in that: product gas is made up of the vent gas of step (e) and step (f).
9, according to the pressure swing adsorption process of claim 1 or 2, it is characterized in that: the displacement gas that is provided in displacement step is the vent gas that comes from step (e) and step (f), and compressed machine is compressed to and is higher than the required pressure of displacement, finally is controlled at displacement and enters in the tower under the required pressure.
10, according to the pressure swing adsorption process of claim 1 or 2, it is characterized in that: when depressurization steps forward, need return the unstripped gas surge tank by tower exit end expellant gas and recycle.
11, according to the pressure swing adsorption process of claim 1 or 2, it is characterized in that: when displacement step, by tower and need return the unstripped gas surge tank from tower exit end expellant gas and be recycled.
12, according to the pressure swing adsorption process of claim 1 or 2, it is characterized in that: must on the vacuum pump inlet pipeline, establish a vacuum tank.
13, according to the pressure swing adsorption process of claim 1 or 2, it is characterized in that: when the array configuration that adopts three adsorption towers, and carry out, can between step (f) and step (g), increase an isolation step along falling when putting program.
14, according to the pressure swing adsorption process of claim 1 or 2, the vent gas of step (e) and step (f) can be collected respectively, the former is as displacement gas, and the latter is a product.
15, according to the pressure swing adsorption process of claim 1 or 2, it is characterized in that: handled unstripped gas should dewater with any method before advancing pressure-swing absorption apparatus in advance.
16, according to the pressure swing adsorption process of claim 2, it is characterized in that: will forward put and press end pressure to be controlled at the 0.05MPa(gauge pressure) below, the pressure equalization end pressure can be lower than barometric point.
17, according to the pressure swing adsorption process of claim 16, it is characterized in that: carry out along falling when putting program, when pressure equalization step end of a period pressure is negative pressure, can save displacement step.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN88105938A CN1019475B (en) | 1988-08-16 | 1988-08-16 | Pressure-gradient adsorption method for extracting of carbon dioxide from gaseous mixture |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN88105938A CN1019475B (en) | 1988-08-16 | 1988-08-16 | Pressure-gradient adsorption method for extracting of carbon dioxide from gaseous mixture |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1040354A CN1040354A (en) | 1990-03-14 |
| CN1019475B true CN1019475B (en) | 1992-12-16 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN88105938A Expired CN1019475B (en) | 1988-08-16 | 1988-08-16 | Pressure-gradient adsorption method for extracting of carbon dioxide from gaseous mixture |
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| Country | Link |
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| CN (1) | CN1019475B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100434409C (en) * | 2004-07-09 | 2008-11-19 | 张双永 | Method for separating and recovering chloroethylene by pressure swing adsorption method |
| FR2933313B1 (en) * | 2008-07-03 | 2011-07-22 | Air Liquide | TREATMENT OF WET GAS CONTAINING DUST |
| CN102078740B (en) * | 2010-12-13 | 2013-02-27 | 甘肃银光聚银化工有限公司 | Method for separating and purifying hydrogen from water gas by pressure swing adsorption |
| CN102657996A (en) * | 2012-05-28 | 2012-09-12 | 四川亚连科技有限责任公司 | Double-tower low-pressure method for acquiring CO2 in flue gas |
| CN104386694A (en) * | 2014-10-24 | 2015-03-04 | 中国石油天然气股份有限公司 | Hydrogen-producing purge gas recycling method |
| CN112607738A (en) * | 2020-12-29 | 2021-04-06 | 张家港保税区安瑞森化工品有限公司 | Carbon dioxide purification process |
| CN114849425A (en) * | 2022-04-13 | 2022-08-05 | 辽宁石油化工大学 | Equipment and method for separating and enriching carbon dioxide in flue gas |
| CN117101335A (en) * | 2023-10-08 | 2023-11-24 | 成都益志科技有限责任公司 | Low-pressure low-energy-consumption flue gas carbon dioxide recovery system and recovery process |
| CN117205717B (en) * | 2023-11-09 | 2024-02-09 | 陕西宝昱科技工业股份有限公司 | Low-concentration waste gas treatment system and method |
-
1988
- 1988-08-16 CN CN88105938A patent/CN1019475B/en not_active Expired
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| Publication number | Publication date |
|---|---|
| CN1040354A (en) | 1990-03-14 |
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