METHOD FOR MANUFACTURING A CARBON DIOXIDE
ADSORBENT, METHOD FOR REDUCING CARBON DIOXIDE AND
APPARATUS FOR SAM5 E
¡iTechnical Field¡j
The present invention relates to an adsorbent collecting carbon dioxide,
and more particularly, to a method of manufacturing a carbon dioxide adsorbent,
and a method and an apparatus for reducing carbon dioxide.
10 ¡iBackground Art¡j
Carbon dioxide generated when fossil fuel is combusted is a
representative greenhouse gas causing global warming, and recently,
regulations on discharge thereof have become stricter. A gas containing a
large amount of carbon dioxide, such as a combustion exhaust gas or a blast
15 furnace gas, generated in an iron works is added to a general pressure swing
adsorption (PSA) process to collect and recover carbon dioxide.
A general pressure adsorption device is constituted by an adsorption
column collecting carbon dioxide by using an adsorbent, and a regeneration
column applying heat to the adsorbent collecting carbon dioxide to regenerate
20 the adsorbent. The regenerated adsorbent is supplied back to the adsorption
column to participate in a reaction. The adsorbent used for a predetermined
period or more so that it loses an active site is discarded, and a replacement
2
amount of adsorbent is added to the adsorption column.
In the pressure swing adsorption process, a solid adsorbent such as
activated carbon, silica, and alumina is used as the adsorbent, and carbon
dioxide is collected by a physical adsorption method. However, this method
has limitations in that, since the commercially available adsorbent is costly, a5 n
operation cost is high, and since the physical adsorption method is used,
bonding force is weak, and thus collection efficiency of carbon dioxide at a large
capacity and a high concentration is low.
The above information disclosed in this Background section is only for
10 enhancement of understanding of the background of the invention and therefore
it may contain information that does not form the prior art that is already known
in this country to a person of ordinary skill in the art.
¡iDISCLOSURE¡j
¡iTechnical Problem¡j
15 The present invention has been made in an effort to provide a method of
manufacturing a carbon dioxide adsorbent, which has a low manufacturing cost
and an excellent carbon dioxide collection effect, and a method and an
apparatus of reducing carbon dioxide, to which the adsorbent is applied.
¡iTechnical Solution¡j
20 An exemplary embodiment of the present invention provides a method
of manufacturing a carbon dioxide adsorbent, including: providing ironmaking
waste; mixing the ironmaking waste and a binder; manufacturing a pellet by
3
injecting ammonia into the ironmaking waste mixed with the binder; and drying
the pellet.
A concentration of ammonia injected in the manufacturing of the pellet
may be 5 to 30 wt%.
The method may further include performing concentration an5 d
dehydration treatment before the ironmaking waste is mixed with the binder.
A filter press may be used in the dehydration treatment.
The ironmaking waste subjected to the dehydration treatment may
include moisture in an amount of 8 %.
10 The binder may be cement or bentonite.
A size of the pellet may be 1 to 25 mm.
Another exemplary embodiment of the present invention provides an
apparatus for reducing carbon dioxide, including: an adsorption apparatus
adopting an adsorbent manufactured by the method of any one of claims 1 to 7,
15 blowing an exhaust gas including carbon dioxide and adsorbing carbon dioxide
included in the exhaust gas onto the adsorbent; a regeneration apparatus
applying heat to the adsorbent onto which carbon dioxide is adsorbed while
passing through the adsorption apparatus to desorb adsorbed carbon dioxide; a
pH measurement apparatus measuring pH of the adsorbent from which carbon
20 dioxide is desorbed while passing through the regeneration apparatus; and a
rotary chamber spraying ammonia onto the adsorbent passing through the pH
measurement apparatus, in which the pH measurement apparatus selectively
supplies the adsorbent according to the measured pH to the rotary chamber.
Ironmaking waste heat may be used in the regeneration apparatus to
4
supply heat to the adsorbent.
If the pH measured in the pH measurement apparatus is more than 10,
the adsorbent may be supplied to the rotary chamber, and if the pH measured
in the pH measurement apparatus is 10 or less, the adsorbent may be recycled
to manufacture reduced iron5 .
The apparatus may further include a condenser for receiving
compounds of ammonia and carbon dioxide desorbed from the regeneration
apparatus to separate the compounds into ammonia and carbon dioxide by
using a difference in condensation temperatures.
10 The ammonia separated in the condenser may be supplied to the rotary
chamber.
The exhaust gas including carbon dioxide may be at least one selected
from a blast furnace exhaust gas (BFG), a coke oven gas (COG), and a FINEX
exhaust gas (FOG).
15 Yet another exemplary embodiment of the present invention provides a
method of reducing carbon dioxide, to which an adsorbent manufactured by the
method of any one of claims 1 to 7 is applied, including: adsorbing carbon
dioxide from an exhaust gas by bringing the exhaust gas including carbon
dioxide into contact with the adsorbent; desorbing the carbon dioxide adsorbed
20 onto the adsorbent; judging whether pH of the adsorbent from which the carbon
dioxide is desorbed is more than a set value; and if the pH of the adsorbent is
more than the set value, spraying ammonia onto the adsorbent, wherein the
adsorbing of carbon dioxide to the spraying of ammonia are performed again by
using the adsorbent onto which the ammonia is sprayed.
5
Ironmaking waste heat may be used to desorb the carbon dioxide.
If the pH of the adsorbent is not more than the set value, the adsorbent
may be recycled to manufacture reduced iron.
The set value of the pH may be 10.
Compounds of the ammonia and the carbon dioxide may be desorbe5 d
when the carbon dioxide adsorbed onto the adsorbent is desorbed, and the
method may further include separating the compounds into the ammonia and
the carbon dioxide.
The separated ammonia may be used in the spraying of ammonia onto
10 the adsorbent.
The exhaust gas including carbon dioxide may be at least one selected
from a blast furnace exhaust gas (BFG), a coke oven gas (COG), and a FINEX
exhaust gas (FOG).
Still another exemplary embodiment of the present invention provides a
15 carbon dioxide adsorbent manufactured by the method of any one of claims 1 to
7 and carrying ammonia.
A concentration of iron of an ironmaking waste used in the
manufacturing may be 40 to 60 %.
A concentration of carbon of the ironmaking waste used in the
20 manufacturing may be less than 25 %.
Its size may be 1 to 25 mm.
¡iAdvantageous Effects¡j
According to the exemplary embodiments of the present invention, since
6
carbon dioxide is collected by using a chemical absorption reaction, it is
possible to increase collection efficiency of carbon dioxide as compared to an
existing physical adsorbent. Further, since desorption reactivity of carbon
dioxide is improved, efficiency is increased.
Further, it is possible to reduce a manufacturing cost by manufacturing 5 a
low-priced adsorbent.
¡iDescription of the Drawings¡j
FIG. 1 is a flowchart of a method of manufacturing a carbon dioxide
adsorbent according to an exemplary embodiment of the present invention.
10 FIG. 2 is a block diagram showing apparatuses used in the method of
manufacturing the carbon dioxide adsorbent according to the exemplary
embodiment of the present invention.
FIG. 3 is a schematic diagram of an apparatus for reducing carbon
dioxide according to the exemplary embodiment of the present invention.
15 FIG. 4 is a flowchart of a method of reducing carbon dioxide according
to the exemplary embodiment of the present invention.
¡iMode for Invention¡j
An exemplary embodiment of the present invention will hereinafter be
described in detail with reference to the accompanying drawings.
20 FIG. 1 is a flowchart of a method of manufacturing a carbon dioxide
adsorbent according to an exemplary embodiment of the present invention.
Further, FIG. 2 is a block diagram showing apparatuses used in the method of
manufacturing the carbon dioxide adsorbent according to the exemplary
7
embodiment of the present invention.
As illustrated in FIGS. 1 and 2, if ammonia (NH3) is prepared (S100) and
ironmaking waste 1 is provided (S110), the ironmaking waste 1 is supplied to a
concentrator 10. That is, the ironmaking waste 1 is concentrated (S120).
Herein, the ironmaking waste 1 may be an ironmaking sludge generated in a5 n
ironmaking process. Meanwhile, in the provided ironmaking waste 1, a
concentration of iron (Fe) may be 40 to 60 % or a concentration of carbon may
be less than 25%.
The ironmaking waste 1 concentrated in the concentrator 10 is supplied
10 to a filter press 20. The ironmaking waste 1 is subjected to dehydration
treatment in the filter press 20 (S130). The dehydration treatment is performed
so that the ironmaking waste 1 includes moisture in an amount of 8 %. Of
course the dehydration treatment is performed only in the case of the
ironmaking waste 1 including moisture, and may be omitted in the case of the
15 ironmaking waste 1 not including moisture.
The ironmaking waste 1 subjected to the dehydration treatment is
supplied to a mixer 30. Further, a binder is supplied to the mixer 30 to be
mixed with the ironmaking waste 1 (S140). Herein, the binder may be cement
or bentonite.
20 The ironmaking waste 1 mixed with the binder is supplied to a pelletizer
40. Further, prepared ammonia is injected into the pelletizer 40. The
pelletizer 40 manufactures a pellet where ammonia is adsorbed onto the
ironmaking waste 1 (S150). A concentration of ammonia injected in the
manufacturing of the pellet may be 5 to 30 wt%.
8
When the pellet is manufactured in the pelletizer 40, the pellet is dried
(S160). Further, a size of the pellet may be 1 to 25 mm. The drying of the
pellet may be performed at room temperature. The pellet manufactured by the
aforementioned method serves as a carbon dioxide adsorbent 2. That is, the
pellet is supplied to an apparatus 50 for reducing carbon dioxide to redu5 ce
carbon dioxide.
FIG. 3 is a schematic diagram of the apparatus for reducing carbon
dioxide according to the exemplary embodiment of the present invention.
As illustrated in FIG. 3, the apparatus 50 for reducing carbon dioxide
10 according to the exemplary embodiment of the present invention includes an
adsorption apparatus 60, a regeneration apparatus 70, a pH measurement
apparatus 80, a rotary chamber 90, and a condenser 100.
The adsorption apparatus 60 adsorbs carbon dioxide included in an
exhaust gas by using the adsorbent 2 manufactured by the method of
15 manufacturing the carbon dioxide adsorbent 2 according to the exemplary
embodiment of the present invention. That is, the adsorbent 2 and the exhaust
gas including carbon dioxide are supplied to the adsorption apparatus 60, and
the adsorbent 2 and the exhaust gas come into contact with each other to
adsorb carbon dioxide included in the exhaust gas onto the adsorbent 2.
20 Herein, the exhaust gas including carbon dioxide may be at least one exhaust
gas of a blast furnace exhaust gas (blast furnace gas; BFG), a coke oven gas
(COG), and a FINEX exhaust gas (FINEX off-gas; FOG). Meanwhile, an
internal temperature of the adsorption apparatus 60 may be room temperature
to 30 „aC. Further, the exhaust gas from which carbon dioxide is removed
9
according to adsorption of carbon dioxide onto the adsorbent 2 is separated into
materials such as hydrogen (H2), carbon monoxide (CO), and nitrogen (N2).
Hydrogen and carbon monoxide are used to reduce the iron ore, and nitrogen
may be used as a gas for transporting of ironmaking.
The regeneration apparatus 70 desorbs carbon dioxide adsorbed ont5 o
the adsorbent 2. That is, the adsorbent 2 onto which carbon dioxide is
adsorbed while passing through the adsorption apparatus 60 is supplied to the
regeneration apparatus 70. Further, in the regeneration apparatus 70, the
adsorbent 2 onto which carbon dioxide is adsorbed is heated to desorb carbon
10 dioxide. Ironmaking waste heat is used in the heating, and a heating
temperature may be 100 „aC.
Meanwhile, the adsorption apparatus 60 and the regeneration apparatus
70 may be formed to have a fluidization channel shape. Adsorption reactivity
of carbon dioxide may be improved and carbon dioxide may be adsorbed in a
15 large quantity by circulating the adsorbent that is a solid particle between the
adsorption apparatus 60 and the regeneration apparatus 70. Moreover, since
it is unnecessary to add pressure and reduce the pressure, power consumption
is reduced, and thus energy consumption for reducing carbon dioxide is
reduced.
20 The pH measurement apparatus 80 measures pH of the adsorbent 2.
Further, whether the adsorbent 2 is to be reused is judged by comparing the
measured pH of the adsorbent 2 to a set value. If the pH of the adsorbent 2 is
more than the set value, the adsorbent 2 is reused, and if the pH of the
adsorbent 2 is not more than the set value, the adsorbent 2 is used to
10
manufacture a reduced iron (direct reduced iron; DRI). Herein, the set value
may be pH 10.
Meanwhile, as described above, it is easy to replace the initially supplied
adsorbent 2 according to selective reuse of the adsorbent 2. That is, supplying
of carbon dioxide does not need to be stopped, and a replacement cost of th5 e
adsorbent 2 is not accrued.
The rotary chamber 90 receives the adsorbent 2 from the pH
measurement apparatus 80 to spray ammonia onto the adsorbent 2. The
adsorbent 2 onto which ammonia is adsorbed while passing through the rotary
10 chamber 90 is supplied to the adsorption apparatus 60 to be reused. That is,
the adsorbent 2 where the pH measured in the pH measurement apparatus 80
is more than the set value is supplied to the rotary chamber 90.
The condenser 100 receives carbon dioxide desorbed from the
regeneration apparatus 70. When carbon dioxide is desorbed from the
15 regeneration apparatus 70, compounds of carbon dioxide and ammonia are
desorbed. That is, the compounds of carbon dioxide and ammonia are
supplied to the condenser 100. Moreover, the condenser 100 separates the
compounds into carbon dioxide and ammonia. Herein, separated ammonia is
supplied to the rotary chamber 90 to be used as ammonia sprayed onto the
20 adsorbent 2. Separated carbon dioxide may be discharged to the outside, or
may be reused in a CO2 reforming process or a reverse water gas shift reaction
process to manufacture hydrogen and carbon monoxide. As described above,
hydrogen and carbon monoxide may be used to reduce the iron ore.
FIG. 4 is a flowchart of a method of reducing carbon dioxide according
11
to the exemplary embodiment of the present invention.
As illustrated in FIG. 4, if the adsorbent 2 manufactured by the method
of manufacturing the carbon dioxide adsorbent 2 according to the exemplary
embodiment of the present invention is prepared (S200), the adsorbent 2 is
supplied to the adsorption apparatus 60 to which the exhaust gas includin5 g
carbon dioxide is supplied to adsorb carbon dioxide of the exhaust gas onto the
adsorbent 2 (S210).
The adsorbent 2 onto which carbon dioxide of the exhaust gas is
adsorbed is supplied to the regeneration apparatus 70, and the regeneration
10 apparatus 70 desorbs carbon dioxide from the adsorbent 2 by heating the
adsorbent 2 onto which carbon dioxide of the exhaust gas is adsorbed by using
ironmaking waste heat (S220). Herein, desorption of carbon dioxide may be
performed by desorbing the compounds of ammonia and carbon dioxide
adsorbed onto the adsorbent 2.
15 The adsorbent 2 from which carbon dioxide is desorbed is supplied to
the pH measurement apparatus 80, and the pH measurement apparatus 80
measures the pH of the adsorbent 2 (S230). Further, the pH measurement
apparatus 80 judges whether the pH of the adsorbent 2 is more than the set
value (S240). Herein, the set value of the pH may be pH10.
20 If the pH of the adsorbent 2 is judged to be more than the set value, the
pH measurement apparatus 80 supplies the adsorbent 2 from which carbon
dioxide is desorbed to the rotary chamber 90. Further, ammonia is sprayed
onto the adsorbent 2 supplied to the rotary chamber 90 (S250). Herein,
ammonia supplied to the rotary chamber 90 after the compounds of ammonia
12
and carbon dioxide are separated into ammonia and carbon dioxide in the
condenser 100 is used as sprayed ammonia.
If the pH of the adsorbent 2 is judged to be not more than the set value,
the adsorbent 2 from which carbon dioxide is desorbed is used to manufacture
the reduced iron (S260)5 .
According to the exemplary embodiments of the present invention, since
carbon dioxide is collected by using a chemical absorption reaction, it is
possible to increase collection efficiency of carbon dioxide as compared to an
existing physical adsorbent. Further, since desorption reactivity of carbon
10 dioxide is improved, efficiency is increased. Moreover, it is possible to reduce
a manufacturing cost by manufacturing the low-priced adsorbent 2.
While this invention has been described in connection with what is
presently considered to be practical exemplary embodiments, it is to be
understood that the invention is not limited to the disclosed embodiments. On
15 the contrary, it is intended to cover various modifications and equivalent
arrangements included within the spirit and scope of the appended claims.
13
¡iCLAIMS¡j
¡iClaim 1¡j
A method of manufacturing a carbon dioxide adsorbent, comprising:
providing ironmaking waste;
mixing the ironmaking waste and a binder5 ;
manufacturing a pellet by injecting ammonia into the ironmaking waste
mixed with the binder; and
drying the pellet.
10 ¡iClaim 2¡j
The method of claim 1, wherein
a concentration of ammonia injected in the manufacturing of the pellet is
5 to 30 wt%.
15 ¡iClaim 3¡j
The method of claim 1, further comprising
performing concentration and dehydration treatment before the
ironmaking waste is mixed with the binder.
20 ¡iClaim 4¡j
The method of claim 3, wherein
14
a filter press is used in the dehydration treatment.
¡iClaim 5¡j
The method of claim 3, wherein
the ironmaking waste subjected to the dehydration treatment include5 s
moisture in an amount of 8 %.
¡iClaim 6¡j
The method of claim 1, wherein
10 the binder is cement or bentonite.
¡iClaim 7¡j
The method of claim 1, wherein
a size of the pellet is 1 to 25 mm.
15
¡iClaim 8¡j
An apparatus of reducing carbon dioxide, comprising:
an adsorption apparatus adopting an adsorbent manufactured by the
method of any one of claims 1 to 7, blowing an exhaust gas including carbon
20 dioxide and adsorbing carbon dioxide included in the exhaust gas onto the
adsorbent;
a regeneration apparatus applying heat to the adsorbent onto which
15
carbon dioxide is adsorbed while passing through the adsorption apparatus to
desorb the adsorbed carbon dioxide;
a pH measurement apparatus measuring pH of the adsorbent from
which carbon dioxide is desorbed while passing through the regeneration
apparatus; an5 d
a rotary chamber spraying ammonia onto the adsorbent passing through
the pH measurement apparatus,
wherein the pH measurement apparatus selectively supplies the
adsorbent according to the measured pH to the rotary chamber.
10
¡iClaim 9¡j
The apparatus of claim 8, wherein
ironmaking waste heat is used in the regeneration apparatus to supply
heat to the adsorbent.
15
¡iClaim 10¡j
The apparatus of claim 8, wherein
if the pH measured in the pH measurement apparatus is more than 10,
the adsorbent is supplied to the rotary chamber, and
20 if the pH measured in the pH measurement apparatus is 10 or less, the
adsorbent is recycled to manufacture reduced iron.
¡iClaim 11¡j
16
The apparatus of claim 8, further comprising
a condenser for receiving compounds of ammonia and carbon dioxide
desorbed from the regeneration apparatus to separate the compounds into
ammonia and carbon dioxide by using a difference in condensation
temperatures5 .
¡iClaim 12¡j
The apparatus of claim 11, wherein
the ammonia separated in the condenser is supplied to the rotary
10 chamber.
¡iClaim 13¡j
The apparatus of claim 8, wherein
the exhaust gas including carbon dioxide is at least one selected from a
15 blast furnace exhaust gas (BFG), a coke oven gas (COG), and a FINEX
exhaust gas (FOG).
¡iClaim 14¡j
A method of reducing carbon dioxide, to which an adsorbent
20 manufactured by the method of any one of claims 1 to 7 is applied, comprising:
adsorbing carbon dioxide from an exhaust gas by bringing the exhaust
gas including carbon dioxide into contact with the adsorbent;
17
desorbing the carbon dioxide adsorbed onto the adsorbent;
judging whether pH of the adsorbent from which the carbon dioxide is
desorbed is more than a set value; and
if the pH of the adsorbent is more than the set value, spraying ammonia
onto the adsorbent5 ,
wherein the adsorbing of carbon dioxide to the spraying of ammonia are
performed again by using the adsorbent onto which ammonia is sprayed.
¡iClaim 15¡j
10 The method of claim 14, wherein
ironmaking waste heat is used to desorb the carbon dioxide.
¡iClaim 16¡j
The method of claim 14, wherein
15 if the pH of the adsorbent is not more than the set value, the adsorbent
is recycled to manufacture reduced iron.
¡iClaim 17¡j
The method of claim 14, wherein
20 the set value of the pH is 10.
¡iClaim 18¡j
18
The method of claim 14, wherein
compounds of the ammonia and the carbon dioxide are desorbed when
the carbon dioxide adsorbed onto the adsorbent is desorbed, and
the method further comprises separating the compounds into the
ammonia and the carbon dioxide5 .
¡iClaim 19¡j
The method of claim 18, wherein
the separated ammonia is used in the spraying of ammonia onto the
10 adsorbent.
¡iClaim 20¡j
The method of claim 14, wherein
the exhaust gas including carbon dioxide is at least one selected from a
15 blast furnace exhaust gas (BFG), a coke oven gas (COG), and a FINEX
exhaust gas (FOG).
¡iClaim 21¡j
A carbon dioxide adsorbent manufactured by the method of any one of
20 claims 1 to 7 and carrying ammonia.
¡iClaim 22¡j
19
The carbon dioxide adsorbent of claim 21, wherein
a concentration of iron of ironmaking waste used in the manufacturing is
40 to 60 %.
¡iClaim 235 ¡j
The carbon dioxide adsorbent of claim 21, wherein
a concentration of carbon of the ironmaking waste used in the
manufacturing is less than 25 %.
10 ¡iClaim 24¡j
The carbon dioxide adsorbent of claim 21, wherein
its size is 1 to 25 mm.
20