U.S. patent application number 14/134018 was filed with the patent office on 2014-04-17 for hydrogen gas production system utilizing silicon wastewater and method for production of hydrogen energy using the same.
This patent application is currently assigned to COWAY CO., LTD.. The applicant listed for this patent is COWAY CO., LTD.. Invention is credited to Chae-Seok CHOI, Ji-Hyeon HWANG, Youn-Kook KIM.
Application Number | 20140105815 14/134018 |
Document ID | / |
Family ID | 44146951 |
Filed Date | 2014-04-17 |
United States Patent
Application |
20140105815 |
Kind Code |
A1 |
CHOI; Chae-Seok ; et
al. |
April 17, 2014 |
HYDROGEN GAS PRODUCTION SYSTEM UTILIZING SILICON WASTEWATER AND
METHOD FOR PRODUCTION OF HYDROGEN ENERGY USING THE SAME
Abstract
Disclosed is a method for production of hydrogen energy
utilizing silicon wastewater. The method includes treating the
silicon wastewater through UF membrane filtration to separate UF
treated water and a concentrated silicon waste solution therefrom,
admixing the separated silicon waste solution with an alkaline
material, reacting the concentrated silicon waste solution with the
alkaline material in the mixture to produce hydrogen gas and
alkaline water, using an acidic material to neutralize the alkaline
water, thereby forming a supernatant and a precipitate.
Inventors: |
CHOI; Chae-Seok; (Seoul,
KR) ; HWANG; Ji-Hyeon; (Ansan-si, KR) ; KIM;
Youn-Kook; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
COWAY CO., LTD. |
Kongju-si |
|
KR |
|
|
Assignee: |
COWAY CO., LTD.
Kongju-si
KR
|
Family ID: |
44146951 |
Appl. No.: |
14/134018 |
Filed: |
December 19, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13012297 |
Jan 24, 2011 |
8642002 |
|
|
14134018 |
|
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Current U.S.
Class: |
423/657 |
Current CPC
Class: |
C02F 1/444 20130101;
C02F 2103/346 20130101; Y02W 10/37 20150501; C01B 3/065 20130101;
Y02E 60/36 20130101; C01B 3/06 20130101; Y02E 60/32 20130101 |
Class at
Publication: |
423/657 |
International
Class: |
C01B 3/06 20060101
C01B003/06 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 17, 2010 |
KR |
10-2010-0014324 |
Claims
1. A method for production of hydrogen energy utilizing silicon
wastewater, comprising: treating the silicon wastewater through
ultrafiltration ("UF") membrane filtration to separate UF treated
water and a concentrated silicon waste solution therefrom; admixing
the separated silicon waste solution with an alkaline material;
reacting the concentrated silicon waste solution with the alkaline
material in the mixture to produce hydrogen gas and alkaline water;
and using an acidic material to neutralize the alkaline water,
thereby forming a supernatant and a precipitate.
2. The method according to claim 1, further comprising: discarding
solids obtained by dehydration of the precipitate.
3. The method according to claim 1, wherein the alkaline material
is at least one selected from a group consisting of NaOH, KOH,
MgOH, CaOH.sub.2, FeOH.sub.2, NH.sub.4OH, Na.sub.2CO.sub.3,
NaBH.sub.4 and mixtures thereof.
4. The method according to claim 1, wherein the alkaline water has
a pH range of 12 to 13.
5. The method according to claim 1, wherein the acidic material is
at least one selected from a group consisting of HCl, HNO.sub.3 and
a mixture thereof.
6. The method according to claim 1, wherein neutralization is
performed to adjust the pH of the alkaline solution to 7 to 10.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S.
application Ser. No. 13/012,297, filed on Jan. 24, 2011, which
claims a priority to and the benefit of Korean Patent Application
No. 10-2010-0014324, filed on Feb. 17, 2010, the disclosures of
which are incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a system for production of
hydrogen energy utilizing silicon wastewater in order to create an
additional energy resource, and a method for production of hydrogen
energy using the same.
[0004] 2. Description of the Related Art
[0005] As advanced information and communication industries,
semiconductor industries, exhaustion of petroleum energy, as well
as industries using solar energy to prevent global warming recently
come to the fore, demand for silicon wafers is rapidly
increasing.
[0006] In general, a silicon wafer is fabricated by providing a
slurry containing a cutting oil and an abrasive material (i.e.,
silicon carbide, aluminum oxide, silicon dioxide, etc.) and cutting
the wafer using a wire saw.
[0007] The cut silicon wafer, which is generally covered with waste
slurry admixed with saw dust as well as the used slurry containing
the cutting oil and the abrasive material, is then delivered to a
cleaning apparatus (wire saw cleaner) wherein a washing process
involving sonication in a cleaning solution (DI water) containing a
cleaner (surfactant) is executed, thereby producing a silicon wafer
for solar cells. Otherwise, a semiconductor silicon wafer may be
fabricated by polish-etching and washing processes. The forgoing
ingot processing typically generates a certain amount of silicon
wastewater containing cut solids and the slurry in a cleaning
solution.
[0008] Therefore, a conventional method used in the art generally
includes filtering silicon wastewater through a pressure
microfiltration ("MF") membrane to produce industrial water and use
the same while treating concentrated wastewater generated during
filtering by UF membrane filtration, so as to reuse ultrafiltration
("UF") treated water and discard the residual concentrated
wastewater without further treatment.
[0009] However, the concentrated wastewater remaining after primary
treatment of the silicon wastewater is excessively concentrated and
causes abnormal conditions such as clogging of UF membranes to be
used for any further process, for example, UF membrane filtration.
As a result, the conventional method entails a problem in that
recovery of the production water from the silicon wastewater is not
enhanced to a desired level.
[0010] Further, since the concentrated wastewater generated from
the silicon wastewater is discarded without treatment, there may
incur a high relatively disposal cost amounting to from 60,000 to
80,000 won per ton.
SUMMARY OF THE INVENTION
[0011] Therefore, the present invention is directed to solving the
above problems and an object of the present invention is to provide
a hydrogen energy production system utilizing silicon wastewater,
including secondary treatment of the silicon wastewater to improve
recovery thereof to a desired level, and a method for production of
hydrogen energy using silicon wastewater by the foregoing
system.
[0012] Another object of the present invention is to provide a
hydrogen energy production system utilizing silicon wastewater in
order to produce hydrogen gas therefrom and create a new energy
resource, and a method for production of hydrogen energy using
silicon wastewater by the foregoing system.
[0013] A still further object of the present invention is to
provide a hydrogen energy production system utilizing silicon
wastewater, which includes solidification of the residual waste
remaining in the silicon wastewater, thus decreasing waste mass and
efficiently reducing waste disposal costs, and a method for
production of hydrogen energy using silicon wastewater by the
foregoing system.
[0014] In order to accomplish the objects described above, a system
for production of hydrogen energy utilizing silicon wastewater
according to the present invention, comprises: an ultrafiltration
("UF") treatment bath wherein the silicon wastewater is treated
through UF film filtration to separate UF treated water and a
concentrated silicon waste solution therefrom; a line mixer
connected to the UF treatment bath to admix the separated silicon
waste solution with an alkaline material fed from the outside; and
a hydrogen production bath connected to the line mixer, wherein the
concentrated silicon waste solution reacts with the alkaline
material in the mixture, in order to produce hydrogen gas.
[0015] The inventive system also includes a waste solution bath
connected to the UF treatment bath wherein the concentrated silicon
waste solution, after separation, is stored and introduced into the
line mixer.
[0016] The inventive system may further include: a first production
bath connected to the UF treatment bath to store UF treated water;
and a hot water feed tank connected to the first production bath to
add hot water to the UF treated water.
[0017] In addition, the inventive system may include an alkaline
material tank connected to the line mixer wherein the alkaline
material is stored and fed to the line mixer.
[0018] The alkaline material tank of the inventive system may be
electrically connected to a dehumidifier to control humidity of the
alkaline material, thus suitably maintaining a desired humidity
thereof.
[0019] The inventive system may also include a hydrogen gas
collector connected to the hydrogen production bath, in order to
trap and store hydrogen generated in the hydrogen production
bath.
[0020] The inventive system may further have an acidity adjuster
connected to the hydrogen production bath, wherein an acidic
material is stored and fed to the hydrogen production bath in order
to neutralize alkaline water generated in the course of producing
hydrogen gas.
[0021] The inventive system may additionally have a second
production bath connected to the hydrogen production bath to store
a supernatant formed in the hydrogen production bath.
[0022] The inventive system may further include a centrifuge
connected to the hydrogen production bath, wherein a precipitate
formed during neutralization is received, dehydrated and discharged
to the outside.
[0023] The centrifuge of the inventive system is connected to both
the UF treatment bath and the second production bath, and receives
the concentrated silicon waste solution from the UF treatment bath
and the precipitate settled in the second production bath and
discards the same after dehydration.
[0024] In order to accomplish the foregoing objects, a method for
production of hydrogen energy using silicon wastewater according to
the present invention, comprises: treating the silicon wastewater
through UF membrane filtration to separate UF treated water and a
concentrated silicon waste solution therefrom;
[0025] admixing the separated silicon waste solution with an
alkaline material;
[0026] reacting the concentrated silicon waste solution with the
alkaline material in the mixture to produce hydrogen gas and
alkaline water; and
[0027] using an acidic material to neutralize the alkaline water,
thereby producing a supernatant and a precipitate.
[0028] The inventive method also includes dehydrating the
precipitate to obtain solids, which are then discarded.
[0029] The inventive method may use at least one selected from a
group consisting of NaOH, KOH, MgOH, CaOH.sub.2, FeOH.sub.2,
NH.sub.2OH, Na.sub.2CO.sub.3, NaBH.sub.4 and mixtures thereof, as
the alkaline material.
[0030] According to the inventive method, the alkaline water may
have a pH range of 12 to 13.
[0031] The inventive method may use at least one selected from a
group consisting of HCl, HNO.sub.3 and mixture thereof, as the
acidic material.
[0032] According to the inventive method, neutralization is
performed to adjust the pH of the alkaline water to 7 to 10.
[0033] As described above, the present invention may perform
secondary treatment of treated water obtained from silicon
wastewater in order to reuse the finally treated water, thereby
improving recovery of the treated water to a desired level.
[0034] The present invention may trap hydrogen gas from the silicon
wastewater thus realizing a novel energy resource.
[0035] In addition, the present invention may solidify the residual
waste remaining in the silicon wastewater in order to decrease
waste mass, thereby efficiently reducing waste disposal costs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The above and other objects, features and other advantages
of the present invention will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0037] FIG. 1 is a schematic view illustrating a hydrogen energy
production system utilizing silicon wastewater according to the
present invention;
[0038] FIG. 2 is a flow diagram illustrating a method for
production of hydrogen energy utilizing silicon wastewater
according to the present invention; and
[0039] FIG. 3 is photographs showing processes of forming hydrogen
gas and neutralizing the same according to the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] Hereinafter, a detailed description will be given of a
hydrogen energy production system utilizing silicon wastewater
according to preferred embodiments of the present invention, with
reference to the accompanying drawings.
[0041] FIG. 1 is a schematic view illustrating a hydrogen energy
production system utilizing silicon wastewater according to the
present invention.
[0042] Referring to FIG. 1, the hydrogen energy system utilizing
silicon wastewater of the present invention includes an
ultrafiltration ("UF") treatment bath 200, a line mixer 400 and a
hydrogen production bath 500.
[0043] The UF treatment bath 200 receives the silicon wastewater,
filters the same through a submerged type UF membrane 201 installed
inside the UF treatment bath 200, and separates UF treated water
and a concentrated silicon waste solution from the wastewater. In
this case, the silicon wastewater means a silicon-containing waste
solution generated during ingot processing, semiconductor
manufacturing, etc. According to one embodiment of the present
invention, the silicon wastewater generated from an ingot
processing part 100 during ingot processing is delivered to the UF
treatment bath and treated therein.
[0044] A concentrated silicon waste solution and UF treated water
separated in the UF treatment bath 200 are stored in a waste
solution storage tank 300 and a first production bath 220,
respectively, both of which are connected to the UF treatment bath
200. The first production bath 220 is also connected to a hot water
feed tank 210 storing hot water, in order to receive the hot water
therefrom and sterilize the UF treated water.
[0045] A line mixer 400 is connected to the UF treatment bath 200,
receives the concentrated silicon waste solution from the waste
solution storage tank 300 and an alkaline material fed from the
outside, and mixes these materials. The alkaline material
communicates with the line mixer and is provided from an alkaline
material tank 410. The alkaline material tank 410 may be
electrically connected to a dehumidifier 420 to control and
maintain a constant humidity of the alkaline material stored in the
tank.
[0046] The alkaline material is not particularly limited so long as
it reacts with silicon to generate hydrogen gas and may include
hydroxide based alkaline materials. For instance, hydroxides of
alkali metals and/or alkali-earth metals may be used and, more
preferably, at least one selected from a group consisting of NaOH,
KOH, MgOH, CaOH.sub.2, FeOH.sub.2, NH.sub.4OH, Na.sub.2CO.sub.3,
NaBH.sub.4 and mixtures thereof may be used. According to the
present invention, the line mixer 400 admixes the concentrated
silicon waste solution with the alkaline material in the mixture to
increase contact area therebetween, thereby enabling generation of
hydrogen gas in a hydrogen production bath 500.
[0047] The hydrogen production bath 500 is connected to the line
mixer 400 to conduct reaction of the concentrated silicon waste
solution with the alkaline material, both of which were admixed in
the line mixer 400, thus generating hydrogen gas. Such generated
hydrogen gas is trapped in a hydrogen gas collector 510 connected
to the hydrogen production bath 500, and separately stored therein.
Accordingly, the present invention may maintain a predetermined
recovery rate of treated water from silicon wastewater and generate
hydrogen gas from the treated water, which in turn traps and stores
a constant amount of the hydrogen gas in the gas collector 510,
thereby securing an additional energy source (based on the trapped
hydrogen gas).
[0048] The hydrogen production bath 500 is connected to an acidity
adjuster 520 to receive an acidic material stored in the acidity
adjuster 520, neutralizes alkaline water generated in the course of
producing the hydrogen gas, so as to produce a supernatant and a
precipitate. Here, the acidic material may be HCl, NNO.sub.3 or a
mixture thereof. The foregoing acidity adjuster 520 may control
supply of the acidic material to a level sufficient to neutralize
the alkaline water to a desired pH value, through a sensor and a
control part.
[0049] The formed precipitate is delivered to a centrifuge 700
connected to the hydrogen production bath 500 and the centrifuge
700 may dehydrate the precipitate to remove moisture therefrom,
form solids and discharge the same to the outside.
[0050] Meanwhile, a second production bath 600 communicates with
the hydrogen production bath 500 to receive and store the
supernatant.
[0051] Another centrifuge 700 may be connected to both the UF
treatment bath 200 and the second production bath 600. Accordingly,
the centrifuge 700 receives the concentrated silicon waste solution
overflowing from the UF treatment bath 200 and the remaining
precipitate settled in the second production bath 600, dehydrates
and solidifies these materials, and may discharge the formed solids
for disposal purposes to the outside.
[0052] The following detailed description will be given to explain
a hydrogen energy production method using the hydrogen energy
production system utilizing silicon wastewater as described
above.
[0053] FIG. 2 is a flow diagram illustrating a hydrogen energy
production method utilizing silicon wastewater according to the
present invention.
[0054] Referring to FIG. 2, a method for production of hydrogen
using silicon wastewater comprises:
[0055] treating the silicon wastewater through UF membrane
filtration to separate UF treated water and a concentrated silicon
waste solution;
[0056] admixing the separated silicon waste solution with an
alkaline material;
[0057] reacting the concentrated silicon waste solution with the
alkaline material in the mixture, so as to generate hydrogen gas
and alkaline water; and
[0058] neutralizing the alkaline waster with an acidic material to
produce a supernatant and a precipitate.
[0059] Hereinafter, respective processes of the foregoing method
will be described in detail.
[0060] First, the silicon wastewater is treated through UF membrane
filtration.
[0061] According to an exemplary embodiment of the present
invention, silicon wastewater generated during, for example, ingot
processing is delivered from an ingot processing part 100 to a UF
treatment bath 200, and subjected to filtering in a submerged type
UF membrane 201. According to the forgoing process, the silicon
wastewater is separated into UF treated water and a concentrated
silicon waste solution. The UF treated water and the concentrated
silicon waste solution are respectively delivered into a first
production bath 220 and a waste solution storage tank 300.
[0062] In this case, the UF treated water fed to the first
production bath 220 may be admixed with hot water provided from a
hot water feed tank 210, so as to be sterilized and cleaned.
[0063] Following this, the concentrated silicon waste solution is
admixed with the alkaline material.
[0064] The concentrated silicon waste solution stored in the waste
solution storage tank 300 as well as an alkaline material contained
in an alkaline material tank 410 are introduced into a line mixer
400 and admixed therein. The alkaline material is substantially the
same as described above.
[0065] Next, the concentrated silicon waste solution and the
alkaline material in the mixture react with each other to generate
hydrogen gas and alkaline water.
[0066] More particularly, the concentrated silicon waste solution
mixed and the alkaline material in the line mixer 400 interact in a
hydrogen production bath 500 and generate hydrogen gas. In this
case, alkaline water is generated as a by-product.
[0067] For instance, when silicon contained in the waste solution
reacts with NaOH as an alkaline material, hydrogen gas may be
generated according to the following chemical scheme 1:
Si+2NaOH+H.sub.2O(1).fwdarw.NaSiO.sub.3+2H.sub.2(g) [Chemical
Scheme 1]
[0068] Such generated hydrogen gas is isolated and stored in a
hydrogen collector 510 connected to the hydrogen production bath
500.
[0069] Finally, the alkaline water is neutralized using an acidic
material, so as to produce a supernatant and a precipitate.
[0070] After isolation of the hydrogen gas, the alkaline water
remaining in the hydrogen production bath 500 has a pH range of 12
to 13. Using an acidic material provided from an acidity adjuster
520, the alkaline water remaining in the hydrogen production bath
500 may be neutralized to pH 7 to 10.Here, the acidic material may
be HCl, HNO.sub.3 or a mixture thereof.
[0071] FIG. 3 is photographs showing processes of forming hydrogen
gas and neutralizing the same according to the present
invention.
[0072] Referring to FIG. 3, neutralizing the alkaline water with an
acidic material may separate a supernatant and a precipitate in gel
form. Such a supernatant overflows and is delivered from the
hydrogen production bath 500 to the second production bath 600. The
delivered supernatant may be further recycled and reused as
industrial water.
[0073] Accordingly, the present invention may generate hydrogen gas
and enable isolation of a supernatant and reuse thereof as
industrial water, and therefore, may enhance recovery of treated
water, which is reusable in processes, from silicon wastewater.
[0074] Moreover, the precipitate is subjected to dehydration to
provide solid waste which is in turn discarded.
[0075] The present invention may further include dehydration as
described above, so as to solidify a final waste in a cake form to
be disposed of, thereby reducing waste mass and considerably
reducing waste disposal costs.
* * * * *