No. A-13-1E

PJ : Innovative Circular Technologies for Harmful Nitrogen
Compounds/To Solve Planetary Boundary Issues
Organization: AIST and 16 university/companies
Contact: Dr. Tohru Kawamoto(AIST), tohru.kawamoto@aist.go.jp<Concept> NOx in exhaust gas and nitrogen compounds in wastewater are converted to ammonia,
then separated for recycling. Process design and environmental impact assessment are also available.
<Advantages> High energy efficiency. Enables treatment of exhaust gas and wastewater with lessenergy than conventional detoxification technologies. Resources are also recovered.

◆Background◆◆Nitrogen circulation systems◆◆Plant image(NOx to ammonia)◆◆Plant image(Aqueous N to ammonia)◆◆Research theme◆【2-2. ammonia recovery in water】(1) new membrane/adsorption separation(2) Construction of ultra energy-saving separation andconcentration process【1. NOx to ammonia】①concentration of NOx NH3 in gas phase②catalyst for NOx→NH3 at low temperature③catalyst even with O2 coexistence

NH4+濃縮液

Exhaust
gas

NTA

50％
Fuel

NOx NOx

NOx

reductant(HC, CO)

浸透圧駆動(自発的な水透過)
DS

H2O

N2

NH4+

DS
DS

H2O

正浸透膜
駆動溶液(DS)廃水

低浸透圧

50% conversion for complete
purification of NOx , and use
excess NH3 as a resource【2-1. conversion to NH3 in wastewater】
Efficient NH4+ conversion bioprocess for various
conditions●microaerobic conversion to NH4+
・Low NH4+ loss
・Use excess sludge
as nitrogen source

高浸透圧

membranes
アンモニア

distillation(conventional)

廃水

adsorption<1/100 of the energy
consumption of
conventional methods【Theme 3. Process and evaluation】
1) Process design of actual equipment and pilots 2)
economic and environmental impact assessment.
Process simulation●anaerobic membrane bioreactor (AnMBR) for high-NH4+
・work at high NH4concentration
・High energy efficiency andcompact size

EconomyRisk
Environmental
impactRisk

No. A-13-2E
PJ : Innovative circular technologies for harmful nitrogen compounds
Theme: Recycling of Gas-phase NOx : A Single Stage NTA in O2 and H2OOrganization: Waseda University
Contact: Masakazu Iwamoto (Waseda University) m.iwamoto3@kurenai.waseda.jp<Concept> NO is converted to NH3 (NTA) by H2 without any concentration or separations (in asingle stage). The product NH3 is fed to the NH3-SCR or concentrated to the NH3 utilization industry.
<Advantages> Realization of NH3-SCR systems without NH3 supply. Production of industrial NH3
without the Haber-Bosch process.

in O2, H2O
Catalyst

NH3 + H2O

Conc. at Reactor Outlet / ppm

1. Development of an efficient single-stage NTA catalyst, WSD-01, and proposed cross-point
utilization and industrial NH3 production (Figure 1).
Realization of NH3-SCR w/o
1000
NH3 supply
A single stage NTA
Fig. 1
Crosspoint CNO＝CNH3
without concentration
800
Combination of H2-NTA and NH3-SCR
of NO and removal ofNO
realizes a new NH3-SCR system.
O2 and H2O
NH3600
Alternative synthesis of
N2O
NO + 5/2H2
industrially produced NH3
NO2400
When CNH3 ≫ CNO, produced NH3
N2

can be separated and concentrated forindustrial use.

200
0
140

160

180

200

220

240

260

280

300

Produce the required amount
Cat. WSD-01. Reaction Conditions: SV=50,000 h-1, of NH3 on the spot when we
0.1% NO, 1.5% H2, 10% O2, 10% H2O, balance N2need it.
2. Developed a single-stage NTA catalyst, WSD-02, applicable to 100 ppm NO, paving the way torealize ultra-dilute NO detoxification (Figure 2).
Reaction Temp. / ℃

The developed NTA catalyst was effective for the reaction of ultra-dilute NO below the current environmental standards.
Promote further improvement of the atmospheric environment.

3. A hydrocarbon-based NTA catalyst, WSD-03, was developed to provide a temporary solution
until the realization of a hydrogen society (Figure 3).
If a hydrogen supply network is not available, the NTA reaction can be carried out using a hydrocarbon-based reducing
agent. Compatible with current internal combustion engines.

4. Preparation of pellet catalysts for bench-scale experiments and preliminary tests (Figure 4).

120
100

100

Fig. 2
Unreacted NO/%

80

80
60
H2=1.5%H2=1.0%H2=0.5%H2=0.2%H2=0.1%

40
20
0
-20

Yield of NH3/%

Cross Point at H2=0.5%

140 160 180 200 220 240 260 280 300

Reaction Temp. / ℃
Cat. WSD-02, SV 50,000 h-1, 0.01%
NO, 0.1-1.5% H2, 10% O2, 10% H2O,
balanced N2

YNH3 / ％Yield of NH3 & Unreacted NO / %Pellet catalysts were prepared in collaboration with a catalyst manufacturer. Confirmation of crushing strength, specificsurface area, and catalytic activity using a microreactor.

60

Fig. 4

Fig. 32nd Component/wt%
5.0(violet), 2.0(blue),
1.5(green), 1.0(red),
0.7(brown)

Compression
2.93mmΦ
3.01mmhStrength 47N
47.6m2/g
Extrusion
2.64mmΦ
3.23mmhStrength 24N
81.3m2/g

40

20

0
200

300

400

500

Reaction Temp. / ℃
Cat. WSD-03, SV 10,000 h-1, 0.1%
NO, 0.5% C3H6, 10% O2, 10% H2O,
balanced N2

Rolling
3.30mmΦStrength 27N
60.4m2/g【Potential Applications and Impacts】
Small NO sources such as ships, garbage incinerators, etc.
Realization of NH3-SCR with self-consumption of generated NH3 (no need for NH3 supply).
Large NO sources such as thermal power plants, oxidation processes, cement kilns, etc.
Separation and concentration of NH3 to supply industrial NH3. Localization of NH3 production.

No. A-13-3E
PJ: Innovative circular technologies for harmful nitrogen compounds
Theme: Development of honeycomb rotor-type 2step NTA catalyst system
Organization: The Univ. Tokyo, AIST, Tokyo Inst. Tech., Seibu Giken
Contact: Prof. Masaru Ogura(UT), oguram@iis.u-tokyo.ac.jp<Concept> Design of a 2step NTA catalyst system that seamlessly connects NOx selective
adsorption/concentration in the presence of O2 and H2O and NTA reaction under O2-free conditions.
<Advantages> Capable of deNOx at extremely low conc.; respond to NOx concentration fluctuations;world top-level NOx supplying in the reaction temp.; more than 95% yield of NH3; closer to recycling
Bench reactor

NTA catalyst(batch-made＆molded)NH3 yield

100

100

80

80

NO to NH3 (%)

NO Conversion (%)

NO conversion

60
40
20

by
Lab
ラボ合成品
by
company
大 スケール
合成品
ベンチスケール 用触媒
molded

0
100

150

NH3
out

200

60

by Labby company
ラボ合成品
大moldedスケール 合成品
ベンチスケール 用触媒

40
20

250

0
100

300

150

Temperature (°C)

200

250

300

Temperature (°C)

Cat.: 0.15g; flow rate: 250 mL/min (SV 40,000 h-1) ;composition: NO 1000ppm, H2 3000ppm

NTA catalyst(made bycompany)

NTA catalyst（made byLab）

Test-piece honeycombfor the upgrade to abench-scale rotor reactor

NOx in
1200

400

NO

300

200

100

1.5

0

2

4

6

Time ( min )810

ハニカム昇降温(100℃-300℃)
153サイクル

1.6
1.4

1000

NOx

800

600

400

200

1.2

1.0

0.5

NO

0

0

reusability

NOx ad- / de-sorption amount ( mmol )NOx，NO concentration ( ppm )NOxNOx，NO concentration ( ppm)

SV impact

TSA-NOx desorption

Pd effective utilization ratio

500

PSA-NOx adsorption

0

2

4

6

Time ( min )

8

10

0.0
10000

15000

20000

25000

SV ( h-1 )

30000

35000

40000

1
0.8
0.6
0.4
0.2
0
1

3

5

7

9

21

23

Number of NOx adsorption tests

500ppm NO/Air (14.7 L/min) at 100oC; N2 flow(14.7 L/min) 100-300oC temperature ramp (20 K/min)adsorbent: Pd-beta zeolite with 46wt%・94.1kg/m3；honeycomb size：φ25 x 100 mm SV：18000 h-1【Potential Applications and effects】
Large-scale, significantly low temperature and concentration NOx sources such as power plants,
oxidation processes, cement kilns, etc.
Realization of NH3-SCR for local production and local consumption of generated NH3; various utilizationroutes of hydrogen such as green hydrogen, is envisioned for hydrogen supply source.

No. A-13-4E
PJ : Innovative circular technologies for harmful nitrogen compounds
Theme: Gas-phase NOx recycling – NOx Storage Reduction (NSR) for NTA
Organization: AIST
Contact: Dr. Tatsuo Kimura (AIST) t-kimura@aist.go.jp<Concept>
Design for selective conversion from stored NOx to NH3 at constant temp. by switching reaction
gases for eliminating coexisting gases<Advantages>- Performing NOx storage and NH3 recovery at constant temp., that thermal management is not
required, by considering the possibility to recover NOx at high temperatures- Achieving NOx storage, that can be responded to fluctuated operation conditions, and subsequent
NH3 recovery by using one multi-functional nanocomposite catalyst【Potential Applications and effects】
Small-scale NOx generation sources such as garbage incinerators- Designing an onsite NOx reformer system for supplying as a reducing agent (NH3-SCR) as well asa mass-production plant of NH3- Achieving more than 90% selectivity to NH3 at the wide range of temp. possibly optimized by thechemical composition of nanocomposite catalysts, being able to effectively working below 200 °C

No. A-13-5E
PJ : Innovative circular technologies for harmful nitrogen compounds
Theme: Ammonia adsorption and concentration recovery and recycling process.
Organization: AIST
Contact: Kimitaka Minami(AIST), Kimitaka-minami@aist.go.jp<Concept> Technology for the conversion of ammonia into a resource using Prussian blue
analogues from NTA gases in which nitrogen oxide is converted into ammonia.
<Advantages> Large capacity and highly selective ammonia adsorbent, even from gases withcoexisting H2O and CO2. Recovery NH4HCO3 (solid) without heating and with low energy consumption.
Prussian blue analogues(PBA) for Ammonia adsorbent
PBA

H. Usuda, et al., Molecules 27, 8840 (2022).

AxMy[M’(CN)6] zH2O
M=M’=Fe: Prussian blue (PB)
M,M’=Fe, Cu, Zn,Ni, Co , A=Na,K,NH4 : PBA

M-NC-M’-CN-M

2 kinds of adsorption sites

M
M’

Zn2+ Ni2+ Cu2+ Co2+ Mn2+
Fe3+ Fe3+ Fe3+ Fe3+ Fe3+

Ads.
[mmol/g]Des.
[mmol/g]
Stability(XRD)

2.66 5.48 13.2 1.47 4.57

1.5

Interstitial sites: NH3, NH4+

NH3

NH4+

Vacancy sites: H2O, NH3

1 nm

0.26
Ion-exchange resin

0.18
Activated carbon

0.03
H2O
NH3
アンモニア吸着脱離システム

8.3 50 times
capacity

Expected capacityfrom 30ppm-NH3 (mmol/g)

PBA exhibit higher NH3 adsorption capacities than others
Ammonia concentration System

0.53 1.49 8.19 0.14 -0.63
×〇

×

Desorption
NH4HCO3 solution〇

H. Usuda, et al., ACS Sustain. Chem. Eng., Accepted (2023).

Mass Flow Controller
Adsorption〇

Apparatus

Recovery NH4HCO3 (solid)

Ni3[Fe(CN)6]2

Temperature:25℃, Gas Flow rate2.1L/min, NH3 gas 1.9%, H2O vapor 3.1%, Adsorbent 177g

• The NH3 concentration in OUTLET was more than 95% of INLET ina dozen hours.
• Adsorption recovered after desorption.

Adsorption column Pump CO2 NH4HCO3 aq
mixer solution
Temperature :25℃, NH4HCO3 aq solution Flow rate 25~40mL/min• Desorption increases NH4 concentration in NH4HCO3 solutions.
• Change in pH means that CO2 dissolves after NH3 is desorbed.

【Potential Applications and effects】
NO generation sources such as ships, garbage incinerators, thermal power plants, oxidation
processes, etc
For separation and concentration of NH3 from NTA gases.

No. A-13-6E
PJ : Innovative circular technologies for harmful nitrogen compounds
Theme: Wastewater N compounds to NH4+- Microaerobic conversion process(1)Organization: AIST, Kirin Holdings Co., Ltd. (KHD)
Contact: T Hori(AIST)hori-tomo@aist.go.jp; T Shimizu(KHD)takeshi.shimizu@kyowa-kirin.co.jp<Concept>・A set of systems connecting “conversion to NH4+” and “separation and concentration of NH4+”・Ceasing nitrogen discharge to environments and achieving resource and energy recovery<Advantages> Constructing multi-bioconversion processes for various wastewater types and situations● Current state and future image in 2050

● Two important points for bioconversion process
Activated sludge method

N compounds in wastewater
were converted to N2 gas,accompanied with N2O emission
Required massive energy
Residual N discharge

Conversion to NH4+ and subsequent
separation and concentration of NH4+
→ Utilization as ammonia resource● Objectives：Conversion of nitrogen compounds in wastewater to NH4+ using ①Microaerobic system and ②AnMBR● Microaerobic conversion process● R&D Items and Organization
Operation management based on microbial community control (AIST)
Operation management based on nitrogen compound dynamics control (TUAT)
Energy and material balance evaluation and N2O emission mitigation strategy
development（Kyoto Univ.）
Construction, operation and maintenance of the bench-scale microaerobic
conversion process (KHD)

Dr. Hori (AIST)

Prof. Terada (TUAT)

Prof. Fujiwara (Kyoto U) Dr. Shimizu (KHD)● Preparation for bench-scale demonstration＜Location＞＜Material flow＞＜Design chart＞

Wastewater pit

WastewatersupplyTreatedwastewater
discharge

Installation site

<Outlooks> Bench-scale microaerobic conversion from fermentation wastewater N compounds to NH4+● Retrofit technology: Infrastructure for activated sludge method can be utilized for various wastewaterNo. A-9-7E
PJ : Innovative circular technologies for harmful nitrogen compounds
Theme: : Wastewater N compounds to NH4+- Microaerobic conversion process(2)Organization: Tokyo University of Agriculture and Technology, and Kyoto University
Contact: Prof. Akihiko Terada (Tokyo Univ. Agr.&Technol. (TUAT)), akte@cc.tuat.ac.jp
Prof. Taku Fujiwara (Kyoto Univ.), fujiwara.taku.3v@kyoto-u.ac.jp<Concept> By optimizing the operation factors of an activated sludge process, such as dissolved oxygen (DO) and pH,
NH4+ recovery and sufficient organic carbon removal are expected to be achieved under nitrification inhibition andammonification conditions. Also, N2O emissions could be mitigated with nitrification inhibition.
<Advantages> A retrofittable process to adapt to current wastewater treatment plants by adjusting operating conditions.

●Development strategy
Organic-C and
N-wastewater

N2O

NH4+

N2O monitoring

Org-C→CO2
Org-N→NH4＋→NOx-

Operating conditions

Activated sludge tankControl

Feedback

Energy and massbalance analysis

Continuous online
monitoring

For practical application

Org-C removal and deterring
nitrification
High-rate Org-C removal
High-rate NH4+conversion
Preventing nitrification
N2O emission mitigation

Retrofitting a process (TUAT)
Extending (Kyoto U.)
Feedback technology by
Mass balance analysis
N2O monitoring
Optimum operation
Granulation technology
N2O emission mechanisms
Scaleup to abench level●Operation of the 3-reactor system

N2O emissions

R3

ClarifierReturn sludge

Discharged sludge
Duration(days)

pH control DO control
R2＝6.2S164

R2＝6.8S2

MLSS(mg/L)

103036 ± 793

9.6

4

300

2

0

0
7

400
300
200
100
0

14 21 28 35 42 49 56 63
Duration (days)

S1

S2

Synthesized
wastewater• The N2O emissions were 15% less in S1 (pH 6.2) than S2 (pH30

TN = 600 mg/L
NH4-N = 480 mg/L
TOC = 360 mg/L

• With the occurrence of nitrification, R2s contributed the most to N2O

3082 ± 8316.8). The emission factors were similar to activated sludge processes.
emission, followed by R3s.
Relationship between N2O emission and NOx production

CarbonS2 pH(pH6.8
6.8)
8

12

16

20 0

N (g/day)3

6
9
C (g/day)

12

15

N2O-N or CO2-C
Discharged sludge + internal change
Other N
NOx-N
Org-N or IC
NH4-N or TOC• The main nitrogen loss was caused by discharged sludge in both systems.
Reference: Xinyi Zhou et al., Water Research, 247, 120780, 2023.

●Online monitoring for a feedback technology
Continuous industrial wastewater supply

NH4+ suppression → enhancement:
Dynamics of monitored constituents

0.3

R3

0.2
0.1
-2
0
2
NOx production rate
(mg-N/hr/g-MLSS)

R1: Products of denitrification

0.2
0.2
0.4
0.6
NOx production(mg-N/hr/g-MLSS)

0.8

R3: Byproducts of nitrification

R2: N2O was emitted through multiple pathways, leading to emission
rates similar to NOx production rates.

●Formation of microbial aggregates (granules)
Formation of granules for improving sludge settleability (Semi-batch operation)
50

HRT [day]

0.67

ReactorInf. TOC conc. [mg-C/L]

300

7.2 L

Inf. total-N conc. [mg-N/L]

150

2.8 L

0.4

0.0

4

Inf./eff. exchange ratio[%]

Clarifier

0.6

R2

0.0

0.0
-4

• Under the microaerobic conditions, over 90% of total organic carbon (TOC)
removal and over 80% of NH4-N recovery were successfully achieved.

R1

0.8

N2O emission(mg-N/hr/g-MLSS)

Nitrogen

0.4

S1 pH
(pH6.2
6.2)

4

6

500

HRT
（hrs）

Input
Input

0

8

600

N2O emission rate
(mg-N/hr/MLSS)

Mass balance

R2, R3 <1 mg/L

SRT(days)

900

0Operating conditions
System

S1
S2
S1 EF
S2 EF

1200

Outflow

10
N2O emission factor (%)

Inflow

R2

N2O-N emission (mg/day)

1500

R1

For stabilization

N2O-N emission (mg/day)

Concentration &Isotopic information

Detecting N2O
N2O

POC by a simplified NH4+ conversion/retention process (TUAT)

One cycle (8 hours)
air

40–5minFeed(10min)Settling

cycle
start

Correlation of online monitoring
parameters with aeration rate

• Online monitoring of NO and N2O gases can detect the initiation of
unwanted NH4+ oxidation• Semi-batch wastewater supply allowed granular sludge formation• Granulation resulted in high settleability and high NH4+ retention<Outlooks> Assistance in a bench-scale reactor operation for NH4+ conversion/retention from fermentation wastewater●Determination of operation conditions for stable TOC removal, NH4+ conversion/retention, and N2O mitigation●Development of an online monitoring/feedback technology to suppress abrupt unwanted NH4+ oxidation●Formation of granular sludge to suppress discharge of unsettled suspended sludge and to facilitate NH4+ conversion/retention●Application of the developed technologies to other wastewaters

no airEff discharge(10min)No. A-13-8E
PJ : Innovative circular technologies for harmful nitrogen compounds
Theme: Wastewater N compounds to NH4+-high NH4+-tolerant AnMBR system
Organization: Osaka Univ., Hiroshima Univ., Kobe Univ.
Contact: Prof. Michihiko Ike(OU), ike@see.eng.osaka-u.ac.jp<Concept> Efficient conversion of organic carbon and nitrogen in concentrated wastewater by
forward osmosis (FO) to CH4 and NH4+, respectively, by anaerobic digestion in anaerobic membranebioreactor (AnMBR) with the help of bioaugmentation (BA) with highly tolerant microbial consortia<Advantages> Compactness, simultaneous NH3 and CH4 recovery, applicability to harsh conditions● Anaerobic Membrane Bioreactor (AnMBR)● R&D Items and Organization*BA = Bioaugmentation:
Introduction of NH4+/salinity
tolerant microbial consortia

Reinforced NH4+/salinity tolerance by BA• Rational bioaugmentation strategy• NH4+/salinity tolerant microbial consortia

Anaerobic digestion Tolerance to~5000 mgN/L
of concentratedof NH4+wastewater

Concentration ofdilute wastewater
Expected TN ~6000 mg/L

Condensationof ammonia

Industrial
wastewater

NH4+ recovery
≧90%

AnMBR

Improved compactness
and treatment efficiency
by membrane separation● Construction of NH4+ tolerant microbial consortia*Simulated
the organicand NH4+
conc. in FOconcentrated
wastewater

NH4-N (103 mg/L)● Confirmation bioaugmentation effects

0

10

20
Time (d)

A 15%
B 15%
30

40

40
35
30
25
20
15
10
5
0

Control

A 15%

B 7.5%B 15%

NH4 conc. (mg/L)

Methane (mL)

Bioaugmentation with marine sediment-derived tolerant consortia A
and B (A: Marine A, B: Marine B) under NH4+ and salinity inhibition

NaCl
NaCl
g/L
30,00030mg/L
0

10

20
Time (d)

30

RUN1
1-34
5

RUN2
35-77
3

1,170

RUN3
RUN4
RUN5
RUN6
ー
ー
78-159 160-248 249-269 270-371 372-397 398-426
3
5
5
5
5
5
6120
2,1802,4001,800
2,180
2,400
2,800
2,400
2,800

1.2

100

1

80

0.8

Biogas production
Methane content

0.6

40

0.4
0.2

20

0
3,000 0

0
50

100

150

200

250

300

350

400

2,500

100
80

2,000

60

1,500
1,000

NH4 conc.

500

40

NH4 recovery

20

COD removal

0

40

60

0
0

50

100

150

200
250
Time (d)

300

350

400

【Potential Applications and Effects】
Municipal and industrial wastewater treatment facilities
Realization of highly efficient treatment and simultaneous recovery of NH3 and CH4 under inhibitory
conditions in a compact facility by combining FO concentration, AnMBR and bioaugmentation.

Methane content (%)

I: Source
A: NH4-acclimatedNumber: NaCl conc. (103 mg/L)

Biogas production (L/L/d)

NH4+ (mg/L)

Control
B 7.5%

Prof. Ihara(Kobe U)

● AnMBR treatment of high NH4-synthetic wastewater*

Time (d)HRT (d)COD (mg/L)

+ +
NH
mgN/L
NH
5 gN/L
4 45,000

Prof. Tajima(Hiroshima U)

NaCl(103 mg/L)

VS (103 mg/L)

NH4
acclimation

Prof. Ike
(Osaka U)

NH4 recovery・COD removal (%)

FO

40
35
30
25
20
15
10
5
0

Development of bioaugmentation technologyof highly NH4+-tolerant microbial consortia(Osaka U)
Construction of highly NH4+-tolerant microbialconsortia (Hiroshima U)
Establishment of efficient AnMBR operating
methods (Kobe U)

No. A-13-9E
PJ : Innovative circular technologies for harmful nitrogen compounds
Theme: NH4 separation and concentration – Concentration by forward osmosis
Organization: Kobe Univ., Toyobo MC Corp., Waseda Univ.
Contact: Prof. Hideto Matsuyama(Kobe Univ.), matuyama@kobe-u.ac.jp<Concept> Concentrate waste water by a forward osmosis membrane process driven by osmoticpressure differences<Advantages> Low energy consumption due to the spontaneous water permeation

Forward osmosis (FO) Process

FO processprocess
FO
Waste
Waste
water
water

FO membraneFOmembrane

H2O

Sea
Sea
water
water

Require high pressure for water
permeation

Spontaneous water permeation
based on osmotic pressure→High energy consumption→Low energy consumption

Developmentof high-performance
Polymer
membrane

Discharged
Discharged
water
water

• Diluted seawater after the process can be discharged• Energy required for concentration is only pump power

Using seawater as the draw solution allows
to concentrate wastewater at a low cost＋

Zeolite: Crystalline aluminosilicate materials
Hydrophilic zeolites without• Size sieving separation
cation exchange sites
by nanopore
Surface modification to• High thermal, chemical
apply positive charge
stability
Suit to use for highSucceed in developing zeolite
temperature wastewater membrane to concentrate NH +Succeeded in developing a high-performance
FO membrane by controlling the membrane[1]X. Bao et al., J. Membr. Sci., 573 135 (2019)
structure

4

Concentration ratio (-)

Bench scale FO test using actual wastewater

Anti-fouling performance

150
100

5
100 times

500Before After

0 50 100 150 200 250 300
Operation time (min)Concentrated more than 100 times by volume using benchscale modules at FS inlet flow rate of 2 L/min (=2.88 ton/day)

4
Flux (L/m2/hr)

BNH4/Aw (-)

Excellent selective
permeation performance

Equipped with three 5-inch
FO modules (each 60 m2)

+
Na＋
Na
Cl−Cl

NH4+

Concentrated
Concentrated
waste water
wastewater

Development of Zeolite FO membrane
for high-temperature process

polymer FO membrane
100
10
1
0.1
0.01
0.001

NH4+

NH4+

Initial water flux

3
2
1
0
0

50
100
Time (h)No serious membrane fouling wasobserved for 80 h

【Potential Applications and effects】
Efficient concentration of NH4+ from wastewater such as industrial wastewater and sewage
Large scale, energy-saving, 10-100 times concentration to T-N 4000 ppm from very dilute wastewaterNo : A-13-10E
PJ : Innovative circular technologies for harmful nitrogen compounds
Theme: NH4 separation and concentration – Brine concentration process
Organization: Kobe Univ.
Contact: Keizo Nakagawa(Kobe Univ.), k.nakagawa@port.kobe-u.ac.jp<Concept> Hybrid brine concentration (BC) - reverse osmosis (RO) process for simultaneous
NH4+ concentration and recovery and minimal liquid discharge of wastewater<Advantages> More efficient NH4+ concentration and clean water production

Establishment of NH4-N concentration process by BC method and cleanwater recovery by RO method

Brine concentration (BC)Concentration method by osmotically assisted
reverse osmosis using dense membrane【Model wastewater】
Osmotic pressure(concentration degree)increases with increasing
reflux ratio
Osmotic pressure
increases to around 30
MPa (85,000 ppm T-N)
BC-ROハイブリッド膜プロセス

Hybrid membrane processes (BC+RO)
Effective method to enhance concentration of nutrient
and recovery of water from waste streams and canregulate the amount of environmental discharge【Real wastewater】
Feed solution
T-N: 4,501 ppm
FeedRO
retentate

Initial conc:
T-N 2400-6000
ppm
NaCl 0-9000 ppm

RO retantate
T-N: 3,364 ppm
RO permeate
RO permeate
T-N: 110 ppm

Mixed feed solution
T-N: 3.340 ppm
Feed＋
RO retentate

Highpressure side2.0 MPa

RO

Pump
OARO
Permeate

Pump

OARO
High
pressureside

5.8MPaQARO retantate
T-N: 40,300 ppm
Concentrated
stream

低圧側

OARO permeate
T-N: 3,582 ppm

R＝ 6.1

Initial conc：T-N 4,000
ppm, NaCl 5,460 ppm
BC：ΔPBC = 6.5 MPa,
R ＝ 1.04
RO：ΔPRO = 2.0 MPa

BC-RO method
enables efficient
NH4+concentration
NH4Cl concentrationof RO permeate isalmost 0

A hybrid BC-RO method achieves
approximately 10-fold enrichment of NH4+ anda high NH4+ recovery (98%) in real wastewater【Achievements】
Hybrid BC-RO process was applied first time for dewatering and NH4-N concentration of modeland real wastewater
Hybrid membrane process enhanced the recovery of NH4-N and minimized the discharge of
NH4-N-containing waste streams by clean water recovery
A pretreatment process was constructed to remove scale components to prevent scaling duringconcentration, and its effectiveness was confirmed with actual wastewater (patent pending).
【Potential Applications and Effects】
Efficient concentration of ammonia (NH4+) from municipal sewage and industrial wastewater
Ammonia (NH4+) concentrated by forward osmosis (FO) method (T-N 0.04% ➝ 0.4%) can be further concentrated ata low energy consumption (T-N 0.4% ➝ 4%).

No. A-13-11E
PJ : Innovative circular technologies for harmful nitrogen compounds
Theme:
NH4 separation and concentration-Membrane distillation
Organization: Kobe Univ., Hiroshima Univ.
Contact:
Tomohisa Yoshioka(Kobe Univ.), tom@opal.kobe-u.ac.jp<Concept> Membrane distillation (MD) method, in which aqueous NH3 solution is evaporated
through a porous membrane to concentrate NH3<Advantages> Space-saving and highly efficient purification and concentration of volatile NH3Experimental study on development of membranes and membrane processes for membrane distillation (MD) of NH3 aqueous solution (Kobe Univ.)
Air gap membrane
Direct contact membrane
One-pass NH3 recovery system
For NH3 Recovery & Concentration
distillation (AGMD)
distillation (DCMD）
multiple membrane modules
× DCMD (dilution in permeate side)
Pressure gauge
× AGMD (impossible to condense NH3)
○ VMD and SGMD are feasible process
NH3蒸気凝縮液
Condensed
NH3 vapor
N2 cylinder

NH3 3vapor
蒸気 CoolingNH
冷媒

Sweep gas membranedistillation (SGMD)

Optimization of module design& operation condition

50

Optimal results achieving
NH3 recovery ratio > 90%
NH3 conc. in permeate > 20 wt%

Sweep gas flow rate = 2 L/min

45

35%

40

Sweep gas flow rate = 1 L/min

35
30
2

4

6

8

10

Module Inner Diameter (mm)Recovery Ratio (%)

NH3

60

Sweep gas flow rate = 3 L/min

50

2 L/min40

Thermometer

Condensate
廃水 多孔膜Porous 凝縮液
Waste water
membrane (NH3 aq.)

NH3 conc. in permeate (wt%)

Recovery Ratio (%)

Vacuum membranedistillation ( VMD)

medium38 oC
4.5 L/min

Synergy between gas-phase Teamand water-phase Team

Target conc.
/recovery ratio

Feed NH3 aq. (L)

48 oC

30%

3.2 L/min
42 oC

25%

0

100

200

300

NH3(G)
H2O(G)

H2O(G)

20%

Membrane area (cm2)

Sweep gas

NH3
adsorption

48 oC
4.5 L/min

15%80%

NH3(G)+H2O(G)4.5 L/minSolid adsorbate
by Gas TeamNH3
desorption

1 L/min30

Membrane

85%

90%

95%

100%

Recovery Ratio (%)

Conc.
NH3

Demonstrated using a new adsorbent capable foradsorbing NH3 with high efficiency and capacity

SG: Sweep Gas
Feed flow rate (ml/min)

NH3 conc.
in SG (wt%)

Machine learning
prediction value

Modeled segment

Performance prediction andExperimental validation

Recovery ratio (%)

NH3 conc. in SG (wt%)

Real segment

Machine learning
prediction value

Development of a Computational Fluid Dynamics (CFD) model for predicting the performance of MD membrane modules (Hiroshima Univ.)
1. Segment model for performance prediction of
2. Optimization of SGMD process conditions usinglarge SGMD module
machine learning (ML)
Only a modeled segment
ML was performed using the simulation results
is simulated.
with the segment model as the data set.

CFD calculation value

NH3 recovery
ratio (%)

CFD calculation value

ML was integrated with an optimization solver (genetic algorithm).

Feed flow rate (ml/min)

The model predicted well the experimental results of large module.

Optimized

Feed temp.( )320.69298.15

2.5

93.04

Exp.

297.65297.68

7.47

88

.( )

( / )

(%)

i

.
(%)

32.91
40.49

Process conditions for large module were successfully optimized.

【Potential Applications and effects】
Recovery of ammonia from municipal sewage and industrial wastewater
Purification and recovery of NH4+ preconcentrated by forward osmosis (FO) (T-N 0.04% to 0.4%)
and brine concentration (BC) (T-N 0.4% to 4%) technologies, as a highly concentrated NH3 aqueous
solution (4% to 20-25%) with energy-saving without using high temperatures

No. A-13-12E
PJ : Innovative circular technologies for harmful nitrogen compounds
Theme: NH4+ separation and concentration – Ion exchange membrane method
Organization: Yamaguchi University, ASTOM Corporation
Contact: Prof. Mitsuru Higa(Yamaguchi University), mhiga@yamaguchi-u.ac.jp【Concept】 Selective recovery and concentration of NH4+ using ion exchange membranes:
energy-saving concentration by Donnan dialysis for the primary concentration (<400 ppm
to 4,000 ppm T-N) and fast and stable concentration by electrodialysis for the secondary
concentration (4,000 ppm to 40,000 ppm T-N).
【Advantages】 Continuous treatment of wastewater containing fouling components.
BackgroundDonnan dialysis

Cation exchange membrane
(CEM)
+

−

Permeating only
cation−−+Cation−Anion

DC power supplyCS−− ： Fixed charge group

Driving
force

Anion exchange membrane(AEM)
Cathode−DS

Concentrated
saline water

Anode

Merit

Desalination side+

Zero energy

Concentrated side−+

DC power supply
Wastewater

Principle
Wastewater
CEM

Permeating only +anion+Electrodialysis++ ：Fixed charge group

H2O

Processed cations(NH4+ etc.)

Dirt component

Anions(Cl− etc.)

Membranes that selectively
permeate counter ions

Strong point: Selective recovery andconcentration of small amounts of NH4+
in a wastewater containing contaminants

Development of NH4+
selective membranes

NH4+ concentration by
Donnan dialysis system

Demerit
Applicablearea

Slow processing
speed
400ppm→4,000ppm T-N

CS
AEM

CEM

Electrical energy
Fast processing
speed and suitablefor wide range of salt
concentrations
Electrical energy isrequired
4,000ppm→
40,000ppm T-N

NH4+ concentration by
triple electrodialysis system

We have achieved highly selective
concentration of NH4+ using theNH4+ selective membrane

We have achieved 10 times
concentration of NH4+ and 80%
recovery of NH4+ from real wastewater

We have achieved 10 times concentrationof NH4+ and 80% recovery of NH4+ frommodel wastewater

NH4+ selective membrane

Real wastewater concentration test

Model wastewater concentration test
DC power supply

Na+

Na+

−

NH4+

−

Permeating only
NH4+−

Monovalent cation
NH4+
Ca2+

−

Divalent cation
0.5 M NaCl solution Pump

Real wastewater(dilute)In wastewater containing Na+ and Ca2+,
Donnan dialysis
stack (CDD)

Energy generation

T-N,N,ppm
Total
ppm

Concentration [M]

0.10+
Ca2+ Na

Ca2+

3000
2000

2700

6.2

Ca2+

2100

4800

2.2

38000

30000
20000

10 times

10000
Dilute80% recovery

0
0

After

440

10 times

4000

1000

BeforeNa+

Concentrate

400
0.08

Concentration
factor

40000

5000

NH4+

Na+

Concentrate,
ppm

6000

0.14

NH4+

Recovery and concentration

Treatedwastewater(dilute)Model wastewater,
ppm

Concentrate

Tap water

Electrodialysis test using
NH4+ selective membrane

0.12

Electrodialyzer(Astom corp.)
Concentrate

T-N, ppm

・Lower energy in the electrodialysis energy
・Stable, long-term continuous operation
without the need for pre-treatment
・Clear concentrated solution.

Model wastewater(containing NH4+、
Na+ 、Ca2+)

510t [h]time [h]Operation

15

3700
0

Model Concentrate
wastewater【Potential Applications and effects】
Recovery and concentration of NH4+ from wastewater containing foulingcomponents that is difficult to concentrate by membrane filtration

710

80% recovery

DiluteCapable of continuous concentration of low purity NH4+ solution from less than 400 ppm to about
40,000 ppm (T-N) without using chemicals or heatNo. A-13-13E
PJ : Innovative circular technologies for harmful nitrogen compounds
Theme: NH4+ recovery from water with adsorbent
Organization: AIST, The Univ. Tokyo, Fuso Corp.
Contact: Hisashi TANAKA (AIST), hisashi.tanaka@aist.go.jp【Overview】 We aim to concentrate and recycle NH4+ by selectively separating andrecovering the NH4+ ion in wastewater using an adsorbent and desorbing and recovering them.
【Advantage】 Separation & recovery of NH4+ from waters with co-ions in higher concentration.
NH4+ recovery by ion exchange method

Multiple column
adsorption-desorption system
Adsorption Desorption Drying80

NH4 conc.(mmol/L)

KZnHCF Granules
Material：Prussian blue analogs（K2Zn3[Fe(CN)6]2・3H2O）(KMHCF、KMFe(CN)6・nH2O)

Adsorption profile：500th cycle(M =Fe, Ni, Cu, Co, Zn, etc)

60
40
20
0
0

400 800 1,200 1,600 2,000
Flow volume (mL)

By operating in a merry-go-round style,adsorption and desorption is carried out
continuously. It is possible to set and optimize
1) NH4 outlet concentration,2) NH4 concentration rate, etc. as per therequirement of each waste liquid treatment site.

NH4+ and K+ ion exchange of
KMHCF(The crystal structure of KZnHCF
differs from that of Cubic.)

Adsorption：NH4+ ion in; K+ ion out
Desorption：K+ ion in; NH4+ ion out

KZnHCF Column

Electrochemical NH4+ recovery
Adsorption(reduction) process
Adsorp. amount

1,500

0.8
0.6

1,000
0.4

Cl-

500

NH4+

0
0

5,000

10,000Adsorp. time (s)0.2
0.0
15,0002,000

40mA
Concentration

0.4

Cl-

500

NH4+

0

0

5,000

Columnfor stopper

0.0

10,000(NH4)xCu[FeII(CN)6]x→ Cu[FeIII (CN)6]x+ x(NH4+ + e- )Desorption
columnComplete
Adsorption
adsorption

Desorption

Adsorption

Flow of ammonia recycling

Calcinate
H-PoreNH3

NH4 capture in water
Gas. NH3 by heat
Recovery of adsorbate

m/z 19(H3O+)

m/z 16(NH2+)●Unprocessed

Remained NH3 78% Eliminated NH3 22%
Capturable NH3 36%
Recovered NH4Cl Eliminated NH3 58%
2%
40%

50 °C

100 °C
200 °C
300 °C
400 °C
500 °C

On-site test equipment

Pretreatment of pellets
and NH4Cl / NH3 recovery●H2O washTG /%RecoveryNH4-Pore

5 K/min until targeted temp
0.1 K/min
Kept for 5 h

TG-MS Chromatogram+

Intensity (Normalized)

NH4

RecycleNH4+

Add desorbed Complete
Add adsorbed
desorption
columnDesorption
columnResume water
conveyance

TG curves of NH4-Pore

Thermal elimination of
NH3 and H2OColumnfor stopper

Pause water conveyance, Desorption
Switch column

Adsorption

Ion-exchange & thermal elimination
Na-PoreNo hinderance in the adsorption –desorption performance isobserved until the 500th cycle.

Treated Desorption
water water (K)Wastewater

0.2

Desorp. time(s)Cu[FeIII (CN)6]x+ x(NH4+ + e- )→ (NH4)xCu[FeII(CN)6]x

Adsorption
column0.6

Desorp. amount

1,000

40 80 120 160 200
Flow volume (mL)

1.0
0.8

1,500

0

Adsorption column for NH4+
NH4+ Desorp.amount (mmol/g)

40mA

1.0

NH4+ conc. (mg/L)

Concentration

2,000
1,500
1,000
500
0

Applied toOn-site test

Field bench test

Desorption(oxidation) process

NH4+ Adsorp. amount (mmol/g)

NH4+ conc. (mg/L)

2,000

NH4 conc.(mmol/L)

Desorption profile：500th cycle●Acid/NaHCO3

87%
Capturable NH313
29%
42% %
Recovered
NH
Cl
56%
4
2%

Sublimated
NH4Cl

6%
94%
Capturable NH3 20%
6% Recovered NH4Cl 68%
26%●Acid/Na2CO3Time /min～125 ℃：Mainly H2O
Afterwards：NH3 gradually eliminatedTemperature /°C【Potential Applications/Effects】
Recovery and recycling of NH4+ from various industrial wastewater.

9
Capturable NH%
3 26%
35%
4% Recovered NH4Cl 61%
91%

85% recovery of NH4+ ion
as NH3 gas and solid NH4Cl• Recover and recycle NH4+ from various industrial wastewater and wastewater from agriculture, fisheries, etc. with little energy.
Especially applicable to low~high concentration NH4+ solution containing high concentrations of Na ions, coexisting ions, and SS.
• In the future, we aim to purify and treat sewage water that requires mass treatment and environmental water that requires NH4+
treatment at lower concentrations.

No. A-13-14E
PJ : Innovative circular technologies for harmful nitrogen compounds
Theme: Synthesis and evaluation of process technologies for recycling nitrogen compounds
Organization: AIST, Tokyo Tech, Nagoya U.
Contact: Assoc. Prof. H. Matsumoto(Tokyo Tech), matsumoto.h.ae@m.titech.ac.jp<Concept> Development of rate-based process models, Synthesis and evaluation of the gas phase NTA
process systems & the liquid phase concentration process systems for nitrogen compounds<Advantages> Efficient analysis of test data from bench/pilot scale processes【Overview of research and development】
To disseminate the process technologies for NOx in exhaust gas and nitrogen compounds in wastewater developed in thisresearch project by 2050, it is necessary to design an innovative plant system. In this study, our research groups investigate acase study for integration of the elemental process technologies developed in the project.
Examining the ideal structure of the nitrogen circular
process system based on a calculation and visualization
model of mass and heat flow using Microsoft Excel

Conceptual design of elemental processes and evaluation of
the overall system based on steady-state model・Calculation of mass balance for NOx in gas
and nitrogen compounds in wastewater・Calculation of energy balance
・Calculation of CO2 emissions , etc.
ex. NTA (NO to Ammonia) process

Flow analysis of NH3, reactive nitrogen and otherharmful substances
Life cycle assessment of nitrogen circulartechnologies
Risk assessment of nitrogen compound cycle

Poster No.
A-13-15E

Estimation of the CO2 emissions: the process system in the above
figure is less than 1/4 of the application of the selective catalytic
reduction method (SCR)
Optimization of network for recovery and utilization of heat:approximately 65% energy savings (55% reduction in CO2 emissions)

Simulation of Bench/Pilot Scale Process and Dynamic Analysis① Synthesis and design of the NTA process systems
Collection of
catalyst activity
test data usinglab-scale
experiments

Develop reaction
rate equation
model

Build dynamic
models byextending thesteady models

Dynamic analysis
using unsteadyprocess simulation

Adsorption equipment of NO

・Sizing of equipment
・Organizing of system evaluation methods
・Organizing of factors for spatiotemporalvariation

Development ofdynamic simulator② Synthesis and design of the liquid phase concentration
process systems for nitrogen compounds

・Organizing of systemevaluation methods
・Organizing of factors for
spatiotemporal variation
NTA reactor

Influence analysis
of unsteady
operations[Common issues for ① and ②] Synthesis and design of the entire system that establishes
the operation of each process in time and space, since each elemental process has adifferent throughput, residence time, material and energy【Potential Applications and effects】
Shorten lead times for R&D by feeding back information on process design and evaluation that takes
operability and controllability into consideration to R&D for elemental technologies

No. A-13-15E
PJ : Innovative circular technologies for harmful nitrogen compounds
Theme: Environmental impact assessment for nitrogen circular technology
Organization: National Institute of Advanced Industrial Science and Technology (AIST)
Contact: Dr. Kazuya Inoue(AIST), kazuya-inoue@aist.go.jp<Concept> Constructing nitrogen database for assessment of nitrogen circular technologies<Advantage> Existing database has been developed output nitrogen as reactive nitrogen. In
contrast, we developed IDEA database not only output nitrogen, but also nitrogen input. We havebeen finished constructing nitrogen inventory data of approximately 700 products.

①Constructing nitrogen inventory database②Domestic nitrogen flow

Production
volumeCalculating nitrogen inventory; material input, nitrogencontent in products and Nr emissions to environment
Constructing nitrogen inventory data of approximately
700 products

Visualization of domestic nitrogen flow byadapting annual production based on nitrogen
input and output amount of each product<Concept> Estimated the inventory of anthropogenic reactive nitrogen emissions (Nrs) in
2050 and evaluated the effect to secondary generated pollutants such as ozone (O3).
<Advantage> Preparation of future inventories which could be applied to the evaluationof air quality assessment after introducing nitrogen recirculation technology (NRT).
●Aim①：Estimation of the inventory of anthropogenic Nrs emissions (NOx, NH3, …) in 2050
●Aim②：Evaluation of the effect of Nrs reductions to atmospheric O3 and PM2.5 in 2050
●Software：Community Multiscale Air Quality Modeling system（CMAQv5.3.3）●Meteorology in 2050：Medium global warming (RCP4.5)* of global climate model (CCSM4)●Future scenarios：LED=Adaption, ELE=Electrification, H2=Hydrogen society, ZERO=Net-zero*RCP4.5: The climate scenario which corresponds to 1.1~2.6℃ increase of global temp. in 2100.

Spring 2015
O3 conc. (ppb)

O conc. (ppb)

Spring 2050

Fig.2 O3 conc. in 2015 and 2050.
Spring 2015

Spring 2050

< Potential applications and effects >●LCA visualizes energy wellbeing, environmental improvement after installation of NRT.
●Suggesting benefits of NRT to human health and the ecosystem.

PM2.5 (μg m-3)

PM2.5 (μg m-3)

Fig.1 Estimated NOx and NH3 emissions in 2050.
●While NOx emissions are decreased for vehicles, thosefrom stationaries, ships, and NH3 emissions will remain.
●10ppb decrease of O3 due to the decrease of Nrs in 2050.
●Intensified shortwave radiation due to climate change
increases PM2.5.
Fig.3 PM2.5 conc. in 2015 and 2050.
●Similar analysis targeting on global-scale air quality is(Ref.：Hata et al. Sci. Total Environ. (2023))
now under proceeding.