challenges and outlook related to … and outlook related to municipal sewage sludge management in...

Jun TSUMORI, P.E.Jp

Team Leader of Recycling Research Team,

Construction Materials and Resources Research Group,

Public Works Research Institute, Tsukuba, Japan

CHALLENGES AND OUTLOOK RELATED TO

MUNICIPAL SEWAGE SLUDGE MANAGEMENT

IN JAPAN

ISO TC275 Sludge / Biosolids Management Workshop

September 8, 2014 : Burlington, Ontario, Canada

OVERVIEW

1

• Introduction

• Background

• Current Status

• Challenges

• Japanese endeavor to enhance sufficient sludge

management

• Promising advanced technologies in Japan

• Way forward

• Conclusion

INTRODUCTION: JAPAN

2

Present Target

Energy Self-sufficiency: 6.0 % Under Consideration

(2012) (in 20 years)

GHG Emissions: + 2.8 % - 3.8 %

(2011 -2012) (2005-2020)

Final Disposal Amount: 19 m t 25m t >

(Total of Solid Waste) (2010) (2015)

STATUS ON MUNICIPAL SEWERAGE IN

2013

3

• Sewered Population: 76.3 %

• Wastewater Treatment Plants: 2,134

• Treated Wastewater: 14 billion c.m

• Final Disposal of Sludge: 2.2 million DS-t

Generated Sludge Volume: 2.2 m DS-t

Material Reuse Ratio: 77 %

15 15 16 17 20

24 24

30

38

45 48

50 52

56

60 64

67 70

74 77 78 77

0

10

20

30

40

50

60

70

80

0

500

1,000

1,500

2,000

2,500

88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09

Re

cycle

Ra

te（%）

Ge

ne

rate

d S

lud

ge

vo

lum

e（10

3 D

S-ｔ）

Fiscal Year

Sewage Sludge

Recycle Rate

Construction Material (Cement)

Land fill

Fertilizer Construction material （Excluding Cement）

Others

Fuel, etc

（DS=Dry Solid）

Transition of material use

※Utilization of Digestion gas is not included 4

CURRENT STATUS ON SEWAGE

SLUDGE

Final application

Purpose ‘1960 ‘1970 ‘1980 ‘1990 ‘2000 ‘2010 ‘2020

Dewatering Landfill

Incineration Land fill (as ash) Ash utilization

Melting Slag utilization

Carbonization Utilization (fertilizer) Fuel utilization

Multi hearth Incinerator （Total over 30 sets were installed )

Soil improvement/Agricultural utilization

Now in Japan there is

few case of landfill by

dewatered sludge.

1963

1974

1980

1982

2009

2012

2011

After 2011, there is no

new construction.

Sewage sludge treatment in Japan

Fluidized bed incinerator (Total 252 sets were installed.)

Advanced fluidized bed incinerator

Bio- charcoal utilization

5

MOST OF SLUDGE IS INCINERATED IN JAPAN

DUE TO LANDFILL LIMITATION

6

Source : Japan Sewage Works Association (2004)

10.6%

9.7%5.2% 2.6%

71.7%

0.0%

0.1%

Incineration

Compost

Ash Melting

Dewatering

Drying

Carbonization

Others

JAPANESE ENDEAVOR TO ENHANCE SUFFICIENT

SLUDGE MANAGEMENT

7

BASIC ASPECTS OF ENHANCING

SUFFICIENT SLUDGE / BIOSOLIDS

MANAGEMENT

8

• Enhancing Energy Efficiency,

• Accelerating exploitation as Renewable Energy, and

• Advancing development for Cost Reduction of

Recycling Technologies

AMENDMENT TO THE EXISTING POLICY

FRAMEWORK

9

• Laws and regulations

• Low Carbon City Law (2012), Sewerage Law (1964), Environment-related Laws (1970), Waste Management and Public Cleansing (1970) , and related stipulations such as Japanese Industrial Standards (JIS),

• Technical guidelines by Japan Sewage Works Association

• Planning, Design, Construction and O&M, and

• Technical Specifications by Japan Sewage Agency and Major Municipalities

• Materials, facilities, electricity and buildings etc.

Challenges (Cont.)

NATIONAL DEMONSTRATION PROJECT

(B-DASH PROJECT) LAUNCHED IN 2011

10

Breakthrough by Dynamic Approach in Sewage High

Technology

2011 2012 2013 2014

Development

Theme 1 4 2 5 Adopting

Technologies 2 5 5 6 Budget

(Million USD) 22 27 38 38

Challenges (Cont.)

Copyright© 2008 METAWATER Co., Ltd. All Rights Reserved.

<Case Study> Total Optimization for Sludge Incineration

chemicals

Ｍ

Cake

Water

Storage

tank

Centrifuge

Air p

reh

eate

r

Hea

t e

xch

an

ge

r

Ceramic

filter

Sta

ck

Scru

bb

er

MLBI

Air

Thickened

sludge

polymer

FeCl3

Heat recovery air

G

Evaporator

Heater Turbine

Condenser

Treated water

P

P

P

P

① Self-controlled dewatering ② Energy-saving incineration ③ Binary waste heat

power generation

Improvement of

three individual processes

Optimization of

operation by total system control

Total control

Incineration system

control panel

Dewatering system

control panel

Power generation system

control panel

11 In Ikeda City

PROMISING ADVANCED TECHNOLOGIES

IN JAPAN RELATED TO THE WORKING

GROUPS

• Digestion (Working Group 3)

• Thermal process (Working Group 5)

• Thickening and dewatering (Working Group 6)

• Inorganics & nutrients recovery (Working Group 7)

12

Challenges (Cont.)

WG3 Digestion

・Outside-type Digester Mixer

・Digestion(Methane Fermentation Process)

13

Outside-type Digester Mixer (NAS-E)

Horizontal rotational flow

Down flow

◆Background

・Easy installation to existing

gas mixing digester

・Less energy consumption

◆Solution

・Outside type digester mixer

◆Effect

・1/3 energy consumption

compared to gas mixing

・Easy maintenance

◆Reference

・Location: Ryojima WWTP

(Matsumoto city)

・Circulating flow: 9m3/min

14

Copyright© 2008 METAWATER Co., Ltd. All Rights Reserved. Copyright © 2008-2010 METAWATER Co., Ltd. All Rights reserved.

Digestion(Methane Fermentation Process)

◆Back Ground

・Much sludge generate from WWTPs

・Drastic reduction of cost for sludge treatment is required

◆Solution

・Steel digester tank with high functionality

・Low-power impeller agitator

◆Effect

・40% reduction of dehydration sludge

・Create renewable energy “Biogas”

・Enable sedimentation level measurement

◆Reference

・Nambu-plant(from Dec. 2011 to Feb. 2013)

・Higashinada-plant(from April 2012)

Copyright © 2007 KOBELCO ECO-SOLUTIONS Co.,Ltd. All rights reserved.

Low-power impeller agitator

Steel digester tank with high functionality 15

WG５ Thermal process

Incineration ・ Advanced Incineration Technology

・ Pressurized Fluidized Bed Incineration

・ Power Generation System with Sewage Sludge Incineration

Sludge melting ・ Sludge melting technology

Gasification ・ Gasification Technology

Carbonization ・ Carbonization Technology

・ Sludge fuel conversion technology

16

Copyright© 2008 METAWATER Co., Ltd. All Rights Reserved. Copyright © 2008-2014 METAWATER Co., Ltd. All Rights reserved. 17

Advanced Incineration Technology

◆Back Ground

・Much GHG discharged from WWTPs

・24% by N2O of incineration process

(N2O has 310 times as high GHG effect as CO2)

◆Solution

・Multi-Layer Incineration Technology

・Partially higher temperature zone

◆Effect

・80% reduction of N2O

(Greenhouse gas reduction)

◆Reference

・Nambu Sludge Plant #3

(since June 2009)

Comple te Combust ion

High Temperature Zone

Controlled Gasification

Zone Control Technology

Solution

High temp.

zone

N2O from incineration

24% N2O

from

WWT

CH4

from WWT

Fuel Electricity

(Pump station)

Electricity

(WWTP)

CO2 amount

6.95 Mil. t/year

(2004)

(Source: MLIT)

Tsukishima Kikai Co., Ltd. Copyright ©

Pressurized Fluidized Bed Incineration technology

1)Pressurized fluidized bed furnace system consist of combination of fluidized bed

furnace , which is the most suitable furnace for sewage sludge incineration,

and turbo charger.

2)Sewage sludge is combusted under plus pressure (130 to 150kPaG) and pressurized

flue gas compressed air for furnace by using turbo charger.

3)Because flue gas is pressurized, flue gas is emitted by its force.

Sludge

feeder

Pressurized

fluidized bed

incinerator

Air pre

heater Bag filter

Plume prevention

air fan

Scrubber

Plume prevention

air heater Stack Turbo

charger

Solution

Effect, compared to conventional Fluidized bed References Tokyo metro.(Kasai), 300ton/d, 1 train

Tokyo metro. (Miyagi), 300ton/d, 1 train

Kanagawa pref., 100ton/d, 1 train

Kofu city, 60ton/d , 1 train

Osaka pref.,100 ton/d, 1 train

As 40% of flue gas volume is reduced, equipments

size are also compacted

Around 10% of fuel consumption is reduced.

40% of electrical power is reduced.

Because of forming high temperature zone, 50% of

N2O is reduced.

Applying Pressurized furnace

Back ground -Compact facility

-Power saving

-Fuel saving

-GHG reduction

PFBI facility

18

POWER GENERATION SYSTEM WITH SEWAGE SLUDGE INCINERATION

●Background

・Demand for renewable energy

・Needs for CO2 reduction

●Solution

・Low water content dewatered

・Low power furnace

・Steam power generation

●Effect

・Power generation: >100kW

・Supplying surplus power outside

●Project

・Location: Wakayama Central WWTP

・Capacity: 35 wet-t/day

・National high-technology promotion

project entrusted by NILIM, Japan

(Still from June 2013)

Heat recovery

Energy

transduction

technology

Steam power

generation

system

Water content

reduction

technology

Advanced

centrifugal

dehydrator

Next-

generation

step grate

stoker furnace

(with waste-

heat boiler)

Energy

recovery

technology

Low water content

dewatered sludge

Demonstration plant 19


- Prevent heavy metal leach out - Utilization of melting slag - Minimize N2O (GHG) in emission

Sludge melting technology

-Kyoto Pref., Vortex melting150ton/d, 2trains

-Osaka city, Vortex melting 150ton／d, 5trains

-Chiba city, Vortex melting 15ton／d, 1train

-Hyogo pref., Coke bed melting 180ton／d, 3trains

-Osaka pref., Coke bed melting 50 ton/d, 2trains,

75ton/d, 1 train

-Osaka pref., Coke bed melting 80ton／d, 1train，

110ton/d, 2trains

-Nagano Pref., Ash melting plant 3ton／d, 1train

Vortex melting furnace Back ground Bag filter Scrubber Stack

Flue gas heat recovery Slag cooler Sludge dryer

Solution - Sludge melting

- Heavy metal solidification in slag.

- Sludge vitrification and utilization

- NO disposal area for sludge

-Sludge utilization as construction material.

- Heavy metal leakage problem

Effect

References

Melting slag

Example of Melting plant, Vortex melting

Vortex melting facility

20


◆Background



◆Solution

・Sludge gasification

・Fuel gas power generation

◆Effect

・Power generation: 150kW

・CO2 reduction: 12,500 t/year

(in total of WWTP)

◆Project

・Location: Kiyose WWTP

・Capacity: 100 wet-t/day

・Operation: from 2010 for 20 years

Gasification Technology (WtE tech.)

Sludge gasification plant Gasification reactor

Courtesy of TMG

Sludge cake

Rotary drum dryer

Green waste

Air

High temp. ash

Reforming furnace

Gasification

furnace Cooling tower Ash

Waste water

Wate

r

Power

Dust collector

O2

Steam

Scrubber Gas engine Generator

Catalytic reactor

High temp. cyclone

LNG

Fuel gas


METAWATER

SPC Power Plant WWTP

Sludge

Carbonization

Facility

Co-combustion

60% 40% financing

Bio-charcoal

EPC of facility

[Scope of business]

1. O&M of facility

2. Bio-charcoal purchase/sale

Purchase Sale

Chubu Electric Power ◆Background



◆Solution

・Sludge carbonization

・Bio-charcoal for co-combustion

◆Effect

・Power generation: 4,600MWh/year

・CO2 reduction: 8,000 t/year

(in total of WWTP and Power plant)

◆Reference

・Location: Kinuura Tobu WWTP

・Capacity: 100 wet-t/day (Bio-charcoal 8 t/day)

・Operation: from 2012 for 20 years

Carbonization Technology (WtE tech.)


Carbonization furnace

※

※

After

burner Heat

exchanger Scrubber

Granulator

Dryer

Hot blast

furnace

Dewatered

sludge

Fuel product

Hot blast

furnace

Stack

Sludge fuel conversion technology

Back ground

Effects

References

Hiroshima City, 50ton／day, 2 units

Kumamoto City, 50ton／day, 1 unit

Osaka City, 150ton／day, 1 unit Yokohama City, 150ton／day, 1 unit

Kyoto pref. , 50ton／day, 1 unit

- Promotion of recycling sewage sludge

- Reduction of Greenhouse gas

in both Sewage treatment plant and Power plant .

Solutions

-Thermal recycle between Sewage

treatment Plant and Power plant.

- Keep higher calorie in fuel product. - Reduce odor in fuel product.

-Applying low temperature carbonization.

(250 to 350 ℃ carbonization)

- Supplying fuel product to power plant as

fuel.

SPC

Sewage Treatment

Plant

Carbonization

facility

Power Plant

Transportation

・ Renewable energy

Efficient

use Dewatered

sludge

Carbonized

sludge

Valuable

Selling

sludge fuel

23

WG６ Thickening & Dewatering

Thickening ・ Rotary Fin Sludge Collector

Dewatering ・ Centrifugal Dewatering machine

・ ISGK Screw Press(Dewatering Machine)

24

Rotary Fin Sludge Collector (RFC)

◆Background

・Poor settleability

in gravity thicker

・much energy consumption

of mechanical thickening

◆Solution

・Sludge collector with rotary fin

◆Effect

・10 – 20% higher concentration

of thickened sludge

(Certified by JIWET*)

◆Reference

・Tank diameter: φ7.0m – 17.0m

・Units: 14 units

*JIWET: Japan Institute of Wastewater Engineering and Technology

Motor Double cylindrical plates

Center Well

Scam skimmer

Raw sludge

Supernatant

Thickened sludge

Rotary fin

Installation in gravity thicker

25

Centrifugal Dewatering Machine (SDR Impact)

◆Background

・Cost reduction

of sludge disposal


◆Solution

・Inject inorganic coagulant

directly to the “dry beach” area

◆Effect

・7 – 10 point lower water content

(68 – 75% water content)

(Joint research with JS*)

◆Reference

・Capacity: 5 – 40 m3/h

・Units: 36 units

*JS: Japan Sewage Works Agency

supernatant

sludge

in26organic chemical

polymer

“dry beach”

polymer

sludge

68% water content of mixed sludge

26

ISGK Screw Press (Dewatering Machine) Sewage

Treated Water

Digestion

Excess Sludge

Mechanical

Thickening

Anaerobic

Digested Sludge

Reactor Final Settling

Tank Primary

Settling Tank

Screw Press

Thickening Tank

Cake

0

20

40

60

80

100

High EfiiciencyBelt Press

High EfficiencyCentrifuge

ISGK ScrewPress

Comparison with Other Dewatering Machines @ 200000m3/day

Water

Electric Power

Replace parts

Background

• Needs for energy saving

• Needs for easy overhaul

Solution

• Metal filter

• Simple structure

Effect

• Low water consumption

• Low electric power consumption

• Overhaul cost reduction

Reference

Approx. 300 units in Japan

Approx. 70 units outside of Japan

27

WG７ Inorganics & nutrients recovery

Phosphorus Recovery ・ Phosphorus Recovery from Incineration Ash

・ Phosnix® Phosphorus Recovery as struvite

・ Phosphorus Recovery as HAP from Black Water

28


◆Background

・Lack and price increase

of natural phosphorus ore

・High P ratio in incinerated ash

◆Solution

・Alkaline Dissolution Technology

・Regeneration of P and neutralized ash

◆Effect

・Recycled P: Raw material of fertilizer

(certified by MAFF*)

・Neutralized Ash: suitable for cement

◆Reference

・5 wet-ton/day plant (Gifu prefecture)

（Operation started in 2010）

Phosphorus Recovery from Incinerated Ash

Phosphorus ore

Incineration Ash

No difference in P ratio

P2O5 CaO

SiO2 Al2O3 Fe2O3 20～30%

less Ca Other oxides Heavy metals

Others

Incinerated Ash

Recycled Phosphorus

Neutralized Ash

* MAFF : Ministry of Agriculture, Forestry, and Fisheries

Capacity : 5 tons/d (Gifu pref.)

Copyright© 2008 METAWATER Co., Ltd. All Rights Reserved. Copyright © Hitachi Zosen Corporation. All Rights reserved.

Phosnix® Phosphorus Recovery as Struvite

◆Background

・Drying up high-grade P resources

・Clogging trouble in sludge treatment

facilities in SWTP

◆Solution

・Application of Struvite recovery system in

SWTP

◆Effect

・Recovery of fertilizer grade Struvite

(certified by MAFF)

・Prevention of Scaling trouble

・Reduction of Phosphorus discharge

◆Reference

・Shinjiko Tobu SWTP（500m3/day×2）

( Since 1998 )

・Ono SWTP(300m3/day)

Shinjiko Tobu Project

Recovered Struvite

30

Copyright© 2008 METAWATER Co., Ltd. All Rights Reserved. Copyright © Hitachi Zosen Corporation. All Rights reserved.

◆Background

・Drying up high-grade P resources

◆Solution

・Application of HAP recovery system

◆Effect

・Recovery of fertilizer grade HAP

(certified by MAFF)

・Reduction of surplus sludge

◆Project

・Senboku City (60m3/day)

・Kushimoto Town (45m3/day)

and 3 projects

Phosphorus Recovery as HAP from Black Water

Recovered HAP

Senboku City Project

31

WAY FORWARD IN JAPANESE

WASTEWATER TREATMENT PLANTS

• Evolving into urban centers as energy supply and

material recycling hubs.

32

City Gas Plant

Power Plant

Methane Fermentation Facility

Heat Supply Facilities Electricity

City Gas

Heat

(Hot-Water Supply,

Cooling and Heating)

Wastewater

Treatment Plant

Food Waste

Biogas Station

CNG Car Fuel

Bio solid fuel production

Biogas

Solid Fuel

Production

Farm

Sludge

Scrap

Wood

Household

Sewage

Incineration heat

wastewater heat

Energy

Supply Hub

Electric Power Provider

Sewage Heat

（R&D by B-DASH Project）

33

（Wastewater heat

utilization by de-

regulation）

URBAN ENERGY AND MATERIAL

RECYCLING HUB

Office Building

Material

Recycling Hub

CONCLUSION

• Energy security and global warming as well as Natural resource conservation are crucial issues to share the earth.

• Sludge Treatment Plants are responsible for saving energy and reducing Green House Gas emissions, and have great potential as distributed urban energy and material recycling hubs.

• To boost performance of each sludge treatment process in terms of energy sufficiency and GHG reduction must be considered in ISO/TC275 discussion to contribute our future.

34

THANK YOU FOR YOUR KIND

ATTENTION !

35

For email contact: [email protected]

challenges and outlook related to … and outlook related to municipal sewage sludge management in...

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