Sewerage Plan for the Prevention of Global Warming

Passing on a rich global environment to Next Generation

Bureau of Sewerage Tokyo Metropolitan Government

Sludge Carbonizat ion

Digest

Solar Power Generat ion

Micro bubble aerat ion

Woody Biomass

1

1 Basic Policies

2 Objectives

3 Implementation Strategies

Earth Plan-2010 establ ishes targets for global warming countermeasures for the Tokyo Bureau of sewerage and descr ibes concrete measures to be taken by FY 2014 and indicates roles to achieve by FY 2010.

Based on this plan, the Bureau wil l reduce its emissions of greenhouse gases in a planned and example -sett ing way, as well as fulf i l l i ts obl igat ion to reduced carbon dioxide emissions in accordance with Tokyo Cap-and-Trade Program.

Addit ional ly, the Bureau wil l serve as a pioneer in the reduct ion of the metropolis’ greenhouse gases and contribute to the realization of reduction targets under an ini t iat ive cal led the Ten-Year Project for a Carbon-Minus Tokyo.

Final ly, we wil l pass on a r ich g lobal environment to the next generat ion .

We wil l intensively implement measures dur ing the durat ion of the plan in order to real ize reduct ions as ear ly as possible.

Speed Up Implementation of

Measures

Pioneer Use of the Latest Technologies

We wil l pioneer implementat ion of the latest technologies in order to heighten the ef fect of reduct ions.

We wil l implement var ious enhanced sewage funct ions (e.g., f looding countermeasures, combined sewers improvement and advanced treatments) as well as reduct ion of greenhouse gases.

Improve Sewage Functions

Greenhouse Gas Emiss ions by Tokyo Metropol i tan Government

Resul ts f rom Earth Plan -2004

95.6

１９９０年度

基準年度

２００９年度

最終年度（見込）

87.1

２００8 年度

87.6

101.8

アースプラン２０0４

目標ライン６％削減

排出量

（万ｔ-ＣＯ2）

110

100

90

80

70

FY2000 Base Year Emissions

991,000t CO2

FY2014 Reduction Target

At least 18% Emissions

813,000t CO2

FY2020 Reduction Target

At least 25% Emissions

743,000t CO2

E m i s s i o n s ( 1 0 0 , 0 0 t - C O 2 )

T a rg e t L i n e ‒ 6 % Ear th Plan -2004

F Y 1 9 9 0 B a s e Y e a r

F Y 2 0 0 8

F Y 2 0 0 9 F i n a l Y e a r ( e s t i m a t e d )

Bureau o f Transpor tat ion 13%

Bureau o f Sewerage 42 %

Headquar ters o f The Governor , e tc . 30%

FY2008 Results

T o t a l M e t r o p o l i t a n G o v e r n m e n t E m i s s i o n s

2 . 0 8 m i l l i o n t - C O 2

B u r e a u o f S e w e r a g e E m i s s i o n s 0 . 8 7 6 m i l l i o n t - C O 2

Bureau o f W ater works

15%

2

4 Examples of Measures 1. Micro bubble aerat ion

2. Develop Technological Solut ions to Suppress N 2O Product ion dur ing Wastewater Treatment

How N2O Emissions Are Suppressed during Wastewater Treatment

Develop N 2O measuring device and treatment Technology to Suppress N 2O Production dur ing Wastewater Treatment

Reduce energy consumption through the use of micro bubble aerat ion.

*Micro bubble Di f fus ion : These devices generate smal l bubble that more eas i ly d issolve in wastewater ef f luent . Energy savings resul t f rom a reduct ion in a i r generat ion requirements .

Mic roorgan isms in the reac t ion tank work to break down organic sewage mat te r . Sending oxygen in to the tanks helps mic roorganisms work more v igorous ly.

How Micro bubble aeration Reduce Energy Consumption

Energy Use 20% Reduction

Oxygen Solubil ity Low → High

Blower

(React ion Tank)

(React ion Tank) Standard Di f fus ion Device Micro bubb le Di f fus ion * Device

N2O generated during sewage

waste treatment

Step 1 : De te rm ine wha t i s caus ing N 2 O

p roduc t i on. S tep 2 : F ind a so lu t ion t ha t res u l t s i n

suppress ed p roduc t i on. S tep 3 : Sys temat i ze t he s o lu t i on. A t t he s ame t ime, deve lop a dev ic e to cont i nua l l y and acc u ra te l y meas ure N 2 O em iss ion l eve ls .

Ammonia

Inflow Outflow

Nitrogen gas

A m m o n i a

Nitrogen

Nitr ic acid

Ammonia Ni t rous ac id

D e c o m p o s e r o r g a n i s m s

Inside the React ion Tank

Blower

3

送風機

不要

送風機

廃熱有効

利用設備 煙突

排ガス

処理装置集じん機

ターボ

チャージャー

空気

脱水

汚泥

流動焼却炉

空気

廃熱有効

利用設備

排ガス

送風機不要

3. Introduct ion of New Combust ion Systems for Sludge Incinerat ion

How Second-Generation Incinerators Work

排ガス

脱水汚泥

流動焼却炉

空気

廃熱有効

利用設備

排ガス

処理装置送風機

煙突

送風機送風機

空気

空気

集じん機

*Second-generat ion inc inerator : Compared wi th current f lu id ized -bed inc inerators , i t can provide a large reduct ion in greenhouse gases by improving the operat ion of combust ion ins ide inc inerator .

800°C i n c i n e r a t i o n

Large overal l decrease

Comparison of Greenhouse Gas Emissions

Approx. 50% decrease Approx. 20% decrease

1 0 0 ％

3 0 ％

Ｎ 2 O 1 0 0 ％ C O 2

1 2 0 ％

Approx. 70% decrease

1 5 ％ 9 6 ％

Approx. 20% increase

Multi layer Fluidized Bed Incinerator (Example)

Fluidized Bed Incinerator with Turbo Charger (Example)

・ High- temperature regions are created ins ide the inc inerator , caus ing thermal decomposi t ion of N2O.

・ Inc inerator ef f ic iency is improved throughout the inc inerator ③ , which resul ts in a reduct ion of the amount of supplemental fuel used.

・ W aste heat is recovered and sent to the turbo charger① , pressur izing the inc inerator② and increas ing combust ion speed, wh ich a l lows for a h igher inc inerat ion temperature.

・ The bot tom air in let ① and the center a i r in lets ② in let center are int roduced to create mult ip le layers where s ludge is inc inerated.

③

①

②

①

②

Firs t -genera t ion incinerators

Second -genera t ion incinerators

We wil l in troduce second-generation incinerators * wi th new combustion systems that reduce the amount of greenhouse gases generated during incineration.

850°C i n c i n e r a t i o n

D e w a t e r e d s l u d g e

Ai r

Ai r

Ai r

F l u i d i z e d b e d i n c i n e r a t o r

F l u i d i z e d b e d i n c i n e r a t o r

D e w a t e r e d s l u d g e

E x h a u s t g a s

B l o w e r

B l o w e r

B l o w e r

B l o w e r

H e a t r e c o ve r y

e q u i p m e n t

H e a t r e c o ve r y e q u i p m e n t

D u s t c o l l e c t o r

D u s t c o l l e c t o r

S m o k e s t a c k

S m o k e s t a c k

Exhaust gas t rea tment device

E x h a u s t g a s t r e a t m e n t d e v i c e

B l o w e r u n n e c e s s a r y

B l o w e r u n n e c e s s a r y

Turbo charger

・ High- temperature inc inerat ion breaks down N2O, reduc ing greenhouse gas emiss ions. I t a lso reduces the number of b lowers, which real izes a reduct ion in energy use.

E x h a u s t g a s

H e a t r e c o ve r y e q u i p m e n t

Ai r

Ai r

4

4. Unit ize Sludge Treatment System

Uni t i z ing a s ludge t reatment system by moving s ludge concentrato rs and dewater ing equ ipment next to inc inera to rs rea l i zes a reduct ion in both the amount of e lec t r ic i t y needed to power the s ludge t rea tment p rocess and supplementa l fue l fo r s ludge inc inera to r .

・Ref i t as second-generat ion inc inera to rs

Unitization Set up dewater ing equipment next to an incinerator

・Reduce the d is tance dewatered s ludge t rave ls

ＣＯ２

ＣＯ２

ＣＯ２

ＣＯ２

By combining measures, the ent ire sludge treatment system can be opt imized Ｎ２Ｏ

Current Measures

・Higher inc inerat ion temperatures

ＣＯ２

Ｎ２Ｏ

W hen each measure is implemented independent ly

Reduct ion of

・Energy-ef f ic ient concentrators and dewaterers

・Make concent rators and dewaterers more energy ef f ic ient

・Reduce mois tu re con tent o f s ludge

S e c o n d - g e n e r a t i o n i n c i n e r a t o r s , e t c .

How Unitization of Sludge Treatment System Works (Example)

In t roduction of energ y-ef f ic ient concentrators In t roduction of energ y-

ef f ic ient dewaterers

：pump

Ｐ

・Ref i t as second -genera t ion incinera tors

・Reduce mois ture content o f s ludge using dew ater ing equipment

・Reduces the amount o f supplemental fuel used and suppresses emissions o f N 2 O

C o n c e n t r a t o r

D e w a t e r e r

・Set up dewatering equipment adjacent to the incinerator to reduce the distance that dewatered sludge needs to t rave l

・Reduces the energy needed for de l iver y F

rom

tre

atm

ent

faci

lity

S l u d g e t r e a t m e n t b u i l d i n g

5

5 Earth Plan-2010 Measure

・Sewerage P lan for the Prevent ion of Global W arming ・Earth Plan-2010 (Digest) ・Publ ished by Planning Sect ion of the Planning and Coordinat ion Div is ion at the

Tokyo Bureau of Sewerage ・Address 2-8-1 Nishi -Shinjuku, Shin juku Ci ty, Tokyo 163 -8001 ・Tel: (03)5320-6594

CO 2 N 2 O

微細気泡散気装置の導入 ○

省電力型撹拌機の導入 ○

省エネルギー型濃縮機・脱水機の導入 ○

省エネ東京仕様2007 ○

省エネルギー型機器・器具の設置（省エネルギー型ランプ） ○

維持管理の工夫 ○ ○

汚泥の低含水率化 ○

重油から都市ガスへの燃料転換 ○

ハイブリッド自動車など低燃費・低排出ガス車の導入 ○

ばっ気システムの最適化 ○

汚泥処理のユニット化 ○ ○

新たな燃焼方式の汚泥焼却炉の導入 ○ ○

Ｎ２Ｏ分解触媒の導入 ○

小水力発電 ○

アーバンヒート ○

汚泥の炭化 ○

汚泥のガス化 ○ ○

太陽光発電 ○

木質系バイオマスと下水汚泥の混合焼却事業 ○

技術開発の推進 ○ ○

水処理からのＮ２Ｏ排出抑制技術の開発 ○

グリーン電力・熱証書制度 ○

排出量取引制度（環境確保条例） ○

下水熱を利用した熱供給事業 ○

下水道工事における温室効果ガスの削減 ○

雨水地下浸透の促進 ○お客さまとの連携

お客さまとの取組

技術開発

産学との共同研究

協働事業

民間事業者と協働

処理工程・方法の見直し

水処理工程

汚泥処理工程

未利用・再生可能

エネルギーの活用

処理水のエネルギー活用

下水汚泥のエネルギー活用

自然エネルギーの活用

施策 対策削減対象ガス

徹底した省エネルギー

電力使用量の削減

燃料使用量の削減

かくはん

Measure Action

Energy Conservat ion

Rethinking

Treatment

Processes

and Methods

Ut i l iz ing

Unused and

Renewable

Energy Resources

Research and

Development

Customer Liaisons

Cooperat ive

Ventures

Energ y Use Reduct ion

Instal l micro bubble d i f fusers

In troduce energy-ef f ic ient agi ta tors I n t r o d u c e e n e r g y - e f f i c i e n t s l u d g e c o n c e n t r a t i o n a n d d e w a t e r i n g e q u i p m e n t

Tok yo Energ y-E f f i c i enc y Spec i f i ca t ions (2007 ) U s e e n e r g y - s a v i n g e q u i p m e n t a n d f i x t u r e s ( e . g . , l o w -e n e r g y l a m p s )

Device operat ions and maintenance

Fuel Use Reduction

Reduce more moisture content of sludge Switch f rom fuel o i l to natural gas U s e f u e l - e f f i c i e n t a n d l o w - e m i s s i o n v e h i c l e s ( h y b r i d c a r s , e t c . )

Water Treatment Processes

Optimize aerat ion systems

Uni t ize s ludge t reatment Sludge Treatment Processes

I n s t a l l n e w c o m b u s t i o n s y s t e m s f o r s l u d g e i n c i n e r a t i o n

Use N2O decomposi t ion cata lysts

Use of Treated Water as an Energy Source

Use Sludge Energy

Use Natura l Energy

Micro-hydroelectric power generat ion

Urban heat

Sludge carbonizat ion

Sludge gasi f icat ion

Solar energy generation

Col labora t i ve Research w i th I ndust r y and Academi a

Promote Research and development D e v e l o p t e c h n o l o g i c a l s o l u t i o n s t o s u p p r e s s N 2 O f r o m w a s t e w a t e r t r e a t m e n t

Cooperat ion wi th Pr ivate -Sector Companies

Renewable Energ y Cert i f icate system E m i s s i o n s t r a d i n g s y s t e m s ( T o k y o C a p - a n d - T r a d e P r o g r a m )

Heat supply business ( f rom sewage heat ) R e d u c e g r e e n h o u s e g a s e s f r om s e w a g e c o n s t r u c t i o n

Customer Communicat ions Promote ground inf i l t rat ion of rainwater

Reduction in

Mixe d i nc i nera t i on of w oody bi oma ss a nd s l udge