Ministry of Land, Infrastructure, Transport and Tourism

Efforts for effective use of sewerage resources in Japan

Sewerage and Wastewater Management Department Ministry of Land, Infrastructure, Transport and Tourism,

Japan

1

There are about 2100 wastewater treatment plants in Japan. Most plants adopt aerobic treatment methods such as conventional activated sludge process or oxidation ditch process.

As for the GHG emission from sewerage system, the emission from electricity(treatment plant) accounts for 54% and the emission from sludge incineration accounts for 20%.

Greenhouse Gas Emissions from sewerage system In Japan FY 2009

Japan’s Wastewater Treatment System and GHG Emissions

Grit chamber

Final Sedimentation

Tank Aeration

Tank

Electricity（Treatment

Plant）54%

Electricity（Pump Staion）

6%

Fuel6%

Wastewater treatment（CH4）

4%

Wastewater Treatment（N2O）10%

Sludgeinciniration（N2O）20%

Others0%

Total amount 6.7Mt-co2

Primary Sedimentation Tank

The material use of sewage sludge has steadily increased, since the efforts on reduction of sludge volume became obligation by new Sewerage Law

The rate of material use has reached about 77% in 2009. The rate for cement use is the largest in any use.

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

Rec

ycle

Rat

e（%）

Gen

erat

ed S

ludg

e v

olum

e（10

3 DS

-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 2

Material Recycle of Sewage Sludge

3

Fuel Usage

Fuel Methane Fermentation

Electric Generation

Sewage Sludge （Biomass）

【Power Plant】

○Energy Use of Sewage Sludge

Digestion gas usage

12.4%

Solid fuel 0.8%

Use for fertilizer 11.2%

Unused as biomass 75.6%

Biomass Recycle Rate About 24％（2009）

Electric generation by Digestion gas Fuel for natural gas vehicles Injection of biogas into city gas pipe Solid fuel usage

Biogas Solid Fuel

About 80% of sewage sludge comprises organic matter and it can be used to generate energy by producing solid fuel or biogas.

Biomass recycle rate remains 24% in 2009(The rate for energy generation is only 13%). ※Biomass recycle rate: percentage of the organic matter which is efficiently used as digestion gas or fertilizer.

Energy Use of Sewage Sludge

Total amount of biomass 1.79 million tons

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

96 97 98 99 00 01 02 03 04 05 06 07 08 09

Sew

age

Bio

gas

Util

izat

ion

Rat

e

Sew

age

biog

as y

ield

（

one

thou

sand

m3 p

er y

ear)

Fiscal year

Power Generation

Heating digester tanks

Others

Incineration

Biogas Utilization Rate

【Biogas Yield and its Usage】 About 30% of biogas is unused

4

There are digester tanks in about 300 treatment plants. About 70% of the biogas generated by digestion (218 million m3) is utilized, but the rest(86 million m3) is incinerated.

Sewage biogas can be used more efficiently, because although about 20 % of biogas(66 million m3) is used for the power generation, about 30% (86 million m3) is used only for heating digester tanks.

In 2009, electricity generated from sewage biogas covered about 2% of the total electricity consumption in sewerage facilities.

Biogas Use in Sewerage System

5

B-DASH Project（Government funded technology R&D and demonstration project : Breakthrough by Dynamic Approach in Sewage High technology）

【2011～】

(Measure 1) It is necessary to develop technologies such as low cost and high efficient energy utilization technology by the leadership of the government in order to promote the energy use by the local governments.

(Measure 2) It is necessary to prepare for the promotion of energy use of sludge under the cooperation between public and private sectors.

Feed-in Tariff (The Act on Special Measures concerning the Procurement of Renewable Electric Energy by Electric power company)

Obligation of Biogas Use by Energy Supply Companies(Act of Sophisticated Methods of Energy Supply Structures)

Toward Promotion of Energy Use

6

Treatment Plant Effluent

Sludge

The latest renewable energy technology of sludge S

ludge Treatm

ent w

astewater

treatment

Biogas

Biogas

Sludge Fuel Production

Gas Cleaning

Electric Generation

Sludge Fuel

Electricity Use in a treatment plant

City Gas Plant

Power Plant

Refined Gas

Inflow

Heat

Heating Digester Tank

Nutrient Removal

Sewage Heat Utilization

Biogas Recovery

solid-liquid separation

Budget 2.4 billion yen (2011FY) 2.9 billion yen (2012FY)

B-DASH Project （Breakthrough by Dynamic Approach in Sewage High technology）

Accelerate the government-led development of new technology and its practical application by promoting technical validation through installation of actual size plants and by formulating guidelines.

Achieving cost reduction in the sewerage projects and generation of renewable energy. As for the methane gas, implementing high-efficient and high-temperature digestion with carrier filling

digester, and high-efficient gas purification technology, etc.

Since July 1, 2012, electric power providers will be obliged to purchase electricity generated

from renewable energy sources on a fixed-period contract at fixed prices.

7

Feed-in Tariff for Renewable Energy （July. 2012～）

Promote the utilization of non-fossil fuel and the efficient utilization of fossil fuel by operators of

energy utilities(Electric, Oil, Gas Supplier) General gas providers are obliged to utilize more than 80% of biogas generated in their supply

areas in 2015. ( the obligation is only for the biogas available in reasonable price for the gas providers)

Act of Sophisticated Methods of Energy Supply Structures （August. 2009～）

Development of Legislation

8

神戸市東灘処理場

消化槽

・充填台数：10,650台/ 年・08年4月より運転開始・充填台数：10,650台/ 年・08年4月より運転開始

消化タンク 消化ガス精製装置 中圧ガスタンク こうべバイオガスステーションC H4

C O 2高位発熱量

：約60%：約40%：約23MJ /m3

N

C H4C O 2

高位発熱量

：約60%：約40%：約23MJ /m3

N

C H4C O 2

高位発熱量

：97%以上：3%以下：約39MJ /m3

N

C H4C O 2

高位発熱量

：97%以上：3%以下：約39MJ /m3

N 場内利用

精製ガス消化ガス

ご家庭等バイオガス都市ガス導管注入実証事業

大阪ガス（株）

高度精製されたバイオガスの買取

都市ガスとしての供給等

（株）神鋼環境ソリューション

「こうべバイオガス」の高度精製設備を建設・運営

神戸市

「こうべバイオガス」の供給等

ガス導管

こうべバイオガス

導管注入量(当初)：約80万m3N/ 年（45MJ換算）

自動車燃料

市バス宅配車等

水再生

都市ガス供給用

下水

低炭素・循環型のまちづくり

下水汚泥

微量成分除去熱量調整付臭

Injection of biogas into the city gas pipe

Osaka Gas

Buying of highly-refined biogas

Kobe City Shinko Environmental Resolution

Supply as city gas

Construction and operation of high refining facilities of Kobe Biogas

Supply of Kobe Biogas

Digestion gas

Higashinada Treatment Plant Kobe-City

Low-carbon circulation type city planning For City gas supply

Automobiles fuels Refined gas

Gas pipe

City buses, vehicles for

home delivery Kobe biogas

station Middle-pressure gas tank Digestion gas refining facilities Digester

For internal usage

- Operation started in August 2008 - Number of vehicles filled with biogas; 10,650 vehicles/year

CH4: 97% or more CO2: 3% or less

Higher calorific power: about 39MJ/m3N

CH4: about 60% CO2: about 40%

Higher calorific power: about 23MJ/m3N

Was

tew

ater

Reclaimed wastewater

Sew

age

slud

ge

Kob

e bi

ogas

Homes

Kitchen

Bath

Adjustment of calorific

power

Pipe introduction rate (initial); about 80,000 m3

N/year (as converted to 45 MJ)

Odori-zation

Removal of trace

components

Case of Biogas Use in Sewerage System① （Kobe City）

Sludge Dehydration Facility

Sludge Drying Facility

Digester Tank

Use for fertilizer

Digestion gas generation

facility Biogas

Retention Facility

Food Waste(Coffee Grounds)

Wastewater Treatment Plant

Sewage Concentrated

Sludge

PFI project

Dry Sludge

Rural Sewage Sludge

Septic Tank Sludge

Provide Electricity to the Treatment Plant

Raw Garbage (Disposer)

Wastewater Treatment Facility

【PFI (private finance initiative) Project in Kurobe City】

9

Case of Biogas Use in Sewerage System② （Kurobe City）

Increase the amount of biomass by treating not only sewage sludge but also food waste(coffee grounds),raw garbage(disposer) and septic tank sludge, etc.

Generated methane gas is used to generate electricity which is used inside the treatment plant. Dry sludge is used for the fertilizer, etc.

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

Benefits for Community Climate Control

Business Improvement of Sewage Projects

Increasing energy self supply rate by utilizing energy from sewerage Work as Energy Supply Hub by concentrating the treatment of other

biomass which generate in a region. Utilization of wastewater heat from sewerage pipe network in the city

Electric Power Provider

(Feed-in Tariff)

Sewage Heat

（R&D by B-DASH Project）

10

（Wastewater heat utilization by de-regulation）

(Biogas Use Promotion by Act of Sophisticated Methods of Energy Supply Structures)

Wastewater Treatment Plant as an Energy Supply Facility

Office Building