Smart Energy and Reclaimed Water Systems of Hokubu Sewerage Center in Yokohama

Transcription

1 Smart Energy and Reclaimed Water Systems of Hokubu Sewerage Center in Yokohama 10 th June 2015 Toshiaki YOSHIDA Mikio TAKANO Haruhiko KUMAGAI Environmental Planning Bureau City of Yokohama, Japan

2 Contents About Hokubu Sewerage Center Energy recovery from digestion gas Digestion gas generation Integrated power system and FIT Solar power generation Reclaimed water system At the end

3 Contents About Hokubu Sewerage Center Energy recovery from digestion gas Digestion gas generation Integrated power system and FIT Solar power generation Reclaimed water system At the end

4 Yokohama City Tokyo Yokohama 30 km Tokyo Bay City Information Land Area 435 km 2 Population Household 3.69 million 1.6 million

5 Current State of Sewage Works Item Value City Population (A) 3.69mil. Sewered Population (B) 3.68mil. Sewerage Service Rate (B/A) 99.8% Item Value Treated Wastewater 1.6mil.m 3 /day Treatment District 9 Wastewater Treatment Plant 11 Sludge Treatment Center 2 Pumping Station 26 Total Sewer Length 11,600 km Tokyo Bay Wastewater Treatment Plant (WTP) Sludge Treatment Center Pumping Station

6 Flow of Wastewater Treatment Activated Sludge Process Grit chamber/pumping Tank / Facility Primary Sedimentation setting tanktank Final Sedimentation Final setting Tank tank Disinfection Facility facility Reaction Tank conventional activated sludge process Primary Sludge and Excess Sludge Effluent into rivers/ocean Wastewater Treatment Plant Collecting Pipes Sludge Treatment (digestion, dewatering, incineration, etc.) Sewerage System

7 Centralized Sludge Treatment System in Yokohama City Generated Sludge at 11 WTPs is transported to 2 STCs and treated. Tsuzuki WTP Kohoku WTP Kanagawa WTP Hokubu I WTP Hokubu II WTP Hokubu STC Sludge Pipeline Wastewater Treatment Plant Sludge Treatment Center Chubu WTP Pumping Station Nanbu WTP Sakae II WTP Tokyo Bay Seibu WTP Sakae I WTP Kanazawa WTP Nanbu STC

8 Process of Sludge Treatment Digestion Gas Thickening Digestion Dehydration Incineration Concentrates and thickens sludge mechanically in order to improve digestion efficiency. Biological decomposition of the organic substances. Digestion gas is produced. Removes water from sludge and produces dewatered sludge cake. Stabilizes its property by incineration and reduces the volume.

9 Contents About Hokubu Sewerage Center Energy recovery from digestion gas Digestion gas generation Integrated power system and FIT Solar power generation Reclaimed water system At the end

10 Gas Power Generator Flow of Digestion Gas Digestion Gas Low Pressure Gas Holder Moderate-Pressure Gas holder Digestion Gas Power Generator Facility Gas Compressor Digestion Tank Digestion Gas Desulfurization System Incinerator

11 Composition of Digestion Gas 11

12 Quantity of Heat [/m3] 46MJ/m3 Town Gas 25MJ/m3 Digestion Gas Utilize Generator (Electric Power) Incinerator (supplemental fuel)

13 Contents About Hokubu Sewerage Center Energy recovery from digestion gas Digestion gas generation Integrated power system and FIT Solar power generation Reclaimed water system At the end

14 Scheme of Digestion Gas Generation Project Project summary: SPC replaced existing biogas engine system with highly efficient one and has been managed operation and maintenance of the system after ownership transfer (Build-Transfer-Operate) Operation/Maintenance Period: 20 years (until March 31 st, 2030) Concession Agreement: Private Finance Initiative (PFI) Project Yokohama city purchases electric power and hot water produced by gas engine using biogas which is supplied to the SPC by Yokohama city without compensation. NOx Reduction Lean burn and for Emission catalytic reduction Electric Power 900 kw Generation Gas Consumption 378 Nm3/h Recovered Heat 804 kw as hot water

15 Scheme of Digestion Gas Generation Project The city of YOKOHAMA PFI Business Operator Wastewater Treatment Plant Electricity & Heat Supply Digester Sludge Sludge Treatment Plant Digestion Gas Gas Holder Giving license to business operator Checking of business operator s management Payment of the charge Digestion gas & Treated Water supply Digestion Gas Generation System Financing, Renewal of the system and O&M 15

16 16

17 Contents About Hokubu Sewerage Center Energy recovery from digestion gas Digestion gas generation Integrated power system and FIT Solar power generation Reclaimed water system At the end

18 Integrated Energy System Transmission line of power company VCT 66[kV] Power selling Tsurumi Garbage Incineration Plant Steam turbine power generation facility SG No.1TR 10,000[kVA] 66[kV]/6.3[kV] No.2TR 10,000[kVA] 66[kV]/6.3[kV] Power generation GE 22,000[kW] Digestion gas power generation facilities 900[kW] 5 1,100[kW] 1 Power generation Hokubu-Daini WWTP Hokubu Sludge Treatment Plant

19 Feed-In Tariff Law for Renewable Electric Energy Sell electric power Power company Supply electric power Solar energy Buy electric power Surcharge Wind energy Water energy User Geothermal energy Biomass energy Government

20 Digestion gas power generation 23% The inner use The shortage (The shortage) Steam turbine power generation 77% The surplus electric power The inner use

21 Digestion gas power generation 23% Digestion gas power generation 23% The inner The use inner The use shortage The shortage Steam turbine power generation 77% 23% over the surplus electric power The surplus electric power The inner use

22 Digestion gas power generation 23% Steam turbine power generation 77% The surplus electric power FIT is applied. The inner The inner use use The shortage The shortage The surplus electric power The surplus electric power The inner use

23 Contents About Hokubu Sewerage Center Energy recovery from digestion gas Digestion gas generation Integrated power system and FIT Solar power generation Reclaimed water system At the end

24 Solar power generation facilities Sunlight Power company Electric room Existing facilities Only connected during emergencies. Solar panel Junction box Industrial Power Panel board (For accidents) Industrial Power Panel board (Existing) Power conditioner Displaying device

25 Considerations for a location (First) 二次処理棟 沈砂池棟 Maintenance Accident Check H2S Degradation

26 Considerations for a location (Decision) 二次処理棟 沈砂池棟

27 Emergency power source Power company Electric transmission stop by blackouts Normality Actinometer Thermometer Transformer Power conditioner Industrial power Panel board Displaying device

28 Emergency power source Power company Electric transmission stop by blackouts Emergency Actinometer Thermometer Transformer Power conditioner Industrial power Panel board Displaying device

29 Contents About Hokubu Sewerage Center Energy recovery from digestion gas Digestion gas generation Integrated power system and FIT Solar power generation Reclaimed water system At the end

30 Reclaimed water system Biological treatment Sand filtration Public works contractors Inner use

31 Reclaimed water supplying site

32 Contents About Hokubu Sewerage Center Energy recovery from digestion gas Digestion gas generation Integrated power system and FIT Solar power generation Reclaimed water system At the end

33 Scheme of Sewage Sludge Fuelization Project The city of YOKOHAMA Business contract PFI Business Operator Digestion Tank Sludge cake Digestion Sludge Dehydration Payment of the charge Dryer Granulator Carbonization Furnace Sludge Fuel Fuel Wastewater Treatment Plant Payment of the sales Thermal power plant Carriage 33

34 Nocturnal View of Yokohama Harbor