p2m berlin GmbH

Sustainability from Berlin

SLUDGE to ENERGY

Sustainable Sludge Management

Hilmar Rave, October 2018

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Berlin Water Utility:

▪ largest water utility company in Germany

▪ services about 3.8 million people in Germany’s capital

▪ water supply facilities: 700 Wells, 9 Waterworks, 7,900 km supply network

▪ Sanitation facilities: 6 STP’s with digestion, 10,600 km network, 1 sludge incineration, 1 sludge drying

Berlin Water Utility and p2mberlin

Water Supply and Waste Water Disposalfor the Capital of Germany

p2mberlin Engineering Company of Berlinwasser:

▪ Founded in 1992

▪ Offices: Berlin (Headquarter), Kingdom of Bahrain, Albania, Azerbaijan, Georgia

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Algier

DarkhanZürich

Jeddah

Basel

DohaManama

Isfahan

TeheranAhwaz

Baku

Volzhsky

Odessa

IstanbulPrizren

ZagrebVienna

Hanoi

NanchangAmman

Kuwait

BelgradBerat

Buchara

Tra Vinh

Cairo

Madhya Pradesh

Tblisi

p2mberlin

National and International Project Regions

Rising Need for Sludge Management:

▪ Awareness of sewage treatment has risen

▪ Connections of households to public sewage are

increasing

▪ Extension of wastewater treatment produces increased

sewage sludge volumes

▪ No comprehensive sludge management strategies

available in most countries

▪ Sustainable strategies for sludge disposal have to be

developed in the near future

▪ Stricter regulations require improvement of existing

systems

Sludge Management – Why?

Sludge Management – How?

Main Keys to Sustainable Sludge Management:

Sludge Treatment Options depend on 2 key factors

▪ Sustainable Sludge Reuse/Disposal Concepts

▪ Land availability at STPs

▪ Sludge availability and content

▪ Existing agriculture and/or industries

▪ Existing landfill sites

▪ Waste to Energy Concepts (Energy Recovery)

▪ Biogas

▪ Mono-Incineration (sludge only)

▪ Co-Incineration

(cement industry, solid waste)

Sludge Management – Advantages?

Main Advantages for Sludge Incineration:

▪ Increased Energy Efficiency (Energy Recovery)

▪ By heat recovery e.g. for sludge drying

▪ Reduced Land use

▪ By reduces required landfill capacities

▪ Reduced Hygienic Impact from Sludge

▪ By incineration of organic content

▪ Reduced Odour Impact from Sludge

▪ By incineration of organic content

▪ Increased Saving of Resources (Mono-

Incineration)

▪ By future phosphorous recycling

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▪ Develop an Integrated Sludge Management Masterplan including the required sludge drying and/or incineration facilities to comply to reuse and energy production requirements

▪ Negotiations with a BOT Contractor who is interested in taking the sludge from WWTPs and process it further (generate Energy)

▪ Hire a Consultant to develop a BOT tender that can later be tendered for multiple BOT Contractors

Sludge Management – A Way Foreward?

Vielen Dank Thank you 谢谢 Merci

Overview Sludge Treatment - Process Steps

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Raw Sludge

Most WWTPs Stops Here!

During sludge incineration 100 % of the organics are transferred into electrical and thermal energy.

30%

59%

11%

Sludge Incineration (100 % organics)

Electrical Energy

Heat Recovery

Losses

40%

50%

10%

Biogas Incineration in CHP (< 50 % organics)

Electrical Energy

Heat Recovery

Losses

During digestion only < 50 % of the organics are transferred into biogas, which during biogas incineration can be transferred into electrical and thermal energy.

Energy Transformation

For sludge incineration without add. external fuel (autothermalincineration), the incinerated sludge is required to have a specific heat value of more than 4,000 kJ/kg DS.

Due to the reduced content of organic matter in digested sludge autothermalincineration requires a dryness of app. 45–50% DS,

For autothermal incineration of undigested sludge a dryness of app. 33–38% DS is sufficient.

Autothermal Incineration

Basis: 100 tDS/d with 70 % oDS; equiv. to WWTP with app. 400,000 m³/d dry weather inflow

Total organic content of sludge does not change in the individual sludge handling processes, including sludge drying.

The entire sludge energy content can be transferred into electricity and thermal waste energy (heat) in a sludge incineration plant.

Sewage Sludge Composition without Digestion

Generated Sewage Sludge in Germany:

● Total Dry Solids (2014): app. 1,900,000 t/a

● Organic Content: app. 50 - 55 %

● Total Organic Matter (2014): app. 1,000,000 t/a

● Specific Heat Value: app. 23,000 kJ/kg

Total Energy Content in the Sewage Sludge:

● Total Energy Content: app. 23,000,000,000 MJ/a

equivalent to

● Natural Gas: app. 500,000,000 m³/a

● Diesel (fuel): app. 600,000 m³/a

Energy Equivalent

10 kg org. DS ~ 6 ltr. diesel

Energy Content in Sewage Sludge – Germany

Sludge disposal 2012

▪ Landfill 0%

▪ Landscaping 13%

▪ Agriculture 30%

▪ Incineration 55%

Sludge Disposal in Germany

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