Anaerobic Digestion & Municipal Waste Water Treatment
PWR
Anaerobic Digestion &
Municipal Waste Water Treatment
A Project Road-Map For Bulgaria
PWR Presentation Structure
1. Anaerobic Digestion & Waste Water Treatment What are we talking about ? What are the first questions municipalities need to answer? 2. Feedstocks – just sewage sludge? or can other feedstocks be used? What is the gas yield from sewage sludge and other feedstocks? 3. What does AD cost? Does it make any money? • Costs & Possible Revenues • An Outline Action Plan
PWR Why AD?
AD Advantages -
less sludge to dispose of after AD (reduces cost$ for the WWTP) sludge can be spread on agricultural land or $old AD plants can be compact Sewage sludge is stabilised by AD bioga$ production
AD Disadvantages -
no nitrogen elimination, process control & know-how needed, not able to easily adapt to large changes in flow volumes
And of course it is possible to make $$$$$$$ from AD
What are we talking about? Anaerobic Digestion & Waste Water Treatment
Henriskdal WWTP - Sweden
PWR
PWR Question 1a & 1b for Municipalities
1a: What volume of waste water occur 1b. What is the Dry Matter Content of Your Waste Water? Methods 1. Measure off-line through drying and weighing (but only measures samples – not flows) 2. Microwave measurement – on-line - can measure a flow with sampling rate of seconds (but only handles DMs of 3 to 15%). 3. Near Infrared Spectroscopy (NIRS) – on-line technique can be used at various points in the AD process
PWR Question 2 for Municipalities What is the Energy Content ($$$) of Your Waste Water?
Traditional Methods 1. COD: Chemical Oxygen Demand, indirect measurement of organic compounds (but no correlation to energy content) 2. Calorimetry: dry the sample and then “burn it” & measure energy Problem!!:
tends to underestimate energy content of waste water by up to 20%* because “drying” causes loss of volatile matter
*Source: Elizabeth Heidrich, PhD student, Newcastle University UK.
PWR
Decision Point 1
Build MWW System & Plan for AD (later)
Build MWW System & AD
Decision Point 2
AD using only MWW sludge
Availability of other material for AD AD & Co-digestion Suitability of other material for AD
Budget Issue
Build MWW System Only
Gas Yields & Why Co-Digestion is (very) desirable
PWR
More Data on Gas Yields
PWR
PWR Question 3
a. b. c. d.
How much material for co-digestion is available? Is it available on a regular basis? (seasonal basis?) Could the supplier be charged for disposing of it (= revenue stream) How far away is it (transport costs an issue?)
Is the material viable (both from an AD and financial point of view for inclusion in the AD project)
Is Co-Digestion Worth it? 1. 2. 3. 4.
Biogas to produce electricity Biogas to fuel vehicles Pelletised sluge to use in, e.g. cement production* Acceptance fees for industrial/commercial waste
* Biogasmax Report: WWTP Bern
PWR
PWR AD for Municipal Waste Water Treatment
WABIO one step system BTA – single stage Linde KCA process
4. Most common process: activated sludge process (as used in Swedish AD system)
Budget, flexibility of the process, space
1. High rate system (short “hydraulic retention times”) (usually solids retention time = hydraulic retention time) 2. Single stage system (i.e. one AD tank) 3. But several different processes to choose from:
AD System Size
An example from XXXXXXX – for one house
PWR
AD & Energy Self-Sufficiency
Location: System: Politics: End Result:
Juhned, Germany, 800 population AD plant using local biomass (animal manure) plus CHP/district heating System is communally financed & owned Export 50% of power produced, 99% self-sufficient in energy for heating
PWR
PWR Capital Costs – A Swiss Example
WWTP Luzern 2000 to 2006 wastewater treatment plant was redeveloped (to include AD) Total AD module costs 750 €/m³ digester volume (WETT 2009) 10 % costs for machine technology 90 % for physical facilities (KOBEL and BÉGUE 2008). Overhead expenses - approval and planning 10 % total investment costs (KTBL 2007).
Tanks, bases etc (make locally?)
Pumps & controls (import?)
Source: Assessment Report on Operational Experience Biogasmax
PWR Capital Costs II
Capex Costs for Electricity Generation:
Euro 750/kW
(Source: 2008 SLR study)
Similar costs for biogas into gas grid or use with gas engine
Operating Costs vs Gas Market Prices I
PWR
Cost to produce 1m3 biogas from the AD process = Euro 0.09 (From Luzern – Switzerland*) Methane content = 62.5%
Converting to kwhrs = (approx) 7kwhrs (assuming 11kwhrs per m3 natural gas) Cost to produce 1kwhrs of gas from AD with sewage sludge = Euro 0.013 Current Bulgarian (domestic) gas prices (EC web site) = Euro 0.0351/kWhr Current Bulgarian (industrial) gas prices (EC web site) = Euro 0.0215/kWhr
Biogas prices for vehicles: Euro 0.42/m3 Lesson: AD gas can be produced @ 60% less than the selling price of domestic gas, 35% less than the selling price of industrial gas and 66% less than the selling price for gas for vehicles. *Source: Assessment Report on Operational Experience Biogasmax
PWR
France
Rubbish collection vehicles fuelled by….. rubbish
Combined waste treatment plant & bus depot with the buses power by…..
Operating Costs vs Gas Market Prices II
PWR
Cost to produce 1m3 biogas from the AD process = Euro 0.19 (From Henriksdal – Sweden*) Methane content = 65%
Converting to kwhrs = (approx) 7kwhrs (assuming 11kwhrs per m3 natural gas) Cost to produce 1kwhrs of gas from AD with sewage sludge = Euro 0.027 Current Swedish (domestic) gas prices (EC web site) = Euro 0.10/kWhr Current Swedish (industrial) gas prices (EC web site) = Euro 0.05/kWhr
Lesson: Even in a high cost location like Sweden AD & biogas is interesting as a method to turn waste into revenue
*Source: Assessment Report on Operational Experience Biogasmax
PWR Commercial Considerations & Group Action
1. Do Bulgarian municipalities have similar types of waste water to treat? (probably)
2. Should Bulgarian municipalities group together depending on the flow rates of waste water (and thus the size and type of AD system they might need) and act as a single unit when purchasing AD systems? 3. Do you think that the price for a single AD system might be different from the price if 10 or 100 are purchased?
PWR More Decisions
Decision Point 3
Collaborate with other municipalities
Decision Point 4
What to do with the gas?
Option 1 Generate Electricity (CHP?) Clean the gas
Option 2 Gas for Vehicles
Option 3 Sell to gas grid
PWR Project Success Criteria
1. Detailed feasibility study (Answer Questions 1a, 1b & 2 &….) 2. Effective business plan 2a What size of plant is appropriate 2b What type of plant is appropriate) 2c What other feed-stock is available? 2d Citizens participation (partners?) of the bioenergy plant 2e Define revenue streams – are these realistic
PWR Key Documents
Web site: (EU project)
www.biogasmax.eu
Reports
Assessment Report on Operational Experience
Final Assessment Report on Residual Materials Decision Makers Guide: How to Implement a Biomethane Project (for vehicles) Arcadis: Final Report – Assessment of the Options to Improve the management of Biowaste in Europe
PWR AD & Improved Gas Yields
1. 2. 3. 4. 5. 6. 7.
Thermal Hydrolysis (e.g CAMBI method) Chemical Hydrolysis Thermo-Chemical Hydrolysis Ozone Treatment Ultrasound Electroporation Addition of Enzymes
Reference: “Increased Gas Production @ the Henriksdal Waste Water Treatment Plant” ( www.biogasmax.eu ).
Anaerobic Digestion &
Municipal Waste Water Treatment
A Project Road-Map For Bulgaria
PWR Presentation Structure
1. Anaerobic Digestion & Waste Water Treatment What are we talking about ? What are the first questions municipalities need to answer? 2. Feedstocks – just sewage sludge? or can other feedstocks be used? What is the gas yield from sewage sludge and other feedstocks? 3. What does AD cost? Does it make any money? • Costs & Possible Revenues • An Outline Action Plan
PWR Why AD?
AD Advantages -
less sludge to dispose of after AD (reduces cost$ for the WWTP) sludge can be spread on agricultural land or $old AD plants can be compact Sewage sludge is stabilised by AD bioga$ production
AD Disadvantages -
no nitrogen elimination, process control & know-how needed, not able to easily adapt to large changes in flow volumes
And of course it is possible to make $$$$$$$ from AD
What are we talking about? Anaerobic Digestion & Waste Water Treatment
Henriskdal WWTP - Sweden
PWR
PWR Question 1a & 1b for Municipalities
1a: What volume of waste water occur 1b. What is the Dry Matter Content of Your Waste Water? Methods 1. Measure off-line through drying and weighing (but only measures samples – not flows) 2. Microwave measurement – on-line - can measure a flow with sampling rate of seconds (but only handles DMs of 3 to 15%). 3. Near Infrared Spectroscopy (NIRS) – on-line technique can be used at various points in the AD process
PWR Question 2 for Municipalities What is the Energy Content ($$$) of Your Waste Water?
Traditional Methods 1. COD: Chemical Oxygen Demand, indirect measurement of organic compounds (but no correlation to energy content) 2. Calorimetry: dry the sample and then “burn it” & measure energy Problem!!:
tends to underestimate energy content of waste water by up to 20%* because “drying” causes loss of volatile matter
*Source: Elizabeth Heidrich, PhD student, Newcastle University UK.
PWR
Decision Point 1
Build MWW System & Plan for AD (later)
Build MWW System & AD
Decision Point 2
AD using only MWW sludge
Availability of other material for AD AD & Co-digestion Suitability of other material for AD
Budget Issue
Build MWW System Only
Gas Yields & Why Co-Digestion is (very) desirable
PWR
More Data on Gas Yields
PWR
PWR Question 3
a. b. c. d.
How much material for co-digestion is available? Is it available on a regular basis? (seasonal basis?) Could the supplier be charged for disposing of it (= revenue stream) How far away is it (transport costs an issue?)
Is the material viable (both from an AD and financial point of view for inclusion in the AD project)
Is Co-Digestion Worth it? 1. 2. 3. 4.
Biogas to produce electricity Biogas to fuel vehicles Pelletised sluge to use in, e.g. cement production* Acceptance fees for industrial/commercial waste
* Biogasmax Report: WWTP Bern
PWR
PWR AD for Municipal Waste Water Treatment
WABIO one step system BTA – single stage Linde KCA process
4. Most common process: activated sludge process (as used in Swedish AD system)
Budget, flexibility of the process, space
1. High rate system (short “hydraulic retention times”) (usually solids retention time = hydraulic retention time) 2. Single stage system (i.e. one AD tank) 3. But several different processes to choose from:
AD System Size
An example from XXXXXXX – for one house
PWR
AD & Energy Self-Sufficiency
Location: System: Politics: End Result:
Juhned, Germany, 800 population AD plant using local biomass (animal manure) plus CHP/district heating System is communally financed & owned Export 50% of power produced, 99% self-sufficient in energy for heating
PWR
PWR Capital Costs – A Swiss Example
WWTP Luzern 2000 to 2006 wastewater treatment plant was redeveloped (to include AD) Total AD module costs 750 €/m³ digester volume (WETT 2009) 10 % costs for machine technology 90 % for physical facilities (KOBEL and BÉGUE 2008). Overhead expenses - approval and planning 10 % total investment costs (KTBL 2007).
Tanks, bases etc (make locally?)
Pumps & controls (import?)
Source: Assessment Report on Operational Experience Biogasmax
PWR Capital Costs II
Capex Costs for Electricity Generation:
Euro 750/kW
(Source: 2008 SLR study)
Similar costs for biogas into gas grid or use with gas engine
Operating Costs vs Gas Market Prices I
PWR
Cost to produce 1m3 biogas from the AD process = Euro 0.09 (From Luzern – Switzerland*) Methane content = 62.5%
Converting to kwhrs = (approx) 7kwhrs (assuming 11kwhrs per m3 natural gas) Cost to produce 1kwhrs of gas from AD with sewage sludge = Euro 0.013 Current Bulgarian (domestic) gas prices (EC web site) = Euro 0.0351/kWhr Current Bulgarian (industrial) gas prices (EC web site) = Euro 0.0215/kWhr
Biogas prices for vehicles: Euro 0.42/m3 Lesson: AD gas can be produced @ 60% less than the selling price of domestic gas, 35% less than the selling price of industrial gas and 66% less than the selling price for gas for vehicles. *Source: Assessment Report on Operational Experience Biogasmax
PWR
France
Rubbish collection vehicles fuelled by….. rubbish
Combined waste treatment plant & bus depot with the buses power by…..
Operating Costs vs Gas Market Prices II
PWR
Cost to produce 1m3 biogas from the AD process = Euro 0.19 (From Henriksdal – Sweden*) Methane content = 65%
Converting to kwhrs = (approx) 7kwhrs (assuming 11kwhrs per m3 natural gas) Cost to produce 1kwhrs of gas from AD with sewage sludge = Euro 0.027 Current Swedish (domestic) gas prices (EC web site) = Euro 0.10/kWhr Current Swedish (industrial) gas prices (EC web site) = Euro 0.05/kWhr
Lesson: Even in a high cost location like Sweden AD & biogas is interesting as a method to turn waste into revenue
*Source: Assessment Report on Operational Experience Biogasmax
PWR Commercial Considerations & Group Action
1. Do Bulgarian municipalities have similar types of waste water to treat? (probably)
2. Should Bulgarian municipalities group together depending on the flow rates of waste water (and thus the size and type of AD system they might need) and act as a single unit when purchasing AD systems? 3. Do you think that the price for a single AD system might be different from the price if 10 or 100 are purchased?
PWR More Decisions
Decision Point 3
Collaborate with other municipalities
Decision Point 4
What to do with the gas?
Option 1 Generate Electricity (CHP?) Clean the gas
Option 2 Gas for Vehicles
Option 3 Sell to gas grid
PWR Project Success Criteria
1. Detailed feasibility study (Answer Questions 1a, 1b & 2 &….) 2. Effective business plan 2a What size of plant is appropriate 2b What type of plant is appropriate) 2c What other feed-stock is available? 2d Citizens participation (partners?) of the bioenergy plant 2e Define revenue streams – are these realistic
PWR Key Documents
Web site: (EU project)
www.biogasmax.eu
Reports
Assessment Report on Operational Experience
Final Assessment Report on Residual Materials Decision Makers Guide: How to Implement a Biomethane Project (for vehicles) Arcadis: Final Report – Assessment of the Options to Improve the management of Biowaste in Europe
PWR AD & Improved Gas Yields
1. 2. 3. 4. 5. 6. 7.
Thermal Hydrolysis (e.g CAMBI method) Chemical Hydrolysis Thermo-Chemical Hydrolysis Ozone Treatment Ultrasound Electroporation Addition of Enzymes
Reference: “Increased Gas Production @ the Henriksdal Waste Water Treatment Plant” ( www.biogasmax.eu ).
