Module 2 – Alternative Waste Treatment Technologies (AWT - PowerPoint Presentation

Slide1

Module 2 – Alternative Waste Treatment Technologies (AWT)Dr Darren PerrinSlide2

The aim / learning outcome of this module is to provide an overview on the range of technologies that are available for the treatment of mixed waste streams and a brief understanding of the factors which influence the deliverability and operation of different alternative waste treatment technologies (AWTs).

What are AWT’s and their role in a strategic framework

The impact of collection strategies on AWT feedstockFactors influencing the deliverability of AWTClear strategy in procuring an AWT

Module OutlineSlide3

Module 2 – AWT – the technologies Dr Darren PerrinSlide4

What does the definition include?

Track

record Europe, America and Japan - Successful operational experience and knowledge principally within Europe, America and Japan, but examples across the globe.Australia / New Zealand - Mixed performance, recent focus primarily on organics

What do they do ?

Mechanical Sorting / Separation / Pre-treatment

Biological Processes

Physiochemical Processes Thermal Processes No ‘one stop’ solution suitable for allLack of information makes it difficult to compare fairly

What is AWT?Slide5

100% kerbside recycling? - At what cost?

We will always have residual (general mixed) waste

We will always have a need for landfillChallenge is to:Understand how much residual waste

Understand what the residual waste consists of

Design and implement appropriate technology to manage the waste in a manner which meets the local and regional strategic objectives in accordance with the waste hierarchy

Have a common understanding on what the process will and won’t do and manage expectations accordingly.

The role of the AWT to manage wasteSlide6

Biological Technologies:

Composting (in-vessel)

Anaerobic digestion) Mechanical and Biological treatment (MBT)Sort first / bio-treat secondBio-treat first / sort second (bio drying)

Mechanical Heat Treatment (MHT) / Autoclaving

Advanced Thermal Treatment (ATT)

Gasification

Pyrolysis Plasma gasificationMass burn incineration (energy from waste)Grate combustionFluidized bed combustion

The TechnologiesSlide7

AWT within the waste hierarchy

AWT

AWT

AWT

AWTSlide8

AWT - Not the answer, but part of an integrated solution.......

AWT

Avoid

Minimise

RecycleSlide9

Examples of The TechnologiesSlide10

The Waste Management System Slide11

Aerobic Digestion - in the presence of “air”

Anaerobic Digestion- in the absence of “air”

Biological technologies

Windrow

In Vessel

Composting

Biodrying

Slide12

Composting is the microbial decomposition of organic material in the presence of oxygen to produce compost. There are two main types of composting:

Open windrow is most commonly used in Australia for green garden waste

In-vessel composting is common in Europe and increasingly being taken up in Australia for green garden and food waste

CompostingSlide13

Anaerobic digestion is the microbial decomposition of organic matter into biogas (approximately 60% methane and 40% carbon dioxide) and

digestate

(solid or liquid) in an oxygen depleted environment.Two main types: Wet (>80% moisture) and Dry (50 to 80% moisture)Typical waste feedstock include source segregated organics from household and commercial premises, biosolids, manure and farm slurries and purpose grown crops.

Anaerobic DigestionSlide14

Mechanical Biological Treatment is a generic term for an integration of several processes and technologies commonly found in different waste management facilities such as MRFs and biological treatment facilities.

Using mechanical and biological processes to separate / prepare mixed waste into usable fractions and / or render it more ‘stable’ for deposit into landfill.

They commonly use composting or anaerobic digestion for treatment of mixed general waste to separate / prepare this into usable fractions and / or render it more ‘stable’ for deposit into landfill.

Mechanical Biological TreatmentSlide15

Mechanical and Biological Treatment

Inputs

Mixed Waste

Issues

Not an end process in its own right

Outputs need a market

Bio-drying process does not necessarily stabilise

material

Benefits

Can maximise recycling

Relatively proven European track record

Treatment of waste with “no stack”

Outputs

Recyclables

CLO

RDFSlide16

Mechanical Heat Treatment is use of steam based thermal treatment, with or without pressure, in conjunction with mechanical processing for clinical and mixed general waste.

There are two main types of facility that use mechanical heat treatment:

Autoclaving – a batch steam processing in a metal vessel under the action of pressureRotary kiln - continuous heat treatment in a rotating vessel, not under pressure

Mechanical Heat TreatmentSlide17

Mechanical Heat Treatment

Inputs

Mixed Waste Input

Issues

Energy intensive

Need output for biodegradable fraction.

Benefits

Relatively

lower capital cost

Simple technology

Cleans metals and glass inputs

Sanitises waste (pressure cooking)

Separation of waste easier after

processing

Outputs

Clean Dry Recyclables

Fibre FlockSlide18

Advanced Thermal Treatment (ATT) is an umbrella term that is used to categorise waste treatment technologies that utilise thermal processes to treat mixed general waste that are different to incineration.

Primarily those that employ pyrolysis and/or gasification to process mixed general waste and also exclude full combustion thermal processes (i.e. incineration).

Advanced Thermal Treatment (ATT)Slide19

Gasification

Thermal and chemical conversion of carbon based material within mixed general waste into mainly gaseous outputs. Temperatures are in the range of 800-1100°C with air as the gasification agent and up to about 1500°C with oxygen. Overall gasification processes are exothermal, i.e. producing heat

Pyrolysis The thermal degradation of organic materials within mixed general waste MSW in absence of oxygen. Temperatures are typically around 300-800°C. Overall the process is endothermic, i.e., energy is required for the pyrolysis process to proceed.

Advanced Thermal Treatment (ATT)Slide20

ATT – how it worksSlide21

Advanced Thermal Treatment

Inputs

Prefers single / pre-treated waste streams

Issues

A variety of operational risks due to history

Differentiation from

incineration

“true” gasification and “staged” gasification

Not all systems have energy efficiency benefits over incineration

High capital cost

Benefits

Produces renewable energy in the form of syngas

Reduces waste volume, destroys BMW

Potential benefits of small scale or integrated facilities

Smaller scale than mass burn (niche applications)

Potential for smaller Air Pollution Control equipment

Outputs

Gas (Syngas)

Oil and tar

Ash and Metals Slide22

Incineration involves combustion of mixed general, clinical and hazardous waste with sufficient quantities of air in temperatures often in excess of 850°C. The main types are:

Fixed grate

Moving grateFluidised bedRotary kiln

IncinerationSlide23

Incineration

Inputs

Mixed or Single Waste Input

Issues

Poor public perception

Potentially large land take

Capital intensive

Commercially viable approx. 100k

tpa

+

Benefits

Proven technology with long track record

Reduces waste volumes

Established markets for outputs

Outputs

Heat used to produce electricity (and/or a local user)

Bottom ash can be recycled (20 – 30%)

Metals for recycling (3 -5 %)

Air pollution control residues (4 - 7%)Slide24

Levels of Air in Combustion ProcessesSlide25

Module 2 – AWT – the Challenges Dr Darren PerrinSlide26

Challenges

Perceptions

Meeting expectations and risk transfer

Assessing commercial deliverability

Affordability Slide27

What goes in .... must come out! – poor quality input leads to poor quality output

Meeting expectations and risk transfer Slide28

Exercise – AWT Issues

Strengths

X

X

X

Opportunities

X X XWeakness

X

X

X

Threats

X

X

XSlide29

Different composition

Different materials which can be recycled / composted

Materials which can’t be recycled or composted Energy Value Gross Calorific Value (GCV)Moisture Content

Net Calorific Value (NCV)

Ash generation potential

Proportion of Biomass

What is MIXED Residual (GENERAL) Waste ?Slide30

The conundrum – Competition for Material

?

Waste Collection Schemes

Alternative Waste Treatment Technology

Waste Material Slide31

Exercise

Naughts and Crosses Slide32

The conundrum – Different Authorities

Waste Collection Schemes

Alternative Waste Treatment Technology

Waste Collection Schemes

Waste Collection Schemes

Waste Collection Schemes Slide33

The conundrum – Different Schemes

Waste Collection Schemes

Scheme Design

Materials Targeted

Presentation

Separation Efficiency

Contamination

Waste Generated

Demographics

Composition

Area Characteristics Slide34

The Challenge.......

Alternative Waste Treatment Technology

?

?

?

?

?

?

?

?Slide35

Waste CompositionSlide36

Waste Composition Can varySlide37

Material Flows Available

Refuse

Organic

Self Haul

RecyclingSlide38

System interaction

Biological Treatment

IVC

AD

Windrow

AWT

Landfill

ATT

MHT

MBT

EFW

Power

Product

Recycling

General Waste

Organic

MRF

Bulking

Sort and TransferSlide39

Refuse

Recycling

Bring Sites

8.1%

Newspapers

7.9% Glass bottles and Jars

3.4% Drink and Food Cans

OrganicSlide40

Collection Systems Changes

Change number of households offered a service

Change number of households who use the service

Change how often they use the service

Change what materials are targeted

Change how effectively the material is captured i.e. placed in the correct containerSlide41

= 3 / 5 = 60%

Set Out Rate

Wk 3

Refuse

= 4 / 5 = 80%

Participation Rate

= 2 / 5 = 40%

Set Out Rate

Wk 1

= 2 / 5 = 40%

Set Out Rate

Wk 2

RecyclingSlide42

Recognition, Capture and DIVERSION RATE

20

15

5

25%

Capture Rate

= Total

10

10

10

5

5

50%

Recognition Rate

0%

Recognition Rate

10

10

10

5

5

50%

Recognition Rate

0%

Recognition Rate

10

30

15

5

17

% Diversion Rate

= Total

10Slide43

There is material remaining in the General Waste container Slide44

Assumption: No kerbside recyclables collection system in place, 200,000

tpa

of household general waste generated; Question: If ‘you’ introduced a kerbside recycling scheme in your council area, approximately how many tonnes of residual waste would you have left to treat in an mixed waste AWT facility?

Waste Feedstock Exercise (In groups)Slide45

Not All Materials are targeted

Primary Material Category

Primary Composition

Secondary Material Category

Secondary Composition

Paper

14.4%

Newspaper and Magazines

6.7%

Other Recyclable Paper

4.8%

Non-Recyclable Paper

2.9%

Plastic

5.9%

Plastic Bottles

2.6%

Plastic Packaging

2.6%

Other Plastic

0.7%

Glass

10.2%

Glass Packaging

9.6%

Other Glass

0.6%Slide46

Sensitivity of Targeted Materials

Coverage (90%)

Participation (70%)

Recognition (60%)

X

X

Material

Available (Composition 5%

)

Waste Generation

100,000 tonnes

5,000 tonnes

4,500 tonnes

3,150 tonnes

1,890 tonnesSlide47

Assumption: No kerbside recyclables collection system in place, 200,000

tpa

of household general waste generated; Question: - If ‘you’ introduced a kerbside recycling scheme in your council area, approximately how many tonnes of residual waste would you have left to treat in an mixed waste AWT facility?Now Assume

50,000 available in composition

Coverage of 90%

Participation 70%

Recognition 60%Waste Feedstock Exercise (In groups)

Change recognition ?

Change participation ?Slide48

Module 2 – AWT – the Purchase Dr Darren PerrinSlide49

Process in Obtaining an AWT

Define What Your Strategic Priorities

Are

Develop Evaluation Criteria

Develop Procurement Strategy

Develop Weightings

Validate Weighting and Evaluation Criteria

Commence

Procurement Process

Obtain Pre-Procurement InformationSlide50

Reduce the mass and volume of waste?

Produce an end product:

Quality Compost ? Recyclables ?High end value recyclables ? Pre-treat the waste to produce a feedstock for another process?

RDF ?

SRF ?

Generate and export power or heat?

Electricity?Heat / Steam ?Biogas ?Synagas ? Stabilise the waste prior to disposal to landfill?

Maximise the life of landfill assets?

Defining Strategic purpose of AWTSlide51

Understand data available (waste flows, composition, performance, population / household growth

Political landscape and sensitivities

Understand / Map out stakeholdersDetermine Contract SpecificationInput (sets service requirements)

Output (sets performance standards)

Understand and plan programme

Procurement Plan

Pre-Procurement ActivitySlide52

Scope and duration

Contract type (O,DBO, DBFO, DBFOM)

FundingProvision of Facilities / staffing Partnering Market appetite

Planning, sites and approvals

Procurement Plan Slide53

In most cases, a car will get you from A to B

Lots of different cars out there

If entering a car yard, what do you tell the salesman are the key things you want….. Key Questions?What is important to you? e.g. Speed, colour, number of seats, fuel efficiency, age, reliability, appearance, reputation of manufacturer, cost

Are any of these more important?

If so, which are more important and by how much?

Are any of these show stoppers? i.e. you have 3 kids therefore a 2 seater car is not possible

Can you group some of these together?

Evaluation criteria is like buying a carSlide54

Tier 1 is the main grouping

Tier 2 is the categories within the grouping

PerformanceFuel efficiency Speed Emissions

Cost

Deprecation

Cost to buy

Cost to maintain

Tier 1 and Tier 2 Criteria Slide55

Tier 1 and Tier 2 Weighting

Performance 20%

Fuel efficiency 30%

Speed 50%

Emissions 20%

100%

Cost 50%

Deprecation 20%

Cost to buy 60%

Cost to maintain 20%

100%

Track record 30%

Reliability 50%

Reputation of manufacturer 50%

100%Slide56

Sales man will be unhappy if he has invested ½ day showing you

2 seater cars if you have 3 kids

Cars which are not within your budget Providing a test drive for cars you “know you don’t want” that don’t meet your criteria. A salesman will be more attracted to a customer who has a clear idea of what the car needs to do than a customer who is asking the salesman to pick a car for them

You may be having the car serviced at the garage; therefore you want to start on a “good relationship”.

You are unlikely to take the car with you i.e. needs financing, engine checks, certificates etc.

Remember …… Slide57

Important to have a clear, robust evaluation criteria to communicate to the market “what you want”

Changing criteria through the process “could” result in a challenge i.e. people invested a lot of time and money

A well thought through criteria allows you to “direct” solutions you want and filter out those you don’t wantNeed to be VERY aware of incorrect criteria weightings which can result in the wrong solution being selected

Remember……………..