Landfill Gas Model for the Philippines and LFG Energy...

Landfill Gas Model for the Philippines and LFG Energy Project Evaluation and

Assessment

Philippine Landfill Forum

Bryce Lloyd February 21-22, 2012 Manila, Philippines

Presentation Outline

•  GMI - Philippine LFG Model •  Comparison to IPCC model •  LFG and ER Estimation •  LFG Project Assessment •  LFG Project Evaluation •  Q&A

Philippines Landfill Gas Model Version 1.0

Provides landfill owners, operators, and developers with a realistic tool to evaluate the feasibility and potential benefits of recovering and utilizing LFG for production of energy for various potential end uses.

Available on the web at the following link: http://www.epa.gov/lmop/international/index.html • Based on USEPA LandGEM and IPCC guidelines

•  Excel® spreadsheet - FOD model

-  Methane Generation Rate (k) -  Ultimate Methane Generation Potential (L0) - Annual Waste Intake (Mi) - User inputs site-specific data for landfill:

- opening and closure years - landfill characteristics (collection efficiency) - history of landfill fires



•  Based on the user’s input, the model calculates recommended values for the following parameters: – k (Methane Generation Rate) – L0 (Ultimate Methane Generation Potential) – Fire Discount Factor – Collection Efficiency

•  The model estimates LFG generation and recovery rates with parameters using waste intake and recommended values (or user defined values)

•  The recommended values for model parameters were developed using data on Philippines’ – Average waste composition across a number of

cities and regions – Waste disposal methods and practices – Waste composition from various regions – Observed landfill operating practices and

conditions •  Model allows users to override default parameters

(only recommended when confident values are obtained)


Methane Generation Rate (k)

•  The recommended default average k value for Philippines is 0.18

•  In very dry areas (annual rainfall <

1,000mm) and/or for landfills with very dry wastes (water content < 30%), a lower value of k (e.g., 0.10) may be appropriate

•  The recommended L0 value for Philippines is 60 m3/Mg

•  In very dry areas (annual rainfall <

1,000mm) and/or for landfills with very dry wastes (water content < 30%), a higher value of L0 (e.g., 70 m3/Mg) may be appropriate

Ultimate Methane Generation Potential (L0)

Fire Discount Factor •  If the user indicates that signs of current

or past landfill fires were observed, the model will apply a default fire discount factor (30% reduction) to the LFG recovery estimate

Collection Efficiency LFG Recovery = Collection Efficiency x LFG Generation Collection Efficiency = (85% - x1 - x2 - x3 - x4 - x5 - x6 - x7) * ACF Where •  x1 to x7 are discounts based on the landfill’s

construction and operation characteristics •  ACF, the Area Coverage Factor, is determined by

the LFG System Area Coverage Percentage

No. (i)

Question Discount xi (%) Yes No

1 Is the waste placed in the landfill properly compacted on an ongoing basis?

0 3

2 Does the landfill have a focused tipping area?

0 5

Widespread / Focused Waste Placement

Collection Efficiency

No. (i)

Question Discount xi (%)

Yes No 3 Are there leachate seeps

appearing along the landfill sideslopes? Or is there ponding of water/leachate on the landfill surface?

10 0


No. (i) Question Discount, % (xi) Yes No

4 Is the average depth of waste 10m or greater?

0 10

5 Is any daily or weekly cover material applied to newly deposited waste?

0 10

6 Is any intermediate/final cover applied to areas of the landfill that have reached interim or final grade?

0 5

Poor Landfill Cover

Good Landfill Cover


No.

(i)

Question Discount xi (%)

Yes No 7 Does the landfill have a geosynthetic

or clay liner? 0 5


LFG System Area Coverage •  The LFG System Area Coverage Percentage

is defined as the percentage of the landfilled area that has a comprehensive and operating LFG collection system.

•  Brackets I to V are defined in the table below. •  Area Coverage Factor (ACF) associated with

each bracket.

LFG System Area Coverage Percentage

Area Coverage Factor (ACF)

LFG System Area Coverage

Percentage

Bracket Area

Coverage Factor (ACF)

80 – 100% I 0.95

60 – 80% II 0.75

40 – 60% III 0.55

20 – 40% IV 0.35

< 20% V 0.15

Optional Input

•  User can recommend values for: •  k •  L0 •  Collection efficiency (can vary by year)

– Supersedes model recommended parameters

–  Input only if reliable data are available – Actual measured recovery rate (plotted

on output graph only; no calculations performed by model)

Example: Inputs & Assumptions

3 Different Scenarios Analyzed Paramete

r Scenario 1 Scenario 2 Scenario 3

Waste Input

Per waste input table



Lo 60 60 60

k 0.18 0.18 0.40


81% 65% 81%

Example: Results in Graphs

XYZ Landfill LFG Recovery Comparison

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

2000 2005 2010 2015 2020 2025 2030

Year

LFG

Flo

w (

m3/

hr)

Scenario 1

Scenario 2

Scenario 3

Example: Summary of Results Scenario 1 Scenario 2 Scenario 3

LFG Recoverable in 2009 (m3/hr) 3,107 2,501 3,949

LFG Recoverable in 2012 (m3/hr) 3,509 2,825 4,066

Max. Engine Capacity (MW)

6.37 5.13 6.63

ERs from 2010 – 2012 (t CO2 eq.)

670,941 540,077 798,682

Comparison to IPCC model •  CDM Executive Board (EB) released a

“Tool to determine methane emissions from avoided from dumping waste at a solid waste disposal site” EB26 Meeting Report Annex 14 for CDM project methane calculations

•  Parameters chosen according to the IPCC 2006 Guidelines for National Greenhouse Gas Inventories followed Ø Oxidation Factor Ø Fraction of Methane in landfill gas Ø Fraction of degradable organic carbon Ø Methane Correction Factor Ø Fraction of Degradable Organic Carbon by waste Ø Decay rate of each type of waste

Model Comparison Default Values Used in the IPCC 2006 guideline models

Oxidation Factor 0

Fraction of Methane in Landfill Gas 0.5

Fraction of Degradable Organic Carbon

0.5

Methane Correction Factor 1.0 (for managed site)

Model Correction Factor 0.9

Model Comparison

Comparison of LFG Recovery by Different Models at the Bulacan Landfillat San Jose Del Monte City

0

1,000

2,000

3,000

4,000

5,000

6,000

7,00020

09

2010

2011

2012

2013

2014

2015

2016

2017

2018

2019

2020

2021

2022

2023

2024

2025

2026

2027

2028

2029

Year

LFG

Rec

over

able

(m3 /h

r)

IPCC model

The Philippines LFGModel 1.0

LFG Assessment and Evaluation

•  How do you decide if a landfill site is a good candidate for an LFGE project?

•  Experienced LFG professionals assess the landfill

using expertise gained at other sites and thought the employment of a variety of tools: -  Computer modeling (i.e. LFG generation model) -  Monitoring equipment (calibrated) -  Site specific data collection -  Precise observation of design and operating practices -  In-depth technical analysis -  Financial pro-forma

Assessments Tier

•  Tier 1：Desktop Studies -  Data collection via questionnaire -  Perform LFG modelling from data collected

•  Tier 2：Landfill Site Assessment – Data Verification –  Interview with landfill personnel – Site Monitoring/Observation

•  Tier 3：Landfill Pump Test – Pump test to verify Tier 2 outcome

Tier I - Required Information

•  Necessary landfill details, including: –  Waste Composition –  Waste Inflow Profile –  Date opened and closed (actual or projected) –  Waste in place –  Landfilling Practices –  Landfill Gas Management –  Landfill Cover System –  Surface Water Management –  Leachate Management

•  The above information can be collected conveniently through a landfill questionnaire

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Data Analysis • Collect Data and perform screening analysis to check:

– Annual waste intake matches with waste in place

– Both weight and volume of waste in place provided, so to determine density and level of compaction

– Waste inflow data corresponds to regional development data

– Waste composition data is in line with expectations (national studies)

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Pros and Cons • Pros

–  Short turnaround, only simple analysis required

•  Cons –  Have not understood landfill conditions thoroughly –  Data solely provided by landfill and may not fit the

assessment requirements –  Assumptions required when data is incomplete or

missing

A Tier II assessment is required to more accurately project LFG generation and recovery.

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Tier II -Site Assessment

•  Observe landfilll operations –  Checking records

e.g. waste intake & monitoring record –  Observe truck frequency and weight

Site Assessment •  Observe landfill operations

–  Waste composition and placement technique

–  Landfill operations pattern –  LFG sampling and monitoring –  LFG conditions (any gas emissions)

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LFG Potential Assessment

•  Collection Efficiency: –  Radius of Influence –  System Coverage –  Leachate Depth –  Cover Conditions/Cracks –  LF Topography –  Landfill Fires

Leachate

Pros and Cons • Pros

– More complete understanding of actual landfill conditions and operating practices;

– Use data collection to assess factors affecting gas generation and recovery

– Adjust screening level model •  Cons

– Time consuming – Non-invasive analysis of the landfill conditions

Tier III assessment (landfill pump test) is required to further estimate landfill gas potential

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§  Assess gas reservoir within the test area §  Adjust gas estimation using test data and

observed Radius of Influence §  Extrapolate gas extraction data to the

entire landfill site §  Adjust gas modeling results §  Also referred to as a “bankable” feasibility

study

Tier III- Pump Test

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Points to note before test -  Representative area -  Compaction before test -  Treatment of condensate -  Age of waste

Landfill Pump Test

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§  3 gas wells and 9 monitoring probes installed §  Connect to blower and flare §  Monitor gas (methane/oxygen) content and

pressure variations §  Increase flow rate until breakpoint is reached

Landfill Pump Test

Breakpoint

Assessment and Evaluation of LFGE Projects

3 stages to determine landfill gas potential, each with pros and cons

The level of assessment performed on a landfill depends on not only the gas generation and recovery potential, but also other critical factors, such as: – Cooperation of owner / operator –  Landfill design and operating practices; – Energy markets; and – Carbon finance and renewable incentives

Financial Evaluation of LFGE projects

Economic analyses performed to evaluate project financial performance.

Typical considerations include, but are not limited to:

•  NPV •  IRR •  Payback period •  Cash flow •  Sensitivity analyses

Evaluation of risk profile •  Currency risk •  Political risk •  Technology risk •  Payment risk (buyer insolvency) •  Risk of changes to KP (post 2012) •  Other Cap and Trade schemes

All project costs must be considered

Be sure to consider all revenue streams –  CER / ERU / VER –  Power / Gas / Energy sales –  Fossil fuel emission offsets –  Renewable energy credits

Intangibles – social & environmental benefits

Evaluation of LFGE project Cost and Revenue Streams

CAPEX •  PDD Documentation •  Design •  Permitting •  Construction •  Validation

OPEX •  Operation •  Verification •  Monitoring •  Periodic Maintenance

For more information, contact:

Bryce Lloyd – [email protected]

Thank You!

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Landfill Gas Model for the Philippines and LFG Energy...

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