1. TNO Environment, Energy and Process Innovation Intro IPCC-model, Copenhagen Introduction to 2006-IPCC guidelines Workshop CH4 from waste, March 8th -9th, 2006

2. Intro IPCC-model, Copenhagen In the next hour Changes compared to previous methods Some backgrounds Why 1st order decay model (FOD) Changed mathematics FOD Single-phase vs. multi-phase Why default oxidation Measuring and estimating recovery Default values Introduction to the spreadsheet-model

3. Intro IPCC-model, Copenhagen Methane emissions emission = (formation – recovery)*(1-oxidation)

4. Intro IPCC-model, Copenhagen Most important changes compared to ‘96 RG and ‘00 GPG Improved estimate of waste and DOC 1st order decay model (FOD) strongly recommended and facilitated in a model slightly different mathematics FOD improved default values Waste generation Waste composition Model parameters recovery preferably measured, conservative estimation methodology introduced C-storage, harvested wood in landfill

5. Intro IPCC-model, Copenhagen Estimating DOC landfilled Default values for MSW-produced Other wastes produced Composition waste DOC-content waste fractions Fraction landfilled Historical development amounts waste

6. Intro IPCC-model, Copenhagen Estimating DOC landfilled (2) Bulk waste approach: Little information available MSW-generated * % landfilled = MSW landfilled MSW landfilled * DOC MSW = DOC in MSW landfilled

7. Intro IPCC-model, Copenhagen Estimating DOC landfilled (3) Material stream approach: Country specific information available MSW-generated * % landfilled = MSW landfilled MSW landfilled * % food waste = food waste landfilled Food waste landfilled * DOC fw = DOC in food landfilled

8. Intro IPCC-model, Copenhagen Calculation of methane formation Methane potential as in ‘96-RG and ’00-GPG L 0 = 0,5 * 16/12 * DOC f * DOC * MCF Defaults for DOC f and MCF Delayed release of methane potential: first order decay (FOD)-model

9. Intro IPCC-model, Copenhagen Why FOD? Methane is formed throughout decades Starting point emission inventory: ‘where and when’ GPG, 2000: ‘Important when practices change rapidly’ GPG, 2000: ‘1996-default method overestimates effect of reduced landfilling in the period 1990-2010, FOD is good practice’ For transparency reasons FOD for all countries

10. Intro IPCC-model, Copenhagen Better estimation of emission reduction

11. Intro IPCC-model, Copenhagen Better estimation of emission reduction (2)

12. Intro IPCC-model, Copenhagen Changes to ‘96-guidelines/’00-GPG Facilitated by development of internet More complicated methodology Still easy to use Reason for changes

13. Intro IPCC-model, Copenhagen Changes in algorithm FOD 1996: formation = L 0 * k * e -kt (1) GPG ’00: correction factor FOD 2006: formation = L 0 * (e -k(t-1) -e -kt )(2) Validated older models (1) are not „wrong“

14. Intro IPCC-model, Copenhagen Single-phase vs. Multi-phase Waste is not waste but food, paper, wood, etc. Single-phase Average k-value for all streams Reactions are fully dependent Decay of food waste is delayed and wood waste is accelerated Multi-phase Discrete k-values for each stream Reactions are fully independent Wood is wood and degrades as wood, irrespective of other wastes present

15. Intro IPCC-model, Copenhagen Single-phase vs. Multi-phase (2) Truth will lie in the middle No experimental support for either of both options No theoretical support for either of both Both options are facilitated in the model

16. Intro IPCC-model, Copenhagen Recovery Starting point ‘00 GPG: only measured amounts recovered!!!!! (recovery estimates tend to be way too optimistic) ’06-guidelines: Measurements highly recommended Conservative default estimation methods introduced 20% recovery efficiency 35% of installed capacity

17. Intro IPCC-model, Copenhagen Recovery (2) Few measurements available: 10-85% efficiency (Netherlands: 37% average) However mostly closed landfills Most relevant landfills still have parts in exploitation Conservative default efficiency: ~20% (Dutch experience, to my opinion not that conservative)

18. Intro IPCC-model, Copenhagen Recovery (3) Recovery and flare capacity Conservative default utilisation factor: 35% Based on US and Dutch experiences Main reasons for non-use Overestimated gas formation – Overdesigned equipment Poor working hours (down to 80%) Back-up systems

19. Intro IPCC-model, Copenhagen Oxidation default value: 10% No change compared to ’96-RG and ’00-GPG May be higher, but highly uncertain Very difficult to measure 13 C-analysis CO 2 and CH 4 mass balance Heterogeneous pathway of emissions due to cracks, etc. Highly variable (CH 4 -flux, soil-type, vegetation) Dependent on climatological conditions, season Few data available