1/27 11 – Methane capturing 11 Methane capturing 1

2/27 11 – Methane capturing “Landfill gas extraction system in the making”, Braambergen landfill

3/27 11 – Methane capturing Overview 11.1 Types of extraction systems 11.2 Operational aspects 11.3 Management and maintenance

4/27 11 – Methane capturing 11.1 Types of extraction systems 11.1 Types of extractions systems

5/27 11 – Methane capturing Landfill gas dynamics Three main factors influence the migration of landfill gases: n Pressure n Permeability and n Diffusion 11.1 Types of extraction systems

6/27 11 – Methane capturing Landfill gas extraction Landfill gas is: n explosive in air n a Greenhouse Gas (GHG) and n toxic to humans ….and therefore should be controlled on landfills 11.1 Types of extraction systems

7/27 11 – Methane capturing Landfill gas extraction There are two types of landfill gas extraction: 1. passive 2. active 11.1 Types of extraction systems

8/27 11 – Methane capturing Passive landfill gas extraction 11.1 Types of extraction systems

9/27 11 – Methane capturing Active landfill gas extraction Active landfill gas extraction demands the following: 1. Extraction system 2. Compressor 3. Flare installation or 4. Landfill gas utilization 11.1 Types of extraction systems

10/27 11 – Methane capturing Extraction system There are several types of active landfill gas extraction systems: 1. Vertical 2. Horizontal 3. Slope 4. Point 11.1 Types of extraction systems

11/27 11 – Methane capturing Vertical Conventional Cell wise Build upBuild up + early extraction GRAVEL HDPE piping (perforated) HDPE piping (non - perforated) 11.1 Types of extraction systems

12/27 11 – Methane capturing Horizontal 11.1 Types of extraction systems

13/27 11 – Methane capturing Slope 11.1 Types of extraction systems

14/27 11 – Methane capturing Point 11.1 Types of extraction systems

15/27 11 – Methane capturing Gas well connection RULE OF THUMB: 4 GAS WELLS PER HA 11.1 Types of extraction systems

16/27 11 – Methane capturing Gas well connection 11.1 Types of extraction systems

17/27 11 – Methane capturing Compressor 11.1 Types of extraction systems

18/27 11 – Methane capturing 11.2 Operational aspects

19/27 11 – Methane capturing Explosive conditions during start up Due to safety procedures, explosive conditions must be avoided at all times. The start up procedure to avoid explosive conditions is as follows: 1.Every valve in the extraction system must be opened; 2.At the flare installation or the booster station venting piping needs to be constructed at safe place within landfill boundaries (NOT nearby housing, scavengers or registration offices) and 3.Under current conditions, landfill gas will force out the air naturally. 4.Flare and extraction system full with landfill gas 5.Start up flare at lowest extraction rate 6.Monitor landfill gas quality and explosion limits frequently 11.2 Operational aspects

20/27 11 – Methane capturing Explosive conditions  Landfill gas contains methane  Explosive conditions of methane in air achieved between %  Over extraction of the extraction system could result into high infiltration of ambient air and explosive conditions could be reached  Monitoring again is essential! 11.2 Operational aspects

21/27 11 – Methane capturing Landfill gas monitoring n Monitoring equipment Anemo meterDigital manometerGas analyser 11.2 Operational aspects

22/27 11 – Methane capturing Landfill gas monitoring n Gas analyser can measure: 1. CH 4 2. CO 2 3. O 2 4. N 2 (= 100% - CH 4 % - CO 2 % - O 2 %) 11.2 Operational aspects

23/27 11 – Methane capturing Landfill gas monitoring n If CH 4 and O 2 concentration respectively in a gas well is: > 50% and < 1%thenmore extraction 1%then less extraction 11.2 Operational aspects

24/27 11 – Methane capturing Landfill gas monitoring n If N 2 :O 2 ratio is: > 5 indicator suction of ambient air < 4 indicator leakage piping extraction system 11.2 Operational aspects

25/27 11 – Methane capturing 11.3 Management and Maintenance 11.3 Management and maintenance

26/27 11 – Methane capturing Check at the flare installation: n Flowmeter and indicator function (CDM requirements) n State O 2 analyser n Automatic shut down in case of explosive mixtures..on a regular basis 11.3 Management and maintenance

27/27 11 – Methane capturing Maintenance should be performed by: n Maintenance scheme n Arrange spare part list critical items (compressor, flare, extraction system) The later enables planning and minimises down-time of extraction system and, therefore, minimises greenhouse gas emissions 11.3 Management and maintenance