Uses Fleet fueling stations or CNG as vehicle fuel Local power generation for Turbines, Engines or Boilers Augmentation to the CNG gas lines

Transcription

1 November 24, 2014

2 Biogas Renewable and local source of energy Landfills, Digesters, Farm waste Uses Fleet fueling stations or CNG as vehicle fuel Local power generation for Turbines, Engines or Boilers Augmentation to the CNG gas lines Issues Fuel Quality assessment prior to pipeline entry Quantify Methane and CO2 content Determine BTU content In all cases need to determine Impurities and Levels

3 Assess Biogas Fuel Quality Quantify Methane and CO 2 content Verify composition before gas enters pipeline Verify impurity levels Siloxane Impurities High temperature: SiO2 powders form Deposits on cylinder heads, Valves, Pistons, Turbine Blades Engine Oil degradation Turbines - mechanical wear and tear Boilers - particulate build up increase in maintenance frequency SCR Catalysts Poisoning Micro-turbines can be destroyed

4 Prevent Engine / Turbine Damage Instant information rather than quarterly or monthly Maintain engine warranty Feed Forward Process Monitoring Media bed monitoring at multiple points Siloxane breakthrough Replacement / Timing for Regeneration Engine oil change timing CH 4, CO 2, H 2 O process control Chiller failures

5 Engine MFG Siloxane (mg/m 3 ) Maximum Limit Caterpillar 28 Jenbacher 10 Waukesha 25 Deutz 5 Solar Turbines 0.1 IR Microturbines 0.06 Capstone Microturbines 0.03 State of California 0.1 mg Si /m 3 (w/ 0.01 mg Si /m 3 DLs)

6 Process Landfill gas sample collected at site Sample sent to off site analytical lab Analysis results generally take 1 week turn around time Traditional Sampling Methods Extraction / Concentrators Thermal Desorption tubes (Tenex) Impingers (methanol) JetCare (oil-based extraction) Extra processing needed to release or determine Siloxane content Direct Sampling Methods Tedlar bags Suma Canisters Canisters must be coated with glass

7 Not representative One shot analysis over 2 30 minutes Sample prep or conditioning required Remove H 2 O Concentrate sample Recover / extract from media - Some Siloxanes unrecoverable Inconsistencies in reported values Sampling issues (repeatability, process) Inter-Lab as well as Intra-Lab results don t always match Contamination from bag shutoff valves Conversion of TMS and Siloxanes during transportation, due to media or H 2 O content

8 Sampling Advantage No sample conditioning required Gas pushed straight into FTIR No H 2 O removal On Site continuous analysis Pre-Filter and Post-Filter analysis with same system FTIR Analysis FTIR detects multiple species at same instance CH 4 (0-100%), CO 2 (0-60%),, H 2 O, CO, NH 3, Hydrocarbons, Siloxanes, etc. Siloxanes have strong FTIR signal L2 L4 straight chain siloxanes D3 D6 cyclic siloxanes Detection limits at low ppb levels

9 Based on IR light absorption Energy (IR radiation) heats molecule - vibrations and rotations The pattern and intensity of the spectrum provides all the information about gas (type and concentration) symmetric stretch v S asymmetric stretch v as bend δ 9

10 D3 D4 D5 Ethane Butane Propane L4 L3 L2

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12 On Line FTIR Process Monitor 24 / 7 monitoring 1 minute sample rate Biogas from any point on stream can be monitored Real time Analysis (30 60 seconds) Continuous Analysis No Daily Calibration Zero Gas only (24 hrs) No purge gas required No field adjustments required Permanently aligned spectrometer Permanent calibrations Transportable

13 Provides one number for all of the main straight chain (L2-L5) and cyclic (D3 D6) siloxanes Reports Trimethylsilanol (TMS) as well as Total Si at current CH 4 content Total Siloxanes as mg/m 3 and Si (mg/m 3 ) Total TMS as mg/m 3 and Si (mg/m 3 ) Total TMS and Siloxanes as Si (mg/m 3 ) Scale reported values to the Laboratory value Calibrations based upon Permeation Devices Permeation device mechanism NIST Traceable

14 Si (mg/m 3 ) Raw Wet TMS Post Chiller Total Siloxanes Siloxane Spikes Outlet Dry TMS Spikes Time (minutes)

15 Si mg/m3 TMS Total Siloxanes Raw Wet Post Chiller 6 4 Outlet Dry Seconds

16 MKS FTIR Technology Clearly capable of analyzing siloxanes and TMS to very low concentrations At-line analysis in high level CH 4, CO 2 and H 2 O Fixed installations or transportable to site Total Siloxane and Total Silicon Method Works well in raw or scrubbed biogas applications TMS and Siloxane continuous monitoring at < 0.2mg/m 3 FTIR Field Validation Laboratory analysis varies so too much to determine which is correct Better MDLs once field validation is completed