Subject: Optimizing Landfill Gas (LFG) Flow Monitoring with Thermal Instrument Company Equipment: Model 62-9TEF Insertion Probe / Integral 9500P Electronics
Author: Thermal Instrument Company Engineering Team
Abstract
Landfill Gas (LFG) extraction and flare/energy monitoring present harsh operational environments characterized by variable gas compositions, moisture, particulate build-up, and wide dynamic flow ranges. Regulatory compliance mandates accurate, repeatable flow rate monitoring for both environmental reporting and bio-energy production efficiency. This paper details the operational advantages of applying the Thermal Instrument Company (TIC) Model 62-9TEF Insertion Probe paired with Integral 9500P Electronics, highlighting sensor architecture, operational durability, and TIC’s comprehensive lifecycle support programs (recalibration, loaner meter support, and field service).
1. Landfill Gas Generation & Regulatory Context
Landfill Gas is produced as solid organic waste undergoes anaerobic decomposition within sealed landfill cells. Isolated from oxygen, groundwater, and ambient air by composite liners and soil covers, methanogenic bacteria break down organic matter into a combustible gas stream consisting primarily of:
Methane (CH4): 50% – 60% by volume
Carbon Dioxide (CO2): 35% – 45% by volume
Trace Components: Nitrogen (N2), Oxygen (O2), moisture (H2O vapor), hydrogen sulfide (H2S), and non-methane organic compounds (NMOCs).
Federal environmental regulations dictate that landfill operators capture LFG via a network of extraction wells, header pipes, and blower skids. Captured gas must be utilized for renewable energy generation (e.g., direct-use boilers, gas-to-grid processing, or power generation) or destroyed via thermal flaring. Environmental authorities mandate continuous, accurate mass flow rate measurement and data logging for emissions accounting and compliance verification.
Process:
2. Technical Challenges of LFG Flow Measurement
Measuring LFG accurately presents severe technical challenges for traditional flow measurement technologies:
Compositional Variations: Fluctuations in the CH4/CO2 ratio affect thermodynamic gas properties.
Dynamic Range Requirements: Seasonal changes, well field balancing, and blower output lead to wide velocity swings between peak production and low-flow flare conditions.
Contaminants & Condensate: Entrained particulate matter, siloxanes, and moisture build up on exposed flow elements, drift sensor calibration, and increase maintenance cycles.
Pressure Drops: Unnecessary pressure drops burden blower skids and decrease system extraction efficiency.
3. Technology Principles: Model 62-9TEF Thermal Mass Flow Sensor
Thermal Mass Flow Measurement operates on the principle of thermal dispersion, measuring mass flow directly without requiring separate pressure or temperature compensation inputs.
Key Engineering Features of the Model 62-9TEF:
Direct Mass Flow Measurement: Automatically compensates for process temperature and pressure variations.
100:1 Dynamic Turndown Ratio: Accurately registers low ambient flare flows as well as high-velocity production runs.
Non-Obstructive / Low Pressure Drop: Insertion probe geometry minimizes head loss across the header line, optimizing blower power consumption.
Solid-State Construction (No Moving Parts): Eliminates mechanical wear, bearing failures, and jammed impellers.
Protected Sensor Architecture: Unlike standard thermal sensors where RTDs are directly exposed to process fluids, TIC sensors are housed inside our 316SS insertion probe, ensuring the sensing elements never come into direct contact with the LFG stream.
Teflon Coating: Protects the sensor tip area from sticky particulate, moisture, and siloxane build-up, preserving flow profile consistency and reducing cleaning frequency.
Redundant Back-Up Sensors: Built-in redundancy inside every probe tip extends operating life and ensures continuous uptime in remote, harsh monitoring environments.
4. Advanced Signal Processing: Integral 9500P Electronics
When paired with the Model 62-9TEF Insertion Probe, the Integral 9500P Electronics transmitter converts raw thermal dispersion signals into precision flow measurements.
Key Features & Benefits:
Factory-Calibrated Gas Curve (Exact CH4 / CO2 Mix). Ready to go right out of the box
Temperature & Pressure Compensation
Linearized Output Signal: Standard 4-20mA Current Loop
Integrated Diagnostic Routines & Local Display Capability
System Configuration Comparison
Operational Feature Standard Flow Meters Thermal Instrument 62-9TEF/9500P
Pressure / Temperature Compensation Requires external sensors & computers Inherent (Direct Mass Flow)
Turndown Ratio 10:1 to 15:1 Average 100:1 Wide Dynamic Range
Sensor Protection Exposed Sensing Elements Fully Protected. No Direct Contact
Sensor Redundancy Single point of failure Built-in Redundant Back-up Sensors
Pressure Drop Moderate to high (Orifice Plate / Turbines Negligible
Maintenance Impact High (frequent cleaning) Low (No Moving Parts, Single Piece Construction, Teflon Coated)
5. Lifecycle, Recalibration & Compliance Support
Accurate flow monitoring over years of continuous operation requires reliable field support and calibration maintenance. Thermal Instrument Company provides tailored service structures to ensure zero downtime and ongoing regulatory compliance:
Factory Gas-Specific Recalibration: Recalibration services tailored to your exact site gas composition and line dimensions, easily managed via TIC's streamlined web-based order system.
On-Site Field Service & Calibration Options: Factory-trained technicians conduct on-site verification, functional testing, and field calibration to ensure zero interruption to reporting schedules.
Loaner Meter Program: To ensure continuous compliance and uncompromised flow logging during routine factory maintenance or recalibration, TIC provides temporary loaner meters.
4-Year Factory Warranty: Backed by decades of dedicated service to the landfill and biogas industries, TIC delivers long-term operational confidence.
6. Conclusion
Accurate landfill gas monitoring requires equipment capable of handling fluctuating gas ratios, harsh environments, and wide flow ranges without maintenance-heavy downtime. The Thermal Instrument Model 62-9TEF Mass Flow Insertion Probe combined with Integral 9500P Electronics offers a robust, low-maintenance, and highly accurate solution tailored to regulatory and bio-energy monitoring demands.
For more information please contact us.
Thermal Instrument Company
217 Sterner Mill Road, Trevose, PA 19053
Phone: (215) 355-8400 | Fax: (215) 355-1789
Web:
www.thermalinstrument.com | Email: Office@thermalinstrument.com