Fuel Gas Analysis with MAX100-BTU

The MAX100-BTU from Extrel is designed for a fast, high precision measurement of heating value and gas composition for best combustion control and environmental compliance. Variable composition gas streams, like coke oven off-gas or refinery flare vent gas, make effective combustion control a challenge. Fast, accurate gas analysis is vital to allow operators to maintain important set points by incorporating the appropriate amount of supplemental gas or steam.

  • Speciated gas composition
  • Real-time heating value analysis
  • EPA flare compliance
  • Combustion control optimization

The MAX100-BTUTM uses cutting-edge quadrupole mass spectrometer technology to supply a continuous online analysis of fuel gas and vent streams comprising of hydrocarbons, H2, CO, H2O, CO2, H2S and other gases. It has the speed essential for analyzing the total composition of the sample and report the Heating Value within seconds.

The mass spectrometer makes use of an ionizer to break sample molecules into charged fragment ions. They are then divided, based on their mass-to-charge ratio, as they travel through the electric fields produced by the quadrupole mass filter. The ions register a current at the detector, producing a set of peaks termed as a mass spectrum. Each compound has a distinctive spectrum, making mass spectrometry a very selective, flexible method.

The MAX100-BTU is a 24-7 online gas analyzer for combustion control and environmental compliance.

Heating Value Analyzer Applications

  • Landfill vent gas
  • Fuel gas analysis
  • Cogeneration
  • Gas turbine efficiency
  • Gas mixing/recapture
  • Glass plant gas blending
  • Combustion control optimization
  • Refinery flare RSR compliance
  • Coke oven and blast furnace off-gas
  • Natural gas processing and distribution

Fuel Gas Analysis with MAX100-BTU

For fast Heating Value analysis and real-time combustion control, the MAX100-BTU offers a remarkable list of Extrel advantages:

  • Speciated analysis of: H2, C1-C6+ hydrocarbons, N2, O2, H2O, H2S, CO, CO2 and other gases
  • Heating Value reported in seconds
  • Extreme resistance to corrosion from H2S
  • Low maintenance, utility and calibration requirements
  • Multiport sample selector for up to 46 sample streams
  • Extra parameters available: Wobbe Index, Specific Gravity, CARI, Density etc.


Fuel Gas Analysis with MAX100-BTU

Net Heating Value (NHV) changes quickly as regulated material is sent to a refinery flare. Out of the 14 hydrocarbons being measured, the five key contributors to NHV are exhibited along with hydrogen. The MAX100-BTU analysis provides the refinery with the NHV vital for the regulation, as well as speciated component concentrations for use by operations, or for effective root cause analysis.

Component Concentration (%) Precision (% absolute)
Hydrogen 5.07 0.01
Methane 5.05 0.006
Ethylene 17.03 0.026
Nitrogen 56.35 0.033
Ethane 9.99 0.017
Propylene 2.99 0.008
Propane 3.00 0.012
Butane 0.51 0.021
Net Heating Value 665.51 BTU/scf 0.53 BTU/scf


A speciated MAX100-BTU analysis of a certified gas mixture contains hydrocarbons and hydrogen to mimic refinery vent gas. The high precision of the concentration data transfers through the calculation to generate a highly repeatable Net Heating Value (NHV). Latest RSR updates allow the use of 1212 BTU/scf for measuring hydrogen’s NHV contribution. This makes hydrogen speciation an important component of accurate NHV reporting.

Performance Specifications

  • Detectable compounds: H2, C1-C6+ hydrocarbons, O2, CO, CO2, N2, H2S, H2O and other gases
  • Number of sample streams: 16, 31, 46
  • Detection range: 100%-100 ppm*
  • Dual filaments
  • Analysis rate: ~1 second per component
  • Mass range: 1-100 amu
  • Number of components: Unlimited
  • Number of analysis routines: Unlimited
  • Number of user configurable data tags: Unlimited
  • Precision: < 0.75% RSD**
  • Roughing pump: 6-12 months†
  • Analyzer maintenance: 1-3 years†
  • Manual or fully automated calibration and validation
    • 3-12 month calibration intervals

* Matrix dependent.
** Based on the analysis of 1% argon, scan speed 1 second per analysis.
† Application dependent.

Low Maintenance, Easy to Use

The Questor5TM control software that runs the MAX100-BTU measures all fuel or flare gas streams in a totally customizable sequence for site-specific, automated combustion control. The smart web-based interface allows users to check review data, instrument status, or run a validation sequence from anywhere on the plant network, while maintaining government and industry security regulations for login and electronic record keeping (21 CFR 11).

MAX100-BTU System Specifications

Power Supply Options:

  • 110 VAC, 50/60 Hz, Two 15 Amp circuits
  • 230 VAC, 50/60 Hz, One 20 Amp circuit

Power Consumption:

  • Nominal 2740 Watts
  • Heat Load: 2700 Watts (9215 BTU/h)


  • Standard Enclosure: 450 lbs (205 kg)
  • Optional cart: 40 lbs (18 kg)

Ambient Requirements:

  • Temperature: - 4 °F to 120 °F (- 20 °C to 49 °C)
  • With A/C, cold start ≥54 °F (12 °C)
  • Area Classification Options:
    • General Purpose
    • Class 1, Division 2, Groups B, C, D, T4

Additional Utilities:

  • Purge gas (for hazardous area installations)
  • Base calibration requirement: Two gas bottles

Data System and Communications:

  • Login security levels: Administrator, User, Viewer
  • External communications:
    • Ethernet, Modbus serial, digital I/O, analog I/O, OPC

Fuel Gas Analysis with MAX100-BTU

Exceptional Worldwide Service and Support

For over 50 years, Extrel has been committed to offering maximum quality support services for numerous instruments installed around the world. Factory trained and certified personnel provide industry-leading support to Extrel customers at all stages of the combustion control application.

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