Syngas and Gasification Gas Analysers

Quick answer

Syngas analysis measures CO, CO2, CH4, H2 and O2. Tar and condensables decide the sample system, so a heated probe, blowback and conditioning come first. Streams containing H2S, HCl or HF are outside the standard i-Cons and SGI-320 limits.

Updated 2 November 2026 · Figures from Sarvesh datasheets

The measurement and why it matters

Gasification converts coal, biomass or waste into a gas rich in carbon monoxide and hydrogen. Pyrolysis heats waste plastic, tyres or biomass without oxygen to produce oil, gas and char. In both, gas composition sets heating value or the downstream route, and oxygen in a process meant to be oxygen-free is a safety signal.

The analysers: CO in ppm by electrochemical and percent by NDIR; CO2 and CH4 in percent by NDIR; hydrogen from ACCURRA-TCD, binary or as required; and oxygen from trace to percent from ACCURRA-S or ACCURRA-Hz.

Tar and condensables decide the sample system. Send composition, temperature and particulate load. A heated probe and line keep tar from condensing, blowback keeps the filter open, and a conditioner dries the gas before the analysers. i-Cons and SGI-320 are not suitable for samples containing H2S, HCl or HF.

Models and ranges

Model	Measures	Range	Sensor and notes
2015 / 2030	CO	ppm and percent	Electrochemical and NDIR
6030, 4030	CO2 and CH4	Percent	NDIR
ACCURRA-TCD	Hydrogen	Binary or as required	Thermal conductivity
ACCURRA-S / ACCURRA-Hz	Oxygen	Trace to percent

Process notes

Syngas and coal gasification

Gasification converts coal, biomass or waste into a gas rich in carbon monoxide, hydrogen and some methane. The composition changes with feed, temperature and the oxygen or steam supplied, and it sets the heating value or the downstream synthesis route. Raw gas leaves the gasifier hot and carries tar, dust and water.

Measuring that gas means managing the sample first. A probe with a heated filter keeps tar from condensing, automatic blowback keeps the filter open, and a Peltier conditioner dries the gas before it reaches the NDIR cells. The analyser then reports CO, CO2 and CH4 reliably, and a TCD or Hz analyser covers hydrogen.

Pyrolysis

Pyrolysis heats waste plastic, tyres or biomass without oxygen to produce oil, gas and char. The gas stream is a mix of hydrogen, methane, other light hydrocarbons, CO and CO2, plus condensable vapours. The plant burns or recovers this gas, so its quality and flow matter.

Two measurements dominate. Oxygen, because air ingress during feeding or at flanges creates an ignition risk, and combustible gases, because their share shows whether the process is running as intended. Sampling is the difficult part: the gas is hot, and vapours condense as it cools, so heated probes, heated lines and a conditioner with a condensate drain are normal.

Sampling and installation

Tar and condensables decide the sample system. Send composition, temperature and particulate load.
Check for H2S, HCl and HF: i-Cons and SGI-320 are not suitable for samples containing them.
Use a heated probe and line, blowback, and a condensate drain and detector.
Safe venting of the analyser exhaust.

ACCURRA-S sample specification: non-corrosive, non-toxic, non-flammable, non-condensing and dry, free from entrained oil; sample pressure 2 to 10 psig, regulated externally; flow about 1 LPM; dust below 3 micron. Where your sample differs, we design conditioning around it.

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Application data sheet

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What the data sheet asks for

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The gases to measure, the range, and the accuracy you need
Background gases and their typical composition
Sample temperature, pressure and dew point at the tapping point
Dust level, and whether the gas carries tar, oil or condensable vapour
Process connection and, for ducts, the duct diameter
Where the sample vents to, and at what pressure
Area classification of the tapping point and of the analyser location, and the IP protection needed
Distance between the tapping point and the analyser
Outputs you need: 4-20 mA, dual range, relays, Modbus RTU
Calibration approach, calibration gas available, and whether blowback is required
Utilities at site: power supply, instrument air, nitrogen, steam and cooling water, and the ambient temperature range
Tar and particulate loading, and the sulphur content of the gas