Gas analyzers for syngas and hydrogen production on steam methane reformers

Working for you to enhance operational safety, maximize process efficiency and optimize product yield


Process control gas analyzers improve operational economics and environmental performance

The fundamentals of SMR operational economics are universal: maximize the hydrogen production and minimize hydrocarbon consumption.  For this, we use instrumentation to measure temperature, pressure and analyze gas compositions. Beyond that, expert operators and sophisticated process control algorithms have oversight 24 hours a day to ensure that the SMR runs at its sweet spot.

Production of hydrogen on an SMR consumes methane or other feedstocks in the reaction. These hydrocarbons are also used as supplemental fuel to generate the heat that is required to drive the SMR reaction kinetics forwards. Efficient hydrogen production minimizes the amount of fuel and feedstock required.  In addition to better process economics, this results in environmental benefits with fewer emissions of carbon dioxide, nitric oxide and sulfur dioxide.  Some of the most fundamental gas analysis requirements on an SMR are:

  • calculation of the energy calorific value (BTU/scf) of the incoming feedstock;
  • monitoring methane slip through the SMR;
  • controlling the steam to carbon ratio in the SMR and;
  • measurement of the final hydrogen product purity

For these diverse requirements, a wide range of gas analyzers will be required and a key factor in selecting the right analyzer is to decide what the most essential functionality is.  Perhaps the priority is continuous and instantaneous measurement of a specified molecule such as online carbon dioxide measurement using one of our direct read Uras26 NDIR gas analyzers. Or, the critical issue may be simultaneous measurement of a diverse mix of gases, for which a small delay in receiving the signal may be acceptable. For example, the BTU/scf value of the natural gas coming into the SMR is best measured using a rapid response process GC-TCD such as the PGC1000 which is optimized for natural gas BTU analysis. This instrument can analyse and characterise a gas mixture sample every two minutes.  From a precise analysis of the gas composition it is possible to calculate its BTU value using formulae described in ISO 6976:1995 Natural gas — Calculation of calorific values, density, relative density and Wobbe index from composition.


Direct read analyzers mean instant optimisation response

Direct read techniques are good for looking at individual components, but do not have the flexibility of a GC which is able to see across a broad range of species. However, the advantage of direct read gas analyzers is that they provide continuous information. There are no blind spots in the intervals between samples. Every tiny change in the process can be observed and reacted to within seconds.

Methane slip from the SMR is a perfect case for a direct read gas analyzer. Methane is IR active and can be detected with high accuracy using a non-dispersive infra-red (NDIR) analyzer such as the Uras26. Methane should be reacted to carbon dioxide, carbon monoxide and hydrogen in the SMR and if excessive amounts of methane slip through the process it is a clear sign that something is sub-optimal. For example, it could indicate that the catalyst needs replacement, or it could be caused by low temperatures in the SMR which can be corrected by increasing the amount of fuel gas supplied to the burners. Some of these changes, such as catalyst performance, are longer term. Others, such as temperature changes can happen quickly, and a direct read instrument will help to fix the issue with minimal delays meaning that the operation returns to its optimum as soon as possible.

NDIR analyzers are also ideal for measurement of the final hydrogen purity.  However, there is an irony here: to measure hydrogen, a TCD analyzer such as the Caldos27 is often used. Hydrogen is not IR active and is not detected on an NDIR. So, why do SMR operators choose an NDIR instrument to measure the final hydrogen gas purity? Because it is generally taken for granted that the gas coming off the SMR will be hydrogen but what really matters is the absence of carbon monoxide and carbon dioxide. These two gases are poisons to the hydro-treating catalysts in the subsequent processes where the hydrogen is used on the refinery. Typically, the final hydrogen product specification will have a maximum total carbon monoxide and carbon dioxide content of 10 VPM. The Uras26 is ideal for simultaneous measurement of these two components


Continuous gas analyzers for process control, energy efficiency and SMR yield optimisation

Flexibility to customize your instrument from these continuous gas analyzer modules

Uras26Uras26 – NDIR (non-dispersive infrared) analyzer. Flexible to be used across a range of gases including carbon monoxide, carbon dioxide, methane and other light hydrocarbons. Often used for steam to carbon ratio process control on steam methane reformers to optimize hydrogen or syngas production. These continuous gas analyzers are direct read instruments and therefore give maximum speed of response in process control loops.

HP30 – direct read hydrogen specific analyzer using solid state technology to eliminate interferance from matrix gases. Ideal for syngas production and SMR process control applications.

Caldos27 – TCD (thermal conductivity detector) analyzer for hydrogen measurement. Typical applications include SMR process control, especially in the PSA hydrogen purification system.


Process GCs for multicomponent gas or liquid stream analysis


PGC1000 series
 – rapid response process gas chromatograph for SMR feed gas analysis. Fitted with a TCD detector, it is ideal for calorific value (BTU) value determination of natural gas or naptha feed to SMRs. The response time is generally 2 to 3 minutes meaning that it is suitable for trimming and process optimisation. It is also often used for syngas analysis and SMR process optimisation through steam to carbon ratio control as an alternative to, or in addition to, a Uras26 NDIR gas analyzer or the HP30.
PGC5000 series – highly flexible and robust process gas chromatograph for gas and liquid stream analysis. Typical applications include full compositional analysis of pure carbon monoxide and hydrogen streams on SMRs. Can also be applied to a wide range of process and safety applications in the hydrocarbon processing industry, e.g. LNG, syngas, ethylene, methanol, ammonia.
NGC8200 series – purpose built range of high precision process GCs for natural gas composition and energy value analysis.  Especially suited to custody transfer and product metering applications. Ensures accurate invoicing and fair value exchange for traded LNG.
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