This project will evaluate the industrial biomethane measurement capability for total silicon and total sulphur impurities with traceable primary gas standards and provide training in best practice sampling and analysis of biomethane within industry. It will also promote the wider uptake of standardisation of biomethane purity requirements. Furthermore, the project will meet industry’s need for standardised, reliable impurity measurements, thus improve the overall quality of the framework within the biomethane distribution network.


A key output of the preceding EMRP project ENG54 Metrology for biogas was the development of metrological infrastructure for the measurement of impurities in biogas at NMIs.

Impurities in biogas can cause extensive damage to the gas infrastructure if the impurity thresholds are not set lower than certain critical thresholds. Therefore, accurate measurement of impurity content is vital and will also help to better support the growing European biogas industry. In response to EC mandate M/475, two standards have been published which specify the maximum recommended impurity threshold levels within biomethane (EN 16723-1 and EN 16723-2).

Now that these standards are available, there is a need to increase industry’s awareness of them, in order to prepare for future legislation and facilitate the uptake of standardisation within currently employed ad-hoc gas network-entry agreements (within which local gas distributors and independent gas transporters sign unique contracts with biomethane producers to specify the level of purity testing required). These purity measurements are currently being performed throughout Europe. However, there is a lack of traceability so, robust validation through a coordinated comparison of measurement capability is required.

Additionally, there is a need to educate the industrial biomethane purity laboratories in best practice sampling and measurement in order to avoid hidden measurement bias, which can lead to incorrect pass / fail criteria being reported for biomethane purity tests due to impurities being adsorbed during sampling and analysis. Specifically, the two most challenging measurements that prone to these errors within the EN standards are total silicon and total sulphur contents, due to their highly adsorptive nature. The project will meet these needs by providing round robin comparisons of industrial laboratory measurement capability. The comparisons will be performed in conjunction with a workshop and webinar-based training on best practice in sampling and measurement of total silicon and total sulphur in biomethane. The results of the measurement capability comparison, along with the requirements of EN 16723-1 and EN16723-2, will be promoted at international events and be communicated to gas network operators and distribution companies to highlight the importance of traceability within the gas quality infrastructure.


The overall aim of the project is to use traceable primary gas standards to evaluate total silicon and total sulphur impurities in biomethane. The specific objectives are:

  1. To evaluate the measurement capability of industrial laboratories performing measurement of total silicon and total sulphur concentration in biomethane with traceable primary gas standards, and to publish the results in an industry publication or an open-access peer-reviewed journal.
  2. To disseminate knowledge outputs of EMRP project ENG54 Metrology for biogas in best practice sampling and analysis of total silicon and total sulphur concentration of biomethane to industrial analysis laboratories.
  3. To increase the awareness of standards EN 16723-1 and EN 16723-2 within the wider biogas and biomethane industry to support their wider uptake, and to provide input to ISO working group ISO/TC193/SC1/WG25 Biomethane.