Project - Metrology for Sampling and Conditioning SO₂ Emissions from Stacks: Sulf-Norm

NPL with 8 other partners have been awarded a European project to investigate sampling and conditioning of SO₂ emissions from stacks, click here to view the synopsis of the project.

The current SRM for SO₂ involves extracting industrial emissions and stack gas and passing it through a series of glass impingers filled with H₂O₂(aq) in which the SO₂ is dissolved as sulphate. Off-line analysis of each sample performed in a chemistry laboratory then gives a sulphate concentration, which can be related back to the in-stack concentration. Hence, the SRM is based on ‘unconditioned sampling’ as there is no need to remove water vapour from the extracted stack gas. Many in the community wish to move towards using direct analysis instrumental techniques (e.g. non-dispersive infrared: NDIR) in order to realise the uncertainty and sensitivity requirements needed for enforcing increasingly stringent emission limits. However, such techniques rely on “conditioned sampling” and there is as yet insufficient evidence that the various conditioned sampling approaches proposed are able to transfer extracted stack gas streams to the analytical instrument without physical and chemical changes occurring. If the community is to move towards such instrumental techniques for SO₂ it must first be demonstrated that conditioned sampling can be carried out compliant with current and future uncertainty requirements.

One of the first activities, which is led by the STA, is to canvass opinion from European companies involved in emission monitoring of SO₂.
We invite you to participate in a survey.

This project has received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme’.