Work packages

IMPRESS is made up of three technical workpages (WP1-WP3), supported by Impact (WP4) and Management (WP5) activities. The diagram below summarises the work flow within the project, showing how underpinning research and development will lead to new capabilities that will address real issues in the measurement, reporting and regulation of industrial emissions.

Work Packages

More information on the activities within each technical workpackage can be found below.

WP1: Stack Emissions - Performance of Existing SRMs and Development of Next Generation of Protocols / Techniques / Facilities

The aim of this work package is to determine to what extent existing Standard Reference Methods (SRMs) and the emissions monitoring industry proficiency are meeting recent reductions in emission limits; to develop measurement methods written into protocols for standardisation under CEN; and to both develop techniques and provide test facilities to cope with increasingly stringent emission limits in the future. This work is all geared toward periodic monitoring techniques which in accordance with EN 14181 are used to calibrate CEM systems, which most plant operators use to demonstrate compliance with emission limits.

A task group of NMI and stakeholder representatives will review the impact of recent and upcoming regulatory requirements and measurement issues with respect to current capabilities. A baseline for this will be established in terms of a robust metrological determination of current capabilities. This will be carried out by testing the performance of existing SRMs and also testing for common issues within the stack testing industry through analysis of proficiency testing data.

The outputs from the review will guide the development of measurement methods and protocol documents for submission to CEN for acceptance as Technical Specification, or where applicable, full EN standards. As an example, the project has contributed to a re-draft of EN 14181, the standard covering calibration of CEM system using periodic monitoring techniques.

A key aspect of this work will be to test techniques / protocols under real stack conditions and develop new stack simulation facilities for the future underpinning of technique development and testing monitoring industry proficiency. This later aim is particularly geared to the proficiency testing of stack sampling, one of the most challenging aspects of stack monitoring due to the difficult nature of the sample (i.e. hot, steam, dust, corrosive, etc.).

WP2: Uncertainty of Flow and Annual Emission Determination

The aim of this work package is to address the challenges related to reporting annual mass emissions for complex processes and emission patterns. This includes the need for obtaining estimates of measurement uncertainty in the emission figures. The calculation of the annual mass emission is based on synchronous measurements of flow rate and concentration, both with estimated measurement uncertainties. Measurement campaigns to establish knowledge on how the emission process varies are needed to find the correct sampling density in time and space. Infrequent sampling is, in some situations, a major source to measurement uncertainty of the reported annual mass emission. At the same time insufficient spatial distribution of flow probes in emission sources with inhomogeneous flow can lead to significant uncertainty of flow measurement.

This work package is divided into the tasks related to the:

  • identification of relevant and typical emission sources and measurement techniques of emissions to air where the annual mass emission is estimated based on data with infrequent to continuous measurements of flow rate and concentration. This will cover a range of emission patterns from stacks and buildings, flow regimes and flow measurement techniques, sampling methods and integration time for observing concentration levels, and process situations;
  • uncertainty of flow and concentration measurements for emission sources such as stacks and buildings which is related to varying speed of a pollutant in different positions in the source and in different times (inhomogeneous dynamic flow) ;
  • propagation of the uncertainties of instantaneous flow and concentration measurements into the uncertainty of the annual mass emission and the influence of sampling distribution to this uncertainty;
  • creation of a guidance document based on the simulations and the related statistical analysis for the identified typical situations. The guidance document will in particular deal with how measurement uncertainty of flow measurement and analytical values for concentration propagate to the estimated uncertainty in the reported annual mass emission.

WP3: Remote Sensing of Area Source Emissions

The aim of this work package is to carry out developmental work and author protocols to facilitate the application of open path techniques to the remote sensing of area source emissions. Existing monitoring approaches of acquiring point measurements and scaling up to represent an area have been shown to be unreliable as with many sources there are high spatial and temporal variances in emission, i.e. the measured quantity is heterogeneous in nature. Furthermore, an important part of area emissions is leaks, which given that these by definition are unexpected often escape measurement and hence are generally absent from reports. For example, in Houston, USA it has been reported that local air pollution is far higher than can be accounted for from emissions from known sources alone (e.g. stacks), which has led to proposals that the shortfall is due to leaks. Such observations have led many to question if the status-quo (i.e. point measurements, emission factors, etc.) is adequate for demonstrating compliance with emission limits.

The research and protocol development will focus on three different types of optical remote sensing techniques that can be applied to area source emissions:

  • single-ended, range-resolved measurements using Differential Absorption Lidar, where work is needed to fully characterise the emission measurement uncertainties;
  • double-ended, path-integrated measurements using tunable diode laser absorption spectrometry, where the main challenge is the derivation of emission data from the path-integrated concentration measurements;
  • optical imaging of emissions using infrared camera, where moving from visualisation to quantification of emissions requires significant research.

The experimental work on the techniques and the preparation of operational protocols will be supported by the development of test and validation facilities that enable the methods to be evaluation under controlled conditions that recreate the field conditions under which the methods will be used. The resulting validated procedures will be demonstrated during field campaigns at industrial area emission sites.