CEM 2020

CEM 2018 - Abstract

Abstract Title: Reference Values in Synthetic Emission Monitoring Bench Loops
Abstract Type: Seminar
Session Choice: Emission regulation and future monitoring challenges
Presenter Name: Dr Domenico Cipriano
Company/Organisation: RSE
Country: Italy

Abstract Information :

Modern emission monitoring requires nowadays deeper skills from either Laboratories and Control Agencies. In order to fulfil such requirements and to guarantee the comparability of the measurements, Inter Laboratory Comparisons (ILCs) and Proficiency Tests (PTs) on Emission Monitoring are more and more considered as fundamental key points.

Furthermore, ILCs and PTs are tools suitable for different purposes, such as evaluation of laboratory's performances, new measurement methods, method validations and personnel training, representing one of the pillars of the quality assurance and quality control activity (QA/QC) within a laboratory.

One of the key points in the organisation of inter-laboratory comparisons is the definition of the reference material to be used and, consequently, the way to assign the reference value to the properties of interest. In the field of ILCs/PTs for emission measurements two different approach are basically followed:

  • by carrying out measurements on gas effluents produced by reals stacks;
  • by using wind galleries, in which test atmosphere is realised synthetically in order to reproduce typical stack gases.
The first solution is the most common as it has minor investments costs related to the use of existing hardware (i.e. industrial stacks). But the availability of industrial stacks is negatively compensated by the nature of the gas effluent that comes from a real combustion process, doesn't allow metrological knowledge of the chemical components present in the gas, nor, of course, modification of theirs values. In these cases, references values assigned are normally defined on the basis of a 'consensus value' calculated as the mean value of the measurement results of the laboratories participating in the ILC/PT. Such solution is commonly used to evaluate repeatability of laboratory's measurement results or to assess a formal implementation of measuring methods, but neither allows to approach the issue of the method validation nor to properly obtain information on the reproducibility.

The second approach (i.e. the wind galleries) is based on controlled flow injections of known gases in the wind gallery; this let a better definition of the effluent gases and of the related reference values. Another obvious big advantage is due to the possibility to choose different target values for every component, aspect that cannot be achieved using real stack. On the other hand, the main disadvantages are due to major complexity and higher costs of the system (building and management).

This paper presents the methodology used to implement the PTs at RSE experimental setup.