International Organization for Standardization

Stationary source emissions - Determination of the mass concentration of ammonia in flue gas - Performance characteristics of automated measuring systems - First Edition
 N 17179

Annotation

This International Standard specifies the fundamental structure and the most important performance characteristics of automated measuring systems for ammonia (NH3) to be used on stationary source emissions, for example, combustion plants where SNCR/SCR NOx control systems (deNOx systems) are applied. The procedures to determine the performance characteristics are also specified. Furthermore, it describes methods and equipment to determine NH3 in flue gases including the sampling system and sample gas conditioning system.

This International Standard describes extractive systems, based on direct and indirect measurement methods, and in situ systems, based on direct measurement methods, in connection with a range of analysers that operate using, for example, the following principles:

— ammonia conversion to, or reaction with NO, followed by chemiluminescence (CL) NOx difference measurement for ammonia (differential NOx);

— ammonia conversion to, or reaction with NO, followed by non-dispersive ultraviolet (NDUV) spectroscopy NOx difference measurement for ammonia (differential NOx);

— Fourier transform infrared (FTIR) spectroscopy;

— non-dispersive infrared (NDIR) spectroscopy with gas filter correlation (GFC);

— tuneable laser spectroscopy (TLS).

The method allows continuous monitoring with permanently installed measuring systems of NH3 emissions, and is applicable to measurements of NH3 in dry or wet flue gases, for process monitoring, long term monitoring of the performance of deNOx systems and/or emission monitoring.