CEN/TC 264/WG 8 - Measurement of total mercury emissions

This document specifies requirements for the calibration and validation (QAL2), the ongoing quality assurance during operation (QAL3) and the annual surveillance test (AST) of AMS used for monitoring total mercury emissions from stationary sources to demonstrate compliance with an emission limit value (ELV). This document is derived from EN 14181 and is only applicable in conjunction with EN 14181.
This document is applicable by direct correlation with the standard reference method (SRM) described in EN 13211.

The purpose of this document is to establish performance benchmarks for, and to evaluate the acceptability of, sorbent trap monitoring systems used to monitor total vapour- phase mercury (Hg) emissions in stationary source flue gas streams. These monitoring systems involve continuous repetitive in-flue sampling using paired sorbent traps with subsequent analysis of the time-integrated samples.
This document is suitable for both short-term (periodic) measurements and long-term (continuous) monitoring using sorbent traps.
NOTE   When this Technical Specification has been validated, the sorbent trap method will be an Alternative Method subject to the restrictions on applicability defined below. Until that time, EN 13211 is the only accepted Reference Method for both short-term (periodic) measurements and for calibrating continuous monitoring systems, including those with long-term sampling systems. EN 13211 is a wet chemistry approach that relies on absorption of mercury into impinger solutions.
The substance measured according to this specification is the total vapour phase mercury in the flue gas, which represents the sum of the elemental mercury (Hg0) and gaseous forms of oxidized mercury (Hg2+), such as mercury (II) chloride, in mass concentration units of micrograms (μg) per dry meter cubed (m3). The analytical range is typically 0,1 to greater than 50 µg/m3.
The sorbent tube approach is intended for use under relatively low particulate conditions (typically less than 100 mg/m3) when monitoring downstream of all pollution control devices, e.g. at coal fired power plants and cement plants. In this case, the contribution of mercury in the particulate fraction is considered to be negligible (typically less than 5 % of total mercury). However, it shall be noted that the sorbent trap does take account of the finest particle fraction that is sampled with the flue gas, in addition to capturing the vapour phase mercury.
This specification also contains routine procedures and specifications that are designed to evaluate the ongoing performance of an installed sorbent trap monitoring system. The operator of the industrial installation is responsible for the correct calibration, maintenance and operation of this long-term sampling system. Additional requirements for calibration and quality assurance of the long-term sampling system are then defined in EN 14884 and EN 14181.

This European standard specifies a manual reference method for the determination of the mass concentration of mercury in exhaust gases from ducts and chimneys. The method is applicable for the concentration range of total mercury from 0,001 to 0,5 mg/m3 in exhaust gases with the following composition: total suspended matter from 0 to 20 mg/m3; CxHy from 0 to 10 mg/m3; HCl from 0 to 50 mg/m3; HF from 0 to 10 mg/m3; SO2 from 0 to 250 mg/m3; NOx from 0 to 500 mg/m3; CO2 from 0 to 15 vol%; H2O (g) from 10 to 25 vol% (actual); O2 from 8 to 15 vol% (dry, actual); temperature from 60 to 140°C.

This document specifies a manual reference method for the determination of the mass concentration of specific elements in stationary source emissions. The method is applicable to each of the specific elements in the concentration range of 0,005 mg/m3 to 5 mg/m3.
This document has been validated for the determination of the mass concentration of metals in incineration exhaust gases - applying the performance criteria stated in Clause 9 - for the following elements:
-   arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), antimony (Sb), thallium (Tl), and vanadium (V) and their compounds.
The document can be used to determine metals other than those listed above (for example, selenium (Se) (ISO 17211), tellurium (Te), beryllium (Be), tin (Sn) and zinc (Zn)).
NOTE 1   These other metals mentioned above are commonly required by National Regulations, but this document currently has not yet been validated for these metals.
The document was validated for waste incinerators, but it is also applicable to other industrial processes, the practical experience shows that it can be applied over wide concentration ranges and various emission sources.
If mercury is intended to be determined as well, this can be sampled in a side stream arrangement of the sampling train (EN 13211) [5].
NOTE 2   This document has been validated with the described materials, equipment, sampling, and digestion performances etc., followed by analyses with atomic absorption spectroscopy (AAS) and inductively coupled plasma optical emission spectroscopy (ICP-OES,) or inductively coupled mass spectrometry (ICP-MS). This does not exclude the use of other types of equipment or analyses that meet the requirements and have been proven to be equivalent to the described European Standard.