On-line Total Mercury Analysis with DURAG’s HM-1400TRX

DURAG’s modern Total Mercury Analyser allows the automatic online realtime analysis of any kind of emissions for Total Mercury concentration. Due to the analyser’s design it is also possible, without any major modification within the analyser, to receive speciation data, i.e. have one analyser both measure Total Mercury as well as Elemental Mercury separately and also display the concentration of Ionic Mercury. This way the user receives detailed data about the harmful and less harmful concentrations of mercury in the exhaust gas.

Mercury is one of the toxic substances on the top list of the World Health Organisation (WHO). Due to be liquid at ambient conditions Mercury is wide spread in the ambient. Coal (0, 1…0, 5 ppm), crude oil and natural gas (up to 28 mg/m³) have certain amounts of Mercury. Burning coal and natural gas or refining crude oil releases Mercury. Additionally Mercury is present in any emission from sources burning waste (Waste to Energy Plants, Incinerators, Cement Kilns).

The technical use of Mercury especially in the Chlorine Alkaline Process where Mercury is used as a liquid electrode in order to produce elemental Chlorine is the main anthropogenic source for Mercury release to the atmosphere. However, the new energy saving light bulbs are also filled with 4-5mg Mercury per lamp to brighten up the light. There are plenty of other examples for industrial usage of Mercury.

DURAG’s Total Mercury Analyser HM-1400TRX continuously draws sample gas from the emission source by means of a heated sample gas line (length preferably <20 m, however longer sample gas lines can also be realised). The sample gas then passes through a thermo-catalytic high-temperature reactor, where all mercury compounds are stoechiometrically reduced to elemental mercury which online is measured in a dual-beam CVAAS photometer at 254nm. Interferences of SO₂, NO₂, or Aromatic Hydrocarbons known from other analysers are completely eliminated because of the dual-beam UV measurement.

Span check of the analyser works automatically on a daily or weekly basis depending on the requirements of the local authorities. The principal is vaporising a defined amount of a certified Mercury solution (HgCl₂) in a vaporiser (180°C). This vaporised HgCl₂ solution is diluted in a defined amount of carrier gas and introduced right after the sample probe at the stack. This way the complete sample path incl. the heated sample gas line is included in the span check procedure.

DURAG’s Total Mercury Analyser HM-1400TRX is installed in various applications such as for example: Waste-to-Energy Plants; Hazardous Waste Incinerators; Municipal Waste Incinerators; Wastewater Sludge Incinerators; Cement Plants burning secondary fuels; Coal fired Power Plants with or without supplemental fuel; Biomass Plants; and Chemical Applications.

DURAG’s Total Mercury Analyser of course is type-approved according to European regulations. The instrument fulfils all European and US-EPA requirements and is already installed in many installations around the world. It is backed by DURAG’s unsurpassed world-wide service support.