Metrohm has revealed how the LAR QuickTOCloop combustion system can be used to measure TOC values in condensate.
The recovery of condensate in a chemical plant requires stable and reliable TOC values since organic carbon (especially organic acids) can do serious damage in steam-producing devices.
Such condensate may contain higher amounts of salt (up to 10-15 per cent), which puts special demands on the TOC analyser because high salt contents can inhibit the efficiency of the catalyst used in most high-temperature TOC analysers.
An analyser using the UV oxidation method is totally inefficient at such high salt concentrations.
The TOC concentration of condensate water is usually <500ppb.
The speed of the analysis is also an issue.
The capacity of the buffer tanks is usually limited, and so the reaction time therefore hardly exceeds 30 minutes.
The QuickTOCloop uses combustion temperatures of 1,200C and does not need a catalyst.
Another problem when dealing with such high salt concentrations is the problem of blockages.
The QuickTOCloop's high combustion temperature is said to solve this problem.
At 1,200C all the salt will melt and move through the reactor to the condenser, where it is solved in the condense water and drained.
This technique allows the high injection volumes necessary to cover the low measuring range of 500ppb.
Every four minutes, a discrete result is produced by the analyser.
