The determination of water in natural gas using a modified Karl Fischer titration apparatus

Abstract

The Karl Fischer titration procedure has been extensively applied in the determination of water in solids and liquids, but not in gases. In this paper a simple method for the determination of water in natural gas by use of a modified version of a commercially available Karl Fischer titration apparatus is described.

Sample gas is passed at a known flow-rate through an involatile solvent containing a measured volume of standardised Karl Fischer reagent. Complete absorption and reaction of the water in the gas in and with the Karl Fischer reagent occurs. The time taken for complete neutralisation of the Karl Fischer reagent is measured and the water content of the gas deduced.

The procedure has been successfully applied to the analysis of gases containing from 40 to 200 v.p.m. of water with the results showing a standard deviation of 3–4 per cent. Where the composition of the gas has allowed comparisons, results agree with those obtained by gravimetric, phosphorus(V) oxide cell monitor and dew-point measurement procedures.