Determination of Hydrogen Sulfide in Refinery Fuel Gases.

摘要

Several widely employed test methods for the iodimetric measurement of hydrogen sulfide in refinery fuel gases are shown to suffer from serious thiol interferences. An absorbing solution consisting of 0.16 M cadmium sulfate/sulfuric acid at pH 3.0is shown to be effective for the collection of hydrogen sulfide in the 70-700mg/cu m range and to be essentially free from interference by up to 1800mg/cu m of methanethiol. When combined with a single 3percent hydrogen peroxide impinger,sulfur dioxide interferences of up to 1,300mg/cu m are also removed. No measureable interference results from the presence of carbon oxysulfide,ethene,dimethyl sulfoxide,or thiophene. Acetaldehyde and acetone are observed to interfere at the 2,400and 48,000mg/cu m level,respectively. It is proposed that the absorption solution described here be substituted for the cadmium hydroxide/cadmium sulfate mixture used in the EPA test method (Method 11) for determining the hydrogen sulfide content of refinery fuel gases.