The Use Of A Gas Transfer Unit To Sample Fuel Gas Streams Containing Hydrogen Sulfide For EPA Compliance Applications

摘要

Because of the concern for sulfur dioxide emissions, the EPA requires the control of sulfur in fuel gas. Specifically, the EPA requires measurement of the hydrogen sulfide in fuel gas streams. Calibration is typically 0-300 ppm/V with an alarm points at 160 ppm/V. Use of the lead acetate detection for hydrogen sulfide determination is popular because of the specificity of the detector.rnHigh range hydrogen sulfide analysis using lead acetate detection is usually performed by volumetric sampling so that the concentration of hydrogen sulfide going to the detector is within the linear range of the detector. A gas chromatographic type injection valve is used for discrete accurate sampling. Cycle frequencies for continuous on-line analysis are on the order of one injection every six seconds. With such a high injection rate wear and mechanical failure can be expected. Recently, a sampling system based on a gas transfer unit has been developed. Being without moving parts, the gas transfer unit offers an improvement in reliability over a gas chromatographic injection valve. In this paper, recent test results on the gas transfer unit will be discussed as well as its application to the analytical determination of hydrogen sulfide.