Advanced sulfur control concepts in hot-gas desulfurization technology. Quarterly technical progress report, July--September 1995

Both the Antek total sulfur analyzer and the modifications to the Shimadzu GC-14A gas chromatograph to be used for analysis for SO{sub 2} and H{sub 2}S were delivered during the quarter. Problems were faced during the installation and calibration phases of both instruments. By the end of the quarter we believe that the GC problems have been solved, but problems remain with the Antek analyzer. It appears that too much sulfur (as SO{sub 2}) reaches the UV detector and causes it to become saturated. This shows up as a maximum in the instrument calibration curve. At 200 psia, the capillary flow restrictor allows a total flow rate of about 180 sccm, and the maximum occurs at about 1 % H{sub 2}S in the calibration gas. Reducing the pressure so that the total flow is reduced to about 25 sccm shifts the calibration curve maximum to about 5.7% H{sub 2}S. It appears that we must reduce the total flow rate to the detector or provide additional dilution. This may be accomplished by increasing the resistance of the capillary restrictor, by diverting a portion of the flow leaving the pyrotube to vent, or adding an inert such as N{sub 2} to the gases exiting the pyrotube. We are in contact with Antek representatives about the problem. Both the atmospheric pressure and high pressure electrobalances were used during the quarter to study the regeneration of FeS in atmospheres of O{sub 2}/N{sub 2} or H{sub 2}O/N{sub 2}. In the atmospheric pressure unit the effects of temperature (600 - 800{degrees}C), flow rate (130 - 500 sccm), and reactive gas mol fraction (0.005 to 0.03 O{sub 2} and 0.1 to 0.5 H{sub 2}O) are being studied. Regeneration tests completed to date in the high pressure unit have utilized only O{sub 2}/N. and the parameters studied include temperature (600 - 800{degrees}C), flow rate (500 - 1000 sccm), pressure (1 - 15 atm) ad O{sub 2} mol fraction (0.005 - 0.03)