Advanced sulfur control concepts for hot gas desulfurization technology. Quarterly report, October--December 1995

In the area of gas analysis, most of the attention during the past quarter was devoted to gaining an understanding of the operation of the Antek total sulfur analyzer, and making appropriate modifications in the unit. The primary problem is that the resistance of the capillary flow restrictor is not large enough, and the amount of sulfur which reaches the UV-analyzer results in the analyzer becoming saturated. We have added a N{sub 2} diluent flow downstream of the pyrotube tube which, we believe, will permit the unit to be operated at pressures to about 50 psig. Use of larger diluent flow rates to permit higher pressure operation is not feasible since larger diluent rates increase the back pressure on the quartz pyrotube (which operates at 1050{degrees}C) to unsafe levels. In the meantime, Antek is studying the redesign of the capillary flow restrictor to provide larger flow resistance. Studies on the regeneration of FeS in the atmospheric pressure reactor were almost completed during the quarter. Only a series of multicycle sulfidation-regeneration tests remains. The effects of reactive gas mol fraction and temperature have been examined using both O{sub 2}/N{sub 2} and H{sub 2}O/N{sub 2} atmospheres. The initial rate of regeneration was found to be a weak function of temperature and first-order in both O{sub 2} and H{sub 2}O concentration. In a test series in which the reactive gas contained both O{sub 2} and H{sub 2}O, the experimental initial rate was effectively equal to the sum of the individual initial rates, suggesting that the two reactions proceed independently of one another. Detailed correlation and statistical analysis of the data is currently being done. Principal effort during the quarter using the high pressure electrobalance was devoted to studying the regeneration of FeS in a H{sub 2}O/N{sub 2} atmosphere