Advanced sulfur control concepts for hot gas desulfurization technology. Quarterly report, January 1--March 31, 1997

Favorable results were achieved in the sulfidation of CeO{sub 2} by H{sub 2}S and the regeneration of Ce{sub 2}O{sub 2}S by SO{sub 2}. Successful removal of approximately 99% of the H{sub 2}S from the sulfidation gas to levels of about 100 ppmv (or lower), and the production of approximately 12% elemental sulfur (as S{sub 2}) in the regeneration product gas were highlights. Final effort in the preliminary phase included a ten-cycle test at standard sulfidation and regeneration conditions with little or no sorbent deterioration. In the initial test of the detailed experimental phase of the program, the authors investigated the effect of temperature on the regeneration reaction. Results of preliminary tests showed that the Ce{sub 2}O{sub 2}S-SO{sub 2} reaction did not occur at 350 C, and all subsequent regeneration tests were at 600 C where the reaction was rapid. Significant progress has been made on the process analysis effort during the quarter. Detailed process flow diagrams along with material and energy balance calculations for six design case studies were completed in the previous quarter. Two of the cases involved two-stage desulfurization with steam regeneration, three used two-stage desulfurization with SO{sub 2} regeneration, and the sixth was based on single-stage desulfurization with elemental sulfur recovery using the DSRP concept. In the present quarter, major process equipment was sized for each of the six cases. Preliminary annual operating and levelized total cost estimates were then completed for two design cases--one involving two-stage desulfurization with SO{sub 2} regeneration and the second based on single-stage desulfurization with DSRP