This quarter, the authors turned their attention to sorbent durability studies by beginning a multicycle run. By the end of the quarter, nineteen complete cycles had been completed with little or no evidence of sorbent deactivation. Prebreakthrough H{sub 2}S concentrations below the thermal conductivity detector limit of about 100 ppmv were achieved in all cycles. The time, t{sub 0.5}, required for the H{sub 2}S concentration in the product gas to reach 0.5% (50% of the inlet concentration) varied only between 97 and 106 minutes in the 19 cycles. Significant, t{sub 0.5} for the 19th cycle was 103 minutes, among the largest of all cycles. SO{sub 2} breakthrough during regeneration showed similar good reproducibility. t{sub 0.5} for regeneration only varied between 20.6 and 22.9 minutes. The concentration of elemental sulfur (considered as S{sub 2}) in the product gas exceeded 10% for more than 15 minutes in each cycle. By the end of December, the sorbent had been exposed continuously to temperatures ranging from 600 to 800 C for more than one month in gas compositions ranging from 100% H{sub 2} to air, and from 1% H{sub 2}S/10% H{sub 2}N{sub 2} to 12% SO{sub 2}/N{sub 2}. Between regeneration and sulfidate, the system was purged by nitrogen. The sorbent was at the highest temperature of 800 for about 90% of that time. These sorbent durability results are considered to be quite favorable.