Oxidative Decomposition of H₂S over Alumina-Based Catalyst

Abstract

An Al 2 O 3 -based catalyst was employed for the first time in the H 2 S oxidative decomposition in order to obtain simultaneous sulfur and hydrogen. The influence of the reaction temperature (in the range of 700−1100 °C) and the contact time (in the range of 17−33 ms) were investigated in terms of H 2 S conversion, H 2 yield, and SO 2 selectivity. Good catalytic performances were obtained at 1000 and 1100 °C with experimental values very close to those ones expected from the thermodynamic equilibrium. At a temperature of 1000 °C, the H 2 S conversion and H 2 yield were, respectively, about 50% and 17%; in particular, the SO 2 selectivity decreased of a magnitude order ∼0.5% with respect to the value observed in the homogeneous case (4%). A predictive mathematical model of H 2 S oxidative decomposition in the presence of a catalyst was developed through the identification of the main reactions occurring in the system. The results obtained from the kinetic investigations evidenced that the catalyst, in addition to the H 2 S decomposition reaction and the partial oxidation reaction to sulfur, was able also to promote the SO 2 conversion by the Claus reaction allowing it to avoid the presence of SO 2 at the reactor outlet.

H2S Oxidative Decomposition Reaction in the Presence of CH4 over Metal-Sulfide-Based Catalysts: A Preliminary Investigation

“…The signals associated with the support were observed at 31, 33, 38, 39, 46, 60, and 67.5°, and they are all ascribable to Al 2 O 3 crystalline phases 30,31 (Figure 2). As already highlighted in our previous work, 13 the results evidenced the presence of mixed phases of Al 2 O 3 . 32 More precisely, the signals at about 33 and 40°could be due to the presence of the θ phase of the Al 2 O 3 crystalline structure.…”

Honeycomb Structured Catalysts for H2 Production via H2S Oxidative Decomposition

“…The measurement of the temperature in the catalytic bed was realized with a thermocouple placed in a quartz sheath, concentric to the reactor. Sulphur produced by the reaction was trapped by using a quartz-wool filter, located after the reactor in the quenching zone [7].…”

“…Finally, the comparison between the catalysed monolith and the powder catalyst was performed at 1100 • C reaction temperature and 30 ms contact time. The results of the alumina powder catalyst refers to our previous work [7]. The amount of powder catalyst used in the test is equal to 0.2 g; the mass of washcoat deposited on the cordierite monolith (at 30 wt%) is 0.2, considering that the weight of structured catalyst used in the test was 0.67 g.…”

“…In our previous works, we have studied the reaction of H 2 S thermal oxidative decomposition in homogeneous phase [5,6] and with alumina-based catalyst in powder form [7] by investigating the effect of different operating conditions (temperature, O 2 /H 2 S, H 2 S inlet concentration) on the catalytic performance. In the presence of the catalyst, the SO 2 selectivity was about 0.5% at 1000 • C, significantly lower than that observed in the homogeneous phase (4%).…”

Effective Photocatalytic Hydrogen Evolution by Cascadal Carrier Transfer in the Reverse Direction

“…6−8 In addition, the formation of hydrogen sulfide is a local problem arising in places such as volcanic zones, geothermal power plants, and oil-refining plants. 9,10 At present, the main desulfurizing processing method is the Claus process, which includes multiple steps and intense conditions. 11,12 Therefore, a novel method that employs simpler and milder conditions is required.…”