| 19924962 |
Gendel Y, Levi N, Lahav O: H2S (g) removal using a modified, low-ph liquid redox sulfur recovery (LRSR) process with electrochemical regeneration of the Fe catalyst couple. Environ Sci Technol. 2009 Nov 1;43(21):8315-9.
A modified pH 1.0 liquid redox sulfur recovery (LRSR) process, based on reactive absorption of H (2) S ((g)) in an acidic (pH 1.0) iron solution ([Fe (III)] = 9-8 g L (-1), [Fe (II)] = 1-2 g L (-1)) and electrochemical regeneration of the Fe (III)/Fe (II) catalyst couple, is introduced. Fe (II) was oxidized in a flow-through electrolytic cell by Cl (2 (aq)) formed on a Ti/RuO (2) anode. pH 1.0 was applied to retard the potential precipitation of predominantly jarosite group Fe (III) species. At pH 1.0, the presence of chloride ions at [Cl (-)] = 30 g L (-1) allows for both efficient (indirect) electrochemical oxidation of Fe (II) and efficient H (2) S ((g)) reactive absorption. The latter observation was hypothesized to be associated with higher concentrations of Fe (III)-Cl complexes that are more highly reactive toward H (2) S ((aq)) than are free Fe (III) ions and Fe-SO (4) complexes that otherwise dominate pH 1.0 Fe (III) solutions in the absence of a significant Cl (-) concentration. At the described operational conditions the rate of Fe (II) oxidation in the experimental system was 0.793 kg Fe h (-1) per m (2) anode surface area, at a current efficiency of 58%. Electricity cost within the electrochemical step was approximated at $0.9 per kg H (2) S ((g)) removed. |
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