| A kinetic study of ferrous iron oxidation was conducted using redox catalysts such as: {dollar}rm Fesb2(SOsb4)sb3,{dollar} 4H{dollar}sb2{dollar}O and chelated catalysts Fe{dollar}sp{lcub}3+{rcub}/{dollar}EDTA and LO CAT (ARI-310). A synthetic gas containing 0.74% v/v hydrogen sulfide, 5.02% carbon dioxide and 94.24% nitrogen was used in a semi batch process. Hydrogen sulfide oxidation was carried out at variable temperatures, pHs and iron concentrations.; The regeneration of the catalysts was studied with air as well as in the presence of an iron oxidizing bacteria, Thiobacillus ferrooxidans. The variables such as air flow rates, pHs, temperatures and bacterial concentrations were studied and optimized. Kinetic data was also developed for the case of bacterial regeneration of ferric from ferrous iron.; The experimental data shows that all catalysts could oxidize hydrogen sulfide up to 99.75% depending on pH, temperature and iron concentration. During this oxidation process the ferric iron in the catalyst was reduced to the ferrous state. The ferric ion could be easily regenerated by bubbling air through the catalyst. By adding cells of Thiobacillus ferrooxidans, the regeneration rates could be accelerated up to 150% more than the regeneration in absence of bacteria. This finding would enable the industry to use smaller reactor sizes for the sweetening process. |
