Large Volume Inorganic Chemicals - Ammonia ... - ammk-rks.net

Chapter 4Achieved environmental benefitsNote: Conversion rates, tail gas SO 2 concentrations and specific SO 2 load in tail gases arecorrelated, see Figure 4.7, Figure 4.8 and Figure 4.9.Average daily conversion rates of at least 99.7 – 99.9 % with double contact processes [154,TWG on LVIC-AAF]. Conversion rates of 99.8 % are achievable with four catalyst beds andinlet gas of low variabilility. With four catalyst beds and inlet gases from non-ferrous metalproduction (higher variability), 99.7 % are achievable [57, Austrian UBA, 2001]. For examplesof degree of variation of the SO 2 inlet concentration and the variation of the conversion rate, seeFigure 4.12 and Figure 4.13.For energy recovery and export, see Section 4.4.15.99,914Conversion rate in %99,8599,899,75Conversionrate in %SO 2 inlet concentrationin % v/v131211109SO2 inlet cioncentration in % v/v99,724 hours of operation8Figure 4.12: SO 2 inlet concentration and conversion rate of production based on sulphur burning[154, TWG on LVIC-AAF, 2006]99,8012,099,7511,5Conversion rate in %99,7099,6599,6099,5599,5099,4599,4099,3599,30Conversionrate in %SO 2 inletconcentrationin % v/v11,010,510,09,59,08,58,07,57,0SO2 inlet concentration in % v/v24 hours of operationFigure 4.13: SO 2 inlet concentration and conversion rate of production based on Zn roasting[154, TWG on LVIC-AAF, 2006]174 Large Volume Inorganic Chemicals – Ammonia, Acids and Fertilisers