Lifetime of Alumina Catalysts in the Claus Reactor during Sulfur Removal from Coke-Oven Gas

Abstract

To assess the deactivation of Claus catalysts in production conditions, monitoring data for two alumina catalysts in the Claus reactor during sulfur removal from coke-oven gas at PAO Magnitogorskii Metallurgicheskii Kombinat (MMK) are analyzed, when the mean temperature (input/output) is tcat = 251°C and 254°C and the bulk flow rate is W = 800 h–1 and 1100 h–1. Statistical analysis of the rate constants $$K_{{{\text{COS}}}}^{*}$$ of carbonyl-sulfide conversion over three years shows that, in both catalysts, aging over an operational period between a month and two years corresponds to irreversible exponential loss of activity: $$K_{{{\text{COS}}}}^{*}$$ ~ exp(–λt). The parameter λ is constant over time t; that is typical of hydrothermal aging. On that basis, the activity of alumina catalysts in the Claus reactor may be predicted during their basic operating period, which is of most practical interest. The rapid deactivation of the alumina catalysts in the hydrolysis of carbonyl sulfide, which is dominant at first, is also characterized by an exponential time dependence. However, the period of rapid catalyst deactivation is limited to the first two or three weeks of operation on account of the large value of λ.