Effect of the conditions of n-decane dehydrogenation on deactivation of the alumina-platinum catalyst

Abstract

1. Deactivation of the alumina-platinum catalyst in the n-decane dehydrogenation increases with an increase in temperature (430–500°C), and decreases with an increase in either the presence of hydrogen (1·105−2.3·105 Pa) or the molar dilution of the hydrocarbon with hydrogen (4–16). 2. Under all conditions, the degree of deactivation of the catalyst, the accumulation of carbon on the catalyst surface, and combined yield of olefins and diolefins vary in parallel. 3. The degree of deactivation of the catalyst in n-decane dehydrogenation depends on both the amount of coke formed on the catalyst surface, decreasing as the latter increases. 4. Any alteration of parameters (temperature, space velocity, partial pressure of hydrogen, hydrogen dilution) which increases the yield of monoolefins and diolefins in the n-decane dehydrogenation reduces the stability of operation of the catalyst. By varying two of these parameters simultaneously it is possible to increase the yield of unsaturated hydrocarbons and to decrease the degree of deactivation of the catalyst.