An experimental study of oscillatory states in a stirred reactor

The life story of hydrogen peroxide II: a periodic pH and thermochemical drive for the RNA world

“…Experimental evidence [12][13][14][15] tells us that at higher feed concentrations than those used for figure 3, the highly exothermic, deep oxidation reaction R8 in table 1 takes over, with production of trithionate, and the kinetics are described by a simple second-order rate law. Therefore, we will not consider the regime exemplified in figure 5 further in this work, but file it away for possible future reference.…”

Pulsed activation in heterogeneous catalysis

“…The first landmark paper on periodic operation by Horn and Lin in 1967 actually deals with temperature forcing [25] and they calculated that temperature forcing can improve selectivity in a parallel (non catalytic) reaction system operated in a CSTR. This paper was the starting point for more studies, and depending on the reaction schematic and the kinetic parameters other studies found the best performance at quasi steady state (QSS: input frequency lower than system eigenfrequencies) [48,49], at the relaxed steady state (RSS: input frequency much higher than system eigenfrequencies) [50,51] or at intermediate oscillation frequencies [52] (resonance). Solutions for the limiting cases of QSS and RSS operation may be calculated using approximations of the system but for the frequencies in between there are no analytical methods to find solutions [53].…”

Mediating operation of heterogeneous CSTR

“…In this article we draw attention to the heterogeneous CSTR defined as a two-phase system with a gas mixture reacting on the surface of a solid catalyst. As usual (see, for example, Chang and Schmitz, 1975), it is assumed that thermal equilibrium exists between different phases in the reactor at all times. For a first-order reaction the heat and mass balance equations of the CSTR are…”

“…Note that a CSTR model with an added heat capacity term of solid medium mc, has been used in mathematical modeling of catalytic processes, for example, by Sheintuch and Schmitz (1977). A small influence of solid material additions has been researched (Chang and Schmitz, 1975;C h a r et al, 1987a).…”