The critical condition and stability of exothermic chemical reaction in a non-isothermal reactor

Transition from Thermokinetic to Chemical Instabilities in a Modified Sal’nikov Model

“…It has been known for years that thermal oscillations occur in chemical reactions, with autocatalysis as a source of instability, in both isothermal reactors and adiabatic reactors, 16,17,31 the same type of oscillations occur in chemical processes that are known to be thermokinetically unstable. [4][5][6][7] Both kinds of oscillatory behavior (thermal and chemical) have been shown in this paper using a feasible dynamic model, which we have called the Sal'nikov unified model (see equations [8][9][10].…”

“…The model is based on equations 8-10: , where the surface disappears because all points drive the system to a stable state (k 3,0 = k 3 (T a )). (13) Following auxiliary equations for reaction rates, it is assumed that: (14) (15) (16) In this case, thermal dependence is linked to the conversion , where k 3 takes the form:…”

“…Initially, thermokinetic oscillations were of primary interest in the chemical engineering field, where the role of temperature in reactor operation is fundamental, especially if exothermic chemical reactions are involved. 15,16 These oscillations are particularly relevant in cases where uncontrolled temperature increases represent a security risk, since thermal runaway development could be a lethal hazard. 17 Additionally, several examples of thermal oscillatory behavior can be found in combustion reactions, traditionally modeled as the Sal'nikov thermokinetic oscillator.…”

The criteria of critical runaway and stable temperatures of catalytic decomposition of hydrogen peroxide in the presence of hydrochloric acid

“…(21) is the sufficient and necessary conditions for a stable reaction system. These criteria of stability had been analyzed by Luo et al [17][18][19].…”

“…The evaluations of kinetic parameters were incorporated with Semenov's sufficient and necessary conditions of thermal explosion to determine the critical runaway reaction temperatures and stable criteria [7][8][9][10][11][12][13][14][15][16][17][18][19]. The requirements of heat transfer coefficient in the critical conditions can also be estimated.…”