Investigation on Thermal Runaway in Batch Reactors by Parametric Sensitivity Analysis

Abstract

A batch system is an inherently parametric sensitivity system where small changes of input parameters can induce large changes of output variables. In the present work, temperature and temperature sensitivity with respect to the initial temperature were investigated by parametric sensitivity analysis using a dimensionless batch reactor model. The influence of the Semenov number, the heat of reaction parameter and the Arrhenius-type number on reactor temperature and temperature sensitivity were studied. It is demonstrated that batch reactors can exhibit high sensitivity when small changes in input parameters lead to large changes in temperature and temperature sensitivity trajectories. A criterion is established for thermal runaway by analyzing temperature sensitivity trajectories and applied to some experimental examples. This criterion allows runaway and safe conditions to be identified, the results being in agreement with the experimental data. The proposed criterion can satisfactorily predict the safety limits of the operating conditions.

Análisis de la Sensibilidad Paramétrica de la Síntesis de o-Nitroanilina en un Reactor Batch Industrial

“…Existen tres métodos para evaluar los coeficientes de sensibilidad (Jiang et al, 2011): (i) El método diferencial directo; (ii) El método de las diferencias finitas; y (iii) El método de la función de Green. Para el caso bajo estudio se aplicará el método diferencial directo, expresando en términos matriciales como se muestra en la ecuación (8):…”

Thermal risk in batch reactors: Theoretical framework for runaway and accident

“…The chemical reactions running within these kinds of reactors are usually strongly exothermic (De Filippis et al, 2002;Jiang et al, 2011;Liu and Jiang, 2006). Under given conditions, the heat generated by reaction may be much more than the heat evacuated by the system.…”

Parametric sensitivity of pH and steady state multiplicity in a continuous stirred tank bioreactor (CSTBR) using a lactic acid bacterium (LAB),Pediococcus acidilactici

“…Due to open dynamics and nonlinear nature of growth kinetics of microbes, CSTBRs are susceptible to multiplicity of steady states and parametric sensitivity. Although studies on multiplicity and parametric sensitivity of non‐isothermal and non‐adiabatic CSTRs are well advanced and it is now possible to predict a priori the criteria of runaway condition of conventional chemical reactors, more research studies are required for bioreactors, CSTBRs in particular.…”