Investigation into Maximum Temperature of Synthesis Reaction and Accumulation in Isothermal Semibatch Processes

Maximum
temperature of synthesis reaction (MTSR), which is a function
of the process temperature (Tp) and the
maximum accumulation (Xac,max), is an
important criterion for process hazard assessment and reactor design.
For isothermal reactions, Xac,max is influenced
by kinetics, thermodynamics and operating conditions. To analyze the
behaviors of MTSR and Xac,max, a mathematical
model for isothermal homogeneous semibatch reactors is proposed. The
influence of several dimensionless parameters (νADaRE, γ, Δτ) and reaction
orders on MTSR and Xac,max are also studied.
It is found that the MTSR curves for slow and highly exothermic reactions
tend to present a “S” shape. On the basis of the above
analysis, a semiempirical criterion is suggested to quantificationally
decide whether the MTSR curves are monotonously increasing or not.
A typical esterification reaction is conducted to validate the proposed
model and the semiempirical criterion. Applications using the mathematical
model and the criterion in hazard assessment and process optimization
are also discussed.