A Non-Adiabatic Model for Jacketed Agitated Batch Reactors Experiencing Thermal Losses

Abstract

Accurate modeling of process temperatures within jacketed batch reactors has the potential to mitigate the risk of thermal runaways and enhance process control. A non-adiabatic heat-transfer model is derived for the investigation of heat transfer in laboratory to pilot-scale reactors of 0.5–40 L. By accounting for heat removed from the process by a total condenser and losses through the process lid, the model is able to predict process temperature profiles within the uncertainty limits of the experimental measurements. Heat losses from the outer jacket wall had a negligible impact on the evolution of process temperature but may contribute significantly to utility costs. Jacket duty measurements implied greater heat accumulation within the reactor vessel than anticipated, equivalent to ∼60% of that in the process fluid at 40 L scale. This raises the potential for heat-transfer coefficients to be systematically under-estimated by adiabatic models, particularly at the laboratory to pilot scale.

Optimal control in reactive processing for fine chemicals and polymers in stirred jacketed batch and semi-batch reactors: A bibliography

“…Least but not last, the latterly invented models of compartmental mixing (Vivaldo-Lima et al 65 ), and the moments model (Nie et al 66 , are added. But the list is not exhaustive, a reader can find more about the mathematical models in Broadhead et al 67 , Aris 68 , Hamielec et al 69 , Richards and Congalidis 70 , Tobita and Hamielec 71 , Zaldivar et al 72 , Zaldivar et al 73 , Hernandez et al 74 , O'Donnell and Kaler 75 , Jung et al 76 , Johnson et al 77 , Varshouee et al 78 ), etc. In Table 1, a summary is given of all studies done, according to the author's knowledge, on the subject of optimal control for stirred jacketed chemical reactors for both fine chemicals and polymers processing in discontinuous/semicontinuous mode.…”

Heat Transfer and Hydrodynamics in Stirred Tanks with Liquid-Solid Flow Studied by CFD–DEM Method

“…Early research works mainly involved the simulation of heat transfers in mixers with different configurations such as the rounded-bottom vessel with an atypical helical ribbon impeller [9] and the stirred tanks with improved Intermig impellers [10]. Other researchers have focused on the heat transfer characteristics of different fluids in stirred tanks and in a jacketed stirred heat exchanger [3,[11][12][13][14][15]. Johnson et al [15] derived a non-adiabatic heat-transfer model for the study of heat transfers in laboratory to pilot-scale reactors, which could be used to predict the temperature distribution within the uncertainty of the experimental measurements.…”

“…Other researchers have focused on the heat transfer characteristics of different fluids in stirred tanks and in a jacketed stirred heat exchanger [3,[11][12][13][14][15]. Johnson et al [15] derived a non-adiabatic heat-transfer model for the study of heat transfers in laboratory to pilot-scale reactors, which could be used to predict the temperature distribution within the uncertainty of the experimental measurements. Although the above works have done a lot on the numerical study of heat transfers of single-phase flows in stirred reactors, there are still few numerical works on the heat transfer of liquid-solid flows in stirred tanks.…”