Industrial & Engineering Chemistry Research, Vol.52, No.11, 4040-4048, 2013
Equilibrium Model and Performances of an Isopropanol-Acetone-Hydrogen Chemical Heat Pump with a Reactive Distillation Column
The intrinsic kinetic of the liquid-phase dehydrogenation of isopropanol over an amorphous Raney nickel catalyst was determined to be in the temperature range of 348 to 355 K. The kinetic model based on the Langmuir-Hinshelwood mechanism was adopted for experimental data fitting. An isopropanol-acetone-hydrogen chemical heat pump (IAH-CHP) with a reactive distillation column was proposed in this paper. A mathematical model was established to evaluate the energy performance of the IAH-CHP in terms of coefficient of performance (COP) and exergy efficiency, in which the obtained intrinsic kinetic was incorporated. The optimal feed location and operating pressure of the distillation column were determined first. Moreover, the thermodynamic performance of the IAH-CHP improved with the increase of hydrogen-acetone molar ratio in the entrance of the exothermic reactor and the decrease of feed temperature of the distillation. column. The operating performances between IAH-CHP with and without reactive distillation part were compared. The results indicate that the COP and exergy efficiency of an IAH-CHP system with reactive distillation part increase by 19.2% and 16.7% at most, respectively, compared with an IAH-CHP without reactive distillation part.