Design and modeling of a microscale diabatic distillation column for small capacity ammonia-water absorption systems

The concept of diabatic distillation is applied to desorption and rectification in an ammonia-water absorption system. Results of a hydrodynamic investigation of novel components for these processes are used to develop a non-equilibrium model to predict heat and mass transfer performance. A modular modeling approach is proposed whereby physical consistency of various heat and mass transfer processes is achieved while reducing model complexity. A target vapor generation rate of 3 g s(-1) with an ammonia mass fraction of 0.9985 is specified. It is shown that highly compact, lightweight desorption and rectification components can be realized. Heat source temperature and mass flow rate control are used to optimize system performance, and performance predictions are made over wide range of operating conditions. These results are also used to obtain reduced-order heat and mass transfer performance measures that facilitate incorporation of system performance into system level models and dynamic models. (C) 2018 Elsevier Ltd and IIR. All rights reserved.