Pinch‐based shortcut method for the conceptual design of adiabatic absorption columns

Abstract

Shortcut methods are valuable tools for the fast evaluation of key performance indicators in the early phase of conceptual process design. For the design of absorption columns, operation at minimum solvent demand represents a thermodynamically sound indicator, which is, however, difficult to determine because an infinite number of separation stages need to be considered. Instead, the suggested shortcut model exploits the existence of the pinch point to identify operation at minimum solvent demand. Existing shortcut concepts, such as the well‐known equation of Kremser (Natl Pet News, 22, 43–49, 1930), are significantly outperformed by the novel shortcut model, which can be gradually refined to any desired accuracy. Integration into a stepwise procedure results in reliable solutions. The model covers rigorous thermodynamics; no simplifications regarding phase equilibrium, heat effects, or number of components are required. The performance of the method is illustrated by several case studies with up to seven components. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1213–1225, 2017

Optimization of Multiproduct Biorefinery Processes under Consideration of Biomass Supply Chain Management and Market Developments

“…For this purpose, the approach of thermodynamic insights according to Jaksland et al is utilized, which uses property ratios for a driving force determination, thereby identifying potential separations. Finally, the separation tasks are accessed using thermodynamically sound separation models. − The energy or solvent demand required for the separations is then introduced into the PNFA model, and the reaction network is extended toward a processing network containing all the different alternatives for the reactions and separations. Thus, the PNFA model uses a linear flux balance with the stoichiometric matrix A , the flux vector f and the product vector b .…”

An Overview of Computer‐aided Molecular and Process Design

“…For processes involving VLE, these models can provide an estimation of minimum reflux, minimum energy consumption, or minimum solvent demand by assuming an infinite number of separation stages [102]. Because of their thermodynamically consistent and simplified nature, pinch-based short-cut models have been applied in various applications such as adiabatic absorption [103], isothermal extraction [104], hybrid separation [100], reactive separation [105], and extractive distillation [106].…”

From Molecules to Heat‐Integrated Processes: Computer‐Aided Design of Solvents and Processes Using Quantum Chemistry

“…Compared to the original COSMO-CAMPD [25], we further extend property prediction by automated quantum chemistry and thermochemistry calculations for the ideal gas state, enabling us to predict ideal-gas heat capacities of solvents for calculating sensible heats and heat integration. We use computationally efficient pinch-based process models from literature for fast and accurate process design of entire process flowsheets, including extraction, distillation, and absorption [47][48][49] and multiphase equilibrium reactions [50]. To efficiently target the heat-integrated energy demand, we extend the framework by the transshipment model for heat integration [51].…”

“…3.1) Process units are modeled using equilibrium-and pinch-based process models. Pinch-based process models are available for the most common separation unit operations: absorption [48], extraction [49], and distillation [47]. An equilibrium-based multiphase reactor from Scheffczyk et al [50] is available using the homotopy continuation algorithm by Bausa and Marquardt [61] for phase equilibrium calculations.…”