Process simulation and optimization of oxygen enriched combustion using thin polymeric membranes: effect of thickness and temperature dependent physical aging

Abstract

BACKGROUND Limited work has been available to model thickness and temperature dependent physical aging encountered in polymeric membranes for gas separation to provide physically intuitive interpretation underlying the process. The Tait equation of states has been integrated within conventional dual mode mathematical model to characterize the physical aging mechanism, whereby the model requires merely temperature dependent parameters. Subsequently, the Tait‐dual mode mechanism model has been incorporated within a succession of states methodology that quantifies transport mechanism in a countercurrent hollow fiber membrane. Finally, the developed mathematical model has been implemented in Aspen HYSYS to constitute an oxygen enrichment plant. RESULTS The simulation model has been validated with experimental observation with an acceptable error of < 6.5%. The process simulation tool has been used to evaluate the separation performance of oxygen enrichment plant using polymeric membrane with consideration of operating temperature (35–55 °C) and thickness dependent (400–1000 nm) physical aging. It is found that the optimal membrane design that generates highest profitability with physical aging consideration is at film thickness of ∼400 nm and operating temperature of 55 °C. Under such operating condition, the deviation between ideal and non‐ideal simulation model is also the smallest at ∼6%, which implies that physical aging has the least impact to the operability of the plant. CONCLUSION The developed simulation model has the potential to be applied for complex membrane system design (multiple membranes or hybrid system), scale up and optimization study that is essentially required for industrial scale application. © 2019 Society of Chemical Industry

A generalized numerical framework for solving cocurrent and counter-current membrane models for gas separation

“…In particular, it is included in the mass transfer driving force term and the derivation of the Hagen–Poiseuille equation [ 31 ]. The permeate flows inside the fiber for which the Hagen–Poiseuille equation is used [ 25 , 26 , 27 ]. The feed pressure is constant at the feed side of the membrane [ 27 , 32 ].…”

“… The permeate flows inside the fiber for which the Hagen–Poiseuille equation is used [ 25 , 26 , 27 ]. The feed pressure is constant at the feed side of the membrane [ 27 , 32 ]. The effects of pressure on membrane structure and permeability are neglected.…”

“…Lock et al. [ 27 ] utilized the finite element numerical solution for quantification of the physical aging process at different film thicknesses and operating temperatures, while using the succession of states methodology that characterizes solution diffusion model underlying membrane separation mechanism. They implemented the developed model in Aspen Hysys software for the simulation of the oxygen-enriched air combustion process.…”

Physical property and gas transport studies of ultrathin polysulfone membrane from 298.15 to 328.15 K and 2 to 50 bar: atomistic molecular simulation and empirical modelling

“…3 Since air is constituted by merely 21% of O 2 and remaining N 2 in abundance, enhancement of a membrane that exhibits good permeance and selectivity is vital to ensure good O 2 recovery and minimization of heat lost through by-products. 4 In order to be commercially viable in oxygen-enriched combustion applications, it has been reported that polymeric membranes have to minimally exhibit an ideal O 2 /N 2 selectivity of 3-6 and optimum O 2 permeance value. 5 The excellent gas separation properties can be achieved via fabrication of a membrane matrix with ultrathin dimension (<1000 A) 6 to reduce transport resistance while exhibiting satisfactory separation properties to allow transport of O 2 to the permeate while retaining N 2 in the retentate.…”

In focus: recent development of membrane technology for water and environmental applications

“…In this issue of Journal of Chemical Technology and Biotechnology (JCTB), a collection of 9 contributions that dealt with membrane science and technology, including 1 review and 8 research articles, is presented in this ‘ In Focus ’ section. The major topics of the contributions are synthesis of new nanocomposite membranes incorporated with advanced nanomaterials for both water and gas separation processes; fabrication of membranes using new materials for enhanced chlorine and solvent resistance; as well as development of a mathematical model to characterize the physical aging mechanism of polymeric membrane during oxygen enriched combustion process.…”