Mapping the Material-Property Space for Feasible Process Operation: Application to Combined Natural-Gas Separation and Storage

Abstract

A multiscale-optimization-based feasibilitymapping approach is introduced to identify the target properties of materials that would guarantee the desired process performance. The approach is successfully applied to screen a database of 178 known and 139 500 hypothetical zeolites to find materials that are most suited for the combined separation and storage (CSS) of natural gas. Maps of material properties that include the equilibrium adsorption loading and the Henry coefficients are obtained for feasible process operation subject to the constraints imposed. On the basis of these maps, materials with high methane-storage capacities but moderate Henry coefficients, such as SBN and h8124791, are found to be most suitable for CSS applications. The constraints imposed on the purity of stored methane and methane loss during the process operation influence the desired material properties. Beyond identifying feasibility, maps of constraint violations are constructed that can be useful in analyzing the effects of material properties on the deviation from feasibility. Ranges of the continuous material-property space are related to the values of total and individual constraint violations, and it is observed that the constraint on loss of methane through the column outlet primarily restricts overall process feasibility for a wide range of material properties. These insights are useful in the systematic design, synthesis, and tuning of new materials for process innovation.

Nanoporous materials with predicted zeolite topologies

“…6 The PCOD has been extensively screened in the search for zeolites with specic functionalities. [9][10][11][12][13][14][15] The ToposPro program package 16 is a computer program for the topological analysis of crystal structures allowing an objective description and comparison of crystal structures. Recently, the PCOD database has been made searchable with the ToposPro package and the corresponding online TopCryst service.…”

Integrated metal‐organic framework (MOF) and pressure/vacuum swing adsorption process design:MOFmatching

“…Referring to the method proposed by Iyer and Hasan, 28 property‐performance relationships of adsorbent materials are constructed by sampling various adsorption isotherms followed by process optimizations. By doing so, the obtained results can reveal the inherent correlations between adsorption equilibrium and process feasibility.…”

Integrated metal–organic framework and pressure/vacuum swing adsorption process design: Descriptor optimization

“…For the instance of MOFs, hypothetical MOF materials are usually assembled using computational tools (e.g., ToBaCCo) and their structural feasibility is verified via ab initio calculations 26 . In addition, as stated above, computationally expensive molecular simulation is typically used to determine the adsorbent properties 27 . Clearly, it is difficult to incorporate these computations into a mathematical optimization problem.…”