Evolution of the Design of CH4 Adsorbents

Abstract

In this review, the evolution of paradigm shifts in CH4 adsorbent design are discussed. The criteria used as characteristic of paradigms are first reports, systematic findings, and reports of record CH4 storage or deliverable capacity. Various paradigms were used such as the systematic design of micropore affinity and pore size, functionalization, structure optimization, high throughput in silico screening, advanced material property design which includes flexibility, intrinsic heat management, mesoporosity and ultraporosity, and process condition optimization. Here, the literature is reviewed to elucidate how the approach to CH4 adsorbent design has progressed and provide strategies that could be implemented in the future.

A Computational Study on Phenyldiboronic Acid-Pillared Graphene Oxide Frameworks for Gas Storage and Separation

“…The very significant increase in the gravimetric uptake of CO 2 in this small pressure range from 1 to 5 bar also indicates that PIL-GOF-PDBA could be in the list of efficient adsorbents for CO 2 capture applications. , Even in the case of CH 4 adsorption, the calculated gravimetric and volumetric uptakes at the highest pressure studied (50 bar) are about 0.211 g/g and 226 cm 3 (STP)/cm 3 (STP: standard temperature and pressure), respectively. These values, although lower than the recent US-DOE standards (0.5 g/g and 350 cm 3 (STP)/cm 3 ), are comparable with the values obtained for a wide range of investigated adsorbents in the literature at similar thermodynamic conditions …”

“…These values, although lower than the recent US-DOE standards (0.5 g/g and 350 cm 3 (STP)/cm 3 ), are comparable with the values obtained for a wide range of investigated adsorbents in the literature at similar thermodynamic conditions. 84 The calculated adsorption isotherms for SO 2 and SF 6 , presented in Figure 4 as well, also exhibit shapes similar to the ones observed for H 2 S and CO 2 , indicating that the adsorption of SO 2 and SF 6 is very pronounced at near-ambient pressures. The calculated adsorption isotherms for pure CF 4 and N 2 O indicate that PIL-GOF-PDBA is also an efficient adsorbent for these fluids.…”

Surface-Modified Activated Carbon with a Superior CH4/CO2 Adsorption Selectivity for the Biogas Upgrading Process

“…In fact, although surface modifications can affect methane adsorption, its lower polarizability makes its effect not as significant as that for CO 2 adsorption. In several cases, surface modifications could be detrimental to methane adsorption capacity by a greater impact of the loss of surface area and porosity than the slight increase of the interaction forces strength …”

“…In several cases, surface modifications could be detrimental to methane adsorption capacity by a greater impact of the loss of surface area and porosity than the slight increase of the interaction forces strength. 98 Table 5 shows the reported CH 4 /CO 2 selectivities of different adsorbent materials. We noticed that at a pressure of 1 MPa, the two modified activated carbons presented in this work (CNR-115 ox and CNR-115 ox−am ), together with the metal−organic framework MOF-5, show the highest selectivity values.…”

Thermodynamic Behaviors of Adsorbed Methane Storage Systems Based on Nanoporous Carbon Adsorbents Prepared from Coconut Shells

“…The systems, imposing such challenging working conditions for adsorbents, should be assigned to a separate class of high-energy adsorption systems (HEAS). High performance of an adsorbent intended for HEAS requires a “tailored” porous structure [ 3 , 4 , 5 , 7 , 8 , 9 ]. In terms of the Dubinin theory of volume filling of micropores (TVFM) [ 10 ], this means that the efficient adsorbent must possess an optimal micropore half-width or radius x 0 , high micropore volume ( W 0 ), and characteristic energy of adsorption ( E 0 ) [ 11 , 12 ].…”