Characteristics of Methane Adsorption in Micro–Mesoporous Carbons at Low and Ultra‐High Pressure

Abstract

Adsorbed natural gas (ANG) provides a better alternative for onboard storage of methane. We have measured methane adsorption at low pressure (∼1 bar) and ultrahigh pressure (∼400 bar) for three different micro‐mesoporous carbons. The highest methane uptake was below 70 % in near‐ambient temperature and 400 bar, or 25 % at 35 bar. Although gravimetric uptake is lower than the Department of Energy (DoE) target, a comparative study suggests that this adsorption amount is higher than that of most of the metal–organic frameworks (MOFs) and all covalent–organic frameworks (COFs). The highest volumetric methane uptake was above 500 v/v at ca. 400 bar or ∼200 v/v at 35 bar (293 K), which exceeded the DoE volumetric target for methane storage and is higher than most MOFs and COFs. Heat of adsorption values are within the range of 38 to 21 kJ mol−1 in the low‐adsorption regime, higher than most MOFs or COFs. The overall results suggest that carbon‐based adsorbents still remain the most promising adsorbents for the ANG process.

Synthesis of Nitrogen and Sulfur Codoped Nanoporous Carbons from Algae: Role in CO2 Separation

“…The BET surface area, micropore volume, and total pore volume of our algae-derived carbons were higher than that of KOH-activated carbons from N. Salina and spirulina-derived carbons reported in the literature. The maximum BET SSA and total pore volume of the carbons obtained from spirulina were 2390 m 2 /g and 1.15 cm 3 /g, respectively, as observed in the literature .…”

“…We did not try to further optimize the CO 2 activation level owing to the poor pore textural properties of the resultant carbons. The nonlocal density functional theory (NLDFT)-based pore size distribution plots for all the carbons are calculated from N 2 adsorption at 77 K and CO 2 adsorption at 273 K 20,21 (Figure 1c,d). From these plots, it is clear that both spirulinaand chlorella-derived carbons have similar pores that were synthesized under similar conditions.…”

Adsorption of Rare Earth Elements onto DNA-Functionalized Mesoporous Carbon

“…The soft-templated mesoporous carbons were synthesized based on our previous publications. − Typically, 5 g of resorcinol (Sigma-Aldrich) was added to the surfactant Pluronic F127 (BASF) along with 12.5 mL of ethanol and 12.5 mL of deionized water. The mixture was then acidified with 5 mL of 37 % (v/v) hydrochloric acid (HCl) and left under continuous stirring conditions overnight.…”

Evolution of the Design of CH4 Adsorbents

“…Carbons having both mesoporosity and microporosity were found to perform better than most COFs and MOFs [165]. The study was conducted over a pressure range of 1 to 400 bar.…”