Maximizing methane and hydrogen delivery capacity by carbon and boron nitride nanoscrolls

Abstract

The CH₄ and H₂ delivery capacity of carbon and boron nitride (BN) nanoscrolls was investigated, with a focus on optimizing the interlayer and van der Waals spacings to meet the U.S. Department of Energy (DOE) targets. Through computational simulations, the effects of interlayer spacing on CH₄ and H₂ adsorption were evaluated, revealing that while delivery quantities increase with interlayer spacing, achieving DOE targets remains a challenge for CH₄. Notably, BN nanoscrolls exhibited higher adsorption capacities compared to carbon nanoscrolls, especially under low-pressure conditions. Conversely, carbon nanoscrolls displayed greater release quantities than BN nanoscrolls. For H₂, delivery quantities met DOE targets at larger interlayer spacings, with carbon nanoscrolls requiring a spacing greater than 0.9 nm and BN nanoscrolls greater than 1.1 nm. For CH₄ delivery, temperature optimization showed significant peaks in delivery for carbon nanoscrolls at 248 K. In contrast, BN nanoscrolls did not exhibit a peak in delivery. In carbon nanoscrolls, the optimal weight and volumetric capacities for methane delivery are 0.275 g/g and 182 cm³/cm³, respectively. Meanwhile, for hydrogen, the maximum delivery achieved is 8.26 wt% and 0.044 kg/L, which surpasses the DOE's storage target of 5.5 wt% and 0.04 kg/L. The study also highlighted the importance of structural parameter optimization, with a significant increase in weight delivery (>500%) and in volume delivery (>120%) for both gases.