Volume 66

Amino Acid–Modified Ice Cubes as Novel Solid Matrices for Biogas/Biomethane Storage: Kinetic and Morphological Insights Kan Jeenmuang, Chan Hyoung Lee, Praveen Linga

Abstract

Achieving global net-zero targets requires urgent reductions in CO₂ emissions, underscoring the importance of renewable, carbon-neutral fuels such as biogas and biomethane. The growing demand for these fuels has intensified interest in solidified biomethane (Bio-SNG) systems as safe, compact, and energy-dense storage pathways. Conventional hydrate-based storage methods, however, often require stringent operating conditions or complex crystallizer setups, limiting their large-scale applicability. In this work, we introduce a novel concept of utilizing amino acid–modified ice cubes as a simple and low-cost medium for biogas/biomethane storage. The ice cubes, prepared with small amounts of selected amino acids, serve as pre-formed solid matrices that can rapidly encapsulate gas under mild pressure–temperature conditions. Kinetic investigations revealed that amino acid–modified ice cubes significantly reduced hydrate induction times and accelerated gas uptake compared to pure ice and bulk amino acid solution. Morphological analysis showed the development of porous, snowy cloud structures on the ice surface, which facilitated gas interaction and promoted hydrate growth. Together, these effects enabled rapid storage kinetics and high energy density, with storage capacities comparable to advanced hydrate pellet technologies. This work demonstrates amino acid–modified ice cubes as a simple and scalable route for solidified biomethane storage, opening pathways toward cost-effective and sustainable solidified biomethane technologies for renewable energy applications.

Keywords Biomethane storage, Renewable energy, Gas Hydrates, Ice cube medium, Amino acid