Experimental study on methane hydrate formation in the presence of sodium dodecyl sulphate under the influence of different physical properties of silica and composite systems

Abstract

Abstract Natural gas hydrates naturally occur in pores of porous media. This study presents the first systematic investigation of methane hydrate formation in sub‐millimetre silica particles (0.4 and 0.7 mm) and larger sizes (1, 2, and 3 mm) as benchmarks. The combined matrix (0.4–3 mm) allows comprehensive evaluation of saturation, particle size, and amino acid effects with sodium dodecyl sulphate (SDS). Results show liquid‐phase saturation significantly affects gas storage capacity, with storage volume growing linearly as saturation increases. Particle size dominates kinetics by altering pore structure. The 3 mm system shows the fastest kinetics, reducing T90 by 30% and 57% versus 2 and 0.7 mm systems, respectively. However, the highest storage density occurs in 0.7 and 2 mm systems (157.38 and 151.63 V/V), exceeding the 3 mm system (149.70 V/V). Thus, a trade‐off exists between kinetic acceleration and ultimate storage capacity. Smaller sizes (≤1 mm) show hindered mass transfer due to poor pore connectivity, capillary force suppression, and sand bed migration. Conversely, larger sizes (≥2 mm) promote liquid migration by stabilizing pore structure, enhancing formation efficiency. The synergistic interaction between amino acids and SDS depends on hydrophobicity. When combined with SDS, less hydrophobic methionine (M) and valine (V) form ternary composite micelles. M + SDS enhances storage capacity by 26.7% by lowering critical micelle concentration, while V + SDS increases permeability by 52.3% via hydrogen bonding interference. Highly hydrophobic leucine (L) competes with SDS for gas‐water interface adsorption sites, causing an 8.3% storage capacity decrease for L + SDS and loss of nucleation advantage.