High Molecular Permeance Dual-Layer Ceramic Membrane for Capturing CO₂from Flue Gas Stream

With the objective to create technologically advanced materials to be scientifically applicable, dual-layer silica alumina membranes were molecularly fabricated by continuous surface coating silica layers containing hybrid material onto a ceramic porous substrate for flue gas separation applications. The dual-layer silica alumina membrane was prepared by dip coating technique be-fore further drying in an oven at elevated temperature. The effects of substrate physical appear-ance, coating quantity, cross-linking agent, number of coatings and testing conditions on gas separation performance of the membrane have been investigated. Scanning electron microscope was used to investigate the development of coating thickness. The membrane shows impressive perm selectivity especially for CO2 and N2 binary mixture representing a stimulated flue gas stream.

Hydrogen Separation Using Pt-Alumina Impregnated Membrane

A tubular commercial mesoporous support was used to prepare a Pt impregnated membrane using the reservoir method and tested for moderate temperature (300°C) gas transport of hydrogen (H2), helium (He) and nitrogen (N2) gas molecules. H2 and N2 gas permeation of 6.1 and 4.5 l/min at 1.0 barg feed pressure and 25°C respectively was obtained from the support. On the other hand, H2 and N2 gas permeation of 4.6 and 1.7 l/min at 1.0 barg feed pressure and 25°C respectively was also obtained from the Pt membrane. Selectivity of H2 over He of 1.96 at 300°C and 1.6 barg for the Pt membrane was obtained and found to be higher than that of the theoretical Knudsen selectivity. Also, a selectivity of H2 over N2 of 2.72 at 25°C and 1.0 barg was obtained and found to be close to that of the theoretical Knudsen selectivity. The gas permeation and the selectivity performance of the membrane were evaluated.

Experimental Evaluation of the Mobility Profile of Enhanced Oil Recovery Gases

The mobility profiles of gases used in enhanced oil recovery (EOR) have been thoroughly investigated through the coupling operations of data mining of oilfield data and experimental data analyses. Mobility as an EOR objective function has not been previously applied to characterize potential reservoirs for EOR selection and application, even though it is a robust combinatorial function that benefits from two petrophysical variables, permeability and viscosity. The data mining approach identified mobility as a reliable objective function for reservoir characterisation. The data distribution and clustering results indicate that Gas EOR reservoirs have relatively higher mean mobility than Thermal, Microbial and Chemical EOR reservoirs. The experimental approach investigated EOR gases, CO2, CH4, N2, and Air. A modified Darcy Equation of State for gas flow through porous media was applied to evaluate which gas would competitively attain the oil displacement optimisation criterion for mobility ratio, M ≤ 1. Coupling the data mining with the experimental data results reveals that gas reservoirs can be further categorized by mobility. CH4 (18.16 mD/cp) was observed to have the highest mobility followed by Air (14.60 mD/cp), N2 (13.61 mD/cp), and CO2 (12.96 mD/cp). The gas mobility order significantly corresponds with the mobility distribution of reservoirs that implemented gas EOR processes. It was concluded that CO2 offers relatively lower mobility, therefore, it is the most competitive EOR gas to approach the mobility ratio criterion of unity or less.