Mohammed Nasir Kajama

An Experimental Study of Catalysts and Carrier Gas Transport Through Membranes for Improved Yield of Ester Product

In this work, an initial study of heterogeneous catalyst activity and carrier gas transport through inorganic ceramic membrane for improved yield of ester product was carried out. Dowex 50W8x, Amberlyst 36, Amberlyst 15 and Amberlyst 16 cation-exchange resins were used as heterogeneous catalysts. The SEM/EDXA (The Zeiss EVO LS10) of the resin catalyst was investigated in order to determine the surface morphology. The EDXA of the catalysts showed the presence of sulphur which confirms the sulfonic acid group in the structure of the polymeric compound. FTIR (Nicolet iS10) was used for the structural analysis of the resins. The permeation properties of inorganic ceramic membrane with the carrier gases were also analysed between the gauge pressures of 0.01–1.00 bar at the temperature of 60 °C (333 K). The carrier gas permeance showed a linear dependence on the inverse square root of the gas molecular weight indicating Knudsen mechanism of transport.

Catalytic Membrane Reactor for VOC Destruction 1

Platinum-alumina (Pt/γ-Al2O3) membrane was prepared using evaporative-crystallization deposition method for volatile organic compounds (VOCs) destruction. SEM-EDXA observation, BET measurement, permeability assessment and the catalytic oxidation of propane, n-butane and propylene representing VOC was obtained. Remarkable propane conversion of VOC with Pt catalyst was achieved at moderate temperature. The temperature at which the catalytic combustion takes place for the VOC is lower than the one obtained from the literature for the same VOC on Pt/γ-Al2O3 catalysts. The conversion was achieved by varying the reaction temperature using flow-through catalytic membrane reactor operating in the Knudsen flow regime.

Single Gas Permeation on ó-Alumina Ceramic Support

This study examines the characterization (SEM-EDXA observation, BET measurement) and gas transport through a commercial tubular alumina mesoporous (20 and 500 Co) support. Single gas permeation of helium (He), hydrogen (H2), nitrogen (N2) and carbon dioxide (CO2) was measured at a temperature of 450°C and feed pressures between 0.85 up to 1.0 bar. Observation of the permeance of the alumina support revealed that the transport of the gases under these conditions is governed by Knudsen diffusion. Selectivity of 2.7 was obtained for He/N2 at 1 bar. The selectivity obtained is comparable to the theoretical Knudsen value (2.65) for He/N2.

Use Of Nanoporous Ceramic Membranes For Carbon Dioxide Separation

Natural gas processes accounts for about 5.3 billion tonnes per year of carbon dioxide (CO 2 ) emission to the atmosphere. At this rate of emission, the expectation will drastically rise if not curtailed. In order to achieve this, a cost-effective and environmental friendly technology is required. In recent times, membrane technology has been widely applied for CO 2 removal from raw natural gas components. This article examines CO 2 separation from natural gas, mainly methane (CH 4 ), through a mesoporous composite membrane. A laboratory scale tubular silica membrane with a permeable length of 348 mm, I.D and O.D of 7 and 10 mm, respectively, was used in this experiment. Scanning electron microscopy (SEM) was used to analyze the morphology of the membrane. Single gas permeation of helium (He), CH 4 , nitrogen (N 2 ), argon (Ar) and CO 2 were determined at permeation temperature range between 25 and 100 ° C and feed gauge pressure of 0.05 to 5.0 barg. Before silica modification, He recorded the highest flow rate (0.3745 l/min) while CO 2 recorded the least flow rate (0.1351 l/min) at 0.4 barg and 25 ° C. After silica modification, CO 2 flow enhances significantly (3.1180 l/min at 1.0 barg) compared to CH 4 (2.1200 l/min at the same gauge pressure) due to the influence of surface flow mechanism. Temperature variation described the applicability of Knudsen diffusion for He. A combination of viscous, surface and Knudsen diffusion transport mechanisms were obtained throughout the experiment. Membrane thickness was also calculated to be 2.5 × 10 −4 m.

Hydrogen Permeation Using Nanostructured Silica Membranes

This study examines hydrogen (H2) transport and separation factors for various gases on mesoporous membrane for unmodified and dip-coated silica membrane. Single gas permeation of H2, N2, CH4, Ar and CO2 were determined at permeation temperature of 298–373 K and feed gauge pressure of 0.1 to 0.9 barg. H2 permaetion rose from 3.3 to about 6.4 l/min at 0.9 bar. H2 selectivity over N2, CH4, Ar and CO2 for the dip-coated silica membrane at 298 K and 0.9 bar was 2.93, 2.18, 3.51 and 3.61 respectively. Observation of the permeation of these membranes revealed that the transport of gases is governed by a combination of activated transport and knudsen flow.

Experimental study of carbon dioxide separation with nanoporous ceramic membranes

This paper examines carbon dioxide (CO2) separation from natural gas, mainly methane, through a 15 nm alumina tubular ceramic membrane before and after silica modification. A laboratory scale of tubular silica membrane with a permeable length of 348 mm, I.D and O.D of 7 and 10 mm respectively was used in this experiment. Scanning electron microscopy (SEM) i.e. inner surface, outer surface and cross sectional area of the membrane were analyzed in this experiment. Single gas permeation of helium, methane, nitrogen, argon and carbon dioxide were determined at permeation temperature range between 25°C and 100°C and feed gauge pressure of 0.05 to 1.0 barg. Helium recorded the highest flow rate (0.3745 l/min) while carbon dioxide recorded the least flow rate (0.1351 l/min) at 0.4 barg and 25°C before silica modification. After silica modification, the flow rate of CO2 rose to 3.1180 l/min at 1.0 barg whereas CH4 recorded 2.1200 l/min at the same gauge pressure. Temperature variation described the applicability of Knudsen diffusion. A combination of viscous, surface and Knudsen diffusion mechanisms were obtained throughout the silica modification experiment.