Study the Effect of Seeding Suspension Concentration of DD3R Particles on the Modified Surface of Α-Alumina Support for Preparing DD3R Zeolite Membrane with High Quality

In this study, seeding of DD3R particles as an important step in the synthesis of DD3R membrane with secondary growth method was investigated. Dip-coating method is used for seeding of DD3R particles on the modified surface of α-alumina supports. 0.1, 0.2 and 0.3 wt% aqueous suspensions of the DD3R seeds were prepared and each support was coated three times with dipping time of 240 s. Scanning electron microscopy (SEM) analysis was used for the investigation of the quality of seed layer formed on the support. It is shown that the uniform layer of seeds was formed with 0.2 wt% seed suspension concentration. DD3R zeolite membrane was synthesized via hydrothermal method on the support seeded with 0.2 wt% seed suspension concentration. The X-ray diffraction and SEM analysis confirmed the synthesis of uniform DD3R zeolite membrane layer on the support which can be due to the uniform distribution of the DD3R seeds. Single gas permeation tests of N2, CO2 and CH4 were carried out, so that good perm-selectivity for gas mixtures was observed

Hydroisomerization of n-Pentane over Pt/Mordenite Catalyst: Effect of Feed Composition and Process Conditions

The hydroisomerization of pure n-pentane over H-mordenite supported Pt-catalyst was investigated in a fixed bed reactor by changing reaction parameters such as temperature, pressure, and WHSV, as well as the H2/HC ratio. The maximum yield of isopentane over Pt/mordenite catalyst was achieved at 220 °C and a relatively low reaction pressure. To address the effect of feed composition on the catalytic performance of the samples, the catalysts were assessed for activity and selectivity in the isomerization of a mixture consisting of n-pentane (70 wt.%) and isopentane (30 wt.%) at 220 °C. The effects of pressure, WHSV, and H2/HC ratio on the catalyst performance were also studied using binary mixtures of the pentane isomers as a feedstock. It was observed that an effect of WHSV and H2/HC on the catalytic performance was similar to its behavior in pure n-pentane isomerization, while the conversion of n-pentane in the binary mixture showed a different trend and had a minimum value at 1.5 bar. It could be due to the presence of isopentane in feed and adsorption phenomenon of binary mixture on mordenite-supported catalyst

Study of synthesis parameters and photocatalytic activity of TiO2 nanostructures

In this present study, various types of TiO2 nanostructures were synthesised via hydrothermal method from a commercial titanium dioxide. The effects of the initial concentration of titanium dioxide and the reaction time on the morphology of synthesised nanostructures were investigated. The TiO2 nanostructures were calcined at 500 °C and examined for the photocatalytic performance by decomposing formic acid as an organic pollutant. Scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller and X-ray diffraction were employed to characterise the synthesised TiO2 nanostructures. The outcomes showed more influence of reaction time rather than initial TiO2 concentration on the properties of TiO2 nanostructures. Various TiO2 nanostructures such as, nanorods and nanotubes were fabricated at different initial TiO2 concentrations and reaction times. In addition, the synthesised nanorod structures showed higher photocatalytic activity than the nanotubes. This is owing to the presence of rutile–anatase combined crystalline phases in the nanorod structures