Zeolite Beta/MCM-41 composites have been prepared with various crystallinities of zeolite Beta through a twostep crystallization process involving the combination of low crystallinity zeolite Beta synthesis gel with cetyltrimethylammonium bromide surfactant solution. The composites are characterized by XRD, SEM, Si and Al MAS NMR, N2 adsorption, NH3-TPD and catalytic cracking. The experimental ...

The addition of a small amount of NH4+ to a complex medium increased nanaomycin production by Streptomyces rosa subsp. notoensis OS-3966. The best NH4+ donor for nanaomycin production was NH4+-saturated natural zeolite, with which the maximum titer of nanaomycin E was 760 micrograms/ml, about four fold higher than the control titer. In contrast, lowering NH4+ levels by adding NH4+-trapping agen...

The nature of hydrocarbon pool (HCP) intermediates in the methanol-to-hydrocarbons (MTH) process has been thoroughly investigated, especially for BEA- and CHA-type zeolite catalysts like H-β H-SAPO-34. Herein, we further reveal dynamic mechanistic details MTH over H-ZSM-5 catalyst at 400 °C, based on dual-cycle mechanism HCP this medium-pore zeolite. Application switching sequences 13C-labeled ...

The ion exchange of Na for Cr/K, Cr/Mg and Cr/Ca in Y and X zeolites was studied using breakthrough curves. It was observed that Cr ions were able to remove some competitive ions that had already been exchanged at the zeolitic sites, producing a sequential ion exchange. Some mass transfer parameters such as length of unused bed, overall mass transfer coefficient, operational ratio and dimension...

In this paper, a novel nano crystalline sodalite was synthesized and characterized by XRF, XRD, SEM and FTIR analysis. Cu2O nanoparticles (30-60 nm) were loaded on nano zeolite bed and utilized as an adsorbent to remove dimethyl phthalate. The SEM-EDX of modified zeolite indicates that the amount of copper loading on the zeolite was 4.5 wt%. Modified nano zeolite was used as an effective adsorb...

In this work, perlite was used as a low-cost source of Si and Al in the synthesis of sodalite zeolite using hydrothermal synthesis method. Cu2O nanoparticles were coated on a bed of sodalite zeolite and used as an adsorbent for removal of diazinon from aqueous solutions. To analyze the process, a significant variable .i.e. removal efficiency (%) of diazinon and three dependent parameters as the...

Background: Volatile organic compounds (VOC) are considered as major environmental contaminants that have a harmful effect on human and ecosystem health, so much effort has been focused on their removal. The aim of this study was to investigate the removal efficiency of styrene by Zeolite Socony Mobil-5 (ZSM-5) after immobilization of nanoparticles of zinc oxide (ZnO) on it. Materials and Meth...

In the present study, transalkylation of 1,4-diispropylbenzene (DIPB) with benzene in the presence of modified beta zeolite was performed to produce cumene in a fixed bed reactor. Beta zeolite was exchanged with cerium in order to modify its catalytic activity. Activity of the modified catalyst was evaluated in the range of temperature 493K–593K, space time 4.2 kg h/kmol–9.03 kg h/k mol and ben...

Benzene alkylation with propylene was studied in the gas phase using a catalytic membrane reactor and a fixed-bed reactor in the temperature range of 200-300 °C and with a weight hourly space velocity (WHSV) of 51 h-1. β-zeolite was prepared by hydrothermal synthesis using silica, aluminum metal and TEAOH as precursors. The membrane's XRD patterns showed good crystallinity for the β-zeolite fil...