Authors:Roman Bulánek, Karel Frolich, Eva Frýdová, and Pavel Čičmanec
alkali-metal exchanged MFI zeolites with various Si/Al ratios. Adsorption is common industrial separation process, but its application to CO 2 capture is relatively new and very attractive topic at present time because the importance of the carbon
Authors:L’. Fortunová, M. Reháková, S. Nagyová, S. Dolinská, S. C. Mojumdar, and E. Jóna
The study of the sorption of pyridine derivates by copper forms of synthetic zeolite ZSM5 and natural zeolite of the clinoptilolite type (CT) is a continuation of our previous study of copper forms of zeosorbents
Authors:E. Kontori, T. Perraki, S. Tsivilis, and G. Kakali
In this work, the hydration rate and products of blended zeolite cements were studied for periods up to 360 days. Thermoanalytical
methods (TG/DTG and DTA) were applied in order to evaluate the hydration rate of blended cements, while. X-ray diffraction
and FTIR spectroscopy were used in order to identify the hydrated products. As it is concluded the incorporation of zeolite
in cement contributes to the consumption of Ca(OH)2 formed during the cement hydration and the formation of cement-like hydrated products. The pozzolanic reaction of the zeolite
is rather slow during the first days of hydration but it is accelerated after the 28 days.
Authors:A.-R. Attiah, R. Blackburn, A. Dyer, and C. Willams
Zeolites A (LTA), gismondine (GIS) and the zeotype CoAPO4-34 (CHA) were synthesised. During the syntheses, additions of Cs-137, Sr/Y-90, U and Th were made. Measurements of residual
activities at the conclusion of the syntheses enabled the estimation of the zeolite efficiency to scavenge the isotopes from
the initial solution. The majority of systems examined showed excellent radioisotope uptakes. PXRD was used to characterise
the synthesis products.
In this work, Cs+ ion sorption on some clays and zeolite were investigated. 137Cs was used as a tracer. Activities were measured with a NaI crystal gamma counter. The particle size distribution was determined
by a laser sizer. Surface area of the particles were determined by BET (Brunauer, Emmett and Teller method). Structure analysis
was made by using X-ray diffraction. The chemical compositions of the solid samples were determined using a ICAP-OE spectrometer.
Kinetic and thermodynamic parameters were determined. Due to very high uptake results; clay and zeolite can be proposed as
a good sorbents in waste management considerations.
The catalytic properties of a novel MFI-type zeolite with different SiO2/Al2O3 ratio in the dehydration of glucose to levulinic acid (LA) were investigated in this work. The results demonstrate the strength
of acidic sites and the mesoporosity of the zeolites have significant effects on LA formation.
Authors:Maria Gonçalves, Joyce Barreto, Wildson Cerqueira, and Ana Teixeira
This work evaluates the effect of the FCC catalyst components—Y zeolite, kaolin and alumina—on the formation of coke during
the cracking of heavy residue (HR) of petroleum. The Y zeolite, kaolin and alumina were mixed with a HR at a ratio of approximately
1:4. The effect was studied using dynamic thermogravimetry at a heating rate of 50 K min−1, with N2 (between 35 and 700 °C) and air (in the 700–1,000 °C temperature range). The HR analyzed in these conditions formed 8.1%
of coke. All the mixtures presented larger coke formation than that observed in pure HR. The Y zeolite presented fourfold
larger coke formation, while kaolin and alumina showed twofold higher formation than pure HR. The major focus of this study
was to verify the sensitivity of the TG technique in providing information about coke formation in the fluid catalytic process
Authors:Weihua Zou, Hongjuan Bai, Lei Zhao, Ke Li, and Runping Han
A continuous fixed-bed study was carried out by using zeolite as a low-cost adsorbent for the removal of uranium(VI) ions
from aqueous solution under the effect of various process parameters such as the pH the bed depth, the flow rate, the presence
of salt and the initial U(VI) ion concentration. The U(VI) ion uptake by zeolite increased with initial U(VI) ion concentration
and bed height, but decreased as the flow rate increased. The adsorption capacity reached a maximum at pH of 6.0. A shorter
breakthrough time was observed in the presence of salt. The experimental data obtained from the breakthrough curves were analyzed
using the Thomas model. The BDST model was also applied to predict the service times for other flow rates and initial concentrations.
The results showed that the Thomas model was suitable for the description of the whole breakthrough curve, while the data
were in good agreement with the BDST model. The columns were regenerated by eluting the bound U(VI) ions with 0.1 mol L−1 NaHCO3 solution after the adsorption studies. After desorption and regeneration with deionized water, zeolite could be reused to
adsorb uranium(VI) at a comparable capacity.