Papers by Keyword: Zeolite

Abstract: Bioalcohol is one of reliable renewable energy source in the future bioeconomy. Butanol is the next generation bioalcohol because of better quality comparing to lower-carbon alcohols. Its utilization to lower olefins opens the new route as chemical building blocks for polymer and value-added chemical production (instead of fossil fuel route). The n-butanol conversion to olefins was conducted over two different zeolite structures: ZSM-5 and SAPO-34. The small-pore 8-ring SAPO-34 produced exclusively C₄ in the products (more than 97%) and showed high selectivity to butene. The large-pore 10-ring ZSM-5 gave lower yield of C₄ and more classes toward larger hydrocarbon (C₅-C₁₂), which including aromatics and cyclic products. The SAPO-34 is suggested as promising shape-selective catalyst in the n-butanol conversion to butene product. The high purity butene can be used directly without further energy-consuming separation process.

Abstract: Biobutanol is an alternative energy that has been of great interest as a substitute for fossil fuel. It can be obtained from acetone-butanol-ethanol (ABE) fermentation with by-products of acetone and ethanol. In this work, the competitive kinetics of adsorption of butanol from ABE model solution was investigated on Silicalite-1 comparing to commercial ZSM-5. The adsorption was conducted in liquid phase and batch mode at 25°C between 0−90 min with the composition of ABE model solution of 1, 2, 0.33 wt% (acetone, butanol, ethanol) in aqueous solution. The Silicalite-1 shows fast adsorption of butanol from 0.5 min and possesses high adsorption capacity of 0.15 g/g, which is higher than that of the ZSM-5, 0.12 g/g. The Silicalite-1 exhibits high affinity to butanol > acetone > ethanol with selectivity of butanol-to-acetone (S_B/A) of 2.6 and butanol-to-ethanol (S_B/E) of 13.8. The good performance of Silicalite-1 adsorbent could be related to its hydrophobicity and higher micropore surface area and micropore volume as compared to ZSM-5.

Abstract: Zeolite filled polymer has recently emerged as a promising material with its immense applications. When taking water treatment into account, it is potentially an antibacterial film. In this study, poly vinyl alcohol (PVA)/chitosan/zeolite composite membranes were prepared with different proportions, including 5:1, 8:1 and 10:1 of PVA/chitosan ratios. Zeolite available in the film aimed to improve the morphology and the efficiency in water environment, with loading dosages of 10, 20 and 50 wt%, respectively. Characterization using scanning electron microscopy (SEM), SEM/EDX and X-ray diffraction (XRD) were also conducted to have a better view of the membranes. The results of antibacterial activity against aerobic bacteria using the 3M^TM Petrifilm^TM Aerobic Count (AC) Plate. The results indicated that pure chitosan film gave 75.7% of antibacterial activity and the composite film with 5:1 ratio of PVA/chitosan was the effective proportion, revealing the antibacterial rate around 53% to the applications of bacteria inhibition. The time test of antibacterial also reduced the level of bacteria in water environment to 2900 CFU of aerobic bacteria.

Abstract: Zeolite have been widely used as gas separation material with its promising properties. One of gas separation technology available is using membrane composites because of its various benefits. A synthesis of membrane composites consists of zeolite/alginate then caried out to study the effect of the addition of Ethylene Glycol (EG) to the CH₄/CO₂ selectivity performance of the membrane. Membrane synthesis varied by its mass ratio of alginate:EG for 1:0, 1:0.25, 1:0.5, 1:1, and 1:2 and evaporated in the room temperature for 72 h. Characterization of the physico/chemical properties was done with various instruments such as FT-IR (Fourier Transform Infra-Red) Spectroscopy, Texture Analyzer, SEM (Scanning Electron Microscopy), and Permeation Test Cell Unit. Addition of EG into the membrane compositions proven to improve the separation performance showed by permeation rate improvement and selectivity value. Gas selectivity separations of CH₄/CO₂ was also investigated and it can be concluded that the synthesized membranes have several promising properties to be used as CH₄/CO₂ separations membranes.

Abstract: The process of adsorption treatment of effluents from ammonium ions is considered as an integrated two-stage process consisting of the stage of adsorption of contaminants by natural sorbents in the apparatus with a stirrer and the liquid separation stage and solid phases. Mathematical models of ammonium ions adsorption from effluents by natural dispersed sorbents are proposed, based on the assumption that the process is described by Langmuir and Friendlich isotherms. The values of ion exchange equilibrium constants for different types of natural sorbents have been established by identifying experimental data for theoretical dependences. The obtained constants can be used to calculate the average concentration of ammonium ions in the solution and in the grain of the sorbent in the process of integrated adsorption process. Based on the analysis of the research results, the optimum method of the spent sorbent separation was selected - separation of the suspension of purified ammonium-containing effluents - spent sorbent under the action of gravity. Indicators of optimization of complex process of sewage treatment from ammonium ions are offered.

Abstract: In industry, synthetic zeolites are commonly used as ion-exchange materials, catalyst supports, and adsorbents. As a result, a more energy-efficient alternative for its synthesis from low-cost and accessible raw materials is needed. This study, presents the possibility of using class F South African coal fly ash (SACFA) from Lethaba thermal-power station as a precursor to produce zeolites via a microwave (MW) assisted synthesis route. The mineral content of synthetic materials was determined using X-ray florescence (XRF). Morphology was determined using a Scanning electron microscopy (SEM), elemental composition by energy dispersive spectrometer (EDS). X-ray diffractometry (XRD) was used to get structural characterization. Microwave (MW) irradiation time and intensity enhance the crystallization of the zeolite phase as a result of sufficient energy required to enable the solubility of alumina and silica from coal fly ash. The use of MW irradiation provides a green alternative to zeolite synthesis from fly ash (FA) than traditional thermal and fusion techniques, which uses a great deal of energy consumption and a longer reaction time.

Abstract: Due to repeated loads, the pavement structures will experience repeated stresses and strains resulting in permanent deformation even though the working loads are still smaller than the design load. The permanent deformation will lead to cracking and fatigue failure with the life of the pavement. This phenomenon can be reduced by increasing the stiffness, flexibility, durability, stability and water absorption of the pavement. Material modification including the utilization of waste tire rubber (WTR) and natural zeolite is one of the efforts to increase those parameters in semi flexible pavement (SFP). The aim of this study therefore, to assess the deformation and fatigue failure of SFP incorporating WTR and natural zeolite under cyclic loading. The WTR was used as an additive at the level of 3% of asphalt content while natural zeolite was used as cement replacement at the 0, 5, 15 and 25% replacement levels. Permanent deformation tests were conducted by applying wheel tracking loads with the pressure of 6.4 ± 0.15 kg/cm² on the surface of the specimens with 1260 cycles per hour while fatigue tests were conducted on the simple supported beams with the span length of 30 cm by applying forth point loading at the frequency of 10 Hz. The test results showed that the best performance in sustaining cyclic loading was achieved at the zeolite content of 5%.

Abstract: Since experiment scheme is relatively expensive and time-consuming, it is essential to combine between experiment and computer modelling modes. Artificial Neural Network (ANN) has capability to model and predict the behavior that is resulted from the experimental data. This paper presented a model of modified zeolite to enhance indoor air quality. The natural zeolite was activated and evaluated by using a set of CO₂ sensor that connected to microcontroller of Arduino. Additionally, to model and predict the output of CO₂ sensor, an optimum of ANN model was built using two hidden layers. The high correlation coefficient (R²) was 0.5264 with Mean Square Error (MSE) = 7.8714.Consequently, the prediction of ANN model was a remarkable breakthrough as indicated by its percentage difference values that is categorized into tolerable range. Ultimately, ANN model could predict and solve the technical obstacle effectively. . Keywords: Artificial Neural Network, Zeolite, Adsorption, Arduino, CO₂

Abstract: Synthesis of alginate/zeolite membrane with the glycerol plasticizer for separation of CH₄ towards CO₂ has been carried out. This study aimed to investigate the effect of glycerol addition towards physical and mechanical properties of membrane on the permeability and selectivity of CH₄/CO₂. Membrane fabrication was done with mixing of alginate and activated zeolite in the aquabidest with glycerol addition as plasticizer with mass ratio of alginate:glycerol 1:0, 1:0.25, 1:0.5, 1:1 and stirring for 24 h and templeting at room temperature. Membrane formed was tested with FTIR, XRD, SEM, Texture Analyzer and Permeation gas cell. Result showed that glycerol addition into alginate can decrease tensile strength and increase elongation value for about 20% on the mass ratio alginate:glycerol 1:1. Besides, gas permeation rate was also influence by the glycerol addition. The highest permeability of CH4 was obtained with alginate:glycerol 1:0,25 and with permeation rate 1.03 × 10^-4 cm³ (STP) cm^-2 s^-1 cmHg^-1. Meanwhile, the highest permeability of CO₂ was obtained with the mass ratio alginate:glycerol 1:0,5 with permeation rate about 1,19 × 10-5 cm³ (STP) cm^-2 s^-1 cmHg^-1. The highest selectivity indicated that separation of CH₄/CO₂ occurred well about 49.2 for alginate:glycerol 1:1.

Abstract: The article considers issues relating to the decorative concrete stability to frost impact. The study of the influence of prescription factors on the frost resistance value of composite compositions, manufactured of high-mobility mixtures, was carried out according to a symmetrical 5-factor plan with 27 experiments. Depending on the nature of the effect on the decorative composite, the variable raw materials are grouped into two groups of factors - modifications of cement-sand system, parameters of dispersed reinforcement. Kinetic curves, correlation, experimental-statistical model were constructed based on the results of the field experiments. The results of the research demonstrated – the use of zeolite instead of part of cement, glass fibres and fillers of optimal granulometric composition in combination with a plasticiser contributes to reducing integral porosity and provides the preservation of composite strength, and accordingly, resistance to climate impacts, saving the decorative properties during the operation of the decorative composite.