Different Types Of Porosity Research Articles

Petrophysical Parameters and Electrofacies Models of the Itararé Group Applying Multi-Resolution Graph-Based Clustering Method, Paraná Basin

Volume shale (Vsh) and effective porosity (Φe) were calculated and partially applied as petrophysical input parameters to generate electrofacies models using the Multi-Resolution Graph-Based Clustering method in sedimentary successions of the Itararé Group. The petrophysical parameters and electrofacies models were determined from geophysical data from two wells located in the eastern portion of the Paraná Basin. The stratigraphic intervals in each well (analogues of hydrocarbon reservoirs) allowed petrophysical analysis and the determination of electrofacies models based on gamma ray profiles, apparent density and neutron porosity, together with lithological data. The petrophysical parameters were calculated by different procedures, and the effective porosity results were applied as input parameters for electrofacies modeling. The electrofacies models were correlated to lithological data and patterns of gamma ray profiles and apparent density, as well as different types of porosity. The generated models provide differences related to the type of porosity, the method applied to calculate the effective porosity and present probable relationships with the lithological units of the wells.

Characterization of porosities and optimization of mix design of pervious concrete using image analysis

Although pervious reduces surface runoff and replenishes groundwater resources, industrial applications are hindered by uncertainty in properties during mass productions. Most experimental studies correlated design parameters to performance parameters predominantly analysing porosity measured from water replacement method. This explains only a fraction of porosity and leads to inappropriate correlations between the influencing parameters. This study quantified porosity using a novel image analysis. 480 samples of pervious concrete were cast varying aggregate to cement ratio and compaction levels and performance parameters such as, wet-density, compressive strength, apparent, actual and effective porosities were assessed. The developed novel image analysis method facilitates accurate computation of porosity and actual, apparent and effective porosities was analysed quantified and optimised. An optimum A/C ratio was observed as 4.0 corresponding to 30 blows of compaction and a resultant actual porosity of approximately 0.2. Further the study establishes relationships between different types of porosities and their performance implications.

Influence of Different Porosities of Titanium Meshes on Bone Neoformation: Pre-Clinical Animal Study with Microtomographic and Histomorphometric Evaluation.

The aim of this study was to evaluate the influence of different types of porosity of titanium meshes on the bone neoformation process in critical defects surgically created in rat calvaria, by means of microtomographic and histomorphometric analyses. Defects of 5 mm in diameter were created in the calvaria of 36 rats, and the animals were randomly treated and divided into the following groups (6 animals per group): NCOG (negative control, only blood clot), TEMG (Polytetrafluoroethylene-PTFE-membrane), SPTMG (small pore titanium mesh), SPMMG (small pore mesh + PTFE), LPTMG (large pore titanium mesh), and LPMMG (large pore mesh + PTFE). After 60 days, the animals were sacrificed, and the bone tissue formed was evaluated with micro-CT and histomorphometry. The data were compared using an ANOVA followed by the Tukey post-test (p ≤ 0.05). The microtomographic results showed that the SPTMG group presented the highest numerical value for bone volume/total volume (22.24 ± 8.97), with statistically significant differences for all the other groups except LPTMG. Considering the histomorphometric evaluation, groups with only porous titanium meshes showed higher values compared to the groups that used the PTFE membrane and the negative control. The SPTMG group presented higher values in the parameters of area (0.44 mm2 ± 0.06), extension (1.19 mm2 ± 0.12), and percentage (7.56 ± 1.45%) of neoformed bone. It was concluded that titanium mesh with smaller pores showed better results and that the association of PTFE membranes with titanium meshes did not improve the outcomes, suggesting a correlation between mesh porosity and underlying bone repair.

Prediction of nuclear magnetic resonance porosity well-logs in a carbonate reservoir using supervised machine learning models

Porosity estimation is a fundamental input for reservoir management and petrophysical characterization, and this feature is usually estimated based on laboratory measurements or through the use of well-logs. As an important resource for porosity quantification, nuclear magnetic resonance (NMR) well-logs are extremely useful; they allow geologists and petrophysicists to rapidly quantify different types of porosities (including total, effective, and free fluid porosity), and to perform a full formation evaluation and a reservoir quality analysis. However, the activation of wireline tools, the signal-to-noise ratio, the environmental conditions, and the characteristics of the formation fluid can create expensive and adverse conditions for subsurface acquisition. This research aims to develop machine learning models for the creation of synthetic NMR well-logs, assisted by auxiliary well-logging features. Four supervised models: multilayer perceptron neural network, AdaBoost, XGBoost, and CatBoost, comparing the adjusted R2 and RMSE. Of these, the CatBoost regressor provided the most highly optimized model. It was able to reduce local dissimilarities with the real dataset, and returned a better global metric score, yielding an adjusted R2 of 0.87 and an RMSE of less than 0.01. Moreover, all of the machine learning models provided substantial improvements in total porosity estimation, particularly compared to conventional empirical calculations based on density and sonic well-logs. An improvement of 0.5520 in the adjusted R2 was achieved for the density porosity, and 0.2 for the sonic porosity. The differences between real NMR well-logs and the machine learning outputs were in general less than 5%, for most of the well-logging interval. In addition, a tree boosted porosity model based on well-logs is presented for the first time, and the contributions and impacts of the input features on the model predictions are explored. Finally, the behaviors of the linear and nonlinear features of the model are examined, which allows us to better understand the complex relationships among the features and the dataset used.

Upscaled elasticity modulus for nuclear fuel pellet (UO2) with porosity effects

The nuclear fuel pellet is a sintered material with heterogeneous characteristics constituted of the solid- (fuel particle) and gas-phase (space between solids). For these fuel pellets, the volume averaging method (VAM) was applied to the equations governing mechanics at the microscale to calculate the upscaled elasticity modulus, which resulted in being a function of the porosity. The systematic application of VAM leads to one equation valid at pellet scales, which includes two effective tensors related to the elastic modulus and one new effective vector (interfacial elasticity coefficient) quantifying the deformation for strongly deformed materials. The analysis presented in this work considers the computation of the upscaled coefficients for four microstructure cases: slit, spherical-cup-slit, symmetric and asymmetric configurations with which is feasible to consider the different types of porosity that can occur within UO2 fuel during reactor operation. In addition, a Young's modulus correlation is proposed as a function of porosity and pressure that can be implemented in computational subroutines.

Suitability analysis of sustainable nanoporous adsorbents for higher biomethane adsorption and storage applications

Compatible pore structure of activated carbons (AC) has important role in development of adsorbed natural gas (ANG) technology. ANG has attracted attention due to mild storage conditions which makes it more easy in operation. Porous materials have played a significant role for the storing the methane rich gas on the surface. Therefore, their synthesis with compatible structures has a vital role in technological development. Activation of biomass/biochar with KOH produces hierarchical porous networks as required. However, based on the nature of biomass yields different types of porosity. Therefore, to examine it further, we have selected 10 different biomasses, especially waste for AC production. These prepared carbons were then analyzed with different techniques such as Brunauer-Emmett-Teller, X-ray diffraction, scanning electron microscope, and FT-infrared. AC produced from coconut and pistachio shells that are hard in nature are found to produce pore structure in relevant width size range for methane adsorption. Whereas other softer biomass tended to have wider pore distribution relatively. The highest volumetric ratio of ~251 v/v (uptake) and ~217 v/v (delivery) has been recorded on coconut shell AC, whereas the highest gravimetric uptake of ~0.32 g/g at 6.5 MPa recorded on karanja shell AC. Furthermore, all the properties impacting the adsorption are discussed in the view of ANG technology. Highlights Ten different waste biomass has been utilized to produce activated carbons. Methane adsorption studies are carried out to find the most competent material. Coconut shell-based carbons have shown the best storage and release capacities amongst all. Hardness in the physical nature gives narrower pore size distribution, whereas softer biomass produces wider pore distribution. Softer biomass such as agro-residues is to be avoided for the use of methane storage.

A new approach to modelling closed cell nanofoams and analysis of their mechanical properties

A new approach which is based on the discreet element method and can be used for modelling closed cell nanofoams is revealed in this study. Atomistic models of closed cell nanofoams with five different types of porosity are generated with the help of a proposed modelling technique in order to examine the role of the porosity. Following the generation of atomistic models, the mechanical behaviour is investigated by performing molecular dynamic analyses. The findings signify that such mechanical properties as elastic moduli, ultimate and yield stresses rise with decreasing porosity for both loading types. Additionally, dislocation extraction algorithm (DXA) analysis is carried out to observe the evolution of the deformation mechanism of atomistic models. Dislocation analyses show that the Shockley partial dislocation plays a huge role in the deformation mechanism.

Sedimentological and diagenetic impacts on porosity systems and reservoir heterogeneities of the Oligo-Miocene mixed siliciclastic and carbonate Asmari reservoir in the Mansuri oilfield, SW Iran

The Asmari Formation is largely affected by some diagenetic processes such as dolomitization, fracturing, and dissolution in the Mansuri oilfield. These features have commonly caused the development of different types of porosities, resulting in various pore throats throughout the reservoir rock units. In this study, the porosity system and pore throat radius were considered as the main characteristics to separate the reservoir rocks into different units with distinct petrophysical attributes. Consequently, two petrophysical methods that have the direct link with pore throat and geometry including pore throat radius at 35% of non-wetting saturation using Winland equation (R35) and hydraulic flow units using flow zone indicator (FZI) were employed to define different rock types (RT) based on their pore system. The results of the current study show that the contribution of dolomitizing fluids to precipitation of dolomite crystals and dissolution of precursor limestone compositions resulted in prevailing various porosities and pore types. This study reveals that reservoir quality decreases from rock units dominated by dolomitization and dissolution overprints (e.g., RT-1) due to improvement in connectivity between pore networks, while some particular diagenetic features such as cementation (evaporite and calcite) occluded pore throats and then decline reservoir quality in their host rock units (e.g., RT-4 and RT-5). Afterward, distribution of RTs, throughout reservoir zones proposes that the middle part of the reservoir demonstrates higher reservoir quality compared to the upper and lower part of it. Occurrence of selective (e.g. intercrystalline and intergranular) and non-selective (fracturing and vuggy) porosities in middle parts promoted reservoir quality, while domination of isolated pores (e.g., moldic and intraparticle) in upper part decreases reservoir quality.

RESERVOIR QUALITY REDUCTION CAUSED BY CLAY INDUCED DUCTILITY

Ductile components including rock fragments, clay, and matrix material are often consideredas the most important factors that control quality of shaly sandstones, which are usually characterized by low porosity and permeability. In presence of ductile components, the degree of quality reduction is affected mainly by distribution, occurences, and amounts of the ductile components. Therefore, the presence of ductile components affects rock petrophysics, and consequently has effect on fluid movements in reservoir during production. This paper presents results of the study on plug samples taken from five wells from various fields in Cooper Basin (Tirrawarra Sand), South Australia. The samples were studied petrographically using x-ray diffraction, optical petrography, and scanning electrone microscope. The results were integrated with routine and special core analysis data. The overall results show that the distribution and the amount of ductile components have significantly reduced porosity, hence the quality of the reservoir. However, the effect is different for different types of porosity, and this certainly is valuable addition to our understanding over permeability behavior of shaly sandstones.

Thermal buckling analysis of porous FGM plates

The interest of this study is the analysis of the thermal buckling problem of porous thick rectangular plates made of FGM material using high order shear theory. Material properties like Young's modulus and coefficient of thermal expansion of the plate are assumed to vary continuously in the thickness direction as a function of the volume fraction of the constituents defined with the modified mixture rule including the volume fraction of porosity with three different types of porosity distribution.The equilibrium and stability equations are obtained based on the present theory. The nonlinear governing equations are solved for simply supported plates. The thermal loads are assumed to be uniform, linear and non-linear distribution across the thickness. A parametric study will be carried out in order to underline the effects of the various parameters governing the response of thick FGM plates on the critical buckling temperature.

Microfacies, Depositional Model and Reservoir Characterization of Upper Cretaceous Kawagarh Formation, Qamar Mela Section, Nizampur Basin, Khyber Pakhtunkhwa, Pakistan.

The present study main focused on reservoir Characterization of the Upper Cretaceous Kawagarh Formation from Qamar Mela Section, Nizampur Basin. The samples were collected from the field by using standard procedures involving section measurement, lithological logging and photography. The collected samples were used to prepare the thin sections followed by petrographic analysis using Optika microscope in the laboratory. To explore the reservoir potential, we studied the impact of diagenesis on reservoir potential, supplemented by plug porosity and permeability, and SEM analysis. The outcrop is mainly composed of limestone and marl. Fifteen samples were studied from 45m thick section and two main microfacies were identified. The microfacies includes; (1). Mudstone microfacies (planktonic foraminiferal mudstone and dolomitic mudstone sub-microfacies), (2). Radiolarian bioclastic planktonic foraminiferal wackestone microfacies. The environment of deposition interpreted on the basis of microfacies for Kawagarh Formation is inner ramp to outer ramp and deep basinal settings. The Kawagarh Formation is also modified by various diagenetic features including compaction, dolomitization, dissolution, pyrite precipitation, cementation and spar filled fractures representing meteoric to marine phreatic with mixing zone and burial diagenetic environments. Dissolution, fracturing and dolomitization are the diagenetic processes which enhanced the porosity while cementation, pyrite precipitation and compaction decreased the porosity. Plug porosity and permeability of four rock samples averages 1.69% and 0.267 Ka/md, respectively. SEM analysis shows different types of porosity includes vuggy, shelter and intergranular. The low porosity and permeability levels of Kawagarh Formation suggest only a modest reservoir potential. The present study main focused on reservoir Characterization of the Upper Cretaceous Kawagarh Formation from Qamar Mela Section, Nizampur Basin. The samples were collected from the field by using standard procedures involving section measurement, lithological logging and photography. The collected samples were used to prepare the thin sections followed by petrographic analysis using Optika microscope in the laboratory. To explore the reservoir potential, we studied the impact of diagenesis on reservoir potential, supplemented by plug porosity and permeability, and SEM analysis. The outcrop is mainly composed of limestone and marl. Fifteen samples were studied from 45m thick section and two main microfacies were identified. The microfacies includes; (1). Mudstone microfacies (planktonic foraminiferal mudstone and dolomitic mudstone sub-microfacies), (2). Radiolarian bioclastic planktonic foraminiferal wackestone microfacies. The environment of deposition interpreted on the basis of microfacies for Kawagarh Formation is inner ramp to outer ramp and deep basinal settings. The Kawagarh Formation is also modified by various diagenetic features including compaction, dolomitization, dissolution, pyrite precipitation, cementation and spar filled fractures representing meteoric to marine phreatic with mixing zone and burial diagenetic environments. Dissolution, fracturing and dolomitization are the diagenetic processes which enhanced the porosity while cementation, pyrite precipitation and compaction decreased the porosity. Plug porosity and permeability of four rock samples averages 1.69% and 0.267 Ka/md, respectively. SEM analysis shows different types of porosity includes vuggy, shelter and intergranular. The low porosity and permeability levels of Kawagarh Formation suggest only a modest reservoir potential.

Nonlinear Flutter Analysis of Porous Functionally Graded Plate in Yawed Hypersonic Flow

An aerothermoelastic analysis of functionally graded plate containing porosities in ‎yawed hypersonic flows is investigated. Due to some incorrect manufacturing processes, two ‎different types of porosity, namely, even and uneven distributions are taken into account. The ‎third-order piston theory is utilized to estimate the unsteady aerodynamic pressure induced by the ‎hypersonic airflow. The material properties of a plate are assumed to vary across the thickness ‎direction according to a simple power law. Based on classical plate theory, the motion equations are ‎developed with geometric nonlinearity taking into consideration of von Karman strains. The ‎formulations are established based on Hamilton’s principle while the generalized differential ‎quadrature method is employed to solve the nonlinear aerothermoelastic equations. Due to lower ‎computational efforts‎‏, ‏the method of generalized differential quadrature (GDQM) is used to obtain ‎accurate results. Moreover, the assumed mode method along with the Runge-Kutta integration ‎algorithm is used as a solution method. The reliability and precision of the obtained results are ‎validated by published literature. Then, the influence of porosity distribution, porosity coefficient, ‎and yawed flow angle are discussed in detail. In general, this paper shows that even porosity ‎distribution would have a more destabilizing effect compared with the ‎uneven porous model.‎ And also, for both porosity distributions, the chaotic behavior appears in higher top surface ‎temperature but even porosity distribution has a profound effect on chaotic motion.‎

Advances in conceptualizing transport in chalk aquifers

Abstract The conceptualizations of matrix, fracture and fissure porosity are important for understanding relative controls on storage and flow of groundwater, and the transport of solutes (and non-aqueous phase liquids) within chalk aquifers. However, these different types of porosity, rather than being entirely distinct, represent elements in a continuum of void sizes contributing to the total porosity of the aquifer. Here we define such a continuum and critically examine the selection of appropriate values of effective porosity, a widely used parameter for mass transport modelling in aquifers. Effective porosity is a transient phenomenon, related to the porosity continuum by the timescales under which mass transport occurs. An analysis of 55 tracer tests and 20 well inflow tests in English Chalk aquifers identifies spatial scaling in groundwater velocity and groundwater flow respectively, which are interpreted within the context of the wider literature on carbonate aquifers globally. We advance transport modelling in the Chalk by developing a fissure aperture velocity mapping method using transmissivity data from existing regional groundwater models, together with the identified transient and spatial scaling phenomena. The results show that chalk aquifers exhibit widespread rapid groundwater flow which may transport contaminants rapidly in almost any setting.

Quantitative Characterization of Shale Porosities of Different Origins by Integrating Pore Genesis and Logging Analysis

Abstract In this paper, a new and pragmatic technique has been developed to identify pore types and characterize porosities of shales with various origins. By comparing the genesis of pore types (i.e., organic, brittle, and clay mineral porosities) in shales, the corresponding pore volumes per unit mass are determined as a function of the total porosity, density, and the content of each pore type from core samples. Subsequently, a new inverse framework was proposed and successfully applied to quantify different types of porosities in the Silurian Longmaxi formation shale in the Zhaotong area. The pore volume per unit mass of organic matter is calculated to be around 0.185–0.190 cm3/g, which is 10–21 and 8–19 times more than that of brittle mineral and clay mineral, respectively, indicating that pore space of organic matter contributes greater to the total porosity than that of the clay and brittle minerals. Using single well data, the porosity in organic matter is found to follow the same pattern as the total porosity in the vertical direction. Such an identified porosity type leads to more accurate sweet spots as well as more appropriate drilling locations for horizontal wells in shale reservoirs.

Statistical Analysis of Porosity and Process Parameter Relationships in Metal Additive Manufacturing

Metal additive manufacturing is susceptible to formation of porosities in the build. Numerous process and material parameters have been reported to impact formation and evolution of different types of porosities in metallic additively manufactured parts. Conducting extensive experiments is a typical approach to investigate the effects of process and material parameters to formation of porosities. In this work, a computational framework is proposed to use two-point correlations to capture statistical distribution of porosities in metallic additively manufactured parts. The proposed scheme is robustly built based on mathematics of correlation functions, by combining the overall effects of all the parameters impacting porosity formation, into a coefficient term in a Fourier-type expansion of two-point correlation statistics. The functionality of the coefficients with respect to scanning speed (i.e. a process parameter) in selective laser melting of 304L stainless steel is derived numerically and consistency of the trend in change of the coefficient values compared to porosity volume fraction is confirmed. The formalism outlined and tested in this work provides a robust framework for prediction of porosity volume fraction as a function of process parameters for metal additive manufacturing.

Influence of the Infill Orientation on the Properties of Zirconia Parts Produced by Fused Filament Fabrication.

The fused filament fabrication (FFF) of ceramics enables the additive manufacturing of components with complex geometries for many applications like tooling or prototyping. Nevertheless, due to the many factors involved in the process, it is difficult to separate the effect of the different parameters on the final properties of the FFF parts, which hinders the expansion of the technology. In this paper, the effect of the fill pattern used during FFF on the defects and the mechanical properties of zirconia components is evaluated. The zirconia-filled filaments were produced from scratch, characterized by different methods and used in the FFF of bending bars with infill orientations of 0°, ±45° and 90° with respect to the longest dimension of the specimens. Three-point bending tests were conducted on the specimens with the side in contact with the build platform under tensile loads. Next, the defects were identified with cuts in different sections. During the shaping by FFF, pores appeared inside the extruded roads due to binder degradation and or moisture evaporation. The changes in the fill pattern resulted in different types of porosity and defects in the first layer, with the latter leading to earlier fracture of the components. Due to these variations, the specimens with the 0° infill orientation had the lowest porosity and the highest bending strength, followed by the specimens with ±45° infill orientation and finally by those with 90° infill orientation.

Prediction of filtration and capacitive properties and oil saturation characteristics of complex structure carbonate reservoirs (on the example of the Northwestern part of DDB)

The world achievements of the study of carbonate reservoir rocks with secondary voids have been analyzed. An integrated approach to the study of this type of reservoir has been demonstrated on the example of reservoir rocks of the Visean strata of the South-Berestivske field in the North-Western part of the Dnipro-Donets Basin. The purpose of this article is to predict the reservoir filtration-capacitive properties, as well as oil saturation characte-ristics of complex carbonate reservoir rocks using well logging data. To solve this problem, an integrat-ed approach is used. It includes the methods of porosities balance and functional transformations (normalization) of the electrical and radioactive well logging curves (lateral logging - neutron gamma ray logging, impulse neu-tron-neutron logging - neutron gamma ray logging). As a result, the authors have identified intervals in the Visean carbonate deposits with cavernous voids and cracks. Each individual geophysical method is influenced by the structure of the void space. Due to this, when calculating the porosity coefficient for different probes, the au-thors identify intervals represented by carbonate deposits, mainly of the porous-cavernous type. However, there is an interval of 4287.6-4289.6 m of porous-cavernous-fractured type. It is established that in the selected layers the coefficients of different types of porosity are: secondary - 2.5-6%, cavernous - 1.7-5% and fracture -0.2%. The thickness of pro-ductive sediments varies within 0.8 - 2.4 m (the average value is 2 m). The authors also substantiated the choice of parameters when calculating the saturation coefficient in complex structural reservoirs. Moreover, it is noted that the reservoir properties are provided by the presence of secondary voids, namely the cavities through which the fluid is filtered, and the rock matrix is compacted, poor-porous and low-permeable.

Modelling and evaluating thermal conductivity of porous thermal barrier coatings at elevated temperatures

Thermal conductivity of various porous thermal barrier coatings (TBCs) used at elevated temperatures for gas turbines has been evaluated using the proposed six-phase model. These TBCs rely on microstructural properties and yield different types of porosities. This paper studies the thermal conductivity of TBCs based on microstructural features to evaluate the effect of different types of porosities on thermal conductivity. The first part of this paper investigates the microstructural characterization of various TBCs using image analysis (IA) technique. The second part of this paper evaluates the thermal conductivity using the image analysis. The volumetric fraction of porosities along with their orientation, shape and morphology, shows a considerable impact on the overall thermal conductivity of TBCs. The proposed six-phase model can predict thermal conductivity of porous TBCs with a good agreement with the measured values. The model results can help to better understand the effect of microstructural changes on thermal conductivity and can provide useful guide to fabricate TBCs with low thermal conductivity.

Thermal buckling of porous symmetric and non-symmetric sandwich plate with homogenous core and S-FGM face sheets resting on Pasternak foundation

The effect of porosity and thermal environment on buckling responses for the sandwich plates with different boundary conditions is analyzed and discussed in the present study. The author’s recently developed sandwich plate using a new modified sigmoid function based functionally graded material (S-FGM) plate of different symmetric and asymmetric configurations is considered. A new temperature distribution through the thickness based on modified sigmoid law is proposed in which temperature is assumed to be conducted in the thickness direction. Three different types of porosity are considered viz. even, uneven but symmetric and uneven but non-symmetric. A new uneven non-symmetric porosity model is used in which micro-voids are varied in accordance with material property variation in the thickness direction to capture the accurate distribution of voids on the plate. The principle of virtual work is employed to derive equilibrium equations. An exact solution is obtained using the assumed solution with shape functions satisfying the edge boundary conditions. This is implemented using Galerkin Vlasov’s method. The analysis has been performed to study the effect of porosity, geometric configurations, inhomogeneity parameter, and foundation parameter. It is observed that the elastic foundation parameters have the least effect on non-symmetric plate configuration subjected to nonlinear temperature distribution in comparison to other symmetric and non-symmetric plate configurations and temperature distribution. Besides, the non-symmetric plate configuration possesses maximum thermal buckling temperature in comparison to a symmetric configuration. The volume fraction exponent with value 2 is observed as a changeover point where the effect of porosity distribution is null and void for 2-1-1 plate configuration irrespective of boundary conditions. The calculated outcomes and interpretations can be useful as a validation study for the imminent investigation of sandwich S-FGM plates having porosities in the thermal environment.

MCM-22, MCM-36, and ITQ-2 Zeolites with Different Si/Al Molar Ratios as Effective Catalysts of Methanol and Ethanol Dehydration

MCM-22, MCM-36, and ITQ-2 zeolites with the intended Si/Al molar ratios of 15, 25, and 50 were synthetized and tested as catalysts for dehydration of methanol to dimethyl ether and dehydration of ethanol to diethyl ether and ethylene. The surface concentration of acid sites was regulated by the synthesis of zeolite precursors with different aluminum content in the zeolite framework, while the influence of porous structure on the overall efficiency of alcohol conversion was analyzed by application of zeolitic materials with different types of porosity—microporous MCM-22 as well as microporous-mesoporous MCM-36 and ITQ-2. The zeolitic samples were characterized with respect to their: chemical composition (ICP-OES), structure (XRD, FT-IR), texture (N2 sorption), and surface acidity (NH3-TPD). Comparison of the catalytic activity of the studied zeolitic catalysts with other reported catalytic systems, including zeolites with the similar Si/Al ratio as well as γ-Al2O3 (one of the commercial catalysts for methanol dehydration), shows a great potential of MCM-22, MCM-36, and ITQ-2 in the reactions of alcohols dehydration.