Numerical modeling of heat and mass transfer characteristics during the forced convection drying of a square cylinder under strong blockage

Two-dimensional analysis of heat and mass transfer during drying of a square cylinder (SC) for confined flow with a strong blockage ratio (β?=?0.8) was performed using the alternating direction implicit (ADI)-based software. The influence of Reynolds number (Re?=?10–50) and moisture diffusivity number (D?=?1?×?10^?5???1?×?10^?8?m²/s) on the heat and mass transfer mechanisms was investigated. The convective heat transfer coefficients on SC surfaces were obtained using a commercial software package. The moisture content distributions inside a SC under transient conditions were calculated using the ADI method. The calculations showed that a higher Reynolds number enhances the overall mean Nusselt number and heat transfer coefficient value. The largest mean Nusselt number and heat transfer coefficient values were obtained at the front face of the SC, which makes the greatest contribution to the overall mean Nusselt number and heat transfer coefficient values for all surfaces of the SC. The effect of Reynolds number on the overall drying time was also investigated. Low Reynolds number and moisture diffusivity values lead to an increase in the overall drying time (Δt_od). For Re?=?10, the Δt_od values are 502.19?→?220288?s and for Re?=?50, the Δt_od values are 126.14?→?70353.21?s for a moisture diffusivity range of D?=?1?×?10^?5???1?×?10^?8?m²/s. Δt_od-Re?=?10/Δt_od-Re?=?50 ratios are 3.98–3.89 and 3.13 for a moisture diffusivity range of D?=?1?×?10^?5???1?×?10^?8?m²/s. Δt_od-D2/Δt_od-D1 is 7.47 for Re?=?10, and Δt_od-D3/Δt_od-D2 is 7.63 for Re?=?50, whereas Δt_od-D3/Δt_od-D1 is 438.66 for Re?=?10, and Δt_od-D3/Δt_od-D1 is 557.74 for Re?=?50. Additionally, iso-moisture contours of SC were presented and relations for Nusselt number and mass transfer coefficient values were derived.     

Gaseous diffusion coefficients of methyl bromide and methyl iodide into air,nitrogen, and oxygen

The gaseous diffusion coefficients of methyl bromide (CH₃Br) and methyl iodide (CH₃I) into dry air, nitrogen, and oxygen have been measured in the temperature range 303–453 K and at atmospheric pressure via the Taylor dispersion method. Both for methyl bromide and methyl iodide, the diffusion coefficients do not vary in practice on substituting pure nitrogen or oxygen for dry air. The diffusion coefficients for methyl iodide are systematically smaller than those for methyl bromide by about 11%. For the methyl iodide‐oxygen system, the effect of the thermal decomposition of methyl iodide has been observed at 453 K. The present results can be reproduced well by the functional form D = AT^B, where D (cm²s^?1) is the diffusion coefficient at 101 325 Pa (1 atm) and T (K) is the absolute temperature. The constants A and B are as follows: methyl bromide‐(air, nitrogen, oxygen), A = 5.57 × 10^?6, B = 1.76; methyl iodide‐(air, nitrogen, oxygen), A = 5.26 × 10^?6, B = 1.75. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20255     

Prediction of global solar radiation from bright sunshine hours and other meteorological data

Three existing empirical relations which predict global radiation from bright sunshine hours and meteorological parameters, were tried for 14 Indian stations where all relevant data was available. A large amount of error (±50%) was found. So a new empirical relation was established between global radiation and meteorological parameters. The new relation predicted the insolation within a ±10% error limit in most cases. Global radiation dependence on ambient temperature and relative humidity was introduced through atmosperic water content per unit volume. The relation is WAT = RH(4.7923+0.3647×T+0.0055×T²+0.0003×T³)G = G_ext(0.414+0.400×SS-0.0055×WAT)$\text{SS}\text{= S}\text{Z}\text{?}$     

High temperature rate coefficient measurements of CO + O chemiluminescence

Spectral intensities from the chemiluminescent reaction CO + O → CO₂ + hv have been measured in the range 2600–7000 Å from reacting mixtures of H₂O₂COCO₂argon, shock heated in a shock tube to temperatures of 1300 and 2700K. Intergrals of the photon production rate yield an overall rate coefficient I₀ = 6.8 (±0.6) × 10⁵, exp(− 1960/T) cm³ mole⁻¹ s⁻¹. Extrapolated to 300K, this rate coefficient is in excellent agreement with the room temperature measurements of Pravilov.     

Transient Natural Convection in Horizontal Water Pipes with Maximum Density Effect and Supercooling

Abstract

Transient natural convection cooling in a horizontal water pipe with a convective boundary condition is approached by a numerical method considering maximum density effect and supercooling in order to understand the flow and temperature fields before the onset of dendritic ice. Numerical solution is obtained for initial uniform water temperature T₀ = 10[ddot]C, ambient temperature T_∞ = ?10[ddot]C, Biot number 2, size parameter ga³/v ² = 5 × 10⁷, and Pr = 13.6. The time-dependent flow and temperature fields, and mixed mean, center point, and wall temperatures are studied, and comparison is made with photographs showing dendritic ice growth in a plastic pipe for Bi = 0.2 and 15. The maximum density effect in the absence of supercooling is also studied for T₀ = 8[ddot]C, T_∞ = 0[ddot]C, and Pr = 10 with Bi = 2 and ga³/v ² = 5 × 10⁷, or with Bi = 20 and ga³/v ² = 5 × 10⁶ and 5 × 10⁷.     

Photophysical and chemical processes affecting the stability of the thiazine dye-iron system

Photo-electrochemical devices can be used under suitable conditions for production of hydrogen. The thiazine dye-iron redox system has been proposed as a photogalvanic cell, but has not been shown to function very satisfactorily. Some of the photophysical and chemical processes affecting its instability are the subject of the present investigations. The observed fluorescence quenching of electronically excited methylene blue (λ_exc = 300 nm, λ_em = 685 nm) by iron(II) ions with a Stern-Volmer constant of, K_SV = 2.1 M^?1 results in electron and energy transfer reactions. The first process causes production of semiquinone (MBH⁺), which is reversible by iron(III) ions. As a sequence of the energy transfer from the excited dye in the second band (292 to above 400 nm) to the ferrous ions, solvated electrons (e_aq^?) are generated with a quantum yield, Q = 1.4 × 10^?5. This gives rise to the appearance of H atoms, which can attack the dye at various positions with k(MB⁺ + H) = (1.5 ± 0.1) × 10¹⁰ dm³ mol^?1 s^?1 and decompose it. Pulse radiolysis experiments showed the formation of semiquinone and various types of H-adducts as well as scission of the chromophore group.For direct excitation of iron(II)-ions from 292 to 313.4 nm a Q(e_aq^?) = 3.8 × 10^?3 was established and the Q(e_aq) = 7 × 10^?2 for 253.7 nm was reproduced.     

Thermal analysis of natural convective air drying of shrinking bodies

In the present paper, a method for determination of external mass transfer coefficient h_m, during drying of shrinking bodies is described under simulated natural convective air drying conditions. The effects of sample shrinkage and air temperature on h_m during drying of cylindrical potato samples of diameter 0.01 m and length 0.05 m were experimentally investigated at air temperatures 40, 50 and 60°C. The mass transfer coefficient considering shrinkage was found to be independent of sample moisture content during drying process with mean values varying from 1.06 × 10^?7 to 2.60 × 10^?7 m s^?1 for temperature range 40–60°C. However, calculated values of h_m, with no shrinkage effect taken into account, were found to be overestimated. The experimental error in terms of percent uncertainty in mass transfer coefficient measurements was computed and found to be in the range of 0.4–2.0%. It was demonstrated that higher drying air temperature caused increased values of h_m and the variation followed Kelvin's law type relation. A mathematical model to predict the drying process of cylindrical bodies with convective mass transfer boundary condition at air–solid interface is proposed. The low range of various errors between the results of moisture content ratio predicted by the model and those obtained experimentally indicates that the present methodology is capable of simulation of drying kinetics of potato cylinders. Copyright © 2006 John Wiley & Sons, Ltd.     

Efficient photocatalytic H2 production using visible‐light irradiation and (CuAg)xIn2xZn2(1 − 2x)S2 photocatalysts with tunable band gaps

The band structures of semiconductor photocatalysts fundamentally determine the photocatalytic activity and the H₂ production from the visible‐light‐driven water‐splitting reaction. We synthesize a suite of multicomponent sulfide photocatalysts, (CuAg)_xIn_2xZn_{2(1 ? 2x)}S₂ (0 ≤ x ≤ 0.5), with tunable band gaps and small crystallite sizes to produce H₂ using visible‐light irradiation. The band gap of the photocatalysts decreases from 3.47 eV to 1.51 eV with the increasing x value. The (CuAg)_0.15In_0.3Zn_1.4S₂ (x = 0.15) photocatalyst yielded the highest photocatalytic activity for H₂ production owing to the broad visible‐light absorption range and suitable conduction band potential. Under the optimized reaction conditions, the highest H₂ production rate is 230 µmol m^?2 h^?1 with a visible‐light irradiation of 2.7 × 10^?5 einstein cm^?2 s^?1, and the quantum yield reaches 12.8% at 420 ± 5 nm within 24 h. Furthermore, the photocatalytic H₂ production is shown to strongly depend on their band structures, which vary with the elemental ratios and could be analyzed by the Nernst relation. Copyright © 2014 John Wiley & Sons, Ltd.     

Thermal decomposition of ethylene

Laser-schlieren profiles of incident shock waves in 2.5, 5, and 10% C₂H₄ in Ar were recorded for the ranges of shock front conditions 2000 < T₂ < 2540°K, 1.8 × 10^?6 < ? < 5.4 × 10^?6mol/cm³. Data analysis was accomplished by computer modeling using a 14-reaction mechanism. Most, but not all, previous observations could be accounted for with the final rate constant set. For C₂H₄ + M → C₂H₂ + H₂ + M the expression log(k₁/cm³ mol^?1 s^?1) = 17.47 – 340 kJ/RT, for C₂H₄ + M → C₂H₃ + H + M the expression log (k₂/cm³ mol^?1 s^?1) = 17.49 – 400 kJ/RT, and for C₂H₃ + H → C₂H₂ + H₂ the rate constant k₆ = 10¹³cm³ mol^?1 s^?1 were obtained.     

Global solar radiation estimation from measurements of visibility and air temperature extremes

Solar radiation is the main source of energy for the survival of life and its associated activities. It is important to know accurate solar radiation value in areas such as agricultural activities, solar energy systems, heating, and meteorology. In this study, we present a model for the estimation of solar radiation value with other meteorological parameters in cases where solar radiation cannot be measured or not available. This model is based on the relationship between solar radiation and measured air temperature and visibility extremes. As is known, the incident global solar radiation is attenuated by clouds, aerosols, ozone layer, water vapor, etc.. In the model, the attenuation of the solar radiation is expressed by dew point temperature, visibility, and the maximum and minimum air temperatures. Dew-point temperature refers to the effect of water vapor on solar radiation, air temperature extremes are used to signify cloudiness. Visibility also gives the effect on the attenuation of solar radiation by air pollutants and aerosols in the model. The model was applied to the data taken from meteorological stations in Turkey. Error analysis was performed and compared with the models in the literature and satisfactory results were obtained.

Abbreviations H: Daily total global solar radiation, units of MJ ? m^?2 ? day^?1; H₀: Extraterrestrial solar radiation, units of MJ ? m^?2 ? day^?1; H_m: Measured daily total global solar radiation, units of MJ ? m^?2 ? day^?1; H_c: Calculated daily total global solar radiation, units of MJ ? m^?2 ? day^?1; T_min: Daily minimum temperature, units of °C; T_max: Daily maximum temperature, units of °C; RH: T_dew: Relative humidity, units of %rh; Dew-point temperature, units of °C     

Hydrogen recovery from methylcyclohexane as a chemical hydrogen carrier using a palladium membrane reactor

A Pd membrane has been prepared by electroless plating on the surface of a porous TiO₂ tube in this work. The mean thickness of the resulting Pd membrane on the modified tube was 13 µm. The hydrogen permeation flux was as high as 0.16 mol m^?2 s^?1 with a pressure difference of 108.75 Pa at 648 K. H₂ permeances were 1.6 × 10^?7–6.4 × 10^?7/molm^?2 s^?1 Pa^?1/at 580–650 K. The separation factor of H₂/N₂ was over 1,000. Measurements of the temperature coefficient for hydrogen permeation through the membrane gave a value of 9.49 kJ mol^?1 in good agreement with previous reports. The results showed that the prepared membranes can be used in membrane reactors for H₂ permeation in the dehydrogenation of methylcyclohexane.     

Hydrogen effect on 2.25Cr–1Mo–0.25V bainitic steel under aging heat treatment

In the present work, the mechanical properties and hydrogen interaction with microstructures obtained after thermal treatment of a 2.25Cr–1Mo–0.25V bainitic steel were investigated. The samples were heat-treated under two different conditions simulating shop-repairs and manufacturing procedures of reactors. The microstructures after each heat treatment showed MC, M₂C, and M₇C₃ carbides, characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The hydrogen diffusivity values after the first permeation for both conditions were 4.2 × 10^?11 m²s^?1 and 8.6 × 10^?11 m² s^?1, and the solubility was 7.4 molHm^?3 and 5.3 molHm^?3, showing the influence trapping in the behavior of permeation curves. The TDS results indicate that a greater hydrogen trapping capability can be achieved with one of the studied conditions. Tensile testing of the hydrogenated and heat-treated samples, showed that the number of heat treatment cycles has a strong influence on the loss of ductility, which is mainly due to carbide growth and coalescence.     

Relationship between PM2.5 adsorption and leaf surface morphology in ten urban tree species in Shenyang,China

This study investigated the adsorption of particulate matter with a diameter <2.5 µm (PM_2.5) by leaves of ten tree species in Shenyang city. An aerosol generator was used to quantitatively determine PM_2.5 adsorption capacity. Atomic force microscopy was used to determine the micro-morphological characteristics of the leaf surface, including roughness parameters and the PM_2.5 absorption mechanism of the tree leaves. The results showed a positive correlation between PM_2.5 adsorption capacity and PM_2.5 concentration during different months: October (0.618 ± 0.16 μg· cm^?2) > September (0.514 ± 0.14 μg· cm^?2) > July (0.509 ± 0.14 μg· cm^?2) > August (0.487 ± 0.12 μg· cm^?2) > June (0.464 ± 0.08 μg· cm^?2) > May (0.359 ± 0.08 μg· cm^?2). PM_2.5 absorption capacity was higher on leaves where the folded leaf lamina was covered by fine hairs, as they were rough with many protrusions and fillisters on the leaf surface. The tree species with a smooth leaf surface and low stomatal density and stomatal opening had a weak ability to adsorb PM_2.5. The average roughness of the leaves was ranked according to PM_2.5 adsorption per unit leaf area, and leaf roughness was significantly correlated with PM_2.5 adsorption capacity per unit leaf area (R² = 0.706). Tree species with a leaf surface morphology that facilitates absorption of PM_2.5 and other particles, such as Pinus tabulaeformis and Platycladus orientalis, should be selected to improve the environmental effects of urban forest on air quality.     

Production of butanol and polyhydroxyalkanoate from industrial waste by Clostridium beijerinckii ASU10

This study demonstrated a biotechnological approach for simultaneous production of low‐cost H₂, liquid biofuels, and polyhydroxyalkanoates (PHAs) by solventogenic bacterium (Clostridium beijerinckii) from renewable industrial wastes such as molasses and crude glycerol. C beijerinckii ASU10 (KF372577) exhibited considerable performance for hydrogen production of 5.1 ± 0.84 and 11 ± 0.44 mL H₂ h^?1 on glycerol and sugarcane molasses, respectively. The total acetone‐butanol‐ethanol (ABE) generation from glycerol and molasses was 9.334 ± 2.98 and 10.831 ± 4.1 g L^?1, respectively. ABE productivity (g L^?1 h^?1) was 0.0486 and 0.0564 with a yield rate (g g^?1) up to 0.508 and 0.493 from glycerol and molasses fermentation, respectively. The PHA yields from glycerol and sugarcane molasses were 84.37% and 37.97% of the dried bacterial biomass, respectively. Additionally, the ultrathin section of C beijerinckii ASU10 showed that PHA granules were accumulated more densely on glycerol than molasses. Gas chromatography–mass spectrometry (GC‐MS) analysis confirmed that the PHAs obtained from molasses fermentation included 3‐hydroxybutyrate (47.3%) and 3‐hydroxyoctanoate (52.7%) as the main constituents. Meanwhile, 3‐hydroxybutyrate represented the sole monomer of PHA produced from glycerol fermentation. This study demonstrated that C beijerinckii ASU10 (KF372577) is a potent strain for low‐cost PHA production depending on its high potential to produce high‐energy biofuel and other valuable compounds from utilization of organic waste materials.     

Hydrogen evolution under visible light over the heterojunction p‐CuO/n‐ZnO prepared by impregnation method

The semiconducting properties of the heterojunction CuO/ZnO, synthesized by impregnation method from nitrates, are studied for the first time to assess its feasibility for the hydrogen production under visible light, an issue of energy concern. CuO exhibits a direct optical transition at 1.33 eV, due to Cu²⁺: 3d orbital splitting in octahedral site, and possesses a chemical stability in the pH range (4–14). The Mott–Schottky plot in (Na₂SO₄, 0.1 M) medium indicates p‐type conduction with a flat band potential of 0.70 V_SCE and a holes density of 1.35 × 10¹⁷ cm^?3. As application, hydrogen evolution upon visible light is demonstrated on the heterojunction ×%CuO/ZnO (x = 5, 10 and 20 wt.%). The best performance occurs at pH ~12 with an evolution rate of 4.8 cm³ min^?1 (g catalyst)^?1 and a quantum yield of 0.12%. The improved activity is attributed to the potential of the conduction band of CuO (?1.34 V_SCE), more negative than that of ZnO, the latter acts as electrons bridge to water molecules. The presence of SO₃^2? reduces the recombination process, thus resulting in more H₂ evolution. Copyright © 2015 John Wiley & Sons, Ltd.     

Thermal Conductivity of Evacuated Highly Transparent Silica Aerogel

The thermal loss coefficient k of evacuated load bearing transparent silica aerogel tiles is determined for temperatures between 280 K and 400 K. The measurements were performed with the large guarded hot plate high vacuum system LOLA I, the reference plates of which can be pressed onto the samples with an adjustable load (0... 1 bar). For a 22mm layer of aerogel (density ρ ≈ 100...110g/liter) the loss coefficient varied between about k = 0.36 W//m² K) at 280 K and k = 1.45 W/(m².K) at 400 K, corresponding to a pseudo-conductivity λ = 8. 10^?3 W/(m. K) and λ = 32. 10^?3 W/(m. K), respectively. Thus at typical winter temperatures (inside 20 °C, outside ?10 °C to 0 °C), evacuated transparent aerogel could provide excellent thermal insulation as a spacer in double pane windows. It also could be used in passive solar systems, for example as a cover for Trombe walls or as a transparent insulating structure around house walls. The dramatic increase of thermal losses at higher temperatures is due to a transmission window for infrared radiation between 3 and 7 μm, Additional data reveal the influence of water adsorption and of air pressure on the thermal conductivity of aerogel.     

Evaluation of the composition of continuously-cultivated Arthrospira (Spirulina) platensis using ammonium chloride as nitrogen source

This work is focused on the influence of dilution rate (0.08 ≤ D ≤ 0.32 d^?1) on the continuous cultivation and biomass composition of Arthrospira (Spirulina) platensis using three different concentrations of ammonium chloride (c_No = 1.0, 5.0 and 10 mol m^?3) as nitrogen source. At c_No = 1.0 and 5.0 mol m^?3 the biomass protein content was an increasing function of D, whereas, when using c_No = 10 mol m^?3, the highest protein content (72.5%) was obtained at D = 0.12 d^?1. An overall evaluation of the process showed that biomass protein content increased with the rate of nitrogen supply (D c_No) up to 72.5% at D c_No = 1.20 mol m^?3 d^?1. Biomass lipid content was an increasing function of D only when the nitrogen source was the limiting factor for the growth (D c_No ≤ 0.32 mol m^?3 d^?1), which occurred solely with c_No = 1.0 mol m^?3. Under such conditions, A. platensis reduced its nitrogen reserve in the form of proteins, while maintaining almost unvaried its lipid content. The latter was affected only when the concentration of nitrogen was extremely low (c_No = 1.0 mol m^?3). The most abundant fatty acids were the palmitic (45.8 ± 5.20%) and the γ-linolenic (20.1 ± 2.00%) ones. No significant alteration in the profiles either of saturated or unsaturated fatty acids was observed with c_No ≤ 5.0 mol m^?3, prevailing those with 16 and 18 carbons.     

Current carrying friction and wear characteristics of Ti3AlC2 by novel method of infiltration sintering

Abstract

High purity Ti₃AlC₂ samples were prepared by an infiltration sintering method. The current carrying friction and wear characteristics of high pure bulk Ti₃AlC₂ dry sliding against a GCr₁₅ bearing steel disc were experimentally investigated on a pin-on-disk type tester at several sliding speeds from 20 to 60 m s^?1, different electric currents from 0 to 100 A and normal pressures from 0·1 to 0·6 MPa. It was found that the highly pure Ti₃AlC₂ exhibits an increasing friction coefficient (0·11–0·65) and an increasing wear rate (2·13–7·75×10^?6 mm³ N^?1 m^?1) with the electric current increasing from 0 to 100 A; the normal pressure (0·1–0·6 MPa) and the sliding speed (20–60 m s^?1) also have a complex but relatively weak influence on them. The minimum value of friction coefficient was 0·11 when the sliding electric current, speed and normal pressure were set to 0 A, 60 m s^?1 and 0·6 MPa; the wear rate reached the maximum value 7·75×10^?6 mm³ N^?1 m ^?1 when the sliding electric current, speed and normal pressure respectively were set to 100 A, 60 m s^?1 and 0·6 MPa. The low friction coefficient can be attributed to the presence of a continuous frictional oxide film consisting of an amorphous mixture of Al, Ti and Fe oxides on the friction surface, which have a significant antifriction effect on the friction surfaces. The percentage of oxide film cover was relatively higher when the electric current was 0 A, while the percentage of oxide film cover decreased with increasing electric current. The increase in the wear rate was ascribed to the ablation of the electric arc when the electric current was high.     

An experimental study of heat transfer in an open thermosyphon

An experimental study was performed on heat transfer of an open thermosyphon with constant wall heat flux. Water and aqueous glycerin were used as working fluids. The experimental range of modified Rayleigh number was 1 × 10³ < Ra_m < 3 × 10⁵. The average and local heat transfer coefficients, vertical temperature distributions of the tube wall and fluid at the centerline of the tube, and temperature fluctuations of the fluid were measured. Flow patterns were observed by adding tracer powder to the fluid. Fluid velocities were measured by laser Doppler velocimeter. Experimental results indicate that, for a water thermosyphon, there are three regimes where different heat transfer characteristics and flow patterns occur. For 1 × 10³ < Ra_m < 3 × 10³, the flow was laminar and the thermal boundary layer reached the center of the tube. Heat was exchanged between the wall and descending flow. Wall temperature increased in the downward direction. For 4 × 10³ < Ra_m < 3 × 10⁴, no turbulence was observed in the flow and the thermal boundary layer was localized in the vicinity of the wall. The wall temperature increased upward. For 3 × 10⁴ < Ra_m < 3 × 10⁵, flow was considerably disturbed by the mixing of upward and downward flow in the upper part of the tube. However, the flow was laminar in the lower part of the tube. Reduction of the flow rate induced by the flow mixing at high Ra_m can be one of the major causes of the deterioration of heat transfer from Lighthill's theory. © 2001 Scripta Technica, Heat Trans Asian Res, 30(4): 301–312, 2001     

Preparation and characterization of mica glass-ceramics as hydrogen storage materials

This work is an attempt to study storing hydrogen in safe, reliable, compact, and cost-effective glass-ceramics materials for the first time. The effect of replacing K⁺ by Na⁺ or Li⁺ in the fluorophlogopite formula KMg₃AlSi₃O₁₀F₂ was studied using DTA, XRD and SEM. Also the effect of the crystallized phases within glass-ceramics on the surface area and capacity of storing hydrogen under different pressures were studied. Replacement of K⁺ by Na⁺ or Li⁺ leads to increase the temperature of crystallization in the same order. XRD revealed crystallization of spodumene (LiAlSi₂O₆) and forsterite (Mg₂SiO₄) in GLi and Na-fluorophlogopite (NaMg₃AlSi₃O₁₀F₂) and Na-mica (NaAl₃Si₃O₁₁) in GNa while Lucite (KAlSi₂O₆) and forsterite in GK. Surface area measurements for optimum samples showed low values in the range 0.48–0.58 m²/g; also total pore volumes have low values 9.4 × 10^?4–6.99 × 10^?3 cm³/g. The hydrogen adsorption content reached 1.25, 2.5, 1.34 sand 1.9 wt% for GLi, GNa, GK and GK samples heated for 2 h at 770,1100, 1000 and 1100 °C, respectively. The results obtained that, Na-bearing samples are the proper for hydrogen storage wherein sodium mica and phlogopite with characteristic sheet structure were crystallized.