Thermal Behavior of Ceramic Bodies Based on Estonian Clay from the Arumetsa Deposit with Oil Shale Ash and Clinker Dust Additives

The thermal behavior of green clay samples from the Arumetsa and Füzérradvány deposits (Hungary) and the influence of two new types of Estonian oil shale (OS) ashes and cement bypass dust (clinker dust) additives on it were the objectives of this study. Thermal and thermo-dilatometric analysis methods were applied using a Setaram Setsys 1750 thermoanalyzer coupled with a Pfeiffer Omnistar spectrometer and a Setaram Setsys 1750 CS Evolution dilatometer. The kinetic parameters were calculated based on the differential isoconversional method of Friedman. The results of the thermal analysis of clays and blends indicated the emission of physically bound water at 200–250 °C. At temperatures from 200–250 °C to 550–600 °C the release of water is caused by oxidation of organic matter and dehydroxylation of different clay minerals like illite, illite-smectite, mica and kaolin. From blends, in addition, also from the decomposition of portlandite. The emission of CO2 at these temperatures was a result of the oxidation of organic matter contained in the clays. In the temperature range from 550–600 °C to 800–900 °C, the mass loss was caused by ongoing dehydroxylation processes in clay minerals but was mainly due to the decomposition of the carbonates contained in the OS ashes and clinker dust. These processes were accompanied by contraction and expansion of the ceramic bodies with the corresponding changes in the SSA and porosity values of the samples. Therefore, the decomposition of the clays took place in one step which blends in two steps. At first, dehydroxylation of the clay minerals occurs, followed by decomposition of the carbonates. The value of the conversion-dependent activation energy E along the reaction progress α varied for the Arumetsa and illitic clay between 75–182 and 9–206 kJ mol−1, respectively. For the blends based on Arumetsa and illitic clay, the activation energy of the first step varied between 14–193 and 5–205 kJ mol−1, and for the second step, it was between 15–390 and 135–235 kJ mol−1, respectively, indicating the complex mechanism of the processes.

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Effect of Shale Ash-Based Catalyst on the Pyrolysis of Fushun Oil Shale

Catalysts ◽

10.3390/catal9110900 ◽

2019 ◽

Vol 9 (11) ◽

pp. 900

Author(s):

Hao Lu ◽

Fengrui Jia ◽

Chuang Guo ◽

Haodan Pan ◽

Xu Long ◽

...

Keyword(s):

Activation Energy ◽

Transition Metal ◽

Oil Shale ◽

Metal Salt ◽

Metal Salts ◽

Aliphatic Hydrocarbons ◽

Shale Oil ◽

Transition Metal Salt ◽

Transition Metal Salts ◽

Shale Ash

The effect of shale ash (SA)-based catalysts (SA as carriers to support several transition metal salts, such as ZnCl2, NiCl2·6H2O, and CuCl2·2H2O) on oil shale (OS) pyrolysis was studied. Results showed that SA promoted OS pyrolysis, and the optimum weight ratio of OS:SA was found to be 2:1. The SA-supported transition metal salt catalyst promoted the OS pyrolysis, and the catalytic effect increased with increasing load of the transition metal salt within 0.1–3.0 wt%. The transition metal salts loaded on the SA not only promoted OS pyrolysis and reduced the activation energy required but also changed the yield of pyrolysis products (reduced shale oil and semi-coke yields and increased gas and loss yield). SA-supported 3 wt% CuCl2·2H2O catalyst not only exhibited the highest ability to reduce the activation energy in OS pyrolysis (32.84 kJ/mol) but also improved the gas and loss yield, which was 4.4% higher than the uncatalyzed reaction. The supporting transition metal salts on the SA also increased the content of short-chain hydrocarbons in aliphatic hydrocarbons in shale oil and catalyzed the aromatization of aliphatic hydrocarbons to form aromatic hydrocarbons. The catalytic activity of the transition metal salt on the SA-based catalyst for OS pyrolysis decreased in the order of CuCl2·2H2O > NiCl2·6H2O > ZnCl2.

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Thermal behavior of some Estonian clays and their mixtures with oil shale ash additives

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-014-3797-0 ◽

2014 ◽

Vol 118 (2) ◽

pp. 891-899 ◽

Cited By ~ 10

Author(s):

Tiit Kaljuvee ◽

Igor Štubňa ◽

Peeter Somelar ◽

Valdek Mikli ◽

Rein Kuusik

Keyword(s):

Thermal Behavior ◽

Oil Shale ◽

Oil Shale Ash ◽

Shale Ash

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Heating rate effect on the thermal behavior of some clays and their blends with oil shale ash additives

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-016-5347-4 ◽

2016 ◽

Vol 127 (1) ◽

pp. 33-45 ◽

Cited By ~ 4

Author(s):

Tiit Kaljuvee ◽

Igor Štubňa ◽

Tomáš Húlan ◽

Rein Kuusik

Keyword(s):

Thermal Behavior ◽

Heating Rate ◽

Oil Shale ◽

Rate Effect ◽

Oil Shale Ash ◽

Shale Ash

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Study of the thermal behavior in solid state of Mn(II)-Diclofenac Complex

Eclética Química Journal ◽

10.26850/1678-4618eqj.v43.1.2018.p59-66 ◽

2018 ◽

Vol 43 (1) ◽

pp. 59 ◽

Cited By ~ 1

Author(s):

Marcelo Kobelnik ◽

Valdecir Ângelo Quarcioni ◽

Adélia Emília De Almeida ◽

Clóvis Augusto Ribeiro ◽

Marisa Spirandeli Crespi

Keyword(s):

Phase Transition ◽

Activation Energy ◽

Thermal Decomposition ◽

Solid State ◽

Thermal Behavior ◽

Isoconversional Method ◽

Exothermic Peak ◽

X Ray ◽

Purge Gas ◽

Dsc Curves

The preparation, characterization and thermal behavior of Mn(II)-diclofenac solid-state complex was investigated by simultaneous TG/DTA and DTG curves, DSC, X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) techniques. The thermal evaluation was carried out with sample masses of 2 and 5 mg, with the purpose of comparing the values of activation energy regarding dehydration, monotropic phase transition and thermal decomposition in both samples mass. The DSC curves were obtained in opened and with crimped lids crucibles of aluminum under oxygen purge gas and static air (without purge gas). The DTA and DSC curves show an exothermic peak between 150-180 °C depending on heating rate, which can be attributed to the monotropic non-reversible reaction. The activation energy (Ea/kJ mol-1) to dehydration, the monotropic phase transition and the first thermal decomposition step were determined by Capela-Ribeiro nonlinear isoconversional method. The activation energy under oxygen dynamic purge gas shows lower values compared to those obtained under static air.

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Particle Size Effects on Concentration of Metals in Lake Erie Bottom Sediments

Water Quality Research Journal ◽

10.2166/wqrj.1984.003 ◽

1984 ◽

Vol 19 (1) ◽

pp. 27-36 ◽

Cited By ~ 7

Author(s):

Alena Mudroch

Keyword(s):

Particle Size ◽

Organic Matter ◽

Clay Minerals ◽

Surface Sediment ◽

Size Effects ◽

Lake Erie ◽

Size Fraction ◽

Mineralogical Composition ◽

Major Elements ◽

Sediment Samples

Abstract Surface sediment samples obtained at the offshore and nearshore area of Lake Erie were separated into eight different size fractions ranging from <2 µm to 250 µm. The concentration of major elements (Si, Al, Ca, Mg, K, Na, Fe, Mn and P), metals (Zn, Cu, Cr, Ni, V, Co and Pb) and organic matter was determined together with the mineralogical composition and morphology of the particles in each size fraction. The distribution of the metals in the offshore sediment was bimodal with the majority of the metals divided between the 63 to 250 um size fraction which also contained the highest concentration of organic matter (about 20%) and the <4 µm fraction containing up to 60% of clay minerals. However, the metals in the nearshore sediment were associated mainly with the clay minerals.

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Development of HPLC Method for the Purity Test by Design of Experiments and Determination of Activation Energy of Hydrolytic Degradation Reactions of Sofosbuvir

Current Pharmaceutical Analysis ◽

10.2174/1573412915666190225161007 ◽

2020 ◽

Vol 16 (7) ◽

pp. 976-987

Author(s):

Jakub Petřík ◽

Jakub Heřt ◽

Pavel Řezanka ◽

Filip Vymyslický ◽

Michal Douša

Keyword(s):

Activation Energy ◽

Design Of Experiments ◽

Mobile Phase ◽

Hydrolytic Degradation ◽

Isoconversional Method ◽

Hplc Method ◽

Organic Modifier ◽

Calculation Methods ◽

Degradation Reactions

Background: The present study was focused on the development of HPLC method for purity testing of sofosbuvir by the Design of Experiments and determination of the activation energy of hydrolytic degradation reactions of sofosbuvir using HPLC based on the kinetics of sofosbuvir degradation. Methods: Following four factors for the Design of Experiments were selected, stationary phase, an organic modifier of the mobile phase, column temperature and pH of the mobile phase. These factors were examined in two or three level experimental design using Modde 11.0 (Umetrics) software. The chromatographic parameters like resolution, USP tailing and discrimination factor were calculated and analysed by partial least squares. The chromatography was performed based on Design of Experiments results with the mobile phase containing ammonium phosphate buffer pH 2.5 and methanol as an organic modifier. Separation was achieved using gradient elution on XBridge BEH C8 at 50 °C and a flow rate of 0.8 mL/min. UV detection was performed at 220 nm. The activation energy of hydrolytic degradation reactions of sofosbuvir was evaluated using two different calculation methods. The first method is based on the slope of dependence of natural logarithm of the rate constant on inverted thermodynamic temperature and the second approach is the isoconversional method. Results and Conclusion: Calculated activation energies were 77.9 ± 1.1 kJ/mol for the first method and 79.5 ± 3.2 kJ/mol for the isoconversional method. The results can be considered to be identical, therefore both calculation methods are suitable for the determination of the activation energy of degradation reactions.

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