Thermogravimetry-differential Thermal Analysis Research Articles

Mechanical and Microstructural Properties of Cement-Stabilized Soft Clay Improved by Sand Replacement and Biochar Additive for Subgrade Applications

Biochar (BC) is an eco-friendly material produced through coal pyrolysis and can improve the mechanical properties of cement-based construction and building materials. This research study explored the effects of BC and natural sand (Sand) replacement on the improved static and cyclic response of blended hydraulic cement (BHC) stabilized soft clay (SC) as a greener subgrade material. Unconfined compressive strength (UCS), indirect tensile stress (ITS), and indirect tensile fatigue life (ITFL) of the BHC-stabilized SC-BC-Sand samples were examined. Adding 10% BC to the BHC-stabilized samples was found to enhance cementitious products due to its porous structure and high water absorbability. The UCS, ITS and ITFL at this optimum ingredient were improved up to 315%, 347% and 862%, respectively, compared to the BHC-stabilized SC. Fourier transform infrared spectrometer, thermogravimetry differential thermal analysis and a scanning electron microscope with energy-dispersive -ray spectroscopy analyses the BHC-stabilized sample at the optimum ingredient showed the highest C-S-H and Ca(OH)2 in the pores. This investigation will encourage the utilization of BC to create both environmentally friendly and durable stabilized subgrade material.

Effect of trace oxygen on smelter off‐gas reduction desulphurization process over FeSx/γ‐Al2O3 catalysts

AbstractEffects of trace oxygen on iron sulphides‐supported catalysts (FeSx/γ‐Al2O3) were evaluated through smelter off‐gas reduction process for sulphur synthesis. Catalytic performance was evaluated under different oxygen content conditions. The properties of fresh and used catalysts were investigated by means of X‐ray diffraction (XRD), thermogravimetry‐differential thermal analysis (TG‐DTA), X‐ray photoelectron spectroscopy (XPS), and elemental analysis and relationships of active phases and activity were analyzed. The relationship between different active crystal crystals (FeSx, FeS2, Fe, FeO, γ‐Fe2O3) and SO2/O2 adsorption and conversion was investigated. The mechanism of oxygen influence on the FeSx/γ‐Al2O3 surface was given and the lifetime of the catalyst in the reaction atmosphere close to real smelter off‐gas after dust and oxygen removal steps containing trace oxygen (0.5 O2 v/v.%) was explored.

Revealing Active Sites and Reaction Pathways in Direct Oxidation of Methane over Fe-Containing CHA Zeolites Affected by the Al Arrangement.

Fe-containing zeolites are effective catalysts in converting the greenhouse gases CH4 and N2O into valuable chemicals. However, the activities of Fe-containing zeolites in methane conversion and N2O decomposition are frequently conflated, and the activities of different Fe species are still controversial. Herein, Fe-containing aluminosilicate CHA zeolites with Fe species at different spatial distances affected by the arrangement of framework Al atoms were synthesized in a one-pot manner in the presence or absence of Na. The arrangement of framework Al atoms was identified by 27Al and 29Si MAS NMR spectra and thermogravimetry-differential thermal analysis (TG-DTA) curves. Ultraviolet (UV)-vis, X-ray absorption spectroscopy (XAS), and NO adsorption fourier transform infrared spectroscopy (FTIR) spectra were adopted to analyze Fe speciation. The higher proportion of Fe species in the 6 MR of Fe-CHA zeolites in the presence of Na was confirmed by the NO adsorption FTIR spectrum. The activities of proximal and distant Fe sites in reactions including direct oxidation of methane to methanol, methanol to hydrocarbon, and N2O decomposition were compared at different temperatures to provide the corresponding active sites and reaction pathways. The distant, isolated Fe and isolated proton were more active in the direct oxidation of methane to methanol and tandem conversion of methanol to hydrocarbon reactions than the proximal, isolated Fe and paired protons, respectively. Additionally, proximal, isolated Fe sites afforded higher activity in N2O decomposition. These findings guide the design of highly active catalysts in methane oxidation, methanol to hydrocarbon, and N2O decomposition reactions, addressing energy and environmental concerns.

Vitrified metal composite bond for diamond grinding tools used for silicon carbide wafer thinning

The refractoriness of the vitrified bond significantly influences the properties of the vitrified metal-composite bond. In this study, we examined the effects of refractoriness and number of vitrified bonds incorporated into vitrified metal composite bonds in diamond abrasive tools. Furthermore, the effects of vitrified metal composite bonds on the microstructure, mechanical properties, and sintering process were systematically evaluated. Techniques, such as X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), and white light interferometry (WLI) were employed to analyze the phase composition of the vitrified metal composite bond, changes during the hot-pressing sintering process, microstructural morphology, and friction and wear behavior of the diamond abrasive composite bond. The flexural and impact strengths of the composite bond decreased with an increase in the refractoriness of the vitrified bond and number of bonds introduced. In particular, as the refractoriness of the vitrified bonds increased, their fluidity decreased. Finally, the hardness of the vitrified metal composite bond containing 3% vitrified bond (4#) reached 66.34–69.2 HRB, the porosity was 22.08%, and the surface roughness of the workpiece was 0.06 μm.

Temperature-Dependent Compressive Strength Modeling of Geopolymer Blocks Utilizing Glass Powder and Steel Slag

This article investigates the development of geopolymers as a modern, environmentally sustainable binder with ceramic-like properties, offering exceptional thermal and fire-resistant characteristics. The study primarily utilized fly ash (FA) in combination with glass powder (GP) and steel slag (SS). The SS content varied between 30% and 40%, while the molarity of NaOH was set at 10M, 12M, and 14M. Based on these variables, a total of 18 mixes incorporating GP and SS were formulated. The samples were subjected to elevated temperatures of 200 °C, 400 °C, 600 °C, and 800 °C, after which their compressive strength was measured. To better understand the material formation, scanning electron microscopy and energy dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetry differential thermal analysis analyses were conducted. The study aimed to examine the influence of oxide ratios (Na/Si, Si/Al, H2O/Na2O, and Na/Al) on compressive strength at elevated temperatures. Additionally, the research sought to develop a predictive model, elucidating the relationship between these oxide ratios and compressive strength of geopolymers. To achieve this, ten machine learning techniques were applied, revealing the complex connection between oxide ratios and the strength properties of geopolymers. The support vector regressor (SVR) model outperformed other regression and boosting models, achieving a high coefficient of determination (R2) value of 0.95, indicating superior predictive accuracy. The reduced error levels and high R2 values highlighted the enhanced performance of the SVR model. A sensitivity analysis was done to understand the contributions of each parameter to the outcome predictions further. Employing machine learning techniques to forecast compressive strength of geopolymer blocks under various elevated temperature conditions improves predictive accuracy and optimizes resource utilization, leading to significant time savings.

Liquid-phase synthesis of a Li3PS4 solid electrolyte using ethyl isobutyrate as a synthetic medium

A β-Li3PS4 solid electrolyte was prepared via liquid-phase synthesis using ethyl isobutyrate as a synthetic medium. The precursor and solid electrolyte structures were characterized using thermogravimetry–differential thermal analysis and X-ray diffraction techniques. The dielectric relaxation analysis showed two relaxation regions, which revealed a bulk and grain boundary ionic migration process. At a temperature lower than 90°C, the frequency dependence of the dielectric constant of the prepared sample was different from that of glassy Li3PS4, indicating that the motion of the PS4 unit enhances the ionic conductivity of the Li3PS4 solid electrolyte. The ionic conductivities of the cold-pressed and warm-pressed pellets at 25°C were 6.8 × 10−5 Scm−1 and 3.6 × 10−4 Scm−1, respectively.

Phase stability of solid solution La1-xRxRh3B (R = Gd, Lu and Sc) compounds with cubic anti-perovskite type structure

We have investigated the solid solution range of single phase La1-xRxRh3B (R = Gd, Lu and Sc) compounds with a cubic anti-perovskite type structure. The behaviors of lattice parameters, hardness, and thermogravimetry–differential thermal analysis (TG-DTA) were also investigated. The cubic anti-perovskite phase exists over the entire composition range x from 0.0 to 1.0 for all La-Gd, La-Lu and La-Sc systems. Both the lattice parameters and the hardness in all La-Gd, La-Lu and La-Sc systems show a linear dependence on the degree of the substitution x of La atom. The results of TG-DTA measurements indicate that oxidation of the compounds in air begins at about 500–600 K. The mixed phases of RBO3, R2O3 and Rh are identified as oxidized products around x = 0.4 to 0.6 composition. The oxidation onset temperature, and weight gains due to the oxidation depend on the degree of substitution x. The behavior of crystallographic and physical/chemical properties in the present compounds La1-xRxRh3B strongly depend on the atomic size of the rare-earth atoms that form the cubic framework.

Characterization of Stone Waste Sludge and Preliminary Investigation on Green Materials Based on Traditional Lime Putty for Sustainable Construction

Very large quantities of stone waste sludge are disposed in exhausted quarries and have a very low reuse rate to date. The paper considers the possibility of using these types of industrial waste in partial substitution of natural aggregates for the production of lime-based plasters. Traditional materials based on lime, the only material with a carbon neutrality life cycle, have considerable potential for use as components of green materials for plastering and finishing building surfaces in both new construction and historic heritage conservation. The paper presents the preliminary results of a research activity aimed at developing pre-packaged products based on Traditional Lime Putty (TLP) by partially replacing natural aggregates with Stone Waste Sludge (SWS), with a low rate of recovery from the Apricena limestone production district in Apulia. The mineralogical and chemical analysis carried out using XRD (X-Ray Diffraction), TG-DTA (Thermo Gravimetry-Differential Thermal Analysis), and hydrochloric acid attack test showed that the SWS consisted of 98.4 % CaCO3 by mass. The particle sizes measured by laser diffraction technique are below 22.5 μm for the 92% mass of the sample. The high fineness of the stone waste was confirmed by the Blaine-specific surface method, which equals to 9273.79 cm2/gr. The behavior of three fresh mixtures for prepacked coarse plaster, fine plaster, and finishing plaster with 12.90%, 17.94%, and 18.90 by mass of SWS, respectively, was evaluated by spreading test and applicability tests on a perforated ceramic slab. The finishing plaster has the highest consistency value of 235 mm, while the fine plaster and the coarse plaster have values of 205 mm and 155 mm, respectively. The coarse plaster is suitable for use as base plaster (arriccio) or second layer rendering (tonachino) up to a thickness of approximately 1 cm. Both the fine plaster and finishing plasters can be used for the surfaces finishing with the application of layers of a few millimeters thick.

Effect of Morphology and Concentration of CeO2 Nanoceria on the Thermal Stability of Polyvinyl Alcohol Films

Objective: To determine the thermal stability of polyvinyl alcohol films under different concentrations of CeO2 nanoceria. Method: Cerium Oxide doped polyvinyl alcohol (PVA) nano-composites were synthesized by the traditional solution casting method for various concentrations of nano CeO2 by solution combustion method. The thermal properties of prepared PVA-2.5 wt% CeO2, PVA-7.5 wt% CeO2 , PVA-12.5 wt% CeO2, and PVA-25 wt% CeO2 composite films were elucidated by using techniques such as Differential Scanning Calorimetry, Thermogravimetry analysis and Differential Thermal analysis. Findings: The glass transition temperature of the pure PVA is found to be 114°C, whereas it varies between 110°C-120°C for composite films. The melting temperature of the composite films is the same as that of pure PVA except in the case of 7.5wt% CeO2 and 25wt% CeO2 composites. The reduced melting point of these composites elicits a decrease in crystallinity. A 12.5 wt % and 25 wt% CeO2-PVA nano-composite films exhibit an increase in the final degradation temperature, a high specific heat capacity, low mass loss, and a larger residual weight, indicating their potential applicability in thermal coating and thermal sensing applications. Polyvinyl alcohol (PVA) films are being used routinely as a dielectric layer for electrical applications due to the good physiochemical and dialectic properties of the material. An incorporation of CeO2 nanoceria improves not only the thermal but also the mechanical properties of PVA and extends its application for electrical and optical operation. Here in the present study, different concentrations of CeO2 were incorporated with the PVA and analysed for the thermal properties. The study showed that 12.5 wt % and 25 wt% CeO2-PVA nano-composite enhanced PVA film thermal stability. Keywords: PVA-CeO2 Nanocomposites; Differential Scanning Calorimetry; Thermogravimetry Analysis and Differential Thermal Analysis; Physical properties and thermal properties

Green Synthesis Study: Adsorption of Congo Red Dye with Selenium Nanoparticles Obtained from Prunus Armeniaca L. Leaf Waste

AbstractIn this study, it was aimed to remove Congo Red (CR) dye in aqueous solution by biosynthesized Selenium Nanoparticles from Prunus armeniaca L. (PAL‐SeNPs) leaf wastes by green synthesis method. The characteristic structure of PAL‐SeNPs was determined by UV‐vis spectroscopy, X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscope (SEM), energy dispersive X‐ray (EDX), fourier transform infrared spectroscopy (FTIR), thermogravimetry‐differential thermal analysis (TGA‐DTA), dynamic light scattering (DLS), zetasizer, and point of zero charge (pHpzc). The effects of pH, adsorbent amount, time, initial concentration, and temperature were investigated by batch adsorption studies. 2 different kinetic and 4 isotherm models were tested and error analysis functions were determined for the most suitable model. Accordingly, the particle size, crystallinity, pHpzc value and average surface charge of PAL‐SeNPs were determined as 9.969 nm, 48.50 %, 3.47, and −23.6 mV, respectively. Also, the most suitable kinetic and isotherm models for the removal of CR dye with PAL‐SeNPs were found as Pseudo‐second‐order and Freundlich, with R2 values of 0.996, respectively. Also, where the optimum pH was 7.00, the maximum adsorption capacity was calculated as 96.59 mgCR/gPAL‐SeNPs. The results obtained show that environmentally friendly and low‐cost PAL‐SeNPs produced by the green synthesis method are a suitable alternative for the removal of CR dye.

Adsorption of Methylene Blue and Eriochrome Black T onto Pinecone Powders (Pinus nigra Arn.): Equilibrium, Kinetics, and Thermodynamic Studies

In this study, methylene blue (MB) and eriochrome black T (EBT) dyes were removed with the waste Pinus nigra Arn. powders from Anatolian black pinecone (PC-PnA) within the framework of sustainability. UV–Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray (EDX), fourier transform infrared spectroscopy (FTIR), thermogravimetry–differential thermal analysis (TGA-DTA), Brunauer–Emmett–Teller (BET) surface area, and point of zero charge (pHpzc) analyses were performed for the characterization of PC-PnAs. The effects of pH, amount of adsorbent, time, initial concentration and temperature were determined by batch adsorption experiments. Four kinetic and isotherm models were examined, and error function tests were used for the most suitable model. According to this, the average pore diameters, mass losses at 103.9 and 721.6 °C and pHpzc values of PC-PnAs were found as 61.661 Å, 5.9%, 30%, and 5.77, respectively. Additionally, the most suitable kinetic and isotherm models for the removal of both dyes were Langmuir and pseudo-second-order. The maximum removal efficiencies (qmax) for MB and EBT dyes was calculated as 91.46 and 15.85 mg/g, respectively and the adsorption process was found to be endothermic. As a result, PC-PnA particles can be used as an alternative sorbent for the removal of MB and EBT dyes.

Room temperature synthesis of BaTiO3 nanoparticles using titanium bis(ammonium lactato) dihydroxide

BaTiO3, known for its exceptional ferroelectric properties, is extensively applied in multi-layer ceramics capacitors (MLCCs). Achieving reliable, high-performance MLCCs requires sophisticated ceramics processes, notably in synthesizing submicron-order BaTiO3 powder with a narrow size distribution. Among various synthesis methods explored for submicron-size BaTiO3 powder, room temperature liquid-phase synthesis is most desirable due to its cost-effectiveness and large batch availability. In this study, we propose a synthesis method for obtaining BaTiO3 nanopowder at room temperature using titanium bis(ammonium lactato) dihydroxide and Ba(OH)2·8H2O as starting materials, reacted in tert-butylamine with NaOH and ethanol. The resulting powder, exhibiting a cubic phase of BaTiO3 with an average particle size of 35.8 nm, was obtained after a 7-day reaction at room temperature. Characterization involved X-ray diffraction, differential thermal analysis‒thermogravimetry, and scanning electron microscopy. Subsequently, the powder was used to sinter a BaTiO3 ceramic, whose dielectric performance was then evaluated.

Study on synthesis and mechanism of high temperature resistant suspension stabilizer for spacer fluid

With 2-acrylamido-2-methylpropanesulfonic acid (AMPS), YX-1 (a monomer containing an amide group) as the main chain, DX-2 (a monomer containing a hydrophobic group), N-vinylpyrrolidone (NVP) as the side chain, the high temperature resistant suspension stabilizer for spacer was prepared by free radical aqueous solution polymerization and characterized. The structure was characterized by fourier transform infrared (FTIR) spectroscopy and thermogravimetry-differential thermal analysis (TG-DTA), which proved that the synthesized product was the target product. The performance of the copolymer was evaluated. The experimental results showed that it could be used in the spacer fluid at 30 ∼ 210 °C, and its sedimentation performance could also meet the requirements in the spacer fluid system containing saturated brine. In order to explore the mechanism of the polymer, the polymer solution was tested by six-speed rotational viscometer, pyrene fluorescence probe test, environmental scanning electron microscopy (ESEM) test, and the isolation solution containing the copolymer was tested by Zeta potential test and X-ray diffraction (XRD). Based on the above test results, it is shown that the suspension stabilizer synthesized in this paper has the characteristics of thickening, physical plugging, chemical and physical adsorption, which can effectively ensure that the spacer fluid has excellent suspension performance at high temperature.

Influence of Glycerol on the Surface Morphology and Crystallinity of Polyvinyl Alcohol Films.

The structure and physicochemical properties of polyvinyl alcohol (PVA) and PVA/glycerol films have been investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetry/differential thermal analysis (TG/DTA), and advanced scanning probe microscopy (SPM). In the pure PVA films, SPM allowed us to observe ribbon-shaped domains with a different frictional and elastic contrast, which apparently originated from a correlated growth or assembly of PVA crystalline nuclei located within individual PVA clusters. The incorporation of 22% w/w glycerol led to modification in shape of those domains from ribbon-like in pure PVA to rounded in PVA/glycerol 22% w/w films; changes in the relative intensities of the XRD peaks and a decrease in the amorphous halo in the XRD pattern were also detected, while the DTA peak corresponding to the melting point remained at almost the same temperature. For higher glycerol content, FT-IR revealed additional glycerol-characteristic peaks presumably related to the formation of glycerol aggregates, and XRD, FT-IR, and DTA all indicated a reduction in crystallinity. For more than 36% w/w glycerol, the plasticization of the films complicated the acquisition of SPM images without tip-induced surface modification. Our study contributes to the understanding of crystallinity in PVA and how it is altered by a plasticizer such as glycerol.

Spark plasma sintering of cenosphere-derived Cs/Sr-aluminosilicates for 137Cs and 90Sr immobilization in mineral-like ceramics

In this study, a promising method of spark plasma sintering (SPS) was investigated for the fabrication of ceramic matrices designed for the reliable immobilization of highly radioactive radionuclides 137Cs and 90Sr. The ceramic matrices were derived from a mixed composition of two aluminosilicate mineral-like phases – pollucite (Cs,Na)AlSi2O6 and gehlenite Sr2Al2SiO7. The originality of the developed approach lies in the utilization of hydrothermal synthesis for obtaining granulated precursor material. Hollow aluminosilicate microspheres (cenospheres) from coal fly ash served as the initial raw material, which were treated with alkaline solutions containing Cs+ and Sr2+ ions as simulants for the corresponding radionuclides. This method facilitated the achievement of high efficiency in cation removal from solutions exceeding 98 %. For a comprehensive examination of the composition and morphology of cenosphere-derived precursor particles, and the influence of sintering temperature on phase and structure formation of ceramic matrices under non-equilibrium conditions of spark plasma heating, various analytical techniques were employed. These included thermogravimetry/differential thermal analysis (TG/DTA), powdered X-ray diffraction analysis (PXRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), as well as the method of low-temperature nitrogen adsorption for determining the specific surface area. The obtained ceramic samples exhibited high values of specific density (2.688–2.915 g/cm³), compressive strength (666–808 MPa), and Vickers microhardness (1.8–2.5 GPa), attesting to their high quality and stability. The results of the hydrolytic stability assessment revealed that the leaching rates of Cs+ and Sr2+ ions from the ceramics are extremely low, within the range of 10−5–10−6 g/cm²·day. These values fully satisfy the requirements of GOST R 50926–96 and the international standard ISO 6961:1982 for solidified forms of high-level waste.

Physico-chemical characterization of cupola slag: Enhancing its utility in construction

Cupola slag is a waste material of the steel and iron industries. Its composition is determined by the cupola furnace and other elements used in steel and iron manufacturing. This paper investigates the characterization behavior of various cupola slag materials. As a result, x-ray fluorescence (XRF), x-ray diffraction (XRD), thermogravimetry differential thermal analysis, and scanning electron microscopy (SEM) methods were used to characterize three cupola slag samples from distinct origins. In addition, various physical properties were used to compare different cupola slags. The specific gravity values of CS-1 (cupola slag-1 sample), CS-2 (cupola slag-2 sample), and CS-3 (cupola slag-3 sample) are 1.36, 2.5, and 2.917, respectively. The density and water absorption for CS-1, CS-2, and CS-3 are 1414.86, 1477.71, and 1796 kg/m3, and 0.37%, 0.32%, and 0.26%, respectively. Cupola slag also includes a larger percentage of lime, according to XRF data, which contributes to its improved binding characteristics. A higher calcium oxide content in CS-3 could facilitate the pozzolanic process. The presence of angular particles that aid in material binding is seen in the SEM image. Compounds with a nanostructure are then flawlessly blended into the mixture and grouped with calcium alumina silicates formed by cement hydration. The XRD pattern of cupola slag exhibits high peaks, indicating that the material is crystalline in character and can be utilized as sand. It also shows the presence of other chemical compounds, such as silica, which ranges from 30% to 45%. CS-1 and CS-2 have comparable XRD patterns. However, CS-3 has a somewhat different pattern because of the greater CaO content. Weight loss begins at higher temperatures, which shows that the material is stable at higher temperatures, according to a thermo-gravimetric study. The differential thermal analysis curve of CS-3 indicates that the material remains stable up to a temperature of 600 °C. The physical characteristics of all cupola slag samples show that cupola slag may be utilized to make sustainable building materials because of its lower specific gravity, density, and water absorption.

Synthesis and characterization of Ketotifen Fumarate Intercalated Zn–Al Layered Double Hydroxides as sustained-release carriers

The present study seeks to synthesize, characterize, and sustain the release of properties of Ketotifen Fumarate Intercalated Zn–Al Layered Double Hydroxides (Zn-Al-KF-LDHs) by the chemical co-precipitation method. A variety of techniques were used to analyze the synthesized products, including Elemental Analysis, X-ray diffraction (XRD), Scanning electron microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), and Thermogravimetry Differential Thermal Analysis (TG-DTA). The XRD patterns successfully highlighted the remarkable crystallinity of the typical hydrotalcite-like materials, Zn-Al-KF-LDHs. While the FT-IR analysis indicates the chemical functional groups and interlayer anions of Zn-Al-KF-LDHs, the elemental analysis determines the content of Zn, Al, S, C, H, and N. The TG-DTA results show that Zn-Al-KF-LDHs possess improved thermal stability. These findings provide an empirical understanding of the supramolecular structure of Zn-Al-KF-LDHs, enabling its comprehensive structural analysis. Additionally, the sustained-release properties of simulated gastric juice and intestinal juice, which followed the theoretical models of Higuchi and Riger-Peppas, indicated that the layered double hydroxides have potential applications as sustained-release carriers for ketotifen fumarate.

Thermal Transformation of Kaolinite Clays: Analyzing Dehydroxylation and Amorphization for Improved Pozzolanic Performance

This study explores the impact of heat treatment parameters on the dehydroxylation and amorphization processes of kaolinite-based materials, in particular natural kaolin clays. It develops a quantitative method for estimating the amorphous phase in heat-treated kaolinite, using differential thermal analysis/thermogravimetry (DTA/TGA), mass spectrometry, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Kaolin clays, subjected to controlled heat treatments between 600°C and 800°C, undergo significant structural transformations. The study identifies the degree of dehydroxylation (DTG) as a crucial measure of kaolinite performance after heat treatment, calculated as a function of sample weight loss. The transition from a crystalline to an amorphous phase strongly influences pozzolanic activity, characterized by its ability to react with portlandite (Ca(OH)₂) in water-rich environments.The materials used, including clay from the Benslimane region of Morocco, were finely ground and subjected to various thermal treatments. Thermal analyses revealed characteristic patterns of mass loss and phase transformation. XRD and FTIR analyses provided detailed information on structural changes, confirming the amorphization of kaolinite after dehydro.

Low-rank coal upgrading to optimize its utilization as fuel

Abstract Indonesia’s coal resources and reserves are mostly categorized as low-rank coal, lignite and sub-bituminous coals. Most of them have a high content of moisture, a low calorific value, and a high tendency to low-temperature oxidation and self-combustion, making them difficult to transport over long distances. To increase the utilization of the low-rank coals, a drying treatment was carried out by heating the coal at a temperature and pressure of 160°C and 3.5 Bar respectively for about 15 minutes. Two low-rank coal samples, from South Sumatra (A coal) and South Kalimantan (B coal) were used in this research. The result indicates that the degree of dewatering of A coal is 89.00% while B coal is 95.5%. B Coal has a higher inherent moisture content which generally has more capillary water which is relatively easier to remove. The higher the degree of dewatering the higher the calorific value degree of improvement. The calorific value of the A coal increased by 27.16% and the B coal increased by 40.65%. The combustion characteristic obtained from the thermogravimetry-differential thermal analysis shows that the A and B upgraded coals have a lower tendency to spontaneous combustion than that of the raw coals.

Cu MOF-biocarbon functional catalysts as adsorbent for oxygen-linked carbon capture via thermo-catalytic pyrolysis: A low-carbon fuel synthesis strategy

Low-carbon fuel synthesis is encouraged as it is environmentally benign and aims to lessen the impact of global warming. This experimental investigation examines the synthesized Bombax ceiba oil (Bio-oil) based pyrolyzed oil utilizing Cu MOF-biocarbon catalysts (0.15 wt.%) via thermo-catalytic cracking and adsorption. The structural and thermal characteristics of the developed Cu MOF - biocarbon catalysts are investigated using Field Emission – Scanning Electron Microscopy/Energy Dispersive Spectroscopy (FE-SEM/EDAX), Attenuated Total Reflectance-Infrared Spectroscopy (ATR-IR), X-Ray Diffraction (XRD), Thermogravimetry-Differential Thermal Analysis (TG-DTA) and Brunauer-Emmett-Teller (BET). Following a thermo-catalytic reaction with a hot plate magnetic stirrer (600 rpm, 100 °C, and 1 h), the oily Cu MOF-biocarbon catalysts are separated from the pyrolyzed green fuel using high-speed centrifugation. The cracking and adsorption of the pyrolyzed green oil compounds are studied using 1H NMR, GC–MS, and thermal conductivity. The results indicate that alkane compounds increase from 3.25 to 6.70 % whereas oxygen incorporated compounds decrease from 96.75 to 93.30 % in the pyrolyzed oil. Furthermore, the GC–MS study shows that the separated oily catalysts adsorb 44.52 % of hydrocarbon (CH) and oxygen-linked (CHO) hydro-carbon compounds. Overall, the newly synthesized Cu MOF-biocarbon is considered as a potential functional catalyst for cracking and adsorption of alkane/oxygen bonded compounds (e.g., CH, CO etc.,), promoting the pyrolyzed oil as low-carbon fuel for better sustainable environment.