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In recent years, algae have emerged as a promising feedstock for biofuel production, due to their eco-friendly, sustainable, and renewable nature. Various methods, including chemical, biochemical, and thermochemical processes, are used to convert algal biomass into biofuels. Pyrolysis, a widely recognized thermochemical technique, involves high temperature and pressure to generate biochar and bio-oil from diverse algal sources. Various pyrolytic processes transform algal biomass into biochar and bio-oil, including low pyrolysis, fast pyrolysis, catalytic pyrolysis, microwave-assisted pyrolysis, and hydropyrolysis. These methods are utilized to convert a range of microalgae and cyanobacteria into biochar and bio-oil. In this publication, we will discuss catalytic pyrolysis using mesoporous materials, such as SBA-15. Mesoporous catalysts have earned significant attention for catalytic reactions, due to their high surface area, facilitating the better distribution of impregnated metal. Pyrolysis conducted in the presence of a mesoporous catalyst is viewed more as efficient, compared to reactions occurring within the smaller microporous cavities of traditional zeolites. SBA-15 supports with incorporated Zr and/or Ce were synthesized using the direct hydrothermal synthesis method. The catalyst was characterized using structural and morphological technical analysis and utilized for the pyrolysis reaction of the algal biomass. [ABSTRACT FROM AUTHOR]

This review covers recent compositions of bioactive glass, with a specific emphasis on both inorganic and organic materials commonly utilized as matrices for injectable materials. The major objective is to highlight the predominant bioactive glass formulations and their clinical applications in the biomedical field. Previous studies have highlighted the growing interest among researchers in bioactive glasses, acknowledging their potential to yield promising outcomes in this field. As a result of this increased interest, investigations into bioactive glass have prompted the creation of composite materials and, notably, the development of injectable composites as a minimally invasive method for administering the material within the human body. Injectable materials have emerged as a promising avenue to mitigate various challenges. They offer several advantages, including minimizing invasive surgical procedures, reducing patient discomfort, lowering the risk of postoperative infection and decreasing treatment expenses. Additionally, injectable materials facilitate uniform distribution, allowing for the filling of defects of any shape. [ABSTRACT FROM AUTHOR]

In this paper, based on our previous expertise on ceramic artifacts, several archaeometric methods applied to some samples collected from the Dudești archaeological site (Oltenia region, Romania) are reported for the first time in the literature. The chemical composition, and microstructural and morphological characterization of these samples offer important conclusions about the processing conditions. Some specific techniques such as X-ray diffraction (XRD), wavelength-dispersive X-ray fluorescence (WDXRF), optical microscopy (OM), stereomicroscopy, environmental scanning electron microscopy (ESEM), Fourier-transform infrared spectroscopy (FTIR), and Raman spectroscopy provide compositional information about composition and the decay processes. Additionally, the Brunauer–Emmett–Teller (BET) method helps to estimate pore sizes and specific surface areas. A thermogravimetric analysis (TGA/TDG) was used to establish details regarding the production technology and also the raw materials source used to make the ceramics. The obtained results indicated that the ceramics are based on a paste of muscovite and feldspar, with high plasticity, together with quartz and hematite/goethite and calcite, the latter in very low concentrations. According to the obtained results, we could assume that clays from the investigated samples had a low concentration of calcium. Gypsum is present as paste in a very low concentration, identified by the presence of a sulphate group in WDXRF. In the same context, iron oxides have a significant impact on the firing atmosphere of iron-rich clay, resulting in blackening under reducing conditions and a reddish coloration under oxidative conditions. The use of hematite and gypsum as pigments further contributes to the color variations in the pottery. The consistent firing temperature range of 200–600 °C in Dudești pottery implies a standardized production process, the variation in color being dependent on the specific reducing/oxidative regime conditions (reducing atmosphere followed by rapid oxidation). This relationship between clay composition and local sources suggests a connection to Neolithic pottery production in the region and their color depending on the reducing/oxidative regime conditions. [ABSTRACT FROM AUTHOR]

The dispersion of crumb rubber in road bitumen is essential for enhancing the elasticity of asphalt coatings. However, elastomer cross-linking through vulcanization can reduce the colloidal stability of bitumen. This study aims to enhance compatibility by partially devulcanizing crumb rubber using a pulverulent catalyst, specifically phosphomolybdic acid, in a batch reactor at 270°C. The use of a molybdenum-based catalyst is preferred due to its effectiveness in catalyzing the devulcanization process. Additionally, further conditioning of the catalyst through grinding optimizes contact with crumb rubber, enhancing catalyst activity and improving overall compatibility with road bitumen. [ABSTRACT FROM AUTHOR]

The high elastomer content of the crumb rubber powder obtained from the processing of used tires increases the interest for its valorization when modifying road bitumen in order to improve its elastic characteristics. Sulfur cross-linking of elastomer chains reduces the dispersion of the crumb rubber in the road bitumen during the modification process. A novel approach was explored, involving the partial desulfurization of rubber powder using a natural zeolitic catalyst, clinoptilolite, modified in its acid form. The catalytic desulfurization of the powder was carried out in a batch system at a temperature of 280°C for 6 hours in the presence of high aromaticity solvents. The catalysts' high acidity facilitated the conversion of rubber powder effectively, reaching a more suitable form to use in improving road bitumen. [ABSTRACT FROM AUTHOR]

This paper shows the results of thermal and catalytic pyrolysis of conditioned lignosulfonate from the sulfite process, with a specific focus on the analysis of bio-oil and biochar. The conditioning of lignosulfonate was made by drying and grinding in a planetary ball mill. Thermal and catalytic pyrolysis of conditioned lignosulfonate were carried out under the same temperature and flow conditions. The use of two different catalysts produced via the impregnation method has shown distinctive effects, influencing both bio-oil yield and chemical composition. The resulting biochar exhibits characteristics comparable to nonactivated carbonaceous materials, with variations in its specific surface area and pore size depending on the catalyst. [ABSTRACT FROM AUTHOR]

Sulfur has been used for a long time as a vulcanizing agent for polybutadiene and polyisoprene rubber. The presence of sulfur in the used crumb rubber powder reduces its dispersion in the bitumen and favors its separation from the colloidal structure of the bitumen. For this reason, it does not allow the use of this waste to modify the road bitumen. In this paper, the desulfurization of used crumb rubber is studied by reactive adsorption in the presence of metal oxide adsorbents in pulverized form. Metal oxide adsorbents were prepared based on Fe, Cu and a mixture of the two metal oxides with a bimodal particle size distribution and an average particle diameter between 500 and 800 nm, by the sol-gel precipitation method, in the presence of a Pluronic® surfactant. The morphology of the prepared adsorbents was investigated by Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM) and nitrogen porosimetry analyses (BET method). The desulfurization of crumb rubber experiments was carried out in a high-pressure Parr stainless steel reactor with electric heating and stirring in an inert gas atmosphere (nitrogen). The conversion in the desulfurization process of vulcanized rubber was influenced both by the size of the adsorbent particles and also by the nature of the adsorbent. [ABSTRACT FROM AUTHOR]

Copper nanoparticles on silica support are cheap and effective catalysts for dehydrogenation of n-butanol, a biomass-derived building block which is increasingly used. Ultrasonically assisted Cu catalysts are prepared, characterized, and tested for the conversion of n-butanol to n-butanal. The best performance in terms of overall conversion of n-butanol and selectivity to butanal was offered by ultrasound-prepared process of the Cu nanoparticles. In conventional wet impregnation method, Cu nanoparticles on the surface of support tend to aggregate in some sort of cubic aggregates with the size of 4–5 µm and because of this, the percentage of the centers of silica (on which intermolecular dehydration reactions occur) is higher compared to Cu metallic centers (that promotes the dehydrogenation reaction). The ultrasound reduction stage used in the preparation of catalysts provides a better coverage of the catalyst surface by Cu nanoparticles that have a more uniform dimension, which offers a greater selectivity to butanal (more than 95%) and a negligible selectivity to butene. [ABSTRACT FROM AUTHOR]

Biomass is one of the most important renewable energy resources to produce sustainable liquid fuel. This study presents the process of hydrodeoxygenation/hydrocracking on a model of oxygenated compounds such as fatty acid methyl esters using a bifunctional catalyst that contains a metallic function based on copper and palladium and an acid function type ZMS-5. Hydrocracking of methyl esters on the bifunctional catalyst CuPd/γ-Al2O3–ZSM-5 realized on a fix bed reactor led to obtaining of n-alkanes, iso-alkanes, saturated and aromatic cyclic hydrocarbons with 9 to 18 carbon atoms. The conversion reach 100% value at temperature higher than 350 °C. The yield in n-alkanes varies with a maximum at temperature of 325 °C, meanwhile, the yield in iso-alkanes remains approx. constant. The cyclization and aromatization reactions are favored at temperatures higher than 350 °C. [ABSTRACT FROM AUTHOR]