Johnson Matthey Technology Review - Fast Track

The influence of Hf content on the recrystallization and aging behavior of hot-rolled Pt-15Ir-xHf-0.5Y alloy was investigated by SEM, EBSD and hardness tests. The results show that the alloy texture evolves from a multi-peak one biased towards rolling direction-transverse direction (RD-TD) in the hot rolling state to a multi-peak one symmetrical along the normal direction (ND) after recrystallization annealing. The fibrous grains become equiaxial after recrystallization annealing, increase of Hf content refines the grains. Pt-15Ir-xHf-0.5Y alloy exhibits age-hardening behavior at the temperature range of 600°C~900°C, which is due to the precipitation of (Pt, Ir)5Y phase. Increasing Hf addition effectively improves the hardness through promoting the precipitated amount of (Pt, Ir)5Y phase. However, the internal oxidation within grain boundaries is deteriorated with the high-content Hf addition. The results of this study provide an insight into tailoring the microstructures and mechanical properties of the Pt-Ir high-temperature alloys.

Abstract: The pursuit of sustainable energy sources on a worldwide scale is a crucial and pressing matter, with the United Nations Sustainable Development Goals (UNSDGs) offering a comprehensive framework for properly addressing this challenge. This paper provides an overview of the various technologies now available for the process of biomass gasification. Compared to other renewable energy sources, which have undergone significant technological advancements in recent years, the field of biomass conversion is still relatively new. Keeping up with the newest breakthroughs becomes increasingly crucial as new conversion techniques are rapidly being created. Keeping up with the latest advancements and potential enhancements in biofuel conversion technology is essential due to their rapid development. In the thermochemical conversion process called "biomass gasification," biomass solid source materials are degraded or incompletely burned in an oxygen-free or oxygen-deficient high-temperature atmosphere, resulting in the production of biomass gas. Biomass gas can be utilized in industry to directly power industrial boilers for steam production, as well as for cooking or heating purposes in rural areas. The purified biomass gas can be utilized to operate a generator set, so facilitating the provision of electricity to areas lacking access to it. The utilization of biomass gasification technology alters the traditional approach of directly igniting biomass to generate power. Gasification technology converts biomass into a clean and combustible gas, significantly improving the efficiency of using biomass energy. This essay will largely concentrate on the methodologies and protocols employed in biomass gasification. The article provides an overview of various gasification procedures and the potential applications of the resulting products. It delves into different biomass gasification techniques, including upstream, gasification, and downstream processes, highlighting their importance in transforming biomass into clean and combustible gases. The review focuses on methodologies and protocols employed in biomass gasification, recognizing its pivotal role in sustainable energy generation. Additionally, the article discusses the challenges associated with gasification technology, such as tar formation, biomass heterogeneity, and uneven biomass supply in different seasons. It emphasizes the need for further research and infrastructure development to overcome these barriers and facilitate the efficient distribution and commercialization of biomass gasification technology. Overall, the scope of the article extends to providing insights into the status, challenges, and future prospects of biomass gasification for achieving sustainable energy goals.

Heterogeneous Cu/ZnO-based catalysts are widely used for CO₂ hydrogenation to methanol, but limitations remain for industrial applications. These include achieving high methanol selectivity and conversion, and mitigating deactivation by water poisoning. This review explores the role of active sites on Cu/ZnO-based catalysts in CO₂ conversion. The synergistic interaction between Cu and ZnO is emphasized, particularly regarding interfacial effects on CO activation and formate formation. The discussion covers theoretical and experimental perspectives on active site characteristics, including defects, vacancies, steps, and strain. Additionally, the review explores the connection between Cu/ZnO-based catalysts properties and methanol synthesis activity. It examines how preparation methods influence catalyst performance and the impact of doping with elements like CeO₂, Al₂O₃, and ZrO₂ on CO₂ conversion selectivity. We conclude that ZnO enhances Cu dispersion and promotes a synergistic effect at the interface, leading to improved catalytic performance.

The paper presents a mathematical model for describing of thermogravimetric curves of growth of scale with its simultaneous sublimation during oxidation of the surface of a metal or alloy. For alloys FeCr and FeCrAl, a decrease in the effective reaction area as a result of the formation of the oxide of the alloying element - lanthanum or yttrium (together with the formation of the main oxide - Cr2O3 or Al2O3) is considered. For metals, the case of increasing this area is also considered.  During the oxidation of the chromia-forming alloy, another secondary process is added - the evaporation of Cr2O3. Therefore, the equations describing the kinetics of changes in mass of these alloys are different. Equations are also considered that make it possible to describe the kinetics of the oxidation process taking into account the initial non-isothermal heating. The formal equations of the oxidation process with an increase in the reaction surface as a result of crushing metal powder are also considered. The resulting equations are used to describe the kinetic curves of changes in the mass of the samples under study. The given equations can be considered as a more accurate approximation to describe the experimental data than the formulas known so far.

Cellulose is a natural polymer contained in growing fibers, such as pineapple fibers. Cellulose can be modified into cellulose acetate, a modified polymer that can be used in the synthesis of a cellulose acetate/polyethylene glycol (CA/PEG) membrane. The phase inversion method was used in this study to produce CA/PEG membranes. Variations in PEG concentration with a ratio of 1:1 to cellulose acetate, where variations in PEG concentrations used are 2%, 5%, and 8%. Acetone and dimethylformamide are used as organic solvents. Membrane morphological analysis using Scanning Electron Microscope (SEM) and functional group analysis using a Fourier Transform-Infrared (FT-IR) spectrometer were performed for membrane characterization. The result of the synthesis of the CA/PEG membrane is in the form of a thin white layer. The characterization results of the FT-IR spectrometer showed the vibration of the carbonyl bond at wavenumber 1729 cm-1 and the vibration of the hydroxyl bond torque at the wave number 648 cm-1, where the vibration intensity decreased with each addition to the concentration. The results of SEM characterization show that the increase in PEG concentration increases the percentage porosity of the membrane. The membranes with 2%, 5%, and 8% PEG have porosity percentages of 51.54%, 68.70%, and 73.50%, respectively. As the membrane with 2% PEG has the lowest percent porosity, it is more potential in removing or filtering solutes from a fluid.

Abstract. The mineralogical properties and distribution of information established in saprolite from Indonesia were investigated using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy energy dispersion spectroscopy (SEM–EDS), and differential thermal analysis (DTA) measurements. The findings suggest that laterite ore has a complex inner core. The percentages of Ni, Fe, Mg, Al, and Si in saprolite are given in 1.82, 30.47, 10-20, 4.86, and 8.1 weight percent. Saprolite has 53.1 percent iron oxide/oxyhydroxide, 38.3 percent lizardite and 8.7 percent silicate. According to DTA, saprolite undergoes a phase shift from goethite to hematite at low temperatures (200-300ºC). This is a suitable phase to optimize nickel diffusion in iron. Furthermore, the thermal upgrading approach was utilized for this saprolite.