ABSTRACT Oxidative steam reforming is employed to examine the thermodynamic feasibility of the production of hydrogen using propanol as a biomass substrate. For process simulation, the R-Gibbs reactor tool in Aspen Plus is used to check the effects of process variables such as pressure (1–10 atm), temperature (300–1000 K) and molar feed ratio (f 1 = steam to propanol = 1–10 and f 2 = oxygen to propanol = 0.25–1) on hydrogen production. After sensitivity analysis, the maximum hydrogen is found at 1 atm, 573 K, f 1 = 10 & f 2 = 0.25. Under the same conditions, the generation of other products such as methane, carbon dioxide, carbon monoxide and carbon (solid) is also analysed. The same optimal operating conditions of process variables are also used to obtain the thermal efficiency of this reforming.

ABSTRACT Zinc oxide particles doped with copper were produced using a cost-effective sol-gel approach at a temperature of 80°C. The process involved combining Zn(NO3)2, Cu(NO3)2, and citrate precursors. A variety of analytical techniques, including scanning electron microscopy, Energy-dispersive X-ray spectroscopy (EDX), diffuse reflectance spectroscopy (UV-Vis DRS), and energy dispersive X-ray diffraction spectroscopy (XRD), were employed to study the physical and chemical characteristics of the nanoparticles. The addition of copper resulted in a significant decrease in the size of wurtzite ZnO nanoparticles, reducing from 180 nm for undoped ZnO to 133 and 40 nm for 10% Cu-doped and 25% Cu-doped ZnO, respectively. The absorption spectra displayed a gradual shift towards the visible range as the concentration of copper in the ZnO particles increased. The calculated band gaps for the various samples were determined to be 3.1 eV for undoped ZnO, 2.3 eV and for 10% Cu-doped ZnO, and 1.8 eV for 25% Cu-doped ZnO. The antibacterial efficacy of Cu-doped ZnO was observed to be significantly greater than that of the undoped sample. Additionally, it demonstrated antibacterial activity under visible light conditions, which suggests the successful synthesis of zinc oxide particles that are induced by visible light.

ABSTRACT Recent advancements in electrode materials have significantly improved the performance and efficiency of supercapattery devices. By offering a unique combination of high energy density, high power density and fast charging capability, supercapattery is ideal for a variety of applications ranging from electric vehicles to consumer electronics. This article reviews the key progress in electrode material design and composition for supercapattery application. Various types of materials employed to enhance the specific capacity, stability and conductivity of supercapattery electrodes is discussed. Furthermore, an overview of the challenges associated with the development of electrode material and corresponding strategies employed to overcome these challenges is presented. Overall, this review highlights the recent advancements in electrode materials for supercapattery and future research directions and opportunities in this exciting field.

ABSTRACT Magnesium titanate is a versatile ceramic material with remarkable dielectric properties that make it indispensable in various chemical engineering applications, particularly in high-frequency electronics, GPS technology, defense industry components, and microwave dielectric materials. Its unique combination of properties ensures efficient energy storage, precise frequency stabilisation, and effective signal transmission in a wide range of technological applications. In this paper, numerous magnesium titanate production techniques have been reviewed under various working conditions, as well as their characterisation. Magnesium titanate is being studied for its efficient method of synthesis due to its numerous uses. Different researchers employ different synthesis procedures for magnesium titanate depending on the qualities needed for the final product. The manner in which magnesium titanate is produced with the appropriate stoichiometry fraction largely determines its properties. It is highly suggested to use wet chemical processes like sol–gel and co-precipitation methods in order to maintain the stoichiometry %, even though there are several solid-state synthesis methodologies available. One of the main advantages of this strategy is the capacity to alter the composition with remarkable precision. The researchers have also shown how the structure varies at different pressure and temperature settings using XRD and SEM images.

ABSTRACT This study aimed to investigate the adsorptive properties of formaldehyde resin-based activated carbons for the removal of methylene blue. The activated carbons were chemically produced by KOH, NaOH and ZnCl2 as activators. Methylene blue dye was employed as a representative pollutant in the adsorption process. The activated carbons were characterised by BET, FTIR and SEM. The adsorptive performance was studied based on the effects of concentration, contact time and solution temperature. AC-KOH shows the highest surface area of 922 m2/g, followed by AC-NaOH (626 m2/g) and AC-ZnCl2 (83.7 m2/g). Nevertheless, AC-NaOH with a pore width of 2.36 nm exhibits the best performance in methylene blue adsorption with a capacity of 152 mg/g. The equilibrium and kinetic data fitted well with Langmuir and pseudo-first order models, respectively, suggesting the predominance of monolayer accumulation of dye molecules inside the pores. The adsorption process is favourable and spontaneous with increasing solution temperature. The activated carbons hold potential for practical application in dye wastewater treatment, highlighting promising prospects for real-world implementation.

ABSTRACT Investigating the potential of biodiesel production from fleshing wastes derived from Ethiopia's leather industry involves both numerical modelling and experimental approaches. The collection and characterisation of fleshing wastes, followed by the application of transesterification methods to produce biodiesel. This integrated approach not only showcases a sustainable waste management solution but also contributes to renewable energy sources, reducing dependence on fossil fuels while addressing environmental concerns associated with leather waste. In this study, fleshing oil has a high acid value of 24.66 mg KOH/g and a 12.33% FFA level. To lower the FFA to 2.5%, an acid pretreatment and transesterification reaction are required. According to the simulation result, azeotrope did not form in the biodiesel separation column, and standard distillation columns could easily separate the biodiesel. It was also revealed by the distillation column purification process that only four stages were required to produce high-grade biodiesel. 99.9% of the introduced methanol was recovered from the separation column, 95% of the biodiesel yield was acquired from the reactor, and 99.4% of the refined biodiesel was obtained from the purification procedure. the investigation of biodiesel production from Ethiopian leather industry waste represents a significant step towards the development of low-cost renewable energy sources.

ABSTRACT Zirconium-activated carbon nanocomposites (ZANC) are found to have high fluoride removal capacity and thus used as an adsorbent to perform column studies. The adsorbent was characterised using SEM-EDS and FTIR before and after the adsorption of fluoride. A packed bed adsorber prototype of 1 m length was fabricated to carry out defluoridation studies. The effect of varying initial fluoride concentration (2.5–10 ppm) and bed height (6–14 cm) was studied. The maximum fluoride removal was found to be 29.4% and uptake capacity was 4.72 mg/g at an initial fluoride concentration of 10 ppm, flow rate of 2 LPM, and bed height of 14 cm for synthetic samples. The Thomas, Yoon–Nelson and Bed Depth Service Time (BDST) models were employed and their results confirmed the experimental findings. The maximum fluoride adsorption capacities obtained from the Thomas model are 1.9 mg/g and from the BDST model, the N value was 20.979 mg/cm3. Regeneration studies were performed and found that the adsorbent can be regenerated for three cycles. Column studies were also performed using real-field groundwater samples collected from Pavagada of Tumakuru district. All the tested parameters of the treated water were found to be within the permissible limit.

ABSTRACT Recent advances in biological, chemical, and medical sciences have been driven by the unique properties of materials at the nanoscale, which differ significantly from their bulk counterparts. The development of sophisticated synthesis techniques has allowed for precise control over the size and shape of nanoparticles, leading to their increased application in agriculture and medicine. Among these, silver nanoparticles (AgNPs) stand out due to their enhanced chemical and physical properties when scaled down to dimensions between 1 and 100 nanometres. These properties, shaped by the size and morphology of AgNPs, make them highly suitable for diverse applications, including biopharmaceuticals, biosensors, chemotherapy, optical imaging, theranostics, and photothermal therapy. The distinct advantages of AgNPs have captured the attention of researchers, though the field still faces challenges related to precise characterisation, controlled synthesis, stability, toxicity, and specific application needs. Overcoming these challenges is essential for the effective utilisation and commercialisation of AgNPs and requires a combination of innovative methods, advanced techniques, and continuous research. This review compiles comprehensive data on the physical, chemical, and green synthesis of AgNPs, exploring their characteristics—such as SEM, UV-spectroscopy, XRD, FTIR, and optical properties—demonstrating their wide-ranging applicability in cutting-edge technology.

ABSTRACT The drinking water quality is highly affected by industrialisation and by natural geographical features of the region. This work highlights on the quality survey and treatment of drinking water collected from four villages (Kalyanipeta, Kesavadasupuram, Arinam Akkivalasa, and Chilakapalem) near Nagarjuna Agrichem Limited in Srikakulam district, Andhra Pradesh. Physicochemical parameters of the samples were analysed. The presence of phosphates in the samples (3.15 mg/L P) were found to be above the permissible limits (1 mg/L P) which required instant treatment by coagulation process. Various influencing factors like temperature, dosage, mixing speed, and mixing time were considered for optimization of the process. The statistical experimental design was done using central composite approach of response surface methodology to optimise phosphate removal via coagulation and flocculation technique. An optimised removal of phosphates was determined to be 79.5% and 76.06% at a temperature of 27°C and 28°C, dosage of 13.412 and 14.906 mg/L, mixing speed of 91 and 78 rpm, and mixing time of 14.25 and 11.62 min for coagulants ferric chloride and aluminium sulphate respectively. Ferric chloride was found to be a better coagulant with a removal efficiency of 79.5% and the treated water contained 0.645 mg/L of phosphate.

ABSTRACT Solar energy is a well-known and economically efficient energy source. Solar energy is harvested in two modes: one is direct and another is indirect. In the direct type, the global radiation is used directly to dry the food samples, while in indirect mode, solar energy is converted into electricity to operate the integrated exhaust fan for enhancement of the drying rate. Thermal analyses of the various components of the PVT hybrid dryer have been incorporated into this performance evaluation. Carrot has been chosen as a food sample because it has good moisture content and is used for nutritive purposes. The maximum ambient temperature has been monitored as 41°C at maximum global radiation conditions. The effect of the PVT system with solar dryer in both cases i.e. natural convection and forced convection have also been discussed in terms of temperature profiles of the drying chamber, sample temperature, and thermal efficiency. The thermal efficiency has been found as 55.3% for forced convection and 53.4% for natural convection. Similarly, a 3°C temperature increment has been found in food samples. Results have been supported and analyzed by the comparison between outcomes of natural and induced convection.