https://irju.jdvu.ac.in/jspui/handle/123456789/71 Sat, 07 Nov 2026 17:37:55 GMT 2026-11-07T17:37:55Z https://irju.jdvu.ac.in/jspui/handle/123456789/10849 Title: Study of benzene hydrogenation over Ni/Al₂O₃ catalyst in a fixed-bed reactor Authors: Saha, Arijit Abstract: The performance and activity of (2 wt.%)Ni/γ-Al2O3 catalyst in the hydrogenation of benzene reaction was studied in a high pressure continuous up-flow catalytic fixed bed reactor. Aluminium oxide (Al2O3) was employed as a support material to synthesize (2 wt%)Ni/γ-Al2O3 hydrogenation catalyst using excess solution impregnation method (ESI). Two of the characterizations BET and TGA analysis are carried out in this study. The BET surface area of (2 wt.%)Ni/γ-Al2O3 using BET analysis gives 24.79 m2/g and TGA analysis shows an effective thermal stability of the catalyst. Two parameters of the reactor such as pressure and temperature were varied keeping the liquid hourly space velocity (LHSV) = 2 min-1 fixed to understand the effect on benzene conversion. It was observed that benzene conversion was increased with increasing H2 pressure and after that slightly decreases to 25 bar at temperature 3900C and LHSV = 2 min-1. Further, the benzene conversion is dependent upon temperature and shows a maximum at 3300C and activation energy around 23.24 kJ/mol. The study also shows the effect of LHSV on benzene conversion at, T=3900C and P=25 bar. However, Power Law model of hydrogenation of benzene gives a perfect fit on data and it was found that, the order of H2 is 1 represents a 1st order whereas, the order of benzene is 0.8 (close to 1st order). It was found that (2 wt%)Ni/γ-Al2O3 catalyst showed better performance and activity in the hydrogenation of benzene reaction. Mon, 01 Jan 2024 00:00:00 GMT https://irju.jdvu.ac.in/jspui/handle/123456789/10849 2024-01-01T00:00:00Z https://irju.jdvu.ac.in/jspui/handle/123456789/10848 Title: Experimental studies on removal of pollutants by adsorption Authors: Sk Parvej Akthar Abstract: Wastewater treatment has increasingly become a critical focus in recent years due to the escalation in the levels of toxins present in industrial effluents. Of particular concern are the high concentrations of toxic heavy metals like chromium (VI) found in aqueous streams, stemming from the release of untreated effluents containing metals into water sources, posing a significant environmental challenge. Adsorption stands out as an efficient technique for eliminating chromium (VI) from wastewater. The exploration of biosorbents has emerged as a key area of interest for removing chromium (VI) ions from aqueous solutions at ambient temperature. In this study, raw tamarind fruit shells after being activated through treatment with concentrated hydrochloric acid (98% w/w) was used as an adsorbent. Equilibrium studies showed that adsorption of chromium (VI) is more effective at lower solution pH values. Packed beds are known for their ability to remove contaminants efficiently and are generally used in industries. Bed design is crucial for achieving effective contaminant removal. Reducing particle size results in increased mass transfer rates resulting in small mass transfer zones and more effective utilization of adsorbent bed. But challenges related to high pressure drop are encountered with small particles that would effectively stop operation specially when flow through the bed is gravity driven. To overcome the limitations associated with small particles, a potential solution involves coating inert beads with adsorbent particles on the outer surface. The experimental study outlined in this paper provides valuable insights into the practical implications of these design considerations, offering a pathway for enhancing treatment efficiency and addressing challenges effectively. Mon, 01 Jan 2024 00:00:00 GMT https://irju.jdvu.ac.in/jspui/handle/123456789/10848 2024-01-01T00:00:00Z https://irju.jdvu.ac.in/jspui/handle/123456789/10847 Title: Design and simulation of electrochemical regeneration of fuel from direct air capture Authors: Deb, Kundan Abstract: Presently, Direct Air Capture (DAC) stands as a leading contender in the arsenal of strategies to mitigate CO2 emissions, which have reached a critical juncture with the imperative to address 30% of the latest greenhouse gas emissions by 2030. While CO2 removal (CDR) technologies are projected to attain a Technology Readiness Level (TRL) suitable for industrial applications within seven years, the leap to TRL-11, as per the new IEA scale for disruptive technologies, appears improbable due to the intricate process of transitioning from small-scale pilots to industrial implementation, necessitating considerable time and investment. Furthermore, the absence or lack of planning for large-scale validation poses a significant obstacle. This study also pinpoints the critical materials supply chain and the competition posed by the energy transition as additional limiting factors that could impede DAC deployment and diminish its potential contribution during the crucial period when substantial emissions reductions are imperative. The escalating atmospheric carbon dioxide levels, contributing to global warming, underscore the urgent need for sustainable carbon sequestration methods. In this review, we delve into carbon capture, utilization, and storage using microalgae, emphasizing techniques to enhance carbon dioxide uptake. These include systems integrating wastewater and flue gases, machine learning for strain identification, artificial intelligence, automation, and the circular bio economy. Strategies to boost carbon dioxide uptake by microalgae encompass modified photo bioreactors, membranes, chemical methods, solvents, adapted strains, genetically engineered strains, omics, and nanotechnology. Moreover, we explore the economic feasibility of microalgae-based carbon capture and bioenergy production. On average, micro algal cultivation across 13 million acres has the potential to sequester approximately 0.5 giga tons of CO2, yielding over 300 tons of biomass. Mon, 01 Jan 2024 00:00:00 GMT https://irju.jdvu.ac.in/jspui/handle/123456789/10847 2024-01-01T00:00:00Z https://irju.jdvu.ac.in/jspui/handle/123456789/10846 Title: Simultaneous adsorptive removal of cationic dyes from aqueous solution using graphene oxide-incorporated sodium alginate hydrogel beads Authors: Karmakar, Sumana Abstract: In this study, we present a novel approach utilizing a graphene oxide (GO)-based sodium alginate (SA) composite for the efficient removal of hazardous cationic dyes Methylene Blue (MB) and Safranin O (SO) simultaneously from aqueous solutions. The composite material leverages the unique properties of both GO and SA, offering enhanced adsorption capabilities and eco-friendliness. The synthesis of the composite involved the dispersion of GO sheets in a sodium alginate solution, followed by cross-linking to form a stable composite matrix. The resulting GO-SA composite exhibited a high surface area and abundant functional groups, providing favorable sites for dye adsorption. Batch adsorption experiments were conducted to investigate the removal efficiency of MB and SO dyes from aqueous solutions at various initial concentrations(10ppm, 20ppm, 30ppm, 40ppm), contact times(5min, 10min, 30min, 45min, 60min, 75min, 90min, 120min, 180min, 1440min) and temperatures(308k, 318k, 328k).The adsorption kinetics followed the pseudo-second-order kinetics, indicating a chemisorption process, and the equilibrium data were well-described by the Langmuir isotherm model, suggesting monolayer adsorption onto a homogeneous surface. The maximum adsorption removal of the composite for MB and SO were found to be 97% and 95%, respectively, with condition 30ppm initial concentration, pH 8 and 5g beads. Furthermore, graphene oxide (GO)- based sodium alginate (SA) composite was elucidated through Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses, revealing the involvement of π-π interactions, electrostatic attractions, and hydrogen bonding between the dye molecules and the composite surface. Result of thermodynamic study for MB dye change in enthalpy(ΔH) 35455.8 J/mol, change in entropy(ΔS) 125.03 J/mol k and SO dye change in enthalpy(ΔH) 24817.29J/mol, change in entropy(ΔS) 90.58 J/mol k. After 2 cycles of regeneration of the adsorbent, a minor drop in removal efficiency was observed. The developed GO-SA composite demonstrates promising potential as an efficient and eco-friendly adsorbent for the removal of MB and SO dyes from aqueous solutions, contributing to the mitigation of water pollution and environmental remediation efforts. This study provides valuable insights into the design and application of graphene oxide-based composite materials for wastewater treatment. Mon, 01 Jan 2024 00:00:00 GMT https://irju.jdvu.ac.in/jspui/handle/123456789/10846 2024-01-01T00:00:00Z