PREDICTION OF GAS HOLD-UP IN A COMBINED LOOP AIR LIFT FLUIDIZED BED REACTOR USING NEWTONIAN AND NON-NEWTONIAN LIQUIDS

Many experiments have been conducted to study the hydrodynamic characteristics of column reactors and loop reactors. In this present work, a novel combined loop airlift fluidized bed reactor was developed to study the effect of superficial gas and liquid velocities, particle diameter, fluid properties on gas holdup by using Newtonian and non-Newtonian liquids. Compressed air was used as gas phase. Water, 5% n-butanol, various concentrations of glycerol (60 and 80%) were used as Newtonian liquids, and different concentrations of carboxy methyl cellulose aqueous solutions (0.25, 0.6 and 1.0%) were used as non-Newtonian liquids. Different sizes of spheres, Bearl saddles and Raschig rings were used as solid phases. From the experimental results, it was found that the increase in superficial gas velocity increases the gas holdup, but it decreases with increase in superficial liquid velocity and viscosity of liquids. Based on the experimental results a correlation was developed to predict the gas hold-up for Newtonian and non-Newtonian liquids for a wide range of operating conditions at a homogeneous flow regime where the superficial gas velocity is approximately less than 5 cm/

Conversion of ethanol to higher alcohols on Ni/MxOy-Al2O3 (M=La, Ce, Zr, Mg and Ti) catalysts: Influence of support characteristics

9-22A new series of alumina supported nickel (8% w/w) catalysts, modified with promoters, La2O3, CeO2, ZrO2, MgO and TiO2, highly active for the conversion of ethanol to butanol and higher alcohols, at 200°C-220°C, in batch mode, under autogenous pressure, has been investigated. XRD and XPS results indicate the presence of metallic Ni and Ni aluminate as the active phases. H2-TPR studies reveal that the introduction of promoters improves nickel dispersion, reducibility and moderates the metal-support interactions.TPD of ammonia and CO2 studies establish the strong influence of the promoter oxides on the strength and population of acidic and basic sites. Ethanol conversion at 200°C varies in a narrow range, 36-42%. CeO2 and MgO modified catalysts display maximum selectivity towards butanol (48%) and higher alcohols, (81% and 75%) in comparison with the catalyst based on pristine alumina (28.9% and 40.5%). While the selectivity for butanol and higher alcohols is governed by the basicity of the catalysts, both metal function and basicity are required to drive ethanol conversion. Moderation of acidity helps in minimizing the formation of ethylene and other gaseous products. Analysis of used catalyst indicates that the structural and active phase characteristics are retained during use

Clay Minerals Effects for Metal Reclamation from Leached Solution

The recent advancements in technology play a pivotal role in mankind’s life and have a significant stint in the generation of E-waste. The present investigation focuses on the recovery of heavy metals from Printed Circuit boards (PCBs) by applying two efficient techniques viz., leaching and adsorption. A combination of leaching and adsorption is a novel and productive approach to recovering heavy metals from like PCBs. After the phases of chemical leaching, the solution was recovered through adsorption and is eco-friendly. The process is carried out to increase the separation rate, reduce the time spent and reach the limits of incineration and pyrolysis methods. Adsorption provides the recovery of heavy metals with respect to the required adsorbent since it is a surface phenomenon. The optimum condition of process variables was found through response surface methodology (RSM). The maximum recovery of copper ions (97.33%) was obtained at the optimum operating conditions such as adsorbent size of 0.04 mm, adsorbent dosage of 3.5 gm L−1 and the temperature of 80°C with 0.845 desirability. This investigation was found to be an eco-friendly way to recover copper ions and does not cause any environmental issues

Unique cellular immune signatures of multisystem inflammatory syndrome in children

The clinical presentation of MIS-C overlaps with other infectious/non-infectious diseases such as acute COVID-19, Kawasaki disease, acute dengue, enteric fever, and systemic lupus erythematosus. We examined the ex-vivo cellular parameters with the aim of distinguishing MIS-C from other syndromes with overlapping clinical presentations. MIS-C children differed from children with non-MIS-C conditions by having increased numbers of naïve CD8(+) T cells, naïve, immature and atypical memory B cells and diminished numbers of transitional memory, stem cell memory, central and effector memory CD4(+) and CD8(+) T cells, classical, activated memory B and plasma cells and monocyte (intermediate and non-classical) and dendritic cell (plasmacytoid and myeloid) subsets. All of the above alterations were significantly reversed at 6–9 months post-recovery in MIS-C. Thus, MIS-C is characterized by a distinct cellular signature that distinguishes it from other syndromes with overlapping clinical presentations. Trial Registration: ClinicalTrials.gov clinicaltrial.gov. No: NCT04844242

Thevetia Peruviana biodiesel emulsion used as a fuel in a single cylinder diesel engine reduces NOx and smoke

Biodiesel is a promising renewable alternative fuel for diesel. However, its adaptability is limited by its emission levels surpassing the existing emission norms. In this situation, it is essential to search for an economically apt way of reducing the pollutants so as to make biodiesel a viable proposition. Emulsified fuels have more priority in reducing Nitrogen Oxide (NOx) and smoke simultaneously than other fuels. In this study, Thevetia Peruviana biodiesel was emulsified with water in the ratios of 5%, 10%, 15% and 20% to investigate the engine performance and emission characteristics. Emulsified fuels showed an improvement in brake thermal efficiency accompanied by the drastic reduction in NOx. From the detailed study it was found that 15% water emulsified fuel showed the best performance and less emission than the other combinations

Produce Low Aromatic Contents with Enhanced Cold Properties of Hydrotreated Renewable Diesel Using Pt/Alumina-Beta-Zeolite: Reaction Path Studied via Monoaromatic Model Compound

In this present work, Hydro-dearomatisation of toluene and hydro-isomerisation of n-hexadecane (n-C16) in ultralow sulphur diesel (ULSD) using Pt-Cl/H-Beta and Pt/H-Beta catalyst was investigated in a continuous down-flow trickle-bed reactor (DFTBR), and the physicochemical properties of products were studied. The catalytic effect on 40:60 wt% of H-beta-zeolite (H-β) and binder–aluminahydrochlorite extruded was characterized in scanning electron microscopy, nitrogen adsorption and coke testing. The study showed that 80 to 95 wt% of middle distillates recovered in ULSD on elevated temperature between 230 and 270 °C at 5 MPa. With a higher residence time of feed, the middle distillate recovered with 2.2 v/v% of aromatics and −32 °C of cloud point. In the model compound investigation of toluene and n-C16, it was observed that absorption of aromatic ring inhibits the rate of isomerisation; particularly it reduces the yield of branching and rearrangement of n-C16. Also, Cl-incorporated H-β extrudate enhanced the ring saturation and suppressed the reaction path in oligomerisation and cyclisation of paraffin. This methodology achieved asingle-stage upgrading technique involved in the delivery of commercial diesel in the market with low cloud point and aromatic content