Brazilian Journal of Chemical Engineering This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Ni-mo supported nanoporous graphene as a novel catalyst for hds and hdn of heavy naphtha
ABSTRACT Reducing sulfur and nitrogen compounds is essential in producing clean fuels for providing a green environment. In this regard, a novel nanocatalyst has been proposed for Hydrodesulfurization (HDS) and Hydrodenitrogenation (HDN) of heavy naphtha. To this end, Ni-Mo was loaded on nanoporous graphene (Ni-Mo/NG) through the incipient wetness impregnation method. The synthesized nanocatalyst was characterized by FE-SEM, ICP, BET, FTIR, XRD and TPR methods. The catalytic activity of the Ni-Mo/NG catalyst was evaluated at 290 ºC and 30 bar. For the synthesized Ni-Mo/NG catalyst, conversions of total sulfur, total nitro...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research

Preparation and characterization of thin-film composite reverse osmosis membrane on a novel aminosilane-modified polyvinyl chloride support
ABSTRACT Herein, the influence of pure and modified polyvinyl chloride (PVC) support layers on the performance of thin-film composite (TFC) membranes was investigated in water desalination. Accordingly, the PVC support was modified using (3-Aminopropyl) triethoxysilane (APTES) through bulk modification. The supports were synthesized at different doses of APTES (0-6 wt%) and characterized with various analytical techniques. The results showed that APTES affected considerably both the morphology and surface properties of the support layer. Afterwards, the polyamide (PA) layer was formed via an identical interfacial polymeriz...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research

SYNTHESIS, CHARACTERIZATION AND in vitro CYTOTOXICITY OF Acacia mearnsii PROANTHOCYANIDIN LOADED PLGA MICROPARTICLES
ABSTRACT One of the highlighted areas in the development of new materials is the generation of micro- and nanoparticles as drug carriers which allow the progress in formulations with the ability to release active agents in a controlled way. The proanthocyanidins (PAC) extracted from the bark of the Black Wattle have stood out for their biological activities. However, most polyflavonoids have some features which limit their application in the pharmaceutical field, such as light fastness, low bioavailability of active agents, and unpleasant taste. In this context, this study aims to present the synthesis and characterization...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research

Rheological behavior of a silver aqueous nanofluid stabilized with aminosilane-based surfactant under confined flow
ABSTRACT The rheological behavior of an aqueous suspension of silver nanoparticles stabilized with aminosilane-based surfactant flowing under confinement was investigated. Three stability levels were defined based on the zeta potential: high (41.73 mV, pH 4.3), medium (10.44 mV, pH 7.4), and low (0.74 mV, pH 8.6). Furthermore, the preliminary investigation showed that the surface charge remained positive, and the formation of agglomerates was not observed. Due to the particle coating and the ionization of the amino groups of the surfactant an electrosteric stabilization was evidenced. Shear rates ranging from 50 to 1000 s-...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research

Effect of steel plate thicknesses and fluid flow characteristics of an impinging air jet on heat transfer at the stagnation point
ABSTRACT The design and process of heat transfer elements, from its source to heat sink through various media vary according to the product and system concerned. The effect of thickness of a steel plate on heat transfer characteristics with an impinging air jet at the stagnation point was studied. Experiments were carried out with different nozzles, heights, and velocities. It was concluded that the heat transfer increases with the increase in velocity and the increase in Reynolds Number, but decreases with the increase in nozzle height from the impinging point. A maximum stagnation Nusselt number of 309.06 was obtained at...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research

Researching new ways to reduce n2o emission from a granular sludge sequencing batch reactor treating domestic wastewater under subtropical climate conditions
ABSTRACT N2O emissions from wastewater treatment plants have become an important issue, since this compound is a significant greenhouse gas that affects the sustainability of sewage treatment. This work aimed to investigate and to reduce N2O emission from a pilot-scale aerobic granular sludge sequencing batch reactor (AGS-SBR) operated for carbon and nitrogen removal from domestic wastewater under subtropical climate condition. Three operational strategies (S-I, S-II and S-III) with different anoxic phase durations were compared regarding treatment efficiency and N2O emission. For all the studied strategies, volatile suspe...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research

A fair comparison between bismuth catalysts for application in photodegradation under visible and solar light
ABSTRACT Three different bismuth catalysts (Bi2WO6, BiOI and BiVO4) were synthesized using solvo- and hydrothermal methods. Different reaction times, calcination and the addition of poly (vinyl pyrrolidone) during synthesis were tested to investigate the effect of these variables on the catalysts ’ morphology and photocatalytic activity. The photocatalytic activity was evaluated using the degradation of rhodamine B dye under both visible light and natural solar radiation. The Bi2WO6 samples presented good crystallinity and morphological similarities, despite having undergone different treatments. The BiOI and Bi2WO6 cat...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research

The influence of different electrolytes on sulfentrazone dechlorination by iron-nickel bimetallic nanoparticles
ABSTRACT Kinetic studies of sulfentrazone herbicide dechlorination by Fe/Ni nanoparticles were performed in the presence of different electrolytes such as: Cl-, SO42-, NO3-, Cu2+, Na+ and Zn2+. In the presence of Cl- and SO42- the reaction occurred efficiently, reaching approximately 100% of dechlorination after 30 minutes of reaction. In the presence of NO3- and Cu2+ ions the sulfentrazone dechlorination was significantly inhibited, because these ions tend to compete with the substrate for the electrons donated by Fe0. In the presence of Na+ ions, the dechlorination efficiency remained approximately 100%, however, this el...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research

APPLICATION OF POLYCARBOXYLIC ACIDS AS BINDERS FOR TiO2 IMMOBILIZATION ON COTTON TEXTILES
ABSTRACT Immobilizing the photocatalyst on a support is an alternative solution to a critical issue in photocatalysis, which is the need for unit operations to remove the photocatalyst from the effluent. In this work, TiO2 was immobilized onto a cotton textile substrate by polycarboxylic acid binders (succinic and citric acids) using a solution deposition method, and the most appropriate conditions for pre-treatment and the relationship between variables were determined by an experimental design. Then, samples prepared at optimum conditions were exposed to UV for an extended period of time to evaluate the deactivation. The...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research

Optimization of lipase immobilization on maghemite and its physico-chemical properties
ABSTRACT Nanomaterial-based biocatalysts have emerged as current carriers suitable for enzyme immobilization. The nano-sized materials provide large surface area for enzyme attachment, thus increasing the probability for its efficient catalyst activity. By using magnetized nanomaterials, enhancement of the downstream processing is evident as it eases the immobilized enzyme separation from the reaction mixture further. Lipase / maghemite composites were prepared by initial maghemite surface modification to cater to the needs for biocatalyst attachment. Surface modification using chitosan and subsequent cross-linking with gl...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research

Isolation and identification of yeast strains from sugarcane molasses, dates and figs for ethanol production under conditions simulating algal hydrolysate
ABSTRACT Yeast strains were isolated from sugar cane molasses (S1), dates (S2) and figs (S3) and the ethanol production was evaluated in batch condition. A comparison was made with the yeast Saccharomyces cerevisiae. The strains showed tolerant characteristics to stressful conditions like salinity and ethanol. The isolated strains produced ethanol; at 20 h of fermentation ethanol yields were 0.38-0.39 g.g-1, and the productivities were almost 0.58 g.L-1. S. cerevisiae and S1 tolerated up to 14% (v/v) of ethanol; while interestingly the isolates S2 and S3 were highly tolerant, up to 20% (v/v) ethanol. Thus, S2 and S3 could ...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research

Dilute acid hydrolysis of sweet sorghum bagasse and fermentability of the hemicellulosic hydrolysate
This study aimed to determine the best dilute acid hydrolysis condition for the hemicellulosic fraction of sweet sorghum bagasse for ethanol production by Scheffersomyces stipitis. The experiment followed a 23 factorial design with four central points, and had as variables: sulfuric acid concentration, temperature and hydrolysis time. Sorghum bagasse presented the following chemical composition: 24.77% of lignin, 31.28% of hemicellulose and 34.80% of cellulose. The hydrolysis that resulted in the highest sugars concentration (14.22 g/L of xylose and 2.42 g/L glucose) was 1.75% H2SO4, 121 ºC and 40 minutes. This same condi...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research

Influence of pretreatments on crystallinity and enzymatic hydrolysis in sugar cane residues
ABSTRACT This research evaluated the effect of different delignification pretreatments (enzymatic and organosolv), on the crystallinity and enzymatic hydrolysis of harvested sugar cane residues. The Crystallinity Index (CrI), the Relative Number of Intensity (Ir), the degree of cellulose mercerization (IIC-%), and the Global Index of Saccharification (GIS) were used as measurement parameters for six different substrates obtained from sugar cane residues (tops and leaves) by different processes. In this characterization, the spectroscopic ty Techniques of Fourier Transform infrared spectroscopy (FTIR), X-ray diffraction and...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research

Carotenoid-producing yeasts in the brazilian biodiversity: isolation, identification and cultivation in agroindustrial waste
ABSTRACT Different yeast strains from forests located in southern Brazil, with potential to produce carotenoids, were isolated. Three microorganisms were selected as potential carotenoid producers. Sporiodiobolus pararoseus, Rhodotorula mucilaginosa and Pichia fermentans were grown in Yeast Malt (YM) medium and the carotenoids produced identified as cryptoxanthin and β -carotene. In order to reduce production costs, agroindustrial residues were used in the formulation of medium A (parboiled rice water and crude glycerol) and medium B (parboiled rice water and sugar cane molasses). The highest carotenoid production was obt...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research

Biotechnological application of surface modified cerium oxide nanoparticles
ABSTRACT Re-engineering of chemical materials at the nanoscale level that employ modification and improvement in their physical and chemical properties has been constantly pursued for application in biomedical and biotechnology industries. Moreover, immobilization of catalysts on these bio/chemically modified nanomaterials improved the performance of enzymes in a plethora of industrial uses. Hence, in this study, cerium oxide nanoparticles (CNPs) were synthesized and their morphology was investigated by TEM and UV-spectra. They were modified by carboxylation and glutaraldehyde to achieve highly efficient surface functional...
Source: Brazilian Journal of Chemical Engineering - July 16, 2019 Category: Chemistry Source Type: research