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.
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.Energy and exergetic evaluation of the multicomponent separation of petrochemical naphtha in falling film distillation columns
Abstract Multicomponent separation of synthetic petrochemical naphtha (hexane, cyclohexane, toluene and xylene) was carried out in a falling film distillation sequence with heat supply using a vapor chamber (thermosyphon). Tests were carried out by varying feed flow rate and temperatures of the feed and the vapor chamber in two ways of heat supply: isothermal and with a vapor chamber temperature profile. Regarding the distillation behavior of the multicomponent separation with the proposed falling film column, it was verified that the lower values of the studied variables and the profile temperature mode promoted the best ...
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
Separation of sulfur-containing compounds from diesel by oxidation followed by solvent extraction in a single drop column
Abstract Oxidative desulfurization (ODS) is an attractive complementary or alternative process for the hydrodesulfurization (HDS) process due to advantages such as mild operating conditions. In the ODS process, the sulfur-containing compounds are oxidized first to polar sulfoxide and sulfone products and then these polar compounds are separated using solvent extraction or an adsorption process. In the present study, the separation of oxidized sulfur-containing compounds of diesel as a real fuel has been investigated using extraction in a single drop column. The oxidation system was hydrogen peroxide/formic acid. The select...
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
INVESTIGATION OF THE EFFECT OF ELECTRIC FIELD ON CO2 ABSORPTION IN WATER/Fe3O4 NANOFLUID
In this study, a novel strategy for controlling the mass transfer rate in a gas-liquid system was reported and used for the industrially important system of CO2 absorption. The strategy used Fe3O4 nanoparticles in the liquid phase and also exerting an external electric field. To demonstrate this approach, a unique experimental set up was applied to form a falling liquid film, which was water, to be in contact with the gas phase, which was pure carbon dioxide. Nanofluid with concentrations less than 0.03% by volume and field intensities of 133, 200, 266 kV/m were used in this study. Experimental results showed that the exte...
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
Synthesis, characterization, adsorption and thermodynamic studies of pure and binary co2-n2 mixtures on oxygen enriched nanostructured carbon adsorbents
Abstract Oxygen enriched porous carbons have been synthesized by a nanocasting technique using mesoporous zeolite as template and epoxy resin as precursor. Characterization results show the effect of the nanocasting technique on the development of heterogeneous surface, high basicity, and high surface area of 686.37 m2g-1, beneficial for CO2 adsorption. Pure component adsorption isotherms were correlated with Langmuir, Sips, and dual-site Langmuir (DSL) models and found that Sips and DSL isotherm models fitted well, indicating thre heterogeneous nature of the adsorbent surface. Dynamic breakthrough data for the binary syst...
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
Quadrature algorithms for phase equilibrium of continuous mixtures
Abstract Several methods for computing the Gauss-Christoffel quadrature used for the adaptive characterization of continuous mixtures were compared as to their efficiency and robustness. Two mixtures with molar fraction distribution given by truncated gamma distributions were used. We analyzed the Product-Difference, the Golub-Welsch, the Long Quotient-Modified Difference and the Chebyshev algorithms using regular and generalized moments, when applicable. The robustness and computational efficiency of changes in the distribution variable and in the orthogonal polynomial family used to calculate the generalized moments were...
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
Numerical simulation of coal gasification in a circulating fluidized bed gasifier
Abstract This paper presents a 3D full-loop simulation of a circulating fluidized bed gasifier. The model is validated with experimental results from the literature. The validated model is thereupon used to compare Bubbling Fluidized Bed (BFB) and Circulating Fluidized Bed (CFB) gasifiers to highlight the effect of a change in fluidization regime from bubbling to fast fluidization on hydrodynamics, temperature and gas composition. Feed temperature as well as Air/Coal (A/C) and Steam/Coal (S/C) ratios are kept constant, whereas the velocity of the feed (Air-Steam) is increased so as to get into the fast fluidization regime....
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
Numerical study of viscoplastic flow in a t-bifurcation: identification of stagnant regions
Abstract Identification of stagnant regions of viscoplastic fluid flows in production lines and equipment is of paramount importance owing to potential material degradation and process contamination. The present work introduces an assessment strategy to identify, classify and quantify unyielded regions with the objective of optimizing the flow conditions with the purpose of minimizing stagnant regions. Flow of Carbopol ® 980 in a T-bifurcation channel is adopted to illustrate the procedure. The rheological behavior of Carbopol® 980 was simulated using the Herschel-Bulkley viscoplastic model regularized by Papanastasiou â...
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
A methodology to obtain analytical models that reduce the computational complexity faced in real time implementation of nmpc controllers
Abstract Model Predictive Control, MPC and NMPC, and real-time optimization, RTO and D-RTO, are known to help plant operability through the mitigation of impacts caused by external disturbances. However, the usage of these tools in industry requires overcoming some challenges, for instance: accurate models of the process, particularly in regard to nonlinearities; suitable computational time for obtaining the solution of large-scale problems and model mismatch between the RTO or D-RTO and NMPC. In this paper, we present a methodology to obtain analytical model predictions based on a Hammerstein structure to represent the pr...
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
Sucrose crystallization: modeling and evaluation of production responses to typical process fluctuations
Abstract This work describes a phenomenological model of the two-massecuite system for sucrose crystallization, developed using EMSO software. In most Brazilian sugarcane industries, sucrose crystallization is performed using this system. This process is considered to be a fundamental step in obtaining sugar of the desired quality and accounts for a substantial fraction of the production costs. The simulation results - crystal percentage in massecuite, brix and purity of molasses, magma purity, sugar pol, crystal size distribution - were validated by comparing them with real process data of an industrial plant. The interes...
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
Estimation of parameters and states using a bayesian particle filter for the sulfate ion adsorption process in a fixed bed column
Abstract Ensuring that industrial effluents meet quality standards to be released into water bodies is still one of the major environmental concerns. Liquid phase adsoption in fixed bed collumns is one of the most known treatments. Measurements are needed to monitor the process. However, as they are often corrupted by noise from the measuring equipment, performing an accurate analysis becomes an important challenge. The present work demonstrates the effectiveness of particle filter Sampling Importance Resampling as a fast and robust tool for monitoring a problem of sulfate ion removal. Experimental measurements were used t...
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
Integrating real time optimization and model predictive control of a crude distillation unit
Abstract This work reports the integration of Real Time Optimization and Model Predictive Control in the multi-layer control structure of an existing Crude Distillation Unit (CDU) of an oil refinery. The MPC considers output control zones and targets for the inputs or outputs. Both the infinite horizon and the finite output horizon controllers were tested. The plant results show that the infinite horizon controller tends to perform similarly or better then the finite horizon MPC when the CDU system needs to operate at quite different conditions. Although the dynamic layer based on the infinite horizon controller is nominal...
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
Re-esterification of macauba acid oil using glycerol for acidity reduction and biodiesel production
Abstract Biodiesel production using acid oils is an important alternative for biofuel cost reduction. However, it is a huge challenge for homogeneous transesterification, the main industrial route commonly used. This paper presents macauba oil with high acidity, 43.90 w/w%, as a potential raw material for biodiesel production. The acidity was reduced to 0.8 w/w% after re-esterification (80 min) with glycerol at high temperature (235 °C), without catalysts. Zinc (powder and coating) and NbOPO4 were also tested as catalysts in comparison with the reaction without a catalyst. Reactions catalyzed by metallic Zn produced a lar...
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
Synthesis, characterization and evaluation of the heterogeneous basic catalyst dapts-mcm-41 in the interesterification reaction of palm oil and palm kernel oil blends
Abstract In recent years, the replacement of homogeneous catalysts by heterogeneous catalysts has been investigated as a sustainable alternative technology to obtain different products. In this context, this study investigated the activity of the heterogeneous catalyst DAPTS-MCM-41, obtained from the reaction between the MCM-41 molecular sieve and an organic base 3-ethylenediamine (trimethoxy) propyl silane (DAPTS) in the interesterification reaction of palm oil and palm kernel oil blends. The catalyst was characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and textural analysis (ASAP). The interesterifi...
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
CATALYTIC OXIDATION OF ISOPROPYL ALCOHOL OVER PLATINUM BASED CATALYST: A STUDY OF THE EFFECT OF METHYL CELLULOSE ON Pt PARTICLES DISPERSION OVER MULLITE
This study showed that platinum exhibits better dispersion on alumina sites than silica sites. This can be due to a strong interaction between platinum and alumina, leading to a higher dispersion of platinum species. Furthermore, the addition of MC enhanced the Pt dispersion over the mullite, leading to an improvement in the catalytic performance. (Source: Brazilian Journal of Chemical Engineering)
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
GRAPHENE OXIDE AND A GO/ZnO NANOCOMPOSITE AS CATALYSTS FOR EPOXY RING-OPENING OF EPOXIDIZED SOYBEAN FATTY ACIDS METHYL ESTERS
Abstract In this work, the grapheme oxide (GO) and GO/ZnO nanocomposite were successfully obtained from the oxidation of graphite and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). In the GO/ZnO nanocomposite, the GO sheets were coated with aggregated ZnO nanoneedles with ca. 20 nm of diameter. The obtained materials were used as heterogeneous catalysts for acetylation of Soybean Fatty Acids Methyl Esters (FAME), promoting the epoxy ring-opening using acetic anhydride. The epoxy ring was almost completely opened in ...
Source: Brazilian Journal of Chemical Engineering - December 9, 2019 Category: Chemistry Source Type: research
