Nanoparticle Catalyzed Hydrodesulfurization of Diesel Fuel in a Trickle Bed Reactor: Experimental and Optimization Study

This work focuses on the preparation, simulation, and optimization of the hydrodesulfurization (HDS) of dibenzothiophene (DBT) using a nanocatalyst. A homemade nanocatalyst (3 percent Co, 10 percent Mo/γ-Al2O3 nanoparticles) was used in a trickle bed reactor (TBR). The HDS kinetic model was estimated based on experimental observations over ranges of operating conditions to evaluate kinetic parameters of the HDS process and apply the key parameters. Based on these parameters, the performance of the TBR catalyzed by the nanocatalyst was evaluated and scaled up to a commercial scale. Also, the selectivity of HDS reactions was also modeled to achieve the highest yield of the desired hydrogenation product based on the desirable route of HDS. A comprehensive modeling and simulation of the HDS process in a TBR was developed and the output results were compared with experimental results. The comparison showed that the simulated and experimental data of the HDS process match well with a standard error of up to 5%. The best reaction kinetic variables obtained from the HDS pilot-plant (specific reaction rate expression, rate law, and selectivity) TBR have been utilized to develop an industrial scale HDS of DBT. The hydrodynamic key factors (effect of radial and axial dispersion) were employed to obtain the ratio of the optimal working reactor residence time to reactor diameter

Development of Kinetic and Process Models for the Oxidative Desulfurization of Light Fuel, Using Experiments and the Parameter Estimation Technique

YesThe oxidative desulphurization (ODS) of light gas oil (LGO) is investigated with an in-house designed cobalt 11 oxide loaded on alumina (γ-Al2O3) catalyst in the presence of air as oxidizing agent under moderate operating 12 conditions (temperature from 403 to 473 K, LHSV from 1 to 3 hr-1, initial concentration from 500 to 1000 13 ppm). Incipient Wetness Impregnation method (IWI) of cobalt oxide over gamma alumina (2% Co3O4/γ-14 Al2O3) is used for the preparation of the catalyst. The optimal design of experiments is studied to evaluate the 15 effects of a number of process variables namely temperature, liquid hourly space velocity (LHSV) and 16 concentration of dibenzothiophene and their optimal values were found to be 473 K, 1hr-1 and 1000 ppm 17 respectively. For conversion dibenzothiophene to sulphone and sulphoxide, the results indicates that the 18 Incipient Wetness Impregnation (IWI) is suitable to prepare this type of the catalyst. Based on the 19 experiments, mathematical models that represent a three phase reactor for describing the behavior of the ODS 20 process are developed. 21 In order to develop a useful model for simulation, control, design and scale-up of the oxidation process, 22 accurate evaluation of important process parameters such as reaction rate parameters is absolutely essential. 23 For this purpose, the parameter estimation technique available in gPROMS (general Process Modelling 24 System) software is employed in this work. With the estimated process parameters further simulations of the 25 process is carried out and the concentration profiles of dibenzothiophene within the reactor are generated

Optimal Design of a Trickle Bed Reactor for Light Fuel Oxidative Desulfurization based on Experiments and Modelling

YesIn this work, the performance of oxidative desulfurization (ODS) of dibenzothiophene (DBT) in light gas oil (LGO) is evaluated with a homemade manganese oxide (MnO2/γ-Al2O3) catalyst. The catalyst is prepared by Incipient Wetness Impregnation (IWI) method with air under moderate operating conditions. The effect of different reaction parameters such as reaction temperature, liquid hour space velocity and initial concentration of DBT are also investigated experimentally. Developing a detailed and a validated trickle bed reactor (TBR) process model that can be employed for design and optimization of the ODS process, it is important to develop kinetic models for the relevant reactions with high accuracy. Best kinetic model for the ODS process taking into account hydrodynamic factors (mainly, catalyst effectiveness factor, catalyst wetting efficiency and internal diffusion) and the physical properties affecting the oxidation process is developed utilizing data from pilot plant experiments. An optimization technique based upon the minimization of the sum of the squared error between the experimental and predicted composition of oxidation process is used to determine the best parameters of the kinetic models. The predicted product conversion showed very good agreement with the experimental data for a wide range of the operating condition with absolute average errors less than 5%

Linear and Non-linear Multi-Input Multi-Output Model Predictive Control of Continuous Stirred Tank Reactor

<p>In this article, multi-input multi-output (MIMO) linear model predictive controller (LMPC) based on state space model and nonlinear model predictive controller based on neural network (NNMPC) are applied on a <a id="_GPLITA_0" style="border: none !important; display: inline-block !important; text-indent: 0px !important; float: none !important; font-weight: bold !important; height: auto !important; margin: 0px !important; min-height: 0px !important; min-width: 0px !important; padding: 0px !important; text-transform: uppercase !important; text-decoration: underline !important; vertical-align: baseline !important; width: auto !important; background: transparent !important;" title="Click to Continue &gt; by LizardSales" href="#">continuous<img style="border: none !important; display: inline-block !important; text-indent: 0px !important; float: none !important; font-weight: bold !important; height: 10px !important; margin: 0px 0px 0px 3px !important; min-height: 0px !important; min-width: 0px !important; padding: 0px !important; text-transform: uppercase !important; text-decoration: underline !important; vertical-align: super !important; width: 10px !important; background: transparent !important;" src="http://cdncache-a.akamaihd.net/items/it/img/arrow-10x10.png" alt="" /></a> stirred tank reactor (CSTR). The idea is to have a good control system that will be able to give optimal performance, reject high load disturbance, and track set point change. In order to study the performance of the two model predictive controllers, MIMO Proportional-Integral-Derivative controller (PID) strategy is used as benchmark. The LMPC, NNMPC, and PID strategies are used for controlling the residual concentration (C_A) and reactor temperature (T). NNMPC control shows a superior performance over the LMPC and PID controllers by presenting a smaller overshoot and shorter settling time.</p

THERMODYNAMIC MODEL FOR HIGH PRESSURE PHASE BEHAVIOR OF CARBON DIOXIDE IN SEVERAL PHYSICAL SOLVENTS AT DIFFERENT TEMPERATURES

In the present study a thermodynamic model for prediction of gas-liquid equilibrium at high pressures and different temperatures prepared for the binary systems of carbon dioxide (1) with each of the one of the liquid physical solvents (2) (sulfolane, n-methyl-2-pyrrolidone and propylene carbonate) using Peng-Robenson equation of state (PR-EOS) with different mixing rules to show the effect of the type of mixing rule used.Comparison of the experimental phase equilibrium data in the literature with the results of the model showed very good representation for some mixing rules and good for the others.</p

Assessing the Feasibility of Optical Probe in Phase Holdup Measurements and Flow Regime Identification

Despite the Hydrodynamics of Trickle Beds Experiencing Pilot Size, on the Contrary, the Possibility of Measuring Hydrodynamic Parameters Locally and for Large Scale and Finding an Indicator to Pinpoint the Flow Regime from Trickling to Pulsing Remains Obscure, to Assess the Feasibility of Getting Such Information the Reactor Bed Was Randomly Packed with Equal-Sized Spherical Beads of 3 Mm Diameter. Gas and Liquid Holdup Measurements and Flow Regime Identification Were Achieved at Various Flow Conditions from Trickling to the Pulsing Regime by an Optical Probe Method using Time Series Processing Method. This Method is Shown to Be Simple and Efficient Provides Quantitative Information About the Gas and Liquid Holdup Variation in Different Flow Regime. the Various Experimental Results Were Compared to Available Literature Models and Correlations for Confrontation and Recommendations. the Trickle-To-Pulse Flow Transition Boundary Shifted towards Higher Gas and Liquid Superficial Velocities, Aligning with the Findings on a Variation of Holdup Along the Axial Direction Confirmed to Broaden the Trickle Flow Domain. [Correction Added after Online Publication June 26, 2015: to Unify the Adjective Everywhere in This Manuscript, Optic Fiber Probe Was Changed to Optical Probe.

Estimating Of Etchant Copper Concentration In The Electrolytic Cell Using Artificial Neural Networks

In  this paper, Artificial Neural Networks (ANN), which are known for their ability to model nonlinear systems, provide accurate approximations of system behavior and are typically much more computationally efficient than phenomenological models  are used to predict the etchant copper concentration in the electrolytic cell in terms of electric potential, operating time, temperature of the electrolytic cell , ratio of surface area of poles per unit volume of solution  and the distance between poles. In this paper 350 sets of data are used to trained and test the network.. The best results were achieved using a model based on a feedforword Artificial Neural Network (ANN) with one hidden layer and fifteen neurons in the hidden layer gives a very close prediction of the copper concentration in the electrolytic cell.</p

Effect of L/D Ratio on Phase Holdup and Bubble Dynamics in Slurry Bubble Column using Optical Fiber Probe Measurements

In this investigation, time average local gas holdup and bubble dynamic data were achieved for three L/D ratios of slurry bubble column. The examined ratios were 3, 4 and 5 in 18 diameter slurry bubble column. Air-water-glass bead system was used with superficial gas velocity up to 0.24 m/s. The gas holdup was measured using four tips optical fiber probe technique. The results showed that the gas holdup increases almost linearly with the superficial gas velocity in 0.08 m/s and levels off with a further increase of velocity. A comparison of the present data with those reported for other slurry bubble column having diameters greater than 18 and L/D higher than 5 was made. The results indicated a little effect of diameter on the gas holdup. A local, section-averaged gas holdup increases with increasing superficial gas velocity, while the effect of solid loading are less significant than that of the superficial gas velocity. Chaos analysis was used to analyze the slurry system

Investigation of carbon dioxide (CO2) capture in a falling film contactor by computer simulation

In this work, mathematical models of carbon dioxide (CO2) absorption by monoethanolamine amine (MEA) in a falling film contactor are developed. The proposed models aim to predict conversion of the gas–liquid reaction along the contactor, gas–liquid interface temperature profile (axial and radial), liquid film thickness along the contactor length, axial and radial concentration profiles of reactants in liquid film, and axial and radial profiles of velocity in the liquid film. A code written in MatLab was used to obtain these profiles based on multi grid method through programming of kinetic and thermodynamic equations and physical properties of the absorption system. The mathematical model is validated by an experimental measurement based on absorption of CO2 gas by MEA solution. Four parameters are studied as independent variables namely, mole fraction of carbon dioxide in gaseous mixture, molar concentration of absorbent (MEA, volumetric flow rate of MEA, and its temperature. It is found that the entrance effect of the falling film contactor is related to axial distance from the contactor entrance exponentially:           E=B0exp(−B1y) An optimization technique based on minimization of the sum of the squared error between the experimental and predicted composition of absorption process is used to obtain B0 and B1. It is found that reaction between carbon dioxide and MEA is instantaneous, and the axial conversion of carbon dioxide in the gas phase varies exponentially with the contactor length

Investigation of carbon dioxide (CO

In this work, mathematical models of carbon dioxide (CO2) absorption by monoethanolamine amine (MEA) in a falling film contactor are developed. The proposed models aim to predict conversion of the gas–liquid reaction along the contactor, gas–liquid interface temperature profile (axial and radial), liquid film thickness along the contactor length, axial and radial concentration profiles of reactants in liquid film, and axial and radial profiles of velocity in the liquid film. A code written in MatLab was used to obtain these profiles based on multi grid method through programming of kinetic and thermodynamic equations and physical properties of the absorption system. The mathematical model is validated by an experimental measurement based on absorption of CO2 gas by MEA solution. Four parameters are studied as independent variables namely, mole fraction of carbon dioxide in gaseous mixture, molar concentration of absorbent (MEA, volumetric flow rate of MEA, and its temperature. It is found that the entrance effect of the falling film contactor is related to axial distance from the contactor entrance exponentially:           E=B0exp(−B1y) An optimization technique based on minimization of the sum of the squared error between the experimental and predicted composition of absorption process is used to obtain B0 and B1. It is found that reaction between carbon dioxide and MEA is instantaneous, and the axial conversion of carbon dioxide in the gas phase varies exponentially with the contactor length