Modeling product distribution of top-lit updraft gasification

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 6629-6642
Author(s):  
Arthur M. James R. ◽  
Cassie Castorena ◽  
Wenqiao Yuan
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Kinetic Model ◽  
Product Distribution ◽  
Reduction Reaction ◽  
Producer Gas ◽  
Heating Value ◽  
Moisture Contents ◽  
Reaction Zones ◽  
Accurate Quantification

A kinetic model for predicting biochar, producer gas, and tar formations of top-lit updraft (TLUD) gasification was developed. The three main zones within the TLUD gasifier, the pyrolysis, incomplete combustion, and reduction reaction zones, were incorporated into the model and sequentially solved. Validated with experimental data, the model was found capable of predicting biochar yield on pine woodchips at varying airflow rates, biomass moisture contents, and biomass compactness. However, when the particle size was varied, the model underestimated biochar yield. The model also accurately predicted the higher heating value of the producer gas that varied from 3.45 to 3.98 MJ/m3 compared to 3.61 to 3.67 MJ/m3 for the experimental results. The model qualitatively predicted tar content in the producer gas at varying conditions. However, accurate quantification of tar generation in TLUD gasification was not achieved.

Modelling of Fischer-Tropsch Synthesis in a Fluidized Bed Reactor

2012 ◽  
Vol 586 ◽  
pp. 274-281
Author(s):  
Mohammad Kazemeini ◽  
Reza Maleki ◽  
Moslem Fattahi
Keyword(s):  
Experimental Data ◽  
Kinetic Model ◽  
Natural Gas ◽  
Fluidized Bed ◽  
Fluidized Bed Reactor ◽  
Product Distribution ◽  
Operating Conditions ◽  
Distribution Model ◽  
Fischer Tropsch ◽  
Respective Rate

The FT reaction involves the conversion of syngas which is derived from natural gas or coal to different kinds of products according to the operating conditions and the type of the catalyst. In other words, it is a practical way to convert solid fuel (coal) and natural gas to various hydrocarbons (C1-C60) and oxygenates such as alkanes, alkenes etc. The main products of the reaction are naphtha and gasoline. This paper deals with developing a proper product distribution model for FT process using the appropriate kinetic model, optimizing the respective rate constants while applying them in product distribution equations. The results revealed only 8.09% deviations from the olefin experimental data and 10.27% deviations from the paraffin experimental data being acceptable when compared with previous open literature data.

scholarly journals Effect of Ethyl Acetate, Time and Particle Size on the Kinetics of the Oleoresin Extraction Process

2020 ◽  
Vol 7 (2) ◽  
pp. F15-F23
Author(s):  
M. S. Olakunle ◽  
A. O. Ameh ◽  
T. Oyegoke ◽  
H. U. Shehu
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Kinetic Model ◽  
Ethyl Acetate ◽  
Extraction Process ◽  
Single Step ◽  
Particle Sizes ◽  
Order Model ◽  
First Order ◽  
Kinetics Of

The kinetics of the extraction of oleoresin from ginger using ethyl acetate as the solvent was studied in this work. The effects of particle size and extraction time on oleoresin’s solvent extraction were studied to obtain optimization data. The temperature of the process was kept constant at 40 °C. The Ginger particle sizes considered ranged between 1200-250 microns at extraction times ranging between 10–70 minutes. Experimental data generated were fitted into an empirical model to determine the kinetic parameters. The oleoresin yield increases with increasing extraction time up to an optimum time, after which the yield remains constant and yield also increases with decreasing particle size. The results obtained from the kinetics studies revealed that the introduction of the constant term accounting for the diffusion step separately (as an addition) into a single step first-order model (Patricelli’s first order model) raises the R-squared values from 87 % fitness of the model into becoming 99 % with the experimental data. This improved form of Patricelli’s first-order model was found to show a good agreement with Patricelli’s 2-step kinetic model. These findings confirmed that the oleoresin extraction process in the presence of ethyl acetate was found to be first-order kinetics involving two steps mechanism where the use of a single-step first-order model (Patricelli’s first-order kinetic model) and the choice of using ethyl acetate must have contributed to the strong resistance present in the first step of the extraction mechanism especially for the smaller particle size (250 microns). In getting the extraction yield improved, this study, therefore, recommends the use of small particle sizes (< 250 microns), higher temperatures (> 40 °C), and/or better alternative solvents like ethanol. Keywords: ethyl acetate, extraction, oleoresin, modeling.

scholarly journals Effect of Ethyl Acetate, Time and Particle Size on the Kinetics of the Oleoresin Extraction Process

2020 ◽  
Vol 7 (2) ◽  
pp. F15-F23
Author(s):  
M.S. Olakunle ◽  
A.O. Ameh ◽  
T. Oyegoke ◽  
H.U. Shehu
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Kinetic Model ◽  
Ethyl Acetate ◽  
Extraction Process ◽  
Single Step ◽  
Particle Sizes ◽  
Order Model ◽  
First Order ◽  
Kinetics Of

The kinetics of the extraction of oleoresin from ginger using ethyl acetate as the solvent was studied in this work. The effects of particle size and extraction time on oleoresin’s solvent extraction were studied to obtain optimization data. The temperature of the process was kept constant at 40 °C. The Ginger particle sizes considered ranged between 1200-250 microns at extraction times ranging between 10–70 minutes. Experimental data generated were fitted into an empirical model to determine the kinetic parameters. The oleoresin yield increases with increasing extraction time up to an optimum time, after which the yield remains constant and yield also increase with decreasing particle size. The results obtained from the kinetics studies revealed that the introduction of the constant term accounting for the diffusion step separately (as an addition) into a single step first-order model (Patricelli’s first order model) raises the R-squared values from 87 % fitness of the model into becoming 99 % with the experimental data. This improved form of Patricelli’s first-order model was found to show a good agreement with Patricelli’s 2-step kinetic model. These findings confirmed that the oleoresin extraction process in the presence of ethyl acetate was found to be first-order kinetics involving two steps mechanism where the use of a single-step first-order model (Patricelli’s first-order kinetic model) and the choice of using ethyl acetate must have contributed to the strong resistance present in the first step of the extraction mechanism especially for the smaller particle size (250 microns). In getting the extraction yield improved, this study, therefore, recommends the use of small particle sizes (< 250 microns), higher temperatures (> 40 °C), and/or better alternative solvents like ethanol.

Achieving Procedure of a Kinetic Model to Predict the Influence of the Process Global Temperature on a Technological Alcoholic Fermentation II. An Arrhenius type Kinetic Model

2008 ◽  
Vol 59 (4) ◽  
Author(s):  
Neculai Catalin Lungu ◽  
Maria Alexandroaei
Keyword(s):  
Experimental Data ◽  
Saccharomyces Cerevisiae ◽  
Kinetic Model ◽  
Economic Efficiency ◽  
Fermentation Process ◽  
Alcoholic Fermentation ◽  
Global Temperature ◽  
Medium Temperature ◽  
Biotechnological Process

The aim of the present work is to offer a practical methodology to realise an Arrhenius type kinetic model for a biotechnological process of alcoholic fermentation based on the Saccharomyces cerevisiae yeast. Using the experimental data we can correlate the medium temperature of fermentation with the time needed for a fermentation process under imposed conditions of economic efficiency.

Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column

2020 ◽  
Vol 71 (1) ◽  
pp. 1-12
Author(s):  
Salman H. Abbas ◽  
Younis M. Younis ◽  
Mohammed K. Hussain ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Particle Size ◽  
Adsorption Capacity ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Fungal Biomass ◽  
Solution Flow Rate ◽  
Maximum Adsorption Capacity ◽  
Solution Flow

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.

Diffusion model for deposition of epitaxial GaAs layers prepared by the MOCVD method

1991 ◽  
Vol 56 (10) ◽  
pp. 2020-2029
Author(s):  
Jindřich Leitner ◽  
Petr Voňka ◽  
Josef Stejskal ◽  
Přemysl Klíma ◽  
Rudolf Hladina
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Kinetic Model ◽  
Gas Phase ◽  
Substrate Surface ◽  
Deposition Process ◽  
Hydrogen Atmosphere ◽  
Epitaxial Gaas ◽  
Kinetics Of ◽  
Good Agreement

The authors proposed and treated quantitatively a kinetic model for deposition of epitaxial GaAs layers prepared by reaction of trimethylgallium with arsine in hydrogen atmosphere. The transport of gallium to the surface of the substrate is considered as the controlling process. The influence of the rate of chemical reactions in the gas phase and on the substrate surface on the kinetics of the deposition process is neglected. The calculated dependence of the growth rate of the layers on the conditions of the deposition is in a good agreement with experimental data in the temperature range from 600 to 800°C.

Simulation on Extrusion Comminution Model of Roller Press

2010 ◽  
Vol 156-157 ◽  
pp. 1702-1707
Author(s):  
Xiang Wen Cheng ◽  
Jinchao Liu ◽  
Qi Zhi Ding ◽  
Li Ming Song ◽  
Zhan Lin Wang
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Field Experiments ◽  
Size Ratio ◽  
Optimum Operating ◽  
Extrusion Force ◽  
Particle Size Ratio ◽  
Small Constant ◽  
Working Parameters ◽  
The Relationship

How to predict the relationship among particle size and among product size, to establish the relationship between the granularity and working parameters in the process of grinding and to determine the optimum operating parameters. With proposing BS squeeze crush model by L. Bass and the idea of roll surface division as the material uneven extrusion force are adopted. Based on field experiments the experimental data is analyzed, the select function and the breakage functions are fitted with MATLAB software, and obtaining their model. The comminution model is determined by the roller division. We obtain the model parameter through the experimental data. Through model analysis shows: the relationship between particle breakage and energy absorption, namely the smaller size of the same power, the lower broken; the breakage diminishes with the decrease of particle size ratio and it will be tending to a small constant when the smaller particle size ratio. The breakage functions rapidly decrease within ratio of between 0.2-0.7. This shows: the energy consumption will rapidly increase when the particle size of less than 0.2 in broken; the selection diminish with the decrease of particle size. Pressure (8-9MPa) should be the most appropriate value.

scholarly journals Mixed Lithium and Sodium Ion Aprotic DMSO Electrolytes for Oxygen Reduction on Au and Pt Studied by DEMS and RRDE

2021 ◽  
Author(s):  
M. Hegemann ◽  
P. P. Bawol ◽  
A. Köllisch-Mirbach ◽  
H. Baltruschat
Keyword(s):  
Oxygen Reduction ◽  
Product Distribution ◽  
Reduction Reaction ◽  
Mixed Electrolytes ◽  
Peroxide Formation ◽  
Pt Electrode ◽  
Rate Determining Step ◽  
Differential Electrochemical Mass Spectrometry ◽  
Redox Couples ◽  
Pt Electrodes

AbstractIn order to advance the development of metal-air batteries and solve possible problems, it is necessary to gain a fundamental understanding of the underlying reaction mechanisms. In this study we investigate the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER, from species formed during ORR) in Na+ containing dimethyl sulfoxide (DMSO) on poly and single crystalline Pt and Au electrodes. Using a rotating ring disk electrode (RRDE) generator collector setup and additional differential electrochemical mass spectrometry (DEMS), we investigate the ORR mechanism and product distribution. We found that the formation of adsorbed Na2O2, which inhibits further oxygen reduction, is kinetically favored on Pt overadsorption on Au. Peroxide formation occurs to a smaller extent on the single crystal electrodes of Pt than on the polycrystalline surface. Utilizing two different approaches, we were able to calculate the heterogeneous rate constants of the O2/O2− redox couple on Pt and Au and found a higher rate for Pt electrodes compared to Au. We will show that on both electrodes the first electron transfer (formation of superoxide) is the rate-determining step in the reaction mechanism. Small amounts of added Li+ in the electrolyte reduce the reversibility of the O2/O2− redox couples due to faster and more efficient blocking of the electrode by peroxide. Another effect is the positive potential shift of the peroxide formation on both electrodes. The reaction rate of the peroxide formation on the Au electrode increases when increasing the Li+ content in the electrolyte, whereas it remains unaffected on the Pt electrode. However, we can show that the mixed electrolytes promote the activity of peroxide oxidation on the Pt electrode compared to a pure Li+ electrolyte. Overall, we found that the addition of Li+ leads to a Li+-dominated mechanism (ORR onset and product distribution) as soon as the Li+ concentration exceeds the oxygen concentration. Graphical abstract

scholarly journals Micro-kinetic model of electrochemical carbon dioxide reduction over platinum in non-aqueous solvents

2020 ◽  
Vol 22 (16) ◽  
pp. 9040-9045
Author(s):  
Brian A. Rohr ◽  
Aayush R. Singh ◽  
Joseph A. Gauthier ◽  
Michael J. Statt ◽  
Jens K. Nørskov
Keyword(s):  
Carbon Dioxide ◽  
Kinetic Model ◽  
Carbon Dioxide Reduction ◽  
Reduction Reaction ◽  
Proton Donor ◽  
Theoretical Modeling ◽  
Donor Concentration

Theoretical modeling indicates that proton donor concentration and catalyst geometry control the selectivity to multicarbon products in the electrochemical carbon dioxide reduction reaction.

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