scholarly journals Simulation and Optimization of the CWPO Process by Combination of Aspen Plus and 6-Factor Doehlert Matrix: Towards Autothermal Operation

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 548 ◽  
Author(s):  
Jose L. Diaz de Tuesta ◽  
Asunción Quintanilla ◽  
Daniel Moreno ◽  
Víctor R. Ferro ◽  
Jose A. Casas
Keyword(s):  
Kinetic Equations ◽  
Computer Experiments ◽  
Aspen Plus ◽  
Operating Conditions ◽  
Quadratic Model ◽  
Energetic Efficiency ◽  
Process Conditions ◽  
Simulation And Optimization ◽  
Doehlert Matrix ◽  
Autothermal Operation

This work aims to present an industrial perspective on Catalytic Wet Peroxide Oxidation (CWPO) technology. Herein, process simulation and experimental design have been coupled to study the optimal process conditions to ensure high-performance oxidation, minimum H2O2 consumption and maximum energetic efficiency in an industrial scale CWPO unit. The CWPO of phenol in the presence of carbon black catalysts was studied as a model process in the Aspen Plus® v11 simulator. The kinetic model implemented, based on 30 kinetic equations with 11 organic compounds and H2O2 involvement, was valid to describe the complex reaction network and to reproduce the experimental results. The computer experiments were designed on a six-factor Doehlert Matrix in order to describe the influence of the operating conditions (i.e., the different process temperatures, inlet chemical oxygen demands, doses of H2O2 and space time) on each selected output response (conversion, efficiency of H2O2 consumption and energetic efficiency) by a quadratic model. The optimization of the WPO performance by a multi-criteria function highlighted the inlet chemical oxygen demand as the most influential operating condition. It needed to have values between 9.5 and 24 g L−1 for autothermal operation to be sustained under mild operating conditions (reaction temperature: 93–130 °C and pressure: 1–4 atm) and with a stoichiometric dose of H2O2.

Simulation and optimization of CSTR reactor of a biodiesel plant by various plant sources using Aspen Plus

2020 ◽  
Vol 18 (8) ◽  
Author(s):  
Gisele Cristina Rabelo Silva ◽  
Maria Helena Caño de Andrade
Keyword(s):  
Continuous Process ◽  
Simulation Models ◽  
Aspen Plus ◽  
Operating Conditions ◽  
Biodiesel Production ◽  
Biodiesel Fuel ◽  
Separation And Purification ◽  
Continuous Processes ◽  
Simulation And Optimization ◽  
Pure Ester

AbstractIn the present paper, an integrated continuous process of biodiesel manufacturing is proposed using Aspen Plus simulator for different feedstocks. Majority of the reported simulation models in literature are design models for new processes by fixing some level of equipment performance such as the conversion in reactor. Most models assume the feed oil as pure triglycerides or some fatty acids and the biofuel as pure ester. In order to optimize the production of biodiesel, similarity with reality is necessary. For this purpose, this work uses thermophysical property estimation of glycerides, rigorous reaction kinetics, phase equilibrium for separation and purification units, and prediction of essential biodiesel fuel qualities. Detailed operating conditions, equipment designs, and properties of feed and products were obtained. The reactions and parameters kinetics were applied to represent both methanolic and ethanolic transesterification of the biodiesel production. An evaluation of optimal operating conditions (time, temperature, alcohol: oil ratio) for a CSTR reactor was determined. The optimal conversion was achieved at a temperature of 60 °C, 6.00 mol/mol alcohol-oil ratio and 2.0 h residence time when used methanol transesterification reaction as 88.19, 93.77, 89.43, and 89.25%, respectively for sunflower, soybean, palm and macauba oil, on the other hand 86.09, 80.26, 76.54, and 76.39% for transesterification ethanolic. Most of the biodiesel obtained from the simulations presented adequate according to the specifications of the D6751, ANP 45, and EN 14214 standards. Finally, the model proposed can be used for improving operations conditions, new products design and help economic analysis in continuous processes of biodiesel production.

scholarly journals Economic Analysis for Energy Efficient Reactive Distillation

2019 ◽  
Vol 8 (9) ◽  
pp. 1001-1006
Keyword(s):  
Distillation Column ◽  
Reactive Distillation ◽  
Operating Cost ◽  
Cooling Water ◽  
Aspen Plus ◽  
Downstream Processing ◽  
Operating Conditions ◽  
Analysis Tool ◽  
Reflux Ratio ◽  
Simulation And Optimization

Complex chemical reactions and downstream processing can be performed in reactive distillation column to overcome with equilibrium limitations and to make it an economical process. An existing reactive distillation unit is costly to modify due its complex configuration and existing limitations of structure, space area, etc. Modifying an existing plant is a tedious task and more complex than a new process. Thus, to modify the existing operating conditions and input design variables it is necessary to verify by applying the same in real plant condition. This is done using revamping based on rigorous simulation and optimization in Aspen Plus process simulator. The main form of energy generator used in a distillation column is reboiler which directly affects the utilities such as cooling water, electricity and steam. Therefore, optimizing this reboiler duty to reduce energy losses is done using optimization model analysis tool of Aspen Plus. This reduction of energy demands diminishes the operating cost as per the reduction in utility cost. Now this reduction in operating cost is evaluated corresponding to the optimized reflux ratio and number of plates as obtained using sensitivity analysis tool of Aspen Plus.

Threshold square model of the dependence of radiation effects on radiation dose

2020 ◽  
Vol 89 ◽  
pp. 65-74
Author(s):  
A. G. Zavorotnyy ◽  
Keyword(s):  
Radiation Dose ◽  
Emergency Services ◽  
Least Squares Method ◽  
Threshold Model ◽  
Operating Conditions ◽  
Quadratic Model ◽  
Modern World ◽  
Stochastic Effects ◽  
Radiation Accidents ◽  
Increased Risk

Introduction. Operation of radiation hazardous facilities is a reality of the modern world, and the future of the world economy is impossible without the development of nuclear and radiation technologies. At the same time, the widespread use of atomic energy puts forward an important and responsible task of ensuring the safety of the population and the environment in conditions of an increased risk of exposure to ionizing radiation and radioactive substances. In accordance with clause 3.2.1 of the "Radiation Safety Standards NRB-99/2009", the planned increased exposure of persons involved in emergency rescue operations related to the elimination of the consequences of radiation accidents is allowed for men, as a rule, over 30 years old only with their voluntary written consent, after informing about possible radiation doses and health risks. Increased exposure refers to exposure in excess of the basic dose limits under controlled (normal) operating conditions of radiation sources. Goals and objectives. The aim of the study is to increase the functionality of emergency services and fire and rescue subdivisions to perform tasks as intended in the elimination of radiation accidents. The tasks include the construction and substantiation of a model that allows converting the risks of deterministic effects into stochastic effects risks. Methods. When calculating the probability of output of stochastic and deterministic effects depending on the radiation dose and developing a threshold quadratic model, the least squares method and the probabilistic-statistical method were used. Results and discussion. The article shows that a linear non-threshold model of the interaction of radiation with matter greatly overestimates the risk of a stochastic effect emerging at doses of radiation. For example, this overestimation is 8,13 at a dose of D = 0,2 Sv/year. In this regard, a threshold quadratic model has been developed and proposed to be replaced by a threshold quadratic model, which makes it possible to increase the planned irradiation of personnel of emergency services and fire and rescue units during the elimination of radiation accidents in an effective dose from 0,2 Sv to 0,57 Sv, moreover, the probability of emergence of stochastic effects P2 = 0,0084 remains the same for both models. Conclusions. An increase in the maximum permissible dose of radiation for personnel of emergency services and fire and rescue units from 0,2 Sv/year to 0,5 Sv/year will make it possible to increase the functionality of the emergency services and fire and rescue units to perform tasks as intended by 2,5 times when elimination of radiation accidents. For example, the scope of rescue operations may be increased from 100 %, performed at a dose of D = 0,2 Sv/year, to 250 %, performed at a dose of D = 0,5 Sv/year. Key words: emergency services, fire and rescue units, radiation accidents, irradiation, linear no-threshold model, threshold quadratic model.

Influence of the operating conditions of the intermediate thermal hydrolysis on the energetic efficiency of the sludge treatment process

2021 ◽  
Vol 333 ◽  
pp. 125114
Author(s):  
Israel Díaz ◽  
Alina Díaz-Curbelo ◽  
Kevin Ignacio Matute ◽  
María Fdz-Polanco ◽  
Sara Isabel Pérez-Elvira
Keyword(s):  
Treatment Process ◽  
Operating Conditions ◽  
Energetic Efficiency ◽  
Thermal Hydrolysis ◽  
Sludge Treatment

scholarly journals Evaluation of wet air oxidation variables for removal of organophosphorus pesticide malathion using Box-Behnken design

2016 ◽  
Vol 75 (3) ◽  
pp. 619-628 ◽  
Author(s):  
Melike Isgoren ◽  
Erhan Gengec ◽  
Sevil Veli
Keyword(s):  
Removal Efficiency ◽  
Applied Pressure ◽  
Organophosphorus Pesticide ◽  
Operating Conditions ◽  
Quadratic Model ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Reaction Conditions ◽  
Efficient Treatment ◽  
Optimum Reaction

This paper deals with finding optimum reaction conditions for wet air oxidation (WAO) of malathion aqueous solution, by Response Surface Methodology. Reaction conditions, which affect the removal efficiencies most during the non-catalytic WAO system, are: temperature (60–120 °C), applied pressure (20–40 bar), the pH value (3–7), and reaction time (0–120 min). Those were chosen as independent parameters of the model. The interactions between parameters were evaluated by Box-Behnken and the quadratic model fitted very well with the experimental data (29 runs). A higher value of R2 and adjusted R2 (>0.91) demonstrated that the model could explain the results successfully. As a result, optimum removal efficiency (97.8%) was obtained at pH 5, 20 bars of pressure, 116 °C, and 96 min. These results showed that Box–Behnken is a suitable design to optimize operating conditions and removal efficiency for non-catalytic WAO process. The EC20 value of raw wastewater was measured as 35.40% for malathion (20 mg/L). After the treatment, no toxicity was observed at the optimum reaction conditions. The results show that the WAO is an efficient treatment system for malathion degradation and has the ability of converting malathion to the non-toxic forms.

Production of quicklime from Ashaka limestone through calcination process

2021 ◽  
Vol 1 (2) ◽  
pp. 041-048
Author(s):  
Benson Chinweuba Udeh
Keyword(s):  
Particle Size ◽  
Critical Value ◽  
Operating Conditions ◽  
Quadratic Model ◽  
Particle Sizes ◽  
Calcination Process ◽  
Process Effects ◽  
Effects Of Temperature ◽  
The Difference ◽  
The Relationship

This study is on the production of quicklime from Ashaka limestone through calcination process. Effects of temperature, particle size and time on quicklime yield were determined. The experiment was carried out at temperatures of 800, 900, 1000, 1100 and 1200 0C, particle sizes of 80mm, 90mm, 100mm, 300mm and 425mm and times of 0.5hr, 1hr, 2hrs, 3hrs and 4hrs. Analyses of the results showed that quicklime was successfully produced from Ashaka limestone through the calcination process. Quadratic model adequately described the relationship between quicklime yield and calcination factors of temperature, particle size and time. Recorded model F-value of 134.35 implies that the model is significant. The predicted R² of 0.9597 is in reasonable agreement with the adjusted R² of 0.9844; the difference is less than the critical value of 0.2. Optimum yield of 73.48% was obtained at optima operating conditions; temperature of 1000 0C, particle size of 90 µm and time of 3 hrs.

scholarly journals Simulation and optimization integrated gasification combined cycle by used aspen hysys and aspen plus

2015 ◽  
Vol 3 (1) ◽  
pp. 178
Author(s):  
Mohsen Darabi ◽  
Mohammad Mohammadiun ◽  
Hamid Mohammadiun ◽  
Saeed Mortazavi ◽  
Mostafa Montazeri
Keyword(s):  
Gas Turbine ◽  
Coal Gasification ◽  
Aspen Plus ◽  
Combined Cycle ◽  
Parameters Estimation ◽  
Integrated Gasification Combined Cycle ◽  
Support Tool ◽  
Simulation And Optimization ◽  
Aspen Hysys ◽  
Integrated Gasification

<p>Electricity is an indispensable amenity in present society. Among all those energy resources, coal is readily available all over the world and has risen only moderately in price compared with other fuel sources. As a result, coal-fired power plant remains to be a fundamental element of the world's energy supply. IGCC, abbreviation of Integrated Gasification Combined Cycle, is one of the primary designs for the power-generation market from coal-gasification. This work presents a in the proposed process, diluted hydrogen is combusted in a gas turbine. Heat integration is central to the design. Thus far, the SGR process and the HGD unit are not commercially available. To establish a benchmark. Some thermodynamic inefficiencies were found to shift from the gas turbine to the steam cycle and redox system, while the net efficiency remained almost the same. A process simulation was undertaken, using Aspen Plus and the engineering equation solver (EES).The The model has been developed using Aspen Hysys® and Aspen Plus®. Parts of it have been developed in Matlab, which is mainly used for artificial neural network (ANN) training and parameters estimation. Predicted results of clean gas composition and generated power present a good agreement with industrial data. This study is aimed at obtaining a support tool for optimal solutions assessment of different gasification plant configurations, under different input data sets.</p>

Linking Microbial Community Dynamics in BIOX® Leaching Tanks to Process Conditions: Integrating Lab and Commercial Experience

2017 ◽  
Vol 262 ◽  
pp. 38-42 ◽  
Author(s):  
Mariette Smart ◽  
Robert J. Huddy ◽  
Catherine J. Edward ◽  
Charl Fourie ◽  
Trust Shumba ◽  
...  
Keyword(s):  
South Africa ◽  
Community Structure ◽  
Microbial Community ◽  
Research University ◽  
Community Dynamics ◽  
Operating Conditions ◽  
Process Conditions ◽  
Significant Shift ◽  
Engineering Research ◽  
Microbial Community Dynamics

In the commercial BIOX® process, an acidophilic mixed bacterial and archaeal community dominated by iron and sulphur oxidising microorganisms is used to facilitate the recovery of precious metals from refractory gold-bearing sulphidic mineral concentrates. Characterisation of the microbial communities associated with commercial BIOX® reactors from four continents revealed a significant shift in the microbial community structure compared to that of the seed culture, maintained at SGS (South Africa). This has motivated more detailed study of the microbial community dynamics in the process. Microbial speciation of a subset of the BIOX® reactors at Fairview mines (Barberton, South Africa) and two laboratory maintained reactors housed at Centre for Bioprocess Engineering Research, University of Cape Town, has been performed tri-annually for three years by quantitative real-time polymerase chain reaction. The laboratory BIOX® culture maintained on Fairview concentrate was dominated by the desired iron oxidiser, Leptospirillum ferriphilum, and sulphur oxidiser, Acidithiobacillus caldus, when operated under standard BIOX® conditions. Shifts in the microbial community as a result of altered operating conditions were transient and did not result in a loss of the microbial diversity of the BIOX® culture. The community structure of the Fairview mines BIOX® reactor tanks showed archaeal dominance of these communities by organisms such as the iron oxidiser Ferroplasma acidiphilum and a Thermoplasma sp. for the period monitored. Shifts in the microbial community were observed across the monitoring period and mapped to changes in performance of the commercial process plant. Understanding the effect of changes in the plant operating conditions on the BIOX® community structure may assist in providing conditions that support the desired microbial consortium for optimal biooxidation to maximize gold recovery.

scholarly journals Continuous electrochemical reactor improved by the addition of Moringa oleífera lam extract: optimization of operational conditions for Blue 5G dye removal

2019 ◽  
Vol 14 (3) ◽  
pp. 1
Author(s):  
Bruna Souza dos Santos ◽  
Eduardo Eyng ◽  
Paulo Rodrigo Stival Bittencourt ◽  
Laercio Mantovani Frare ◽  
Éder Lisandro de Moraes Flores ◽  
...  
Keyword(s):  
Retention Time ◽  
Moringa Oleifera ◽  
Hydraulic Retention Time ◽  
Operating Conditions ◽  
Current Intensity ◽  
Quadratic Model ◽  
Residual Concentration ◽  
Natural Coagulant ◽  
Operational Conditions ◽  
Moringa Oleifera Lam

Wastewaters from textile industries are known for their difficulty to treat, several alternative technologies are applied for their treatment. In this context, the study examined a hybrid treatment system, composed of electrocoagulation combined with a natural coagulant (extract of Moringa oleífera lam seeds) to remove reactive dye Blue 5G aqueous solutions. The work evaluated the use of milder operating conditions to improve the efficiency of treatment, with reduced demands for electrical power and coagulant.  The following factors were evaluated: electric current intensity, natural coagulant concentration and hydraulic retention time. A quadratic model was adjusted and validated at a 5% significance level. The overall optimization resulted in conditions of 0.28 A for electrical current intensity, 1000.00 mg L-1 of aqueous extract of Moringa oleífera lam and 5 min for hydraulic retention time. While operating under optimal conditions, the removal of 71.38% of color and 5.22 mg L-1 of iron residual concentration was achieved.

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