Difference between revisions of "Literature"
|Line 225:||Line 225:|
'''Authors:''' Juan Felipe Castellanos Salazar
'''Authors:''' Juan Felipe Castellanos Salazar
'''Download Link:''' [https://riull.ull.es/xmlui/bitstream/handle/915/22761/Implementation%20of%20a%20liquid%20air%20storage%20system%20%28LAES%29%20in%20a%20mixed%20renewable%20energy%20system%20%28wind%20and%20photovoltaic%29.%20The%20case%20of%20Tenerife..pdf?sequence=1
'''Download Link:''' [https://riull.ull.es/xmlui/bitstream/handle/915/22761/Implementation%20of%20a%20liquid%20air%20storage%20system%20%28LAES%29%20in%20a%20mixed%20renewable%20energy%20system%20%28wind%20and%20photovoltaic%29.%20The%20case%20of%20Tenerife..pdf?sequence=1 ]
== Thermodynamic and economic analyses of power generation from gas turbine exhaust ==
== Thermodynamic and economic analyses of power generation from gas turbine exhaust ==
Revision as of 22:13, 2 November 2021
This page lists published scientific and/or technical papers/articles which use or cite DWSIM to some extent.
- 1 Technical Papers
- 1.1 Modeling of chemical processes using commercial and open-source software: A comparison between Aspen Plus and DWSIM
- 1.2 Process Simulation Unit Operation Models - Review of Open and HSC Chemistry I/O Interfaces
- 1.3 Implementation of a Property Database and Thermodynamic Calculations in OpenModelica for Chemical Process Simulation
- 1.4 Development of a Thermodynamic Engine in OpenModelica
- 2 Scientific Papers
- 2.1 Methyl Esters Production by Heterogeneous Catalyst Mixtures of CaO/Nb2O5 with Simulation of Analysis of Environmental Impacts
- 2.2 Model and Simulation of a Hydrotreatment Reactor for Diesel Hydrodesulfurization in Oil Refining
- 2.3 Chemical engineering aspects of plasma-assisted CO2 hydrogenation over nickel zeolites under partial vacuum
- 2.4 Techno-Economic Comparison of Onshore and Offshore Underground Coal Gasification End-Product Competitiveness
- 2.5 Mix-n-match Reservoir Coupling in Integrated Modeling and Optimization
- 2.6 Development and Validation of a Thermodynamic Model for Gasification of Tyres
- 2.7 Techno-economic optimization of ethanol synthesis from rice-straw supply chains
- 2.8 Simulação do Processo de Produção de Biodiesel de Óleo de Palma utilizando os softwares Aspen HYSYS e DWSIM
- 2.9 Simulação de uma planta de produção de biodiesel
- 2.10 Avaliação da Consistência de um Projeto de Amostragem Contínua em Unidade de Processamento de Gás Natural
- 2.11 Thermal-Numerical Simulation of the Gas Offshore Production Undersea Facilities at the Amistad Field
- 2.12 An Organic Rankine Cycle Bottoming a Diesel Engine Powered Passenger Car
- 2.13 Simulators Selection for Design and Simulation of a CSP-Driven Forward Osmosis Process
- 2.14 Chemical Process Simulation Using OpenModelica
- 2.15 Performance Comparison of Different Thermal Fluids in Concentrating Solar Plants
- 2.16 Análise técnico-econômica da produção de acrilonitrila via biomassa com simulação
- 2.17 Modeling and Simulation of Manufacturing Process of Paracetamol
- 2.18 Predicción de la producción de metanol en una planta de hidrogenación de dióxido de carbono mediante redes neuronales
- 2.19 Diseño y simulación de un reactor tubular multipropósito para tri-reformado de metano
- 2.20 Otimização do processo de producão de biodiesel e glicerol a partir do óleo de palma e soja por modelagem no software dwsim
- 2.21 Estudio comparativo de cálculo de propiedades entre programas de simulación. el caso de unisim y dwsim
- 2.22 Simulación de producción de ácido succínico a partir de material lignocelulósico
- 2.23 Síntese de metanol via hidrogenação do dióxido de carbono: modelagem e otimização no simulador DWSIM
- 2.24 Comparación de los costos de producción y grado de contaminación por emisiones en el sector industrial del Ecuador usando como combustible gas natural mediante la simulación de process
- 2.25 Fluidos refrigerantes mistos (CO2/CH4) visando novas aplicações em sistemas de refrigeração - EVR2021-0011
- 2.26 “Implementation of a liquid air storage system (LAES) in a mixed renewable energy system (wind and photovoltaic). The case of Tenerife
- 2.27 Thermodynamic and economic analyses of power generation from gas turbine exhaust
- 2.28 Process simulation of biodiesel production from vegetable oil deodorization distillate using hydrotalcite-hydroxyapatite as catalyst
- 2.29 Comparative Analysis of Energy and Exergy Performance of Hydrogen Production Methods
Modeling of chemical processes using commercial and open-source software: A comparison between Aspen Plus and DWSIM
Authors: Kwanchanok Tangsriwong, Puttida Lapchit, Tanatip Kittijungjit, Thepparat Klamrassamee, Yanin Sukjai1 and Yossapong Laoonual1
Abstract: Computer simulation plays a key role in chemical process design. Currently, there are a large number of widely accepted commercial software. For example, Aspen Plus which was used to simulate offshore petroleum production processes, but it is often too costly to purchase and maintain a valid software license. On the other hand, since open-source software is freely accessible, the simulation models developed using open-source software could be studied, reviewed, and modified by any interested parties. This would help promoting technology transfer and knowledge dissemination in both academic and industry sectors. We specifically focus on the simulation of chemical process using the modeling software to evaluate thermal and chemical behaviour of the system which uses the chemical processes related to offshore petroleum production facilities as an example to demonstrate the software capabilities of both Aspen Plus and DWSIM. This work emphasizes on the comparison of simulation results calculated by commercial software namely Aspen Plus vs. open-source software called DWSIM (An open-source sequential modular steady state simulator) . The simulation was carried out under the steady-state conditions, adiabatic processes, and negligible pressure losses. Finally, simulation results from DWSIM and Aspen Plus were compared with the heat and mass flow diagram which was used as reference. It was found that the discrepancy between simulation and reported values was in general less than 5%. It has been demonstrated that free and open-source software like DWSIM could potentially perform similar tasks as commercial software.
Process Simulation Unit Operation Models - Review of Open and HSC Chemistry I/O Interfaces
Author: Marko Leino
Abstract: Chemical process modelling and simulation can be used as a design tool in the development of chemical plants, and is utilized as a means to evaluate different design options. The CAPEOPEN interface standards were developed to allow the deployment and utilization of process modelling components in any compliant process modelling environment. This thesis examines the possibilities provided by the CAPE-OPEN interfaces and the .NET framework to develop compliant, cross-platform process modelling components, particularly unit operations. From the software engineering point of view, a unit operation is a representation of physical equipment, and contains the mathematical model of its functionality. The study indicates that the differences between the CAPE-OPEN standards and Outotec HSC Chemistry Sim are negligible at the conceptual level. On the other hand, at the implementation level, the differences are quite considerable. Regardless of the simulation application being used, the modelling of unit operations requires interdisciplinary skills, and creating tools and methods to ease the development of such models is well justified. The results of this study suggest that CAPE-OPEN both provides various paths to change the way HSC Chemistry Sim works and offers the HSC development team a chance to determine an alternative way to distribute tasks between simulation components. In addition, making HSC Chemistry Sim compliant would bring benefits, such as an extended process modelling component library, and perhaps more publicity. Obviously, the workload required by the changes depends on the chosen path, which invariably entails a lengthy learning curve. This thesis contributes by helping to make that learning curve shorter.
Keywords: CAPE-OPEN, HSC Chemistry Sim, unit operation, process simulation
Implementation of a Property Database and Thermodynamic Calculations in OpenModelica for Chemical Process Simulation
Authors: Rahul Jain, Priyam Nayak, Rahul A. S, Pravin Dalve, Kannan M. Moudgalya, P. R. Naren, Daniel Wagner, and Peter Fritzson
Publication: Ind. Eng. Chem. Res., Article ASAP; DOI: 10.1021/acs.iecr.8b05147; Publication Date (Web): February 20, 2019
Abstract: An attempt has been made to enhance the thermodynamic capability of the general purpose modeling and simulation environment OpenModelica. The property database ChemSep and the thermodynamic algorithms of DWSIM are made available in OpenModelica. The following three approaches, listed in the order of increasing computational efficiency, are attempted in this work: Python-C API, socket programming, and a native port. The most efficient method of native port is adopted to make available NRTL, Peng–Robinson, UNIFAC, and UNIQUAC algorithms in OpenModelica. Through several examples, OpenModelica results are compared with Aspen Plus, indicating a good match in all cases. This work is released as an open source to enhance the collaboration among chemical engineers.
Download link: https://pubs.acs.org/doi/abs/10.1021/acs.iecr.8b05147
Development of a Thermodynamic Engine in OpenModelica
Authors: Rahul Jain, Kannan M. Moudgalya, Peter Fritzson, Adrian Pop
Publication: Proceedings of the 12th International Modelica Conference, Prague, Czech Republic, May 15-17, 2017, Volume , Issue 132, 2017-07-04, Pages 89-99, ISSN 1650-3740
Abstract: OpenModelica, an open source equation oriented modeling environment for steady state and dynamic simulation, lacks good chemical engineering support. This problem is addressed by making available in different ways the thermodynamic library Chemsep that comes with DWSIM, an open source sequential modular steady state simulator. Only slow speeds could be achieved through a Python-C API based interface connecting OpenModelica with the thermodynamic library. A socket programming based interface helps achieve faster speeds. Best results have been achieved by porting the thermodynamic library and the calculation routines to OpenModelica, due to two reasons: (1) thermodynamic equations are solved simultaneously with mass and energy balances (2) overheads in calling the external routines of DWSIM are eliminated. Performances of the above mentioned three approaches have been validated with steady state and dynamic simulations. Benzene - toluene separation, methanol - ethanol - water distillation, and steam distillation of an n-octane - n-decane mixture, have been carried out through these simulations. This work makes available a powerful simulation platform to the chemical engineering.
Keywords: OpenModelica DWSIM Chemsep thermodynamics modeling simulation chemical engineering media Python-C API Socket programming
Download Link: http://www.ep.liu.se/ecp/132/009/ecp1713289.pdf
Methyl Esters Production by Heterogeneous Catalyst Mixtures of CaO/Nb2O5 with Simulation of Analysis of Environmental Impacts
Authors: Cubides-Román, Diana C., Constantino, André F., David, Geraldo F., Martins, Lucas F., Santos, Reginaldo B. dos, Romão, Wanderson, Cunha Neto, Alvaro, & Lacerda Jr., Valdemar
Publication: Journal of the Brazilian Chemical Society, 30(3), 562-570.
Abstract: The conventional biodiesel process, although it reaches high conversion yields and productivity, faces problems related to the use of homogeneous catalysts. This work aims to study mixtures of calcium oxide (CaO) and niobium oxide (Nb2O5) as the heterogeneous catalyst. It was used a full 23 factorial design with four central points to analyze how the mass percentage of the oxides, the molar ratio of reactants, and the reaction temperature affect the conversion yield to methyl esters. The best conversion yield was found near to 89% using 1.8% of catalyst, a 1:36 oil to methanol ratio and at 77 ºC as reaction temperature. Finally, it was performed a simplified simulation to compare the heterogeneous catalyst process with the conventional process, and an algorithm to compare the effects of the exit streams of each process would have on the environment. The simulations results display a better performance for the heterogeneous catalyst process studied.
Keywords: biodiesel; heterogeneous catalyst; calcium oxide; niobium; process simulation
Download Link: http://dx.doi.org/10.21577/0103-5053.20180204
Model and Simulation of a Hydrotreatment Reactor for Diesel Hydrodesulfurization in Oil Refining
Authors: Jorge Buitrago, Dario Amaya and Olga Ramos
Publication: Contemporary Engineering Sciences, Vol. 10, 2017, no. 25, 1245-1254
Abstract: One of the most developed industries in the world is the industry dedicated to extraction and treatment of crude oil, due to his economic profitability. One of the equipment more important in any process is the reactor, which is the place where the physico-chemical transformations of the matter are carried out. The hydrotreatment process is used in oil refining, to decrease the level of different contaminants in the crude. Usually, this process is applied to the clearance of sulphur in contaminated streams. The process was modeled and simulated through the Open Source DWSIM software, using hydrogen as reactant and Ni-Mo 𝛾𝐴𝑙2𝑂3 as catalyst. As product was obtained acid crude. It was chosen the model Chao Seader to predict the main properties of each compound present in the reactor. Through the reuse of hydrogen in the system, it was possible reach a 0.0093% weight of Sulphur in the final crude stream. Furthermore, it was designed the furnace used to warm up the mixture for the reactor and the cooler used to separate the volatile compounds.
Keywords: Heavy diesel, Chemical reactor, Chemical simulation, DWSIM, Chao Seader model, HDS
Chemical engineering aspects of plasma-assisted CO2 hydrogenation over nickel zeolites under partial vacuum
Authors: Federico Azzolina-Jury, Diogo Bento, Carlos Henriques, Frédéric Thibault-Starzyk
Publication: Journal of CO2 Utilization, Volume 22, 2017, Pages 97-109, ISSN 2212-9820
Abstract: Ni-zeolites (ZSM-11 and USY) were prepared for application in carbon dioxide hydrogenation. Structure, physical properties and texture were analyzed by XRD, N2 sorptiometry, SEM and TEM images. The zeolites nickel reducibility (determined by in-situ TPR-MS) was directly related to the catalytic activity of zeolites. Glow-discharge plasma-assisted CO2 hydrogenation was carried out under partial vacuum using a packed-bed catalytic reactor under two different configurations: In-Plasma Catalysis (IPC) and Post-Plasma Catalysis (PPC). CO2 hydrogenation into CO (CO2+H2→CO+H2O) and CO2 methanation (CO2+4H2→CH4+2H2O) reactions were more efficient when the reaction was assisted by plasma using the IPC mode. In IPC mode, a novel phenomenon was observed: a considerable amount of methane was released from the catalyst after plasma extinction. This phenomenon was explained combining the operando IR plasma technique and the analysis of the carbon balance during the plasma-assisted CO2 hydrogenation reaction. Both configurations (IPC and PPC) were studied under different volumetric flow rates and the minimum lifetime of excited species generated within the plasma discharge for methane production was determined. The lifetime of the more active species which are responsible for methane production was lower than 67ms. Under the operation conditions used in this work, methane production was only possible when CO2 hydrogenation was performed in IPC mode. CO2 hydrogenation was found to be more energy efficient when the reaction was carried out under plasma assistance compared to conventional heating. Higher CO2 conversions, CO and CH4 yields were achieved with respect to conventional heating at lower temperatures when plasma assistance was used.
Keywords: Plasma; Glow discharge; CO2 methanation; Nickel zeolites; operando IR
Download Link: https://doi.org/10.1016/j.jcou.2017.09.017
Techno-Economic Comparison of Onshore and Offshore Underground Coal Gasification End-Product Competitiveness
Authors: Natalie Christine Nakaten, Thomas Kempka
Publication: Energies 2017, 10(10), 1643; doi:10.3390/en10101643 (registering DOI)
Abstract: Underground Coal Gasification (UCG) enables the utilisation of coal reserves that are currently not economically exploitable due to complex geological boundary conditions. Hereby, UCG produces a high-calorific synthesis gas that can be used for generation of electricity, fuels and chemical feedstock. The present study aims to identify economically competitive, site-specific end-use options for onshore and offshore produced UCG synthesis gas, taking into account the capture and storage (CCS) and/or utilisation (CCU) of resulting CO 2 . Modelling results show that boundary conditions that favour electricity, methanol and ammonia production expose low costs for air separation, high synthesis gas calorific values and H 2 /N 2 shares as well as low CO 2 portions of max. 10%. Hereby, a gasification agent ratio of more than 30% oxygen by volume is not favourable from economic and environmental viewpoints. Compared to the costs of an offshore platform with its technical equipment, offshore drilling costs are negligible. Thus, uncertainties related to parameters influenced by drilling costs are also negligible. In summary, techno-economic process modelling results reveal that scenarios with high CO 2 emissions are the most cost-intensive ones, offshore UCG-CCS/CCU costs are twice as high as the onshore ones, and yet all investigated scenarios except from offshore ammonia production are competitive on the European market. View Full-Text
Keywords: Underground Coal Gasification (UCG); economics; Cost of Electricity (COE); techno-economic model; methanol; ammonia; Carbon Capture and Storage (CCS); Carbon Capture and Utilisation (CCU); electricity generation; process simulation
Download Link: http://www.mdpi.com/1996-1073/10/10/1643
Mix-n-match Reservoir Coupling in Integrated Modeling and Optimization
Authors: Silvya Dewi Rahmawati (Petrostreamz AS/ITB) | Mohammad Faizul Hoda (Petrostreamz AS) | Daniel Wagner (CAPE-OPEN) | Arif Kuntadi (Petrostreamz AS)
Abstract: Reservoir Coupling (running multiple reservoir models in a concerted manner) features have been offered by software vendors for some time but with severe limitations. The participating models necessarily use the same vendor simulators and the models are usually limited to black-oil versions. This paper presents an integrated modeling and optimization solution with vendor independent participating simulators. The three reservoir models use simulators from different vendors (SENSOR®, ECLIPSE®, and MORE®). One model uses a black-oil PVT formulation while the other uses compositional PVT. The reservoir with the black-oil PVT model will be post-processed using consistent and accurate black-oil to compositional stream conversions. Stream conversion will utilize split factor tables to convert each phase volumetric rate to component molar rates. The split factors are a function of pressure and phase and are pre-generated simultaneously with the black-oil PVT tables. Streams from a “reduced” compositional PVT reservoir model are post-processed with another set of split factor tables, which are also a function of phase and pressure. This will allow the automated conversion of the reduced (or pseudoized) molar rates to equivalent “process” feed molar rates. The resulting comingled molar rates are delivered to the surface process simulator. An open source process simulator DWSIM® is used to model the common process facility. The sales products (gas, natural gas liquid (NGL), and oil) from the process facility model are priced in an economic model and the final results are in terms of the net present value (NPV). The optimization formulation maximizes the NPV while controlling key operating parameters of the integrated model. The approach presented in this paper can be used for integrated modeling within production sharing contracts where different companies may insist on using different reservoir simulators.
Keywords: reservoir coupling; streamz conversion; integrated model and optimization
Download Link: https://www.onepetro.org/conference-paper/IPTC-17727-MS
Development and Validation of a Thermodynamic Model for Gasification of Tyres
Author: C. Freda
Publication: Journal of Renewable and Alternative Energy Technologies, Volume 2, 2016
Abstract: A gasification model for waste tyres was developed using the commercial software DWSIM. A thermodynamic approach was adopted. The process was simulated by using air as gasifying agent. The effects of equivalence ratio and gasification temperature on the process were investigated. Equivalence ratio was varied between 0 and 1, while gasification temperature was varied between 500 and 900 °C. The model predicts the following outputs of the process: yield of producer gas and char, volumetric composition and heating value of the gas. Validation with results of experimental tests was carried out to emphasize the limits of the model.
Download Link: <a rel="nofollow" class="external free" href="http://ncerd-unn.gov.ng/joraet/index.php/JRAET/article/view/23/15">http://ncerd-unn.gov.ng/joraet/index.php/JRAET/article/view/23/15</a>
Techno-economic optimization of ethanol synthesis from rice-straw supply chains
Authors: Yohanes Kristianto, Liandong Zhu
Title: Techno-economic optimization of ethanol synthesis from rice-straw supply chains, In Energy, 2017, , ISSN 0360-5442
Abstract: The objective of this article is to design and plan sustainable bio-ethanol supply chain. Modeling supply chains that achieve economic, social and environmental feasibility through production, process and energy efficiency is a challenge. Life cycle assessment that is coupled with techno-economic optimization of bio-ethanol supply chain is an alternative solution to achieve sustainability. A simulation of the biomass conversion is used to find process parameters of the conversion technology. The results show that the unified model is capable of minimizing both CO2 emissions and energy and utility consumptions. In addition, the supply chain is capable of contributing to local economy through jobs creation. While the model is quite comprehensive, the future research recommendation on energy integration and global sustainability is proposed.
Keywords: ethanol; LCA; optimization; techno-economic analysis; rice straws; supply chains
Simulação do Processo de Produção de Biodiesel de Óleo de Palma utilizando os softwares Aspen HYSYS e DWSIM
Authors: Machado, Nélio & Costa, Elinéia & Araújo, M.E.. (2015).
Title: SIMULAÇÃO DO PROCESSO DE PRODUÇÃO DE BIODIESEL DE ÓLEO DE PALMA UTILIZANDO OS SOFTWARES ASPEN HYSYS E DWSIM
Abstract: O biodiesel é um combustível definido na literatura como uma mistura de ésteres de ácidos graxos derivados de fontes renováveis, produzido a partir da reação de transesterificação de óleos ou gorduras com um álcool mais comumente metanol ou etanol, gerando como subproduto o glicerol. Após a reação de transesterificação ainda devem ser considerados os processos de separação para a recuperação do excesso de etanol, a separação dos ésteres do glicerol, e a purificação do biodiesel propriamente dito. O uso de simuladores comerciais representam uma ferramenta de fundamental importância para o projeto e otimização de unidades de produção como a do biodiesel, com inúmeros parâmetros importantes a serem definidos. Este trabalho teve como objetivo simular o processo de produção de Biodiesel de óleo de Palma utilizando dois diferentes simuladores de processos (o software comercial Aspen Hysys V8.4 e o software de interface aberta DWSIM V3.3). As simulações foram realizadas sob as mesmas condições operacionais em ambos os simuladores, sendo as plantas de processo constituídas da etapa de produção de ésteres via transesterificação do óleo de palma com etanol, e da etapa de purificação dos ésteres etílicos produzidos. Nas etapas de reação os dois simuladores apresentaram resultados próximos não sendo observadas diferenças significativas. Nas etapas de recuperação do etanol em excesso foram observadas diferenças nos resultados referentes às temperaturas das correntes de fundo das colunas de destilação. Analisando os resultados das duas simulações foi possível observar que a etapa de purificação e refino dos ésteres produzidos fornece resultados diferentes entre os dois simuladores. A simulação realizada com o Aspen Hysys obteve uma corrente de biodiesel majoritariamente composta por éster etílico (96,42%) isenta de Etanol e Glicerol, apresentando ainda tripalmitina (3,55%) e uma quantidade reduzida de água (0,03%); a simulação realizada com o DWSIM apresentou uma corrente de biodiesel composta por éster etílico (aproximadamente 93,19 %), isenta de água, contendo, ainda, etanol (0,16%), glicerol (2,02%) e tripalmitina (4,31%).
Simulação de uma planta de produção de biodiesel
Authors: Teixeira, A.C.C.; Pereira, I.M.L.A.; Medeiros, D.; Fernandes, G.A.C.; Coelho, M.G.
Abstract: A utilização de simuladores de processo se mostra eficiente para a análise de processos industriais por tratar de uma ferramenta que além de possibilitar a visualização da planta industrial como um todo, permite também mapear os fatores que interferem diretamente no processo. Nesse contexto, o objetivo desse trabalho é simular a planta de produção de biodiesel, de forma que seja possível obter um maior percentual de biodiesel purificado. Para isso, é utilizado o software DWSIM e considera-se como matéria-prima o Óleo de Palma. Os resultados encontrados mostram que as composições da corrente do biodiesel final foi de 98,20% de éster etílico, etanol (0,05%) e tripalmitina (1,74%). Portanto, a utilização do simulador DWSIM é eficaz para análise deste processo produtivo.
Keywords: Simulação; DWSIM; Biodiesel
Download Link: http://www.abq.org.br/biocom/trabalhos_detalhes,10344.html
Avaliação da Consistência de um Projeto de Amostragem Contínua em Unidade de Processamento de Gás Natural
Author: Roberto Paulo Gomes André
Abstract: Os analisadores de processos são ferramentas importantes para o acompanhamento analítico em diversas indústrias e são aplicáveis às Unidades de Processamento de Gás Natural para monitoração e controle do processo. Esses instrumentos captam amostras e as condicionam para analisá-las de forma contínua. A compatibilização entre as condições físicas da amostra de processo para o analisador é promovida por um sistema de amostragem cujo projeto engloba o dimensionamento de vários itens com diferentes funções. Tal volume de especificações exige a adoção de critérios bem definidos de projeto a fim de mitigar falhas de implantação desses sistemas. O presente trabalho visou consolidar os critérios para o dimensionamento de um sistema de amostragem e avaliar a consistência de um projeto em uma Unidade de Processamento de Gás Natural. Mediante o conhecimento do funcionamento de uma Unidade de Processamento de Gás Natural, da configuração de um sistema de amostragem para análise desse gás e da literatura técnica aplicável, foram elencados os itens de dimensionamento dos componentes para um sistema de amostragem, levando a elaboração de uma lista de verificação de projeto. A avaliação de consistência mostrou haver aspectos na literatura consultada com diferenças significativas de especificações técnicas que podem impactar as definições de projeto. A aplicação da lista de verificação se mostrou eficaz para identificar falhas no projeto estudado neste trabalho, em especial o regime de fluxo, tempo espacial e condicionamento de temperatura. Como resultados, foi possível corrigir o desempenho do sistema, adequando o tempo espacial de 89 min para 1,2 min, eliminar o risco de condensação da amostra no sistema e a redução do consumo de energia de aquecimento de 400 W para 50 W. As correções aplicadas ao sistema tornam viável a medição analítica proposta.
Keywords: Amostragem. Gás natural. Analisadores de processos. Cromatografia.
Thermal-Numerical Simulation of the Gas Offshore Production Undersea Facilities at the Amistad Field
Authors: Félix Gallo Cruz (Petroleum Department of Escuela Politécnica Nacional) | Andrés Leonardo Sola (Petroleum Department of Escuela Politécnica Nacional) | Joshua Andre Rosero (Petroleum Department of Escuela Politécnica Nacional) | Jaime Oswaldo Gonzalez (Petroleum Department of Escuela Politécnica Nacional)
Abstract: Thermal numerical simulation of two undersea flowlines of natural gas production at Amistad field was developed in order to avoid non-productive time caused by plugging of solid precipitation; due to the operation conditions and recorded problems during gas production in this field, a complete study of thermodynamics, heat losses and multiphase behavior of the production fluid becomes imperative to prevent and control solid formation and flow blockage. The thermodynamic behavior of gas was analytically determined based on the thermal and transport properties of fluid phases, beginning with the study of the pressure-temperature diagram of the production fluid to define the type of solids that could precipitate within the flow lines (hydrates). The heat transfer analysis was determined applying two methods, one numerical and one analytical, the numerical by the computational fluid dynamics (CFD) method with the support of the ANSYS-CFX software; and the analytical model obtained from the literature that was used to validate it. The hydrodynamic behavior of multiphase flow and pressure losses were determined by the Beggs & Brill (1973) correlation and were contrasted with the open source DWSIM software tool performance. The overall heat transfer coefficient was determined before continuing with the numerical modeling due to its importance and influence in the CFD simulation, which covers three stages: selection of the most optimum pipeline model, mesh refining, and validation of the developed model for a heat transfer phenomenon in two-phase flow. Once the heat loss model was defined by a steady state simulation, a transient simulation was carried out to calculate the gas cooling time in a case of sudden flow shutdown, considering the standard pipe currently used and three polymers of low thermal conductivity as proposed alternate materials instead of carbon-steel or as or as thermal insulation coatings, as appropriate; these are polypropylene, polyurethane and high density polyethylene. Finally, five analytical correlations of hydrate precipitation obtained from the literature and two software precipitation equilibrium curves were selected to define the precipitation scenarios of the system using the simulation results. According to the P-T diagram, the only solids that could be precipitated in the steel pipelines are methane hydrates due to the composition of the production fluid and the operating conditions of the wells. The thermal gradient of the flowlines is the most relevant result of the numerical heat transfer analysis, this one shows the critical points of the pipes where the fluid reaches its lowest temperature, that is, the temperature of the underwater current. The critical point from the wellhead for both steel lines is 5560 [ft] according to the resulting thermal gradient, although for the second line, it is actually a bit shorter due to its length limit, 5300 [ft]. From the analysis of pressure and temperature conditions at these points, two scenarios of precipitation were established considering all the equilibrium curves. Then, one of the proposed scenarios confirmed the presence of hydrates in these two production lines of the field, providing a clearer realization of the problem that includes the time, distance and critical conditions of pressure and temperature where precipitation occurs. Subsequently, the three analyzes of heat loss of the other proposed materials were compared with the results of the base case to determine the most effective pipeline configuration to avoid the formation of hydrates and it was concluded that precipitation will not occur throughout the entire flowline if any of the polymers is applied as thermal insulator or pipe material, as appropriate. In addition, the effects of the hydrodynamic phenomenon caused by the multiphase flow were studied, determining a mist flow pattern, where the liquid phase of the fluid is dispersed within the gaseous phase in the form of small water droplets.
Download Link: https://www.onepetro.org/conference-paper/OTC-29751-MS
An Organic Rankine Cycle Bottoming a Diesel Engine Powered Passenger Car
Authors: Antonio Mariani, Maria Laura Mastellone, Biagio Morrone, Maria Vittoria Prati and Andrea Unich
Abstract: Organic Rankine Cycle (ORC) power plants are characterized by high efficiency and flexibility, as a result of a high degree of maturity. These systems are particularly suited for recovering energy from low temperature heat sources, such as exhaust heat from other plants. Despite ORCs having been assumed to be appropriate for stationary power plants, since their layout, size and weight constraints are less stringent, they represent a possible solution for improving the efficiency of propulsion systems for road transportation. The present paper investigates an ORC system recovering heat from the exhaust gases of an internal combustion engine. A passenger car with a Diesel engine was tested over a Real Driving Emission (RDE) cycle. During the test exhaust gas mass flow rate and temperature have been measured, thus calculating the enthalpy stream content available as heat addition to ORC plant in actual driving conditions. Engine operating conditions during the test were discretized with a 10-point grid in the engine torque–speed plane. The ten discretized conditions were employed to evaluate the ORC power and the consequent engine efficiency increase in real driving conditions for the actual Rankine cycle. N-pentane (R601) was identified as the working fluid for ORC and R134a was employed as reference fluid for comparison purposes. The achievable power from the ORC system was calculated to be between 0.2 and 1.3 kW, with 13% system efficiency. The engine efficiency increment ranged from 2.0% to 7.5%, with an average efficiency increment of 4.6% over the RDE test.
Download Link: https://doi.org/10.3390/en13020314
Simulators Selection for Design and Simulation of a CSP-Driven Forward Osmosis Process
Authors: Samya Sigue, Souad Abderafi, Sebastion Vaudreuil, Tijani Bounahmidi
Abstract: Coupling of desalination technologies and renewable energy systems is relatively a new concept, which is used either to provide energy to a desalination system or to generate simultaneously power and drinking water. The aim of this paper is to select the most convenient simulator to study a plant combining concentrated solar power and forward osmosis dedicated to electricity and drinking water producing for populations in arid regions. Thus, a state of the art of the available steady-state simulators has been carried out. The design and simulation models and the use of these simulators in the already-published papers have been investigated. It has been revealed that there is a lack of simulators having all the required models to analyze solar energy-driven desalination processes. Thereby, most authors use two simulators, one general for chemical processes and the other specific to renewable energy systems. Besides that, simulators with pre-built models for FO unit does not exist. Open source solutions were selected over commercial ones for several reasons. They offer open access to the application elements, so new modules can be easily added or modified. Furthermore, they can interoperate and communicate with other applications. Finally, based on the supported models and development tools, we have chosen SAM and DWSIM as the suitable open source simulators for our project.
Download Link: https://ieeexplore.ieee.org/document/9078216
Chemical Process Simulation Using OpenModelica
Authors: Priyam Nayak, Pravin Dalve. Rahul Anandi Sai, Rahul Jain, Kannan M. Moudgalya, P. R. Naren, Peter Fritzson, Daniel Wagner
Abstract: The equation-oriented general-purpose simulator OpenModelica provides a convenient, extendible modeling environment, with capabilities such as an easy switch from steady-state to dynamic simulations. This work reports the creation of a library of steady-state models of unit operations using OpenModelica. The use of this library is demonstrated through a few representative flowsheets, and the results are compared with the steady-state simulators Aspen Plus and DWSIM. Being open-source and supported by a large community of developers across the world, OpenModelica provides a convenient platform to train a large number of chemical engineers to increase collaborative research and employment.
Download Link: https://pubs.acs.org/doi/abs/10.1021/acs.iecr.9b00104
Performance Comparison of Different Thermal Fluids in Concentrating Solar Plants
Authors: Maria Laura Mastellone, Antonio Mariani, Ernesto Misso, Biagio Morrone, Andrea Unich, Lucio Zaccariello
Abstract: Concentrating Solar Plants (CSP) represent a feasible alternative to fossil fuel driven power plants. Anyway, technical and economic issues severely prevent their large diffusion over the world. In this paper, a numerical investigation is accomplished to predict the performance of a CSP without thermal storage (TES). A stationary, 1-D model of heat transfer fluid (HTF) is presented, taking into account the heat losses occurring along the Heat Collector Element (HCE). A Southern Italy location is considered for the solar plant simulation, and two HTF thermal oils, Therminol VP1 and Therminol 62, are compared in terms of thermal power delivered to the power plant block. HTF temperature distribution and velocity profile along the solar plant are obtained to evaluate the performance of a coupled Organic Rankine Cycle (ORC) plant, simulated using the DWSIM programme, emphasizing the differences when using three different types of working fluids, i.e. wet, dry and isentropic.
Análise técnico-econômica da produção de acrilonitrila via biomassa com simulação
Author: BRANDÃO, Vitor Cassuce
Abstract: O estudo tem como objetivo avaliar a rota alternativa de produção de acrilonitrila a partir de lignocelulose, analisar técnico e economicamente e simular o processo de produção através do software computacional DWSIM®. Como alternativa às matérias primas com base fóssil como o processo tradicional SOHIO, surgem os chamados processos renováveis e a proposição é de partir da biomassa lignocelulósica e obter a acrilonitrila. Foi simulada uma planta com capacidade produtiva anual de 105,5 mil toneladas de acrilonitrila. Os resultados obtidos foram de um payback de 6,3 anos e o Valor Presente Líquido do projeto é de US$ 121.671.031,32. O processo de produção a partir do propileno tem conversão de 83%, já a partir do 3-HPA é possível chegar a 97%, unidades em mol/mol. A taxa interna de retorno calculada foi de 13,58%, sendo maior que a taxa mínima de atratividade de 8% tornando o projeto viável economicamente e uma viável rota de produção de acrilonitrila.
Download Link: https://app.uff.br/riuff/handle/1/23375
Modeling and Simulation of Manufacturing Process of Paracetamol
Authors: Meda, U. S., Taher Husain, & Vora, K.
Abstract: Paracetamol also known as acetaminophen is a chemical compound derived from its chemical name N-acetyl-para-aminophenol. It is one of the most commonly used analgesics and antipyretic drugs around the world , as an analgesic and an antipyretic most commonly used for headaches and mild fever . Paracetamol is very common and almost every individual on this planet has consumed paracetamol at least once in his/her life. So, with that extensive usage, a highly efficient production process is necessary at a large scale. Process optimization plays an important role in enhancing the efficiency of the production process. Through process optimization, the conversion can be increased, the wastage can be minimized and the product purity can be enhanced. This results in the reduction of production costs either making it profitable or affordable. Process simulation tools come very handy in designing and optimizing the processes.
In this work, the production process was modeled and simulated using open-source software, DWSIM, and the process flow diagram is shown in figure 1. The suitability of different reactors was evaluated, the separation train was optimized by varying many parameters and a sensitivity analysis was carried out. The performance of every piece of equipment involved in the process were finetuned thereby optimizing the entire process.
Download Link: https://spast.org/techrep/article/view/2648
Predicción de la producción de metanol en una planta de hidrogenación de dióxido de carbono mediante redes neuronales
Authors: Raúl Leandro Dávalos Monteiro, Mabel Mariela Parada Rivera, Jimena Alexandra Macas Macas
Abstract: El objetivo de este trabajo de investigación fue diseñar una red neuronal original (RNA) para predecir el flujo de metanol de una planta de deshidrogenación de dióxido de carbono. Para el desarrollo de ARN se generó una base de datos en el software abierto de simulación DWSIM. Ésta se realizó a partir de la validación de un proceso industrial descrito en la literatura. El tamaño de la muestra consistió en 133 pares de datos con 4 entradas: presión y temperatura del reactor, flujo másico de dióxido de carbono e hidrógeno, y una salida: flujo de metanol. La red fue de tipo perceptrón y se diseñó utilizando 12 neuronas en una capa oculta en su arquitectura, se entrenó con el algoritmo de regularización bayesiana para el entrenamiento de Levenberg-Marquardt. Se obtuvo un valor cuadrático medio (MSE) de 0,0085 y un coeficiente de regresión total de 0,9442. La red fue validada mediante el análisis de varianza (ANOVA) lo que indica que la ARN diseñada es estadísticamente válida y puede ser utilizada para predecir el flujo de metanol a la salida de la planta de deshidrogenación y puede ser utilizada como herramienta para la mejora continua de este tipo de procesos. Se recomienda añadir la presión de separación en la zona de recirculación como parámetro de entrada como forma de obtener un resultado más cercano a la realidad.
Diseño y simulación de un reactor tubular multipropósito para tri-reformado de metano
Authors: MF Rodríguez Bonilla, DM Pérez Motta
Abstract: In this work was made a study, about Methane Tri-reforming process by thermodynamic analysis of operating variables and conditions of loading to the reactor, in order to favour the conversion to synthesis gas and hydrogen, to dimension a functional catalytic reactor from a thermal and mechanical viewpoint. In addition to contextualizing chemical concepts used to carry out the project, the simulation software DWSIM was used, to demonstrate the potential of computational simulation and obtain reliable results in stable and dynamics conditions, with practical research applicable to industry, thus encourage the implementation of these technologies.
Download Link: https://repositorio.ecci.edu.co/handle/001/1556
Otimização do processo de producão de biodiesel e glicerol a partir do óleo de palma e soja por modelagem no software dwsim
Authors: Diogens Marco de Brito da Cruz, Camila Manuelle Cardoso Braz da Silva, Jeane Denise de Souza Menezes, Adeildo Moacir Costa Magalhães, Fabricio Santos de Faro
Abstract: O biodiesel é um biocombustível renovável que é obtido através de um processo químico denominado transesterificação. Por meio desse processo, os triglicerídeos presentes em diversos óleos e gorduras animais reagem com um álcool primário mais comumente adotado, o etanol ou metanol, gerando como subproduto o glicerol. Nesse sentido, a utilização de simuladores comerciais para otimização dos processos produtivos em unidades de produção de biodiesel é de fundamental importância, uma vez que estes contribuem para minimização de custos atrelados aos processos fabris. Assim, este trabalho tem por objetivo a simulação de dois processos produtivos, um contendo o óleo de palma e o outro óleo de soja, aplicando o software DWSIM v5.874. Para isso, as simulações foram realizadas adotando os mesmos parâmetros de operação, de forma a identificar como cada matéria-prima se comporta na conversão da transesterificação. Por meio das simulações, foi verificado que o óleo de palma (processo II) obteve um melhor rendimento na etapa de recuperação do etanol de reciclo, sendo observado que houve um excedente de 136,84 kg.h-1 de etanol com temperatura de 79,15 °C, quando comparado com o óleo de soja (processo I), que obteve um excedente de 152,94 kg.h-1 de etanol destilado a 79,12 °C. Analisando os resultados, foi identificado que o processo I obteve uma corrente de operação de saída de 1044,02 kg.h-1 de biodiesel a 71,68° C com 99,97% de purificação e 0,03% de impurezas na composição, e o processo II com um rendimento total de 1049,42 kg.h-1 e 99,99% de pureza e 0,01% de impurezas em sua composição final. Deste modo, foi evidenciado que o processo II obteve um maior rendimento na conversão do etanol em excesso e uma maior produção de biodiesel em relação ao processo I.
Estudio comparativo de cálculo de propiedades entre programas de simulación. el caso de unisim y dwsim
Authors: CD Cañizares Gutiérrez
Abstract: Actualmente la simulación de procesos por ordenador en la ingeniería química es una etapa fundamental en la puesta en marcha y control de cualquier proceso en el campo de la petroquímica, donde permiten predecir los resultados de cualquier etapa del proceso productivo. La comparativa entre el comportamiento de dos simuladores populares, el UNISIM, disponible bajo licencia y el DWSIM, de código abierto, tiene una importancia económica significativa, ya que permite obtener resultados de un programa de aplicación industrial utilizando uno de uso académico. Delimitando el estudio para los hidrocarburos aromáticos Tolueno y Benceno, principales componentes de una mezcla BTX. Mediante la revisión de la bibliografía pertinente se estable una base teórica firme, para a continuación, proceder a modelar el comportamiento de estos componentes y una mezcla equimolar de los mismos, a través de los simuladores se obtienen las principles propiedades físico-químicas de fase y propiedades termodinámicas, luego, de aquellas propiedades que presentan mayores diferencias entre simuladores se proponen medios para corregirlas, buscando así obtener resultados con DWSIM lo más semejantes posibles a los arrojados por UNISIM, para finalizar se proponen recomendaciones para completar el estudio y poder emular el modelado de una columna de platos de simulador bajo licencia en el programa de código abierto.
Download Link: https://riull.ull.es/xmlui/bitstream/handle/915/24753/Estudio%20comparativo%20de%20calculo%20de%20propiedades%20entre%20programas%20de%20simulacion.%20el%20caso%20de%20unisim%20y%20dwsim.pdf?sequence=1
Simulación de producción de ácido succínico a partir de material lignocelulósico
Authors: Villota-Muñoz, B.A, Albahonza-Quenán, D.A., & Verdugo-González, L.
Abstract: El bagazo de caña es un material lignocelulósico, residuo de la producción panelera en el departamento de Nariño. En la actualidad, dicho residuo no hace parte de un proceso de transformación que le genere un valor agregado. Con el fin de contribuir al posible cierre del ciclo productivo de la caña y la generación de nuevas alternativas de trabajo en la región, en esta investigación se realizó la simulación del proceso de producción de ácido succínico (AS) a partir del bagazo de caña, teniendo en cuenta que este compuesto es un ácido carboxílico que se ha considerado como uno de los productos bioquímicos de mayor interés comercial, ya que posee una amplia gama de aplicaciones en la industria química, alimenticia y farmacéutica. Para ello se efectuó una revisión bibliográfica de los pre-tratamientos, condiciones de operación del proceso y producción biotecnológica de AS, de la cual se seleccionó una secuencia de operaciones que incluyen procesos térmicos, mecánicos, químicos y biológicos. La simulación se hizo en el software DWSIM.
Síntese de metanol via hidrogenação do dióxido de carbono: modelagem e otimização no simulador DWSIM
Authors: Leandro Junior, Adilson Oliveira
Abstract: As one of the main causes of the greenhouse effect and global warming, carbon dioxide (CO2) must have its emissions progressively controlled over the years. In this context, it is interesting that it is used as a raw material for obtaining products of commercial interest, such as methanol. In this paper, a simulation of a methanol production process from the hydrogenation of carbon dioxide was performed, using the DWSIM simulator, which is an open-source, free and multiplatform software. In the simulation, some variables were chosen to be optimized in order to make the process more competitive against the traditional methanol synthesis route and to study which parameters influence the process viability. The production costs of the ton of methanol produced via hydrogenation obtained ranged from U$ 325 to U$ 1031 depending on the hydrogen source. Strategically, the direct hydrogenation of CO2 has the potential to be used as an attached process to chemical and industrial plants that have carbon dioxide as a by-product. The main challenges are the costs of obtaining hydrogen, the relatively higher energy costs and the search for efficient and viable catalysts.
Download Link: https://repositorio.ufscar.br/handle/ufscar/14537
Comparación de los costos de producción y grado de contaminación por emisiones en el sector industrial del Ecuador usando como combustible gas natural mediante la simulación de process
Authors: López Díaz, Gabriel Junior
Abstract: En la presente investigación se realizó la comparación de los costos industriales y el grado de contaminación por emisiones que se genera utilizando los combustibles tradicionales en especial el diésel el cual es el más usado en la industria ecuatoriana frente al gas natural por medio de un programa de Ingeniería química de código abierto denominado DWSIM para la simulación de las reacciones químicas de combustión del diésel y el gas natural como generadores de energía en los procesos productivos de las Industrias, en el cual se demostró que llegando a obtener la misma cantidad de energía se pueden reducir hasta en un 22,46% de emisiones de dióxido de carbono al ambiente utilizando gas natural , también se determinó una variación de los costos de producción , el cual está en función de los costos indirectos de fabricación ya que en este elemento de los costos totales de producción se encuentran los combustibles teniendo así un ahorro de un 3,9296% al mes usado gas natural como combustible generador de energía frente al diésel como combustible tradiciona
Download Link: http://repositorio.ug.edu.ec/handle/redug/50358
Fluidos refrigerantes mistos (CO2/CH4) visando novas aplicações em sistemas de refrigeração - EVR2021-0011
Authors: Matheus H. C. Garros 1,*, Robson L. Silva 1,2
Abstract: Sistemas de refrigeração utilizando fluidos refrigerantes naturais são uma demanda atual e ambientalmente relevantes, com uso comercial já existente para CO2/R-744, NH4 e alguns hidrocarbonetos. Tipicamente a obtenção do CH4 ocorre junto ao CO2, a exemplo da extração de gás natural e na produção de biogás. O objetivo é analisar um sistema de refrigeração de configuração simplificada que opere com diferentes misturas de CH4 e CO2 como fluidos de trabalho visando novas aplicações. A metodologia utiliza simulação computacional via software DWSIM para um ciclo termodinâmico e duas condições de contorno (temperatura fixada ou máximo COP). Conclui-se que maiores proporções de CO2 na mistura refrigerante implica em limitações no compressor, especificamente maior demanda de potência/trabalho e temperaturas elevadas na saída do compressor. Além disso, maiores proporções de CH4 na mistura refrigerante implica em redução na capacidade de refrigeração e menor COP. Para as condições de contorno a diferença operacional mais significativa refere-se à pressão de descarga do compressor, em geral duas vezes menor na condição de temperatura fixada em -45oC (~15 MPa). Por fim, identifica-se possível a utilização de misturas CO2/CH4 como fluidos de trabalho em sistemas de refrigeração para armazenamento de vacinas, e para aplicações em temperaturas inferiores a -50oC é necessário considerar configurações termodinâmicas mais elaboradas.
Download Link: https://www.researchgate.net/profile/Matheus-Garros/publication/350075472_Fluidos_refrigerantes_mistos_CO2CH4_visando_novas_aplicacoes_em_sistemas_de_refrigeracao/links/604fbdd492851cd8ce43fc13/Fluidos-refrigerantes-mistos-CO2-CH4-visando-novas-aplicacoes-em-sistemas-de-refrigeracao.pdf
“Implementation of a liquid air storage system (LAES) in a mixed renewable energy system (wind and photovoltaic). The case of Tenerife
Authors: Juan Felipe Castellanos Salazar
Download Link: download
Thermodynamic and economic analyses of power generation from gas turbine exhaust
Abstract: This paper presents the development of a thermodynamic model of natural gas production processes on the offshore platform by applying Organic Rankine Cycle (ORC) technology to the plant. This research considered the thermodynamic performance and economic feasibility of using ORC for electricity production from exhaust gas generated by gas turbine engines which were used as prime movers to drive natural gas compressors. According to the Process & Instrumentation Diagram (P&ID), the process of recovering waste heat from Booster Compression and Sales Gas Compression and Export modules from the entire gas production processes of the plant has been modeled in DWSIM program which is an open-source chemical process simulation. The simulation result showed that the exhaust gas had a temperature at 527 oC at Booster Compression and 504 oC at Sale Gas Compression and Export. The ORC was designed as a simple cycle with no degree of superheating and subcooling due to limited area of the offshore platforms. We have selected the most suitable working fluid for ORC in order to get the highest turbine power and efficiency. From the simulation, Toluene was identified as the most suitable working fluid which provided the highest turbine power and efficiency at 1.9 MW and 24.33%, respectively. So, the installation of 4 cycles of ORC for offshore platform will get total energy at 7.6 MW. To demonstrate the commercial feasibility of this project, a detailed economic analysis has been performed. The results showed that the ORC technology has the net present value (NPV) is 40.141 million Baht, the payback period (PB) is around 16.49 years, the internal rate of return (IRR) is 8.18% per year (from the minimum attractive rate of return or MARR at 8% per year) and the benefit cost ratio (B/C ratio) is 1.10. All indicators show economically favorable results, thus, indicating that this research is economically feasible and worth for the investment.
Process simulation of biodiesel production from vegetable oil deodorization distillate using hydrotalcite-hydroxyapatite as catalyst
Authors: ALMEIDA, L. A. de; VILAS BÔAS, R. N.; MENDES, M. F.
Abstract: In There are few simulation studies in the literature focusing on the production of biodiesel from vegetable oil deodorization distillate (VODD), a waste originating from the vegetable oil processing stage, using hydrotalcite-hydroxyapatite as a heterogeneous catalyst. In this study, the simulation process was performed using open interface software DWSIM® Version 6.3. The motivation relied on the positive performance of the catalyst during the experimental studies. So, in the simulator design, the lipid raw material, ethanol, and the catalyst were fed together in a CSTR-01 conversion reactor. The thermodynamic fluid package used for this process was the Non-Random Two-Liquid (NRTL) activity coefficient model. The process flowchart consisted of the reaction step (oil transesterification), and separation steps of the ethyl esters produced, excess ethanol and purification of biodiesel. As a result, different scenarios were simulated, using commercial soybean oil as a comparative form, different types of catalysts and different molar ratios of alcohol and VODD. Among the main differences between the simulated cases, it was demonstrated that the excess of alcohol (1:45) caused greater quantity of VODD consumption, and consequently the greater formation of ethyl esters (biodiesel), resulting higher conversions (> 95%). In addition, the results obtained confirmed the adequacy of VODD as a potential raw material to produce biodiesel, as it is relatively cheaper than edible oils and contributes to the use of waste. Thus, confirming that the chemical catalyst was able to form the main esters of fatty acids even using a residual raw material.
Download Link: https://www.rsdjournal.org/index.php/rsd/article/view/15452
Comparative Analysis of Energy and Exergy Performance of Hydrogen Production Methods
Authors: Martínez-Rodríguez A, Abánades A.
Abstract: The study of the viability of hydrogen production as a sustainable energy source is a current challenge, to satisfy the great world energy demand. There are several techniques to produce hydrogen, either mature or under development. The election of the hydrogen production method will have a high impact on practical sustainability of the hydrogen economy. An important profile for the viability of a process is the calculation of energy and exergy efficiencies, as well as their overall integration into the circular economy. To carry out theoretical energy and exergy analyses we have estimated proposed hydrogen production using different software (DWSIM and MATLAB) and reference conditions. The analysis consolidates methane reforming or auto-thermal reforming as the viable technologies at the present state of the art, with reasonable energy and exergy efficiencies, but pending on the impact of environmental constraints as CO2 emission countermeasures. However, natural gas or electrolysis show very promising results, and should be advanced in their technological and maturity scaling. Electrolysis shows a very good exergy efficiency due to the fact that electricity itself is a high exergy source. Pyrolysis exergy loses are mostly in the form of solid carbon material, which has a very high integration potential into the hydrogen economy.
Download Link: https://www.mdpi.com/1099-4300/22/11/1286