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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Separação de ácidos graxos livres e triacilgliceróis por destilação a vácuo

ARRUDA, Andréa Leão de Lima 23 February 2016 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-09-16T14:17:18Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Andréa Leão_Ver_Final.pdf: 2849890 bytes, checksum: cd4d0770cfce99861e2cf216c67ed0fb (MD5) / Made available in DSpace on 2016-09-16T14:17:18Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação_Andréa Leão_Ver_Final.pdf: 2849890 bytes, checksum: cd4d0770cfce99861e2cf216c67ed0fb (MD5) Previous issue date: 2016-02-23 / ANP / O presente estudo propõe a separação entre os triacilgliceróis (TAGs), principais constituintes dos óleos vegetais, e ácidos graxos livres (AGLs) através do processo de destilação a vácuo. A possibilidade dessa separação consiste na considerável diferença de volatilidade entre os AGLs e os TAGs. Foram preparadas misturas modelo aos óleos residuais, ou seja, combinações em diferentes proporções em massa de óleo de soja refinado (OS) e o reagente ácido oleico p.a (AO). As misturas foram destiladas nas pressões reduzidas de 0,13; 0,40; 0,67 e 1,33 kPa, sendo o processo realizado em batelada em um único estágio, sem refluxo. As amostras foram caracterizadas antes e após o processo de destilação a vácuo quanto: à massa específica, ao teor de água, ao teor de AGL (%) e à composição de ácidos graxos por cromatografia gasosa. Posteriormente, foram definidos os componentes modelo de TAG e AO e a estimativa dos parâmetros termofísicos das misturas para a simulação do processo de destilação a vácuo no software Aspen Plus V8.8, utilizando tanques flash não adiabáticos em série. O modelo termodinâmico usado foi o Non-Random Two-Liquid (NRTL). As curvas de destilação experimentais da mistura de 89,45% de OS e 10,55% de AO em massa foram melhor representadas pelas curvas de destilação simuladas, apresentando o percentual de desvios médios quadráticos de 2,5; 2,2; 2,4 e 2,5% para operações realizadas em pressões reduzidas de 0,13; 0,40; 0,67 e 1,33 kPa, respectivamente. Os dados de massa específica a 20°C dos produtos das destilações, resíduos e destilados, foram semelhantes aos do OS e AO, respectivamente. Os teores de água dos destilados (0,024% a 0,059%) e dos resíduos (0,001% a 0,014%) estão em níveis adequados para o emprego das reações de esterificação e transesterificação para a produção de biodiesel. Os teores de ácidos graxos livres dos resíduos obtidos após as destilações ficaram dentro da faixa de 0,4% a 1,2%, indicando processo de separação por destilação a vácuo efetivo. / This study proposes the separation of triacylglycerols (TAG), main constituent of vegetable oils, and free fatty acids (FFA) through the vacuum distillation process. The possibility of this separation is the considerable difference in volatility between the FFA and the TAG. Mixtures were prepared with model waste oil, or combinations of different mass ratios of refined soybean oil (SO) and the reagent oleic acid (OA). The mixtures were distilled at reduced pressures of 0.13; 0.40; 0.67 and 1.33 kPa, the process being carried out in batches in a single stage, without reflux. The samples were characterized before and after the vacuum distillation process as: the specific gravity, the water content, the FFA content (%) and the fatty acid composition by gas chromatography. Subsequently, the components were defined template TAG and OA and the estimation of parameters of mixtures thermophysical to simulate the vacuum distillation process in Aspen Plus v8.8 software using non-adiabatic flash tanks in series. The thermodynamic model used was the Non-Random Two-Liquid (NRTL). Experimental distillation curves of mixing 89.45% of SO and 10.55% of mass OA were best represented by simulated distillation curves, showing the percentage of mean deviation squared of 2.5; 2.2; 2.4 and 2.5% for operations in reduced pressures of 0.13; 0.40; 0.67 and 1.33 kPa, respectively. The specific mass of data at 20°C the distillation of the products, residues and distillates were similar to SO and OA, respectively. The content of distilled water (0.024% to 0.059%) and waste (0.001% to 0.014%) were at adequate levels for the use of esterification and transesterification reactions for biodiesel production. The contents of free fatty acids from residues obtained after distillations were within the range of 0.4% to 1.2%, indicating a separation process by distillation under vacuum effective.
2

Integration and Simulation of a Bitumen Upgrading Facility and an IGCC Process with Carbon Capture

El Gemayel, Gemayel 19 September 2012 (has links)
Hydrocracking and hydrotreating are bitumen upgrading technologies designed to enhance fuel quality by decreasing its density, viscosity, boiling point and heteroatom content via hydrogen addition. The aim of this thesis is to model and simulate an upgrading and integrated gasification combined cycle then to evaluate the feasibility of integrating slurry hydrocracking, trickle-bed hydrotreating and residue gasification using the Aspen HYSYS® simulation software. The close-coupling of the bitumen upgrading facilities with gasification should lead to a hydrogen, steam and power self-sufficient upgrading facility with CO2 capture. Hydrocracker residue is first withdrawn from a 100,000 BPD Athabasca bitumen upgrading facility, characterized via ultimate analysis and then fed to a gasification unit where it produces hydrogen that is partially recycled to the hydrocracker and hydrotreaters and partially burned for power production in a high hydrogen combined cycle unit. The integrated design is simulated for a base case of 90% carbon capture utilizing a monoethanolamine (MEA) solvent, and compared to 65% and no carbon capture scenarios. The hydrogen production of the gasification process is evaluated in terms of hydrocracker residue and auxiliary petroleum coke feeds. The power production is determined for various carbon capture cases and for an optimal hydrocracking operation. Hence, the feasibility of the integration of the upgrading process and the IGCC resides in meeting the hydrogen demand of the upgrading facility while producing enough steam and electricity for a power and energy self-sufficient operation, regardless of the extent of carbon capture.
3

Integration and Simulation of a Bitumen Upgrading Facility and an IGCC Process with Carbon Capture

El Gemayel, Gemayel 19 September 2012 (has links)
Hydrocracking and hydrotreating are bitumen upgrading technologies designed to enhance fuel quality by decreasing its density, viscosity, boiling point and heteroatom content via hydrogen addition. The aim of this thesis is to model and simulate an upgrading and integrated gasification combined cycle then to evaluate the feasibility of integrating slurry hydrocracking, trickle-bed hydrotreating and residue gasification using the Aspen HYSYS® simulation software. The close-coupling of the bitumen upgrading facilities with gasification should lead to a hydrogen, steam and power self-sufficient upgrading facility with CO2 capture. Hydrocracker residue is first withdrawn from a 100,000 BPD Athabasca bitumen upgrading facility, characterized via ultimate analysis and then fed to a gasification unit where it produces hydrogen that is partially recycled to the hydrocracker and hydrotreaters and partially burned for power production in a high hydrogen combined cycle unit. The integrated design is simulated for a base case of 90% carbon capture utilizing a monoethanolamine (MEA) solvent, and compared to 65% and no carbon capture scenarios. The hydrogen production of the gasification process is evaluated in terms of hydrocracker residue and auxiliary petroleum coke feeds. The power production is determined for various carbon capture cases and for an optimal hydrocracking operation. Hence, the feasibility of the integration of the upgrading process and the IGCC resides in meeting the hydrogen demand of the upgrading facility while producing enough steam and electricity for a power and energy self-sufficient operation, regardless of the extent of carbon capture.
4

Integration and Simulation of a Bitumen Upgrading Facility and an IGCC Process with Carbon Capture

El Gemayel, Gemayel January 2012 (has links)
Hydrocracking and hydrotreating are bitumen upgrading technologies designed to enhance fuel quality by decreasing its density, viscosity, boiling point and heteroatom content via hydrogen addition. The aim of this thesis is to model and simulate an upgrading and integrated gasification combined cycle then to evaluate the feasibility of integrating slurry hydrocracking, trickle-bed hydrotreating and residue gasification using the Aspen HYSYS® simulation software. The close-coupling of the bitumen upgrading facilities with gasification should lead to a hydrogen, steam and power self-sufficient upgrading facility with CO2 capture. Hydrocracker residue is first withdrawn from a 100,000 BPD Athabasca bitumen upgrading facility, characterized via ultimate analysis and then fed to a gasification unit where it produces hydrogen that is partially recycled to the hydrocracker and hydrotreaters and partially burned for power production in a high hydrogen combined cycle unit. The integrated design is simulated for a base case of 90% carbon capture utilizing a monoethanolamine (MEA) solvent, and compared to 65% and no carbon capture scenarios. The hydrogen production of the gasification process is evaluated in terms of hydrocracker residue and auxiliary petroleum coke feeds. The power production is determined for various carbon capture cases and for an optimal hydrocracking operation. Hence, the feasibility of the integration of the upgrading process and the IGCC resides in meeting the hydrogen demand of the upgrading facility while producing enough steam and electricity for a power and energy self-sufficient operation, regardless of the extent of carbon capture.

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