Coke formation during thermal cracking of a heavy crude oil

A pseudo-mechanism for the production of coke during the thermal cracking of a Colombian heavy crude oil was proposed based on thermal cracking experiments carried out at TGA and at horizontal tube furnace at atmospheric conditions. In-situ combustion (ISC) is a thermal method that improves the reco...

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Autores:
Urán Castaño, Laura Cristina
Tipo de recurso:
Fecha de publicación:
2015
Institución:
Universidad Nacional de Colombia
Repositorio:
Universidad Nacional de Colombia
Idioma:
spa
OAI Identifier:
oai:repositorio.unal.edu.co:unal/55429
Acceso en línea:
https://repositorio.unal.edu.co/handle/unal/55429
http://bdigital.unal.edu.co/50838/
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66 Ingeniería química y Tecnologías relacionadas/ Chemical engineering
In-situ combustion
Thermal cracking
Coke formation
Kinetic pseudo-mechanism
Lowmolecular-weight maltenes (LMWM)
Combustión in situ
Craqueo térmico
Formación de coque
Pseudo-mecanismo de reacción
Máltenos de bajo peso molecular (LMWM)
Rights
openAccess
License
Atribución-NoComercial 4.0 Internacional
id UNACIONAL2_f1b530baf4c337ebdd110789a4c3e367
oai_identifier_str oai:repositorio.unal.edu.co:unal/55429
network_acronym_str UNACIONAL2
network_name_str Universidad Nacional de Colombia
repository_id_str
dc.title.spa.fl_str_mv Coke formation during thermal cracking of a heavy crude oil
title Coke formation during thermal cracking of a heavy crude oil
spellingShingle Coke formation during thermal cracking of a heavy crude oil
66 Ingeniería química y Tecnologías relacionadas/ Chemical engineering
In-situ combustion
Thermal cracking
Coke formation
Kinetic pseudo-mechanism
Lowmolecular-weight maltenes (LMWM)
Combustión in situ
Craqueo térmico
Formación de coque
Pseudo-mecanismo de reacción
Máltenos de bajo peso molecular (LMWM)
title_short Coke formation during thermal cracking of a heavy crude oil
title_full Coke formation during thermal cracking of a heavy crude oil
title_fullStr Coke formation during thermal cracking of a heavy crude oil
title_full_unstemmed Coke formation during thermal cracking of a heavy crude oil
title_sort Coke formation during thermal cracking of a heavy crude oil
dc.creator.fl_str_mv Urán Castaño, Laura Cristina
dc.contributor.author.spa.fl_str_mv Urán Castaño, Laura Cristina
dc.contributor.spa.fl_str_mv Molina, Alejandro
dc.subject.ddc.spa.fl_str_mv 66 Ingeniería química y Tecnologías relacionadas/ Chemical engineering
topic 66 Ingeniería química y Tecnologías relacionadas/ Chemical engineering
In-situ combustion
Thermal cracking
Coke formation
Kinetic pseudo-mechanism
Lowmolecular-weight maltenes (LMWM)
Combustión in situ
Craqueo térmico
Formación de coque
Pseudo-mecanismo de reacción
Máltenos de bajo peso molecular (LMWM)
dc.subject.proposal.spa.fl_str_mv In-situ combustion
Thermal cracking
Coke formation
Kinetic pseudo-mechanism
Lowmolecular-weight maltenes (LMWM)
Combustión in situ
Craqueo térmico
Formación de coque
Pseudo-mecanismo de reacción
Máltenos de bajo peso molecular (LMWM)
description A pseudo-mechanism for the production of coke during the thermal cracking of a Colombian heavy crude oil was proposed based on thermal cracking experiments carried out at TGA and at horizontal tube furnace at atmospheric conditions. In-situ combustion (ISC) is a thermal method that improves the recovery of heavy crude oils and involves complex phenomena such as heat and mass transfers, low-temperature oxidation of the liquid phase (LTO), and cracking reactions that yield coke, a carbonaceous residue that, after high-temperature oxidation (HTO) produces the heat that reduces the oil viscosity increasing the recovery factor. During cracking experiments, Ottawa sand was mixed with crude oil, or with a mixture of maltenes and asphaltenes extracted from that oil, and placed under nitrogen atmosphere and heated at 2oC/min up to di_erent reaction temperatures (300oC, 350oC, 400oC and 450oC) at atmospheric pressure conditions. Even tough atmospheric pressure conditions is not a realistic condition as oil reservoirs operate above atmospheric pressure, this study as part of a bigger project to study ISC it was the _rst that develop a setup and a methodolody able to study ISC reactions. After the _rst approximation that this study made, further work will be carried out to study ISC process at more realistic conditions. This study found that the main cracking products were volatiles that could be condensables and non-condensables and a solid residue. Proximate, elemental, GC-MS and SIMDIS analysis were performed to establish the composition of the cracking products, and to determine the advance in the cracking reactions. During cracking experiments each oil fraction yielded lower- and heavier-molecular weight products. e.g. maltenes yielded gas (mainly composed by methane CH4), distillables (a condensable fraction with maximum 18 carbons), low-molecular-weight maltenes (LMWM, a condensable fraction with maximum 28 carbons, that results from the cracking of maltenes and asphaltenes), and asphaltenes. Whereas asphaltenes leaded to coke formation and to LMWM and gases. The proposed pseudo-mechanism considers the formation of lower- and heavier molecules, separates the evaporation process from the thermal cracking, and proposed new pseudocomponents such as Maltenes* that represents the maltenes fraction after the evaporation process and the one available for thermal cracking, and LMWM that is an upgraded cracking product of the cracking of maltenes* and asphaltenes that had a yield of 0.28 g/gtot. Furthermore, the proposed pseudo-mechanism proposes kinetic parameters for the thermal cracking of a Colombian heavy crude oil under in-situ combustion conditions at atmospheric pressure. The kinetic parameter were optimized by minimizing the sum of square error (SSE) between the experimental and calculated yields. A good coe_cient of determination was obtained, (R2=0; 97), using _rst order kinetic parameters. The physical interpretation of the value of kinetic parameters is complicated given the rather empirical approach used to find the kinetic parameters, it is important to note that most parameters in particular activation energies have values typical for chemical-controlled process, exceptions to this are the activation energies 26.4 and 9760 kJ/mol that are too low and too high that involve the decomposition of asphaltenes and are accompained by very low pre-exponential factor.Future work may focus on reducing the empirical nature of this mechanism.
publishDate 2015
dc.date.issued.spa.fl_str_mv 2015
dc.date.accessioned.spa.fl_str_mv 2019-07-02T11:19:19Z
dc.date.available.spa.fl_str_mv 2019-07-02T11:19:19Z
dc.type.spa.fl_str_mv Trabajo de grado - Maestría
dc.type.driver.spa.fl_str_mv info:eu-repo/semantics/masterThesis
dc.type.version.spa.fl_str_mv info:eu-repo/semantics/acceptedVersion
dc.type.content.spa.fl_str_mv Text
dc.type.redcol.spa.fl_str_mv http://purl.org/redcol/resource_type/TM
status_str acceptedVersion
dc.identifier.uri.none.fl_str_mv https://repositorio.unal.edu.co/handle/unal/55429
dc.identifier.eprints.spa.fl_str_mv http://bdigital.unal.edu.co/50838/
url https://repositorio.unal.edu.co/handle/unal/55429
http://bdigital.unal.edu.co/50838/
dc.language.iso.spa.fl_str_mv spa
language spa
dc.relation.ispartof.spa.fl_str_mv Universidad Nacional de Colombia Sede Medellín Facultad de Minas Escuela de Química y Petróleos
Escuela de Química y Petróleos
dc.relation.references.spa.fl_str_mv Urán Castaño, Laura Cristina (2015) Coke formation during thermal cracking of a heavy crude oil. Maestría thesis, Universidad Nacional de Colombia - Sede Medellín.
dc.rights.spa.fl_str_mv Derechos reservados - Universidad Nacional de Colombia
dc.rights.coar.fl_str_mv http://purl.org/coar/access_right/c_abf2
dc.rights.license.spa.fl_str_mv Atribución-NoComercial 4.0 Internacional
dc.rights.uri.spa.fl_str_mv http://creativecommons.org/licenses/by-nc/4.0/
dc.rights.accessrights.spa.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv Atribución-NoComercial 4.0 Internacional
Derechos reservados - Universidad Nacional de Colombia
http://creativecommons.org/licenses/by-nc/4.0/
http://purl.org/coar/access_right/c_abf2
eu_rights_str_mv openAccess
dc.format.mimetype.spa.fl_str_mv application/pdf
institution Universidad Nacional de Colombia
bitstream.url.fl_str_mv https://repositorio.unal.edu.co/bitstream/unal/55429/1/1020414792.2015.pdf
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bitstream.checksum.fl_str_mv 9647e107d326f27d5ba664505fdb5ca7
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repository.name.fl_str_mv Repositorio Institucional Universidad Nacional de Colombia
repository.mail.fl_str_mv repositorio_nal@unal.edu.co
_version_ 1814089901305495552
spelling Atribución-NoComercial 4.0 InternacionalDerechos reservados - Universidad Nacional de Colombiahttp://creativecommons.org/licenses/by-nc/4.0/info:eu-repo/semantics/openAccesshttp://purl.org/coar/access_right/c_abf2Molina, AlejandroUrán Castaño, Laura Cristinae56953c4-3be4-4b68-9f97-ef5fa567e0033002019-07-02T11:19:19Z2019-07-02T11:19:19Z2015https://repositorio.unal.edu.co/handle/unal/55429http://bdigital.unal.edu.co/50838/A pseudo-mechanism for the production of coke during the thermal cracking of a Colombian heavy crude oil was proposed based on thermal cracking experiments carried out at TGA and at horizontal tube furnace at atmospheric conditions. In-situ combustion (ISC) is a thermal method that improves the recovery of heavy crude oils and involves complex phenomena such as heat and mass transfers, low-temperature oxidation of the liquid phase (LTO), and cracking reactions that yield coke, a carbonaceous residue that, after high-temperature oxidation (HTO) produces the heat that reduces the oil viscosity increasing the recovery factor. During cracking experiments, Ottawa sand was mixed with crude oil, or with a mixture of maltenes and asphaltenes extracted from that oil, and placed under nitrogen atmosphere and heated at 2oC/min up to di_erent reaction temperatures (300oC, 350oC, 400oC and 450oC) at atmospheric pressure conditions. Even tough atmospheric pressure conditions is not a realistic condition as oil reservoirs operate above atmospheric pressure, this study as part of a bigger project to study ISC it was the _rst that develop a setup and a methodolody able to study ISC reactions. After the _rst approximation that this study made, further work will be carried out to study ISC process at more realistic conditions. This study found that the main cracking products were volatiles that could be condensables and non-condensables and a solid residue. Proximate, elemental, GC-MS and SIMDIS analysis were performed to establish the composition of the cracking products, and to determine the advance in the cracking reactions. During cracking experiments each oil fraction yielded lower- and heavier-molecular weight products. e.g. maltenes yielded gas (mainly composed by methane CH4), distillables (a condensable fraction with maximum 18 carbons), low-molecular-weight maltenes (LMWM, a condensable fraction with maximum 28 carbons, that results from the cracking of maltenes and asphaltenes), and asphaltenes. Whereas asphaltenes leaded to coke formation and to LMWM and gases. The proposed pseudo-mechanism considers the formation of lower- and heavier molecules, separates the evaporation process from the thermal cracking, and proposed new pseudocomponents such as Maltenes* that represents the maltenes fraction after the evaporation process and the one available for thermal cracking, and LMWM that is an upgraded cracking product of the cracking of maltenes* and asphaltenes that had a yield of 0.28 g/gtot. Furthermore, the proposed pseudo-mechanism proposes kinetic parameters for the thermal cracking of a Colombian heavy crude oil under in-situ combustion conditions at atmospheric pressure. The kinetic parameter were optimized by minimizing the sum of square error (SSE) between the experimental and calculated yields. A good coe_cient of determination was obtained, (R2=0; 97), using _rst order kinetic parameters. The physical interpretation of the value of kinetic parameters is complicated given the rather empirical approach used to find the kinetic parameters, it is important to note that most parameters in particular activation energies have values typical for chemical-controlled process, exceptions to this are the activation energies 26.4 and 9760 kJ/mol that are too low and too high that involve the decomposition of asphaltenes and are accompained by very low pre-exponential factor.Future work may focus on reducing the empirical nature of this mechanism.Resumen: Se propuso un pseudo-mecanismo para la formación de coque durante el craqueo térmico de un crudo pesado, este pseudo-mecanismo se basa en resultados de pruebas de craqueo térmico llevadas a cabo en TGA y horno horizontal usando como muestra un crudo pesado colombiano. La combustión in situ (CIS) es un método térmico que mejora el factor de recobro de crudos pesados, envolviendo fenómenos complejos como la transferencia de calor y de masa, oxidación a baja temperatura de la fase líquida, reacciones de craqueo que terminan en la producción de coque, un residuo carbonoso que, después de una oxidación a alta temperatura produce el calor necesario para reducir la viscosidad del crudo y con esto, extraerlo más fácilmente incrementando su factor de recobro. Durante los experimentos de craqueo, se mezcló arena Ottawa con crudo, con máltenos o asfáltenos extraídos del crudo, la mezcla se sometió a una atmosfera inerte compuesta de nitrógeno y calentada a 2oC/min hasta diferentes temperaturas (300oC, 350oC, 400oC y 450oC). Este estudio encontró que los principales productos del craqueo térmico fueron condensables, fracciones no-condensables y un residuo sólido. Análisis próximo, elemental, GC-MS y SIMDIS fueron aplicados con el fin de establecer la composición de los productos de craqueo y determinar el avance de las reacciones. Durante los experimentos de craqueo cada fracción del crudo (máltenos y asfáltenos) produjo especies de más alto y más bajo peso molecular. Por ejemplo, los máltenos produjeron fracciones no condensables (principalmente compuesto por metano CH4), destilables (una fracción condensable compuesta de especies de máximo 18 carbonos), máltenos de bajo peso molecular (LMWM, una fracción condensable compuesta de especies de máximo 28 carbonos) y asfáltenos. Los asfáltenos formaron coque, LMWM y gases. El pseudo-mecanismo de reacción considera la formación de especies de alto y bajo peso molecular, separa el proceso de destilación del proceso de craqueo térmico y propone nuevos pseudo-componentes como Máltenos*, que representa la fracción de máltenos luego de un proceso de evaporación y que es la fracción disponible para el proceso de craqueo térmico; también LMWM que es una especie mejorada, producto del craqueo térmico de máltenos* y asfáltenos que tuvo un rendimiento de 0.28 g/gtot. El pseudomecanismo de reacción también propone parámetros cinéticos para el craqueo térmico de un crudo pesado colombiano bajo condiciones de combustión in situ a presión atmosférica. Los parámetros cinéticos se optimizaron minimizando la suma del error cuadrático (SSE) entre los rendimientos experimentales y calculados. Un buen coeficiente de correlación, (R2=0; 97), se encontró usando cinéticas de primer orden. Las energías de activación tuvieron valores que variaron entre 2; 65 x 104 y 9; 67 x 109 J/mol, mientras que los factores pre-exponenciales tomaron valores entre 2; 45 x 10-2 to 1; 07 x 1011s-1Maestríaapplication/pdfspaUniversidad Nacional de Colombia Sede Medellín Facultad de Minas Escuela de Química y PetróleosEscuela de Química y PetróleosUrán Castaño, Laura Cristina (2015) Coke formation during thermal cracking of a heavy crude oil. Maestría thesis, Universidad Nacional de Colombia - Sede Medellín.66 Ingeniería química y Tecnologías relacionadas/ Chemical engineeringIn-situ combustionThermal crackingCoke formationKinetic pseudo-mechanismLowmolecular-weight maltenes (LMWM)Combustión in situCraqueo térmicoFormación de coquePseudo-mecanismo de reacciónMáltenos de bajo peso molecular (LMWM)Coke formation during thermal cracking of a heavy crude oilTrabajo de grado - Maestríainfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/acceptedVersionTexthttp://purl.org/redcol/resource_type/TMORIGINAL1020414792.2015.pdfTesis de Maestría en Ingeniería - Ingeniería Químicaapplication/pdf4357328https://repositorio.unal.edu.co/bitstream/unal/55429/1/1020414792.2015.pdf9647e107d326f27d5ba664505fdb5ca7MD51THUMBNAIL1020414792.2015.pdf.jpg1020414792.2015.pdf.jpgGenerated Thumbnailimage/jpeg3397https://repositorio.unal.edu.co/bitstream/unal/55429/2/1020414792.2015.pdf.jpg361678601b3cfbf8234edfb5166be0bdMD52unal/55429oai:repositorio.unal.edu.co:unal/554292023-10-10 19:33:54.829Repositorio Institucional Universidad Nacional de Colombiarepositorio_nal@unal.edu.co