A. Jim'enez, Juan Carlos Muñoz Cuartas, S. Avendaño, Leonardo Gómez Bernal
Full waveform inversion (FWI) is a tool for the inversion of seismic data. There are several sources of uncertainty in the results provided by FWI. The quantification of such uncertainties has been studied through the resolution matrix (Res), which rests on a quadratic approximation that interprets the Hessian matrix as the posterior covariance matrix. Despite efforts in the use of Res, there is no published analysis of the uncertainties contained in the full correlation matrix, (R). Our approach leads to build the full R matrix, which, at the end of the day, is the final quantity that includes all the information associated with uncertainties.We focused on uncertainties related to variation in the starting models of the FWI, and thus propose a method to study the full R matrix, which is-called the Density of Correlation Map, D. By using the D map, we found that the highest uncertainty zones in the FWI inverted model are near the sources, the model boundaries, and the interfaces. We argue that D can be a complement for the study and estimation of uncertainties in FWI.
{"title":"Analysis of the covariance matrix in FWI through density of covariance maps","authors":"A. Jim'enez, Juan Carlos Muñoz Cuartas, S. Avendaño, Leonardo Gómez Bernal","doi":"10.29047/01225383.163","DOIUrl":"https://doi.org/10.29047/01225383.163","url":null,"abstract":"Full waveform inversion (FWI) is a tool for the inversion of seismic data. There are several sources of uncertainty in the results provided by FWI. The quantification of such uncertainties has been studied through the resolution matrix (Res), which rests on a quadratic approximation that interprets the Hessian matrix as the posterior covariance matrix. Despite efforts in the use of Res, there is no published analysis of the uncertainties contained in the full correlation matrix, (R). Our approach leads to build the full R matrix, which, at the end of the day, is the final quantity that includes all the information associated with uncertainties.We focused on uncertainties related to variation in the starting models of the FWI, and thus propose a method to study the full R matrix, which is-called the Density of Correlation Map, D. By using the D map, we found that the highest uncertainty zones in the FWI inverted model are near the sources, the model boundaries, and the interfaces. We argue that D can be a complement for the study and estimation of uncertainties in FWI.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"97 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85746403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The subsidence and uplift history of the forearc system of southwestern Colombia and northern Ecuador margin is complex and reveals several stages of deformation. The sequential stratigraphy of the forearc area shows the development of three megasequences (M1 to M3). The basal megasequence corresponds to the basement of the forearc, which was formed at the end of the Mesozoic and at the beginning of the Cenozoic and accreted against the Northwestern part of South America related to the accretion of the Late Cretaceous – Paleoceneoceanic plateau. This accretion occurred in a transpressional regime. The second megasequence is composed by deep water sediments, recording the transition between transpressional to compressional stages of the margin from the Late Eocene to the Middle Miocene. The third megasequence is characterized by shallow water sediments strongly constrained by the compressional stage of the margin and the uplift activity of the structural highs since the Late Miocene up to present. The structural geometry of the margin is characterized by basement thrusts that deformed the forearc crust. Westward, the forearc zone -according to the support of the overriding plate -is divided into mantle wedge and lower plate domains. The margin evolution suggests that the subducting plate geodynamical changes affect strongly the interplate coupling and mantle wedge and produce changes in the subsidence or uplift through the double forearc basin systems.
{"title":"Origin of a double forearc basin: The example of the Tumaco - Manglares basin, Northestern Southamerica","authors":"Eduardo López- Ramos","doi":"10.29047/01225383.161","DOIUrl":"https://doi.org/10.29047/01225383.161","url":null,"abstract":"The subsidence and uplift history of the forearc system of southwestern Colombia and northern Ecuador margin is complex and reveals several stages of deformation. The sequential stratigraphy of the forearc area shows the development of three megasequences (M1 to M3). The basal megasequence corresponds to the basement of the forearc, which was formed at the end of the Mesozoic and at the beginning of the Cenozoic and accreted against the Northwestern part of South America related to the accretion of the Late Cretaceous – Paleoceneoceanic plateau. This accretion occurred in a transpressional regime. The second megasequence is composed by deep water sediments, recording the transition between transpressional to compressional stages of the margin from the Late Eocene to the Middle Miocene. The third megasequence is characterized by shallow water sediments strongly constrained by the compressional stage of the margin and the uplift activity of the structural highs since the Late Miocene up to present. The structural geometry of the margin is characterized by basement thrusts that deformed the forearc crust. Westward, the forearc zone -according to the support of the overriding plate -is divided into mantle wedge and lower plate domains. The margin evolution suggests that the subducting plate geodynamical changes affect strongly the interplate coupling and mantle wedge and produce changes in the subsidence or uplift through the double forearc basin systems.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"15 2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75556036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arnold Garcia, Daniel A Antequera, J. Arango, C. A. Gómez‐Pérez, J. Espinosa
In this paper we present the design problem of helical tubular PhotoBioReactors (PBR) based on energy consumption minimization, using the radius of curvature for the cultivation of microalgae. Computational Fluid Dynamics (CFD) is used to design a configuration of the helical pipeline with minimum energy consumption. We determined how flow direction changes affect energy consumption. Additionally, it was found that the radius of curvature affects the pressure drop in the PBR’s pipe, so a cost function has been developed to solve an optimization problem seeking to obtain the optimum radius of curvature and a helical tubular PBR design with low pumping rates.
{"title":"Helical tubular photobioreactor design using computational fluid dynamics","authors":"Arnold Garcia, Daniel A Antequera, J. Arango, C. A. Gómez‐Pérez, J. Espinosa","doi":"10.29047/01225383.117","DOIUrl":"https://doi.org/10.29047/01225383.117","url":null,"abstract":"In this paper we present the design problem of helical tubular PhotoBioReactors (PBR) based on energy consumption minimization, using the radius of curvature for the cultivation of microalgae. Computational Fluid Dynamics (CFD) is used to design a configuration of the helical pipeline with minimum energy consumption. We determined how flow direction changes affect energy consumption. Additionally, it was found that the radius of curvature affects the pressure drop in the PBR’s pipe, so a cost function has been developed to solve an optimization problem seeking to obtain the optimum radius of curvature and a helical tubular PBR design with low pumping rates.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79799444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Vásquez-Capacho, Gustavo Pérez-Zúñiga, Y. Muñoz, A. Ospino
An alarm management methodology can be proposed as a discrete event sequence recognition problem where time patterns are used to identify the process safe condition, especially in the start-up and shutdown stages. Industrial plants, particularly in the petrochemical, energy, and chemical sectors, require a combined approach of all the events that can result in a catastrophic accident. This document introduces a new layer of protection (super-alarm) for industrial processes based on a diagnostic stage. Alarms and actions of the standard operating procedure are considered discrete events involved in sequences, where the diagnostic stage corresponds to the recognition of a special situation when these sequences occur. This is meant to provide operators with pertinent information regarding the normal or abnormal situations induced by the flow of alarms. Chronicles Based Alarm Management (CBAM) is the methodology used to build the chronicles that will permit to generate the super-alarms furthermore, a case study of the petrochemical sector using CBAM is presented to build the chronicles of the normal startup, abnormal start-up, and normal shutdown scenarios. Finally, the scenario validation is performed for an abnormal start-up, showing how a super-alarm is generated.
{"title":"An additional layer of protection through superalarms with diagnosis capability","authors":"J. Vásquez-Capacho, Gustavo Pérez-Zúñiga, Y. Muñoz, A. Ospino","doi":"10.29047/01225383.168","DOIUrl":"https://doi.org/10.29047/01225383.168","url":null,"abstract":"An alarm management methodology can be proposed as a discrete event sequence recognition problem where time patterns are used to identify the process safe condition, especially in the start-up and shutdown stages. Industrial plants, particularly in the petrochemical, energy, and chemical sectors, require a combined approach of all the events that can result in a catastrophic accident. This document introduces a new layer of protection (super-alarm) for industrial processes based on a diagnostic stage. Alarms and actions of the standard operating procedure are considered discrete events involved in sequences, where the diagnostic stage corresponds to the recognition of a special situation when these sequences occur. This is meant to provide operators with pertinent information regarding the normal or abnormal situations induced by the flow of alarms. Chronicles Based Alarm Management (CBAM) is the methodology used to build the chronicles that will permit to generate the super-alarms furthermore, a case study of the petrochemical sector using CBAM is presented to build the chronicles of the normal startup, abnormal start-up, and normal shutdown scenarios. Finally, the scenario validation is performed for an abnormal start-up, showing how a super-alarm is generated.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"88 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78063325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The solution of the Helmholtz equation is a fundamental step in frequency domain seismic imaging. This paper deals with a numerical study of solutions for 2D Helmholtz equation using a Gaussian radial basis function-generated finite difference scheme (RBFFD). We analyze the behavior of the local truncation error in approximating partial derivatives of the 2D Helmholtz equation solutions when the shape parameter of RBF varies. For discretization, we performed, by means of a classical numerical dispersion analysis with plane waves, a minimization of the error function to obtain local and adaptive near optimal shape parameters according to the local wavelength of the required solution. In particular, the method is applied to obtain a simple and accurate solver by using stencils which seven nodes on hexagonal regular grids, wich mitigate pollution-effects. We validated numerically that the stability and isotropy are enhanced with respect to Cartesian grids. Our method is tested with standard case studies and velocity models, showing similar or better accuracy than finite difference and finite element methods. This is an efficient way for interacting with inverse and imaging problems such as Full Wave Inversion.
{"title":"Optimal shape parameter for meshless solution of the 2D Helmholtz equation","authors":"Mauricio Alejandro Londoño-Arboleda, Hebert Montegranario-Riascos","doi":"10.29047/01225383.178","DOIUrl":"https://doi.org/10.29047/01225383.178","url":null,"abstract":"The solution of the Helmholtz equation is a fundamental step in frequency domain seismic imaging. This paper deals with a numerical study of solutions for 2D Helmholtz equation using a Gaussian radial basis function-generated finite difference scheme (RBFFD). We analyze the behavior of the local truncation error in approximating partial derivatives of the 2D Helmholtz equation solutions when the shape parameter of RBF varies. For discretization, we performed, by means of a classical numerical dispersion analysis with plane waves, a minimization of the error function to obtain local and adaptive near optimal shape parameters according to the local wavelength of the required solution. In particular, the method is applied to obtain a simple and accurate solver by using stencils which seven nodes on hexagonal regular grids, wich mitigate pollution-effects. We validated numerically that the stability and isotropy are enhanced with respect to Cartesian grids. Our method is tested with standard case studies and velocity models, showing similar or better accuracy than finite difference and finite element methods. This is an efficient way for interacting with inverse and imaging problems such as Full Wave Inversion.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75119617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Building geological models (integrating stratigraphic, structural and paleo-environmental 3D models) that allow the interpretation of sand bodies deposited by turbidity currents along submarine canyons or channels, is one of the most useful tools used by geoscientists for the definition of new drilling opportunities in both exploration and development phases. In this context, the integration of methodologies such as sequence stratigraphyand seismic attributes, together with well-log and core information, outline the basis for the interpretation of sand-body lithostratigraphy and chronostratigraphy. Similarly, these models allow the interpreter to reconstruct the depositional environment and deformation history of a sedimentary basin [1]. Based on a series of chronostratigraphic stages, this paper proposes a 3D model for the sedimentation history of the Banquereau Formation.This model is based on the integration of seismic stratigraphy, seismic attribute interpretation and well-log analysis. Also, a set of system tracts and corresponding transgression and regression phases were identified for the sedimentary interval of interest. The available dataset provided the information to identify the geometry and changes in the sedimentation patterns of the stratigraphic sequences from the Tertiary to the present, thus defining a 3D model of the sedimentological and structural architecture of this interval. Last but not least, theresulting 3D stratigraphic model made possible the identification and description of an amalgamated channel complex filling a submarine canyon associated with a fluvio-deltaic setting. This sort of analysis might be used as an analog for similar reservoirs, providing key insights and vital information for decision making.
{"title":"Submarine canyon-fill reconstruction from integrated seismic-stratigraphic analysis – application to Banquereau formation, Scotian basin – offshore Canada.","authors":"Patricia Chajin-Ortiz, E. Illidge, S. Khurama","doi":"10.29047/01225383.119","DOIUrl":"https://doi.org/10.29047/01225383.119","url":null,"abstract":"Building geological models (integrating stratigraphic, structural and paleo-environmental 3D models) that allow the interpretation of sand bodies deposited by turbidity currents along submarine canyons or channels, is one of the most useful tools used by geoscientists for the definition of new drilling opportunities in both exploration and development phases. In this context, the integration of methodologies such as sequence stratigraphyand seismic attributes, together with well-log and core information, outline the basis for the interpretation of sand-body lithostratigraphy and chronostratigraphy. Similarly, these models allow the interpreter to reconstruct the depositional environment and deformation history of a sedimentary basin [1]. Based on a series of chronostratigraphic stages, this paper proposes a 3D model for the sedimentation history of the Banquereau Formation.This model is based on the integration of seismic stratigraphy, seismic attribute interpretation and well-log analysis. Also, a set of system tracts and corresponding transgression and regression phases were identified for the sedimentary interval of interest. The available dataset provided the information to identify the geometry and changes in the sedimentation patterns of the stratigraphic sequences from the Tertiary to the present, thus defining a 3D model of the sedimentological and structural architecture of this interval. Last but not least, theresulting 3D stratigraphic model made possible the identification and description of an amalgamated channel complex filling a submarine canyon associated with a fluvio-deltaic setting. This sort of analysis might be used as an analog for similar reservoirs, providing key insights and vital information for decision making.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75721004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Nieto-Londoño, Carlos Andrés Bustamante-Chaverra, Jhon Anderson Buendía-García, L. Novoa, Joao Alexander García-Lázaro, Geoffrey Viviescas-Ibarra
In order to study shutdown and re-start in heavy crude oil pipelines, a model was developed. It simulates, in a transient state, the behavior of pressure, flow and temperature variables, averaged over the cross-sectional area and as a function of time and the axial coordinate. The model was validated with actual operational data from a test case. Results obtained for different operating points, stopping time, crude properties, topographies and lengths are presented. Additionally, the governing equations are converted to dimensionless expressions in order to obtain the dimensionless numbers relevant to the re-start operation for crude oil pipelines.
{"title":"Thermohydraulic modeling in transient state for evaluation of pipeline shutdown and restart procedures","authors":"C. Nieto-Londoño, Carlos Andrés Bustamante-Chaverra, Jhon Anderson Buendía-García, L. Novoa, Joao Alexander García-Lázaro, Geoffrey Viviescas-Ibarra","doi":"10.29047/01225383.179","DOIUrl":"https://doi.org/10.29047/01225383.179","url":null,"abstract":"In order to study shutdown and re-start in heavy crude oil pipelines, a model was developed. It simulates, in a transient state, the behavior of pressure, flow and temperature variables, averaged over the cross-sectional area and as a function of time and the axial coordinate. The model was validated with actual operational data from a test case. Results obtained for different operating points, stopping time, crude properties, topographies and lengths are presented. Additionally, the governing equations are converted to dimensionless expressions in order to obtain the dimensionless numbers relevant to the re-start operation for crude oil pipelines.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"110 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77637643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arnaldo Verdeza-Villalobos, Y. A. Lenis-Rodas, Antonio Bula-Silvera, J. M. Mendoza-Fandiño, R. Gómez-Vásquez
This work analyzes the use of palm kernel shells (PKS) produced by the Colombian palm oil mill industry, for purposes of fueling a commercial downdraft fixed bed gasifier (Ankur Scientific WGB- 20) designed to operate with wood chips. Operational parameters such as hopper shaking time, ash removal time, and airflow were varied in order to get the highest gasifier performance, computed as the ratio between producer gas chemical energy over biomass feeding energy. Experiments were carried out following a half fraction experimental design 24-1. Since these parameters affect the equivalence ratio (ER), behavior indicators were analyzed as a function of ER. It was found that the shaking time and airflow had a significant effect on higher-heating-value (HHV) and process efficiency, while the removal time is not significant. The highest performance for palm shell was reached at ER=0.35, where the resulting gas HHV and process efficiencies were 5.04 MJ/Nm3 and 58%, respectively.
{"title":"Performance analysis of a commercial fixed bed downdraft gasifier using palm kernel shells","authors":"Arnaldo Verdeza-Villalobos, Y. A. Lenis-Rodas, Antonio Bula-Silvera, J. M. Mendoza-Fandiño, R. Gómez-Vásquez","doi":"10.29047/01225383.181","DOIUrl":"https://doi.org/10.29047/01225383.181","url":null,"abstract":"This work analyzes the use of palm kernel shells (PKS) produced by the Colombian palm oil mill industry, for purposes of fueling a commercial downdraft fixed bed gasifier (Ankur Scientific WGB- 20) designed to operate with wood chips. Operational parameters such as hopper shaking time, ash removal time, and airflow were varied in order to get the highest gasifier performance, computed as the ratio between producer gas chemical energy over biomass feeding energy. Experiments were carried out following a half fraction experimental design 24-1. Since these parameters affect the equivalence ratio (ER), behavior indicators were analyzed as a function of ER. It was found that the shaking time and airflow had a significant effect on higher-heating-value (HHV) and process efficiency, while the removal time is not significant. The highest performance for palm shell was reached at ER=0.35, where the resulting gas HHV and process efficiencies were 5.04 MJ/Nm3 and 58%, respectively.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86197989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A kinetic model was developed to describe FAME production from refined, bleached and deodorized palm oil (RBDPO) in a solvent-free system, using Thermomyces lanuginosus lipase, in free and immobilized form. The limitations of substrate mass transfer, enzymatic inhibition and discontinuous feeding of alcohol were considered. The kinetic model for the enzyme in free and immobilized form was validated experimentally, under the same process conditions (34°C, 0.145mg protein/g oil, 4.1:1 Methanol: Oil molar ratio). The kinetic model predicted a FAME content of 73.47 wt % at 9 hours, with a relative error of 0.140% using the enzyme in free form, while the FAME content predicted by the kinetic model was 47.04 wt % at 9 hours with a relative error of 0.026 using the enzyme in immobilized form. The decrease in the percentage of esters using the enzyme in immobilized form was attributed to limitations by external mass transfer.
{"title":"Kinetic model for FAME production using inmobilized Lipase in a solvent- free system","authors":"John Henry Castro Posada, A. A. R. Colorado","doi":"10.29047/01225383.129","DOIUrl":"https://doi.org/10.29047/01225383.129","url":null,"abstract":"A kinetic model was developed to describe FAME production from refined, bleached and deodorized palm oil (RBDPO) in a solvent-free system, using Thermomyces lanuginosus lipase, in free and immobilized form. The limitations of substrate mass transfer, enzymatic inhibition and discontinuous feeding of alcohol were considered. The kinetic model for the enzyme in free and immobilized form was validated experimentally, under the same process conditions (34°C, 0.145mg protein/g oil, 4.1:1 Methanol: Oil molar ratio). The kinetic model predicted a FAME content of 73.47 wt % at 9 hours, with a relative error of 0.140% using the enzyme in free form, while the FAME content predicted by the kinetic model was 47.04 wt % at 9 hours with a relative error of 0.026 using the enzyme in immobilized form. The decrease in the percentage of esters using the enzyme in immobilized form was attributed to limitations by external mass transfer.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76048099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lina Marcela López-Lozano, César Quiñones-Segura, Oscar Rodríguez-Bejarano
Thiophene is a sulfur compound found mostly in gasoline and contributor to air pollution. This paper analyzes UV light photocatalytic desulfurization of model oil using Ag/TiO2. Thiophene concentration in the oil phase was determined by the electrochemical analyzer using Differential Pulse Voltammetry (DPV). The electrochemical experimental works were performed by two methodologies. First, aliquots of the oleic mixture were taken every 30 minutes and the thiophene concentration was measured over 7 hours of degradation. The concentration of thiophene decreased by 37.94%. In the second methodology, the in situ thiophene concentration was determined by DPV, where the reaction mixture was altered by the addition of acetonitrile and a quaternary ammonium salt as solvent-supporting electrolyte system. In this medium, the thiophene concentration was reduced by 43.88% after 4 hours of photocatalytic degradation.
{"title":"Electrochemical monitoring of a photocatalytic desulfurization process of a model liquid fuel","authors":"Lina Marcela López-Lozano, César Quiñones-Segura, Oscar Rodríguez-Bejarano","doi":"10.29047/01225383.180","DOIUrl":"https://doi.org/10.29047/01225383.180","url":null,"abstract":"Thiophene is a sulfur compound found mostly in gasoline and contributor to air pollution. This paper analyzes UV light photocatalytic desulfurization of model oil using Ag/TiO2. Thiophene concentration in the oil phase was determined by the electrochemical analyzer using Differential Pulse Voltammetry (DPV). \u0000The electrochemical experimental works were performed by two methodologies. First, aliquots of the oleic mixture were taken every 30 minutes and the thiophene concentration was measured over 7 hours of degradation. The concentration of thiophene decreased by 37.94%. In the second methodology, the in situ thiophene concentration was determined by DPV, where the reaction mixture was altered by the addition of acetonitrile and a quaternary ammonium salt as solvent-supporting electrolyte system. In this medium, the thiophene concentration was reduced by 43.88% after 4 hours of photocatalytic degradation.","PeriodicalId":10745,"journal":{"name":"CT&F - Ciencia, Tecnología y Futuro","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87090541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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