The production of heavy and extra-heavy oil is challenging because of the rheological properties that crude oil presents due to its high asphaltene content.The upgrading and recovery processes of these unconventional ...The production of heavy and extra-heavy oil is challenging because of the rheological properties that crude oil presents due to its high asphaltene content.The upgrading and recovery processes of these unconventional oils are typically water and energy intensive,which makes such processes costly and environmentally unfriendly.Nanoparticle catalysts could be used to enhance the upgrading and recovery of heavy oil under both in situ and ex situ conditions.In this study,the effect of the Ni-Pd nanocatalysts supported on fumed silica nanoparticles on post-adsorption catalytic thermal cracking of n-C_7 asphaltenes was investigated using a thermogravimetric analyzer coupled with FTIR.The performance of catalytic thermal cracking of n-C_7asphaltenes in the presence of NiO and PdO supported on fumed silica nanoparticles was better than on the fumed silica support alone.For a fixed amount of adsorbed n-C_7asphaltenes（0.2 mg/m～2）,bimetallic nanoparticles showed better catalytic behavior than monometallic nanoparticles,confirming their synergistic effects.The corrected OzawaFlynn-Wall equation（OFW） was used to estimate the effective activation energies of the catalytic process.The mechanism function,kinetic parameters,and transition state thermodynamic functions for the thermal cracking process of n-C_7 asphaltenes in the presence and absence of nanoparticles are investigated.展开更多
In the steam thermal cracking of naphtha,the hydrocarbon stream flows inside tubular reactors and is exposed to flames of a series of burners in the firebox.In this paper,a full three-dimensional computational fluid d...In the steam thermal cracking of naphtha,the hydrocarbon stream flows inside tubular reactors and is exposed to flames of a series of burners in the firebox.In this paper,a full three-dimensional computational fluid dynamics(CFD)model was developed to investigate the process variables in the firebox and reactor coil of an industrial naphtha furnace.This comprehensive CFD model consists of a standard k-εturbulence model accompanied by a molecular kinetic reaction for cracking,detailed combustion model,and radiative properties.In order to improve the steam cracking performance,the model is solved using a proposed iterative algorithm.With respect to temperature,product yield and specially propylene-toethylene ratio(P/E),the simulation results agreed well with industrial data obtained from a mega olefin plant of a petrochemical complex.The deviation of P/E results from industrial data was less than 2%.The obtained velocity,temperature,and concentration profiles were used to investigate the residence time,coking rate,coke concentration,and some other findings.The coke concentration at coil exit was1.9×10^(-3)%(mass)and the residence time is calculated to be 0.29 s.The results can be used as a scientific guide for process engineers.展开更多
A bench-scale fixed fluidized bed reactor was used to study the distribution and quality of productsderived from thermal cracking of VGO. Test results had shown that the space velocity has minor effect onthermal crack...A bench-scale fixed fluidized bed reactor was used to study the distribution and quality of productsderived from thermal cracking of VGO. Test results had shown that the space velocity has minor effect onthermal cracking reaction. The depth of thermal cracking reaction was mainly affected by the reaction temperature.At different reaction temperatures the form of free radicals thus initiated varied, resulting in different productdistribution. At low temperature C10= and C11= olefins dominated in thermally cracked gasoline products,whereas at higher temperature C6=C9= olefins dominated in thermally cracked gasoline products, amongwhich C6 and C7 olefins were mainly composed of 2M1C5= and 2E1C5=. Difference in olefin structure can leadto different reaction pathways of catalytic cycle.展开更多
基金the Natural Sciences and Engineering Research Council of Canada (NSERC)the Department of Chemical and Petroleum Engineering at the Schulich School of Engineering at the University of Calgary
文摘The production of heavy and extra-heavy oil is challenging because of the rheological properties that crude oil presents due to its high asphaltene content.The upgrading and recovery processes of these unconventional oils are typically water and energy intensive,which makes such processes costly and environmentally unfriendly.Nanoparticle catalysts could be used to enhance the upgrading and recovery of heavy oil under both in situ and ex situ conditions.In this study,the effect of the Ni-Pd nanocatalysts supported on fumed silica nanoparticles on post-adsorption catalytic thermal cracking of n-C_7 asphaltenes was investigated using a thermogravimetric analyzer coupled with FTIR.The performance of catalytic thermal cracking of n-C_7asphaltenes in the presence of NiO and PdO supported on fumed silica nanoparticles was better than on the fumed silica support alone.For a fixed amount of adsorbed n-C_7asphaltenes（0.2 mg/m～2）,bimetallic nanoparticles showed better catalytic behavior than monometallic nanoparticles,confirming their synergistic effects.The corrected OzawaFlynn-Wall equation（OFW） was used to estimate the effective activation energies of the catalytic process.The mechanism function,kinetic parameters,and transition state thermodynamic functions for the thermal cracking process of n-C_7 asphaltenes in the presence and absence of nanoparticles are investigated.
基金the support of Bandar-eImam petrochemical company(BIPC),Iran。
文摘In the steam thermal cracking of naphtha,the hydrocarbon stream flows inside tubular reactors and is exposed to flames of a series of burners in the firebox.In this paper,a full three-dimensional computational fluid dynamics(CFD)model was developed to investigate the process variables in the firebox and reactor coil of an industrial naphtha furnace.This comprehensive CFD model consists of a standard k-εturbulence model accompanied by a molecular kinetic reaction for cracking,detailed combustion model,and radiative properties.In order to improve the steam cracking performance,the model is solved using a proposed iterative algorithm.With respect to temperature,product yield and specially propylene-toethylene ratio(P/E),the simulation results agreed well with industrial data obtained from a mega olefin plant of a petrochemical complex.The deviation of P/E results from industrial data was less than 2%.The obtained velocity,temperature,and concentration profiles were used to investigate the residence time,coking rate,coke concentration,and some other findings.The coke concentration at coil exit was1.9×10^(-3)%(mass)and the residence time is calculated to be 0.29 s.The results can be used as a scientific guide for process engineers.
文摘A bench-scale fixed fluidized bed reactor was used to study the distribution and quality of productsderived from thermal cracking of VGO. Test results had shown that the space velocity has minor effect onthermal cracking reaction. The depth of thermal cracking reaction was mainly affected by the reaction temperature.At different reaction temperatures the form of free radicals thus initiated varied, resulting in different productdistribution. At low temperature C10= and C11= olefins dominated in thermally cracked gasoline products,whereas at higher temperature C6=C9= olefins dominated in thermally cracked gasoline products, amongwhich C6 and C7 olefins were mainly composed of 2M1C5= and 2E1C5=. Difference in olefin structure can leadto different reaction pathways of catalytic cycle.
