The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform

Torleif Weydahl - One of the best experts on this subject based on the ideXlab platform.

  • pursuing the pre combustion ccs route in oil refineries the impact on Fired Heaters
    Applied Energy, 2013
    Co-Authors: Torleif Weydahl, Jamal Jamaluddin, Morten Seljeskog, Rahul Anantharaman
    Abstract:

    The work presented in this paper investigates the effect of replacing refinery fuel gas in the radiant section burners of a Fired heater with hydrogen. The aim is to approach pre-combustion CCS to refinery Fired Heaters by identifying the impact on heat-, flow- and radiation distribution in the lower radiant section of the Fired heater when simply switching refinery gas with hydrogen at equivalent power using the same burner geometrics. Additionally the formation of NOx is considered. The investigations are performed using a conventional Reynolds Average Navier Stokes (RANS), Computational Fluid Dynamics (CFD) approach using detailed reaction kinetics consisting of 325 elementary reactions and 53 species. Simplified and generalized furnace and burner geometries are used in the present work. The results show that approximately the same average wall heat flux density is achieved when the refinery fuel is replaced by hydrogen. However, the distribution of heat on the inner surfaces changes. The hydrogen case has, as expected, a higher flame temperature than the base case, nevertheless, the nitric oxide (NOx) emissions are comparable to base case emissions. Several indications point in the direction of a significant contribution to the base case emissions from the less temperature dependent prompt-NO mechanism, which obviously is not contributing to the hydrogen case emissions.

  • Pursuing the pre-combustion CCS route in oil refineries – The impact on Fired Heaters
    Applied Energy, 2013
    Co-Authors: Torleif Weydahl, Jamal Jamaluddin, Morten Seljeskog, Rahul Anantharaman
    Abstract:

    The work presented in this paper investigates the effect of replacing refinery fuel gas in the radiant section burners of a Fired heater with hydrogen. The aim is to approach pre-combustion CCS to refinery Fired Heaters by identifying the impact on heat-, flow- and radiation distribution in the lower radiant section of the Fired heater when simply switching refinery gas with hydrogen at equivalent power using the same burner geometrics. Additionally the formation of NOx is considered. The investigations are performed using a conventional Reynolds Average Navier Stokes (RANS), Computational Fluid Dynamics (CFD) approach using detailed reaction kinetics consisting of 325 elementary reactions and 53 species. Simplified and generalized furnace and burner geometries are used in the present work. The results show that approximately the same average wall heat flux density is achieved when the refinery fuel is replaced by hydrogen. However, the distribution of heat on the inner surfaces changes. The hydrogen case has, as expected, a higher flame temperature than the base case, nevertheless, the nitric oxide (NOx) emissions are comparable to base case emissions. Several indications point in the direction of a significant contribution to the base case emissions from the less temperature dependent prompt-NO mechanism, which obviously is not contributing to the hydrogen case emissions.

  • Performance and NOx emissions of refinery Fired Heaters retrofitted to hydrogen combustion
    Energy Procedia, 2013
    Co-Authors: Mario Ditaranto, Rahul Anantharaman, Torleif Weydahl
    Abstract:

    Pre-combustion CO2Capture applied to industrial sources is an alternative for achieving low CO2emissions at a moderate cost. The potential of the technology to be used as retrofit would further expand its possibilities and could be a real benefit to the industry in terms of achieving CO2emission reduction at relatively low cost. The retrofitting of a boiler to hydrogen fuel bears some difficulties due the significant differences in gas and combustion properties between hydrogen and gaseous hydrocarbon fuels. The present investigations by CFD simulations revealed that the effect on the overall performance of the Fired heater when the fuel is switched to hydrogen is likely to be minimal. The simulations also showed that the NOx-emissions with pure hydrogen fuel is in fact lower than with the refinery fuel gas on mass basis, or similar on ppm basis. This is due to the rather large contribution from the prompt-NO mechanism that obviously is absent in the hydrogen case. Similarly, the effect of switching fuel from methane to hydrogen was investigated experimentally on a lab scale model low NOx burner. The burner, first characterized for methane in terms of emissions and stability, was operated with hydrogen without modification and then by applying a first development modification. The later version of the burner allowed first to solve an overheating issue recognized when in the direct switch configuration. Furthermore, the NOx performance revealed to be even better than with methane as fuel, which contradicts most of the previous studies found on this topic, but confirms the CFD analysis of the full refinery heater simulation. Energetic requirements for post-combustion capture using MEA as solvent, an auto-thermal reformal based pre-combustion scheme with aMDEA as solvent and steam methane reformer with preand post-combustion capture using MEA and aMDEA were evaluated. Post-combustion capture has the least energy requirements followed by auto-thermal reformer based pre-combustion route. It is expected that the pre-combustion route will be competitive when rather than stand-alone H2fuel production for Fired Heaters power production in an integrated reforming combined cycle is also included in the scheme.

Mourhaf Alqassimi - One of the best experts on this subject based on the ideXlab platform.

  • calculation of radiant section temperatures in Fired process Heaters
    Chemical Engineering Science, 2013
    Co-Authors: Hassan Alhaj Ibrahim, Mourhaf Alqassimi
    Abstract:

    Flame and effective gas temperatures are key variables that need to be accurately determined before analysis of heat transfer in the radiant section of Fired Heaters can be meaningfully undertaken. To facilitate the calculation of these temperatures, appropriate equations were derived using two Computer Matlab programmes specially written for the purpose. A third programme was also written for the solution of the derived equations using the Newton-Raphson method. The whole calculation procedure was illustrated by an example worked out for an actual process heater used in a crude oil topping unit.

  • matlab program computes thermal efficiency of Fired heater
    Periodica Polytechnica Chemical Engineering, 2008
    Co-Authors: Hassan Alhaj Ibrahim, Mourhaf Alqassimi
    Abstract:

    Two basic methods are normally employed for the calculation and estimation of the thermal efficiency of Fired Heaters, viz. the direct and the indirect methods, where the net calorific value is used in the former and the gross calorific value is used in the latter. Two Matlab programmes based on these methods were written and applied for the calculation of the thermal efficiency of a crude oil heater. The results are presented in the form of Sankey diagrams.

Mario Ditaranto - One of the best experts on this subject based on the ideXlab platform.

  • Performance and NOx emissions of refinery Fired Heaters retrofitted to hydrogen combustion
    Energy Procedia, 2013
    Co-Authors: Mario Ditaranto, Rahul Anantharaman, Torleif Weydahl
    Abstract:

    Pre-combustion CO2Capture applied to industrial sources is an alternative for achieving low CO2emissions at a moderate cost. The potential of the technology to be used as retrofit would further expand its possibilities and could be a real benefit to the industry in terms of achieving CO2emission reduction at relatively low cost. The retrofitting of a boiler to hydrogen fuel bears some difficulties due the significant differences in gas and combustion properties between hydrogen and gaseous hydrocarbon fuels. The present investigations by CFD simulations revealed that the effect on the overall performance of the Fired heater when the fuel is switched to hydrogen is likely to be minimal. The simulations also showed that the NOx-emissions with pure hydrogen fuel is in fact lower than with the refinery fuel gas on mass basis, or similar on ppm basis. This is due to the rather large contribution from the prompt-NO mechanism that obviously is absent in the hydrogen case. Similarly, the effect of switching fuel from methane to hydrogen was investigated experimentally on a lab scale model low NOx burner. The burner, first characterized for methane in terms of emissions and stability, was operated with hydrogen without modification and then by applying a first development modification. The later version of the burner allowed first to solve an overheating issue recognized when in the direct switch configuration. Furthermore, the NOx performance revealed to be even better than with methane as fuel, which contradicts most of the previous studies found on this topic, but confirms the CFD analysis of the full refinery heater simulation. Energetic requirements for post-combustion capture using MEA as solvent, an auto-thermal reformal based pre-combustion scheme with aMDEA as solvent and steam methane reformer with preand post-combustion capture using MEA and aMDEA were evaluated. Post-combustion capture has the least energy requirements followed by auto-thermal reformer based pre-combustion route. It is expected that the pre-combustion route will be competitive when rather than stand-alone H2fuel production for Fired Heaters power production in an integrated reforming combined cycle is also included in the scheme.

Rahul Anantharaman - One of the best experts on this subject based on the ideXlab platform.

  • pursuing the pre combustion ccs route in oil refineries the impact on Fired Heaters
    Applied Energy, 2013
    Co-Authors: Torleif Weydahl, Jamal Jamaluddin, Morten Seljeskog, Rahul Anantharaman
    Abstract:

    The work presented in this paper investigates the effect of replacing refinery fuel gas in the radiant section burners of a Fired heater with hydrogen. The aim is to approach pre-combustion CCS to refinery Fired Heaters by identifying the impact on heat-, flow- and radiation distribution in the lower radiant section of the Fired heater when simply switching refinery gas with hydrogen at equivalent power using the same burner geometrics. Additionally the formation of NOx is considered. The investigations are performed using a conventional Reynolds Average Navier Stokes (RANS), Computational Fluid Dynamics (CFD) approach using detailed reaction kinetics consisting of 325 elementary reactions and 53 species. Simplified and generalized furnace and burner geometries are used in the present work. The results show that approximately the same average wall heat flux density is achieved when the refinery fuel is replaced by hydrogen. However, the distribution of heat on the inner surfaces changes. The hydrogen case has, as expected, a higher flame temperature than the base case, nevertheless, the nitric oxide (NOx) emissions are comparable to base case emissions. Several indications point in the direction of a significant contribution to the base case emissions from the less temperature dependent prompt-NO mechanism, which obviously is not contributing to the hydrogen case emissions.

  • Pursuing the pre-combustion CCS route in oil refineries – The impact on Fired Heaters
    Applied Energy, 2013
    Co-Authors: Torleif Weydahl, Jamal Jamaluddin, Morten Seljeskog, Rahul Anantharaman
    Abstract:

    The work presented in this paper investigates the effect of replacing refinery fuel gas in the radiant section burners of a Fired heater with hydrogen. The aim is to approach pre-combustion CCS to refinery Fired Heaters by identifying the impact on heat-, flow- and radiation distribution in the lower radiant section of the Fired heater when simply switching refinery gas with hydrogen at equivalent power using the same burner geometrics. Additionally the formation of NOx is considered. The investigations are performed using a conventional Reynolds Average Navier Stokes (RANS), Computational Fluid Dynamics (CFD) approach using detailed reaction kinetics consisting of 325 elementary reactions and 53 species. Simplified and generalized furnace and burner geometries are used in the present work. The results show that approximately the same average wall heat flux density is achieved when the refinery fuel is replaced by hydrogen. However, the distribution of heat on the inner surfaces changes. The hydrogen case has, as expected, a higher flame temperature than the base case, nevertheless, the nitric oxide (NOx) emissions are comparable to base case emissions. Several indications point in the direction of a significant contribution to the base case emissions from the less temperature dependent prompt-NO mechanism, which obviously is not contributing to the hydrogen case emissions.

  • Performance and NOx emissions of refinery Fired Heaters retrofitted to hydrogen combustion
    Energy Procedia, 2013
    Co-Authors: Mario Ditaranto, Rahul Anantharaman, Torleif Weydahl
    Abstract:

    Pre-combustion CO2Capture applied to industrial sources is an alternative for achieving low CO2emissions at a moderate cost. The potential of the technology to be used as retrofit would further expand its possibilities and could be a real benefit to the industry in terms of achieving CO2emission reduction at relatively low cost. The retrofitting of a boiler to hydrogen fuel bears some difficulties due the significant differences in gas and combustion properties between hydrogen and gaseous hydrocarbon fuels. The present investigations by CFD simulations revealed that the effect on the overall performance of the Fired heater when the fuel is switched to hydrogen is likely to be minimal. The simulations also showed that the NOx-emissions with pure hydrogen fuel is in fact lower than with the refinery fuel gas on mass basis, or similar on ppm basis. This is due to the rather large contribution from the prompt-NO mechanism that obviously is absent in the hydrogen case. Similarly, the effect of switching fuel from methane to hydrogen was investigated experimentally on a lab scale model low NOx burner. The burner, first characterized for methane in terms of emissions and stability, was operated with hydrogen without modification and then by applying a first development modification. The later version of the burner allowed first to solve an overheating issue recognized when in the direct switch configuration. Furthermore, the NOx performance revealed to be even better than with methane as fuel, which contradicts most of the previous studies found on this topic, but confirms the CFD analysis of the full refinery heater simulation. Energetic requirements for post-combustion capture using MEA as solvent, an auto-thermal reformal based pre-combustion scheme with aMDEA as solvent and steam methane reformer with preand post-combustion capture using MEA and aMDEA were evaluated. Post-combustion capture has the least energy requirements followed by auto-thermal reformer based pre-combustion route. It is expected that the pre-combustion route will be competitive when rather than stand-alone H2fuel production for Fired Heaters power production in an integrated reforming combined cycle is also included in the scheme.

Hassan Alhaj Ibrahim - One of the best experts on this subject based on the ideXlab platform.

  • calculation of radiant section temperatures in Fired process Heaters
    Chemical Engineering Science, 2013
    Co-Authors: Hassan Alhaj Ibrahim, Mourhaf Alqassimi
    Abstract:

    Flame and effective gas temperatures are key variables that need to be accurately determined before analysis of heat transfer in the radiant section of Fired Heaters can be meaningfully undertaken. To facilitate the calculation of these temperatures, appropriate equations were derived using two Computer Matlab programmes specially written for the purpose. A third programme was also written for the solution of the derived equations using the Newton-Raphson method. The whole calculation procedure was illustrated by an example worked out for an actual process heater used in a crude oil topping unit.

  • Fired Process Heaters
    2010
    Co-Authors: Hassan Alhaj Ibrahim
    Abstract:

    Furnaces are a versatile class of equipment where heat is liberated and transferred directly or indirectly to a solid or fluid mass for the purpose of effecting a physical or chemical change. In industrial practice many and varied types of furnaces are used which may differ in function, overall shape or mode of firing, and furnaces may be classified accordingly on the basis of their function such as smelting or roasting, their shape such as crucibles, shafts and hearths or they may be classified according to their mode of firing into electrical, nuclear, solar, and combustion furnaces. Combustion furnaces are of two general types: Fired Heaters and converters. A converter is a type of furnace in which heat is liberated by the oxidation of impurities or other parts of the material to be heated. Fired Heaters, on the other hand, are furnaces that produce heat as a result of the combustion of fuel. The heat liberated is transferred to the material to be heated directly (in internally-heated furnaces) or indirectly (in externally-heated furnaces). Examples of internally-heated furnaces include submerged Heaters and blast furnaces where a solid mass is heated by a blast of hot gases. Externally-heated furnaces include ovens, fire-tube boilers and tubular Heaters.

  • matlab program computes thermal efficiency of Fired heater
    Periodica Polytechnica Chemical Engineering, 2008
    Co-Authors: Hassan Alhaj Ibrahim, Mourhaf Alqassimi
    Abstract:

    Two basic methods are normally employed for the calculation and estimation of the thermal efficiency of Fired Heaters, viz. the direct and the indirect methods, where the net calorific value is used in the former and the gross calorific value is used in the latter. Two Matlab programmes based on these methods were written and applied for the calculation of the thermal efficiency of a crude oil heater. The results are presented in the form of Sankey diagrams.