ICES Black Liquor Gasification Research

Fluidized Bed Steam Reformer Modeling

A fluidized bed black liquor steam reformer is a very complex reactor. Several bundles of horizontal heat exchange tubes within the bed, introduction of a fuel that vaporizes and locally increases the gas volume, bed growth as the particles become coated by the material remaining after conversion, plus the complex chemistry of the conversion itself make for a very challenging system to model. Reaction Engineering Internaional is developing a model of the full-scale steam reformer at Georgia-Pacific's Big Island mill. The University of Utah has developed a cold flow model of the small scale steam reformer in the ICES gasification research system. Details of these efforts are below.

Computational Modeling of a Full-Scale Fluidized Bed Steam Reformer

Reaction Engineering International has developed a "1½-D" model of the fluidized bed black liquor steam reformer at Georgia-Pacific's Big Island mill. The model is a three-phase countercurrent backmixing model that takes into account vertical temperature and concentration gradients and downflow near the wall. The model for the entire Big Island reactor describes the fluid dynamics, chemistry and heat transfer in the reactor. Details of the system, such as interaction between bubbles and the pulsed heater tube bundles, are estimated from the correlations for heat exchange tubes in fluidized bed combustors. The model has been used to predict the overall performance of the Big Island system and has been a useful tool for gaining insight into system behavior.

In addition to REI's in-house modeling activities, REI and the University of Utah are collaborating with DOE's National Energy Technology Laboratory (NETL) to develop a computational fluid dynamics (CFD) model of the Big Island system. Development of the fluid dynamics portion of the model, coding and and preparation associated results and visualizations are all taking place at NETL. REI and the University of Utah, as well as Georgia-Pacific and MTCI, are providing input and feedback on other aspects of the model, such as liquor injection, conversion chemistry and bed particle size development.

Cold Flow Modeling of the University of Utah Fluidized Bed Steam Reformer

The University of Utah has designed and constructed a Plexiglas cold flow model of the pressurized steam reformer housed in the University's Gasification Research System. Appropriate scaling conventions were followed, and the behavior of the cold flow model accurately represents the fluid dynamics of the real system when it is operating under standard conditions. Initially, the cold flow model was developed as a tool to aid in design of the real system. More recently, however, the cold flow model has been used to gather quantitative data to help validate the computational models being developed at REI and NETL. Novel experimental techniques to measure bubble frequency, average bubble voidage and heat transfer efficiency in the tube bundle region of the cold flow model have been developed and maps of these characteristics throughout the tube bundle regions have been created.




Black Liquor Gasification Primer ICES Gasification Research • Gasification Research Facility • Fluidized Bed Steam Reforming - Experimental Research - Modeling Activities - Reports • Entrained-flow Gasification - Experimental Research - Reports Contact Information	Fluidized Bed Steam Reformer Modeling A fluidized bed black liquor steam reformer is a very complex reactor. Several bundles of horizontal heat exchange tubes within the bed, introduction of a fuel that vaporizes and locally increases the gas volume, bed growth as the particles become coated by the material remaining after conversion, plus the complex chemistry of the conversion itself make for a very challenging system to model. Reaction Engineering Internaional is developing a model of the full-scale steam reformer at Georgia-Pacific's Big Island mill. The University of Utah has developed a cold flow model of the small scale steam reformer in the ICES gasification research system. Details of these efforts are below. Computational Modeling of a Full-Scale Fluidized Bed Steam Reformer Reaction Engineering International has developed a "1½-D" model of the fluidized bed black liquor steam reformer at Georgia-Pacific's Big Island mill. The model is a three-phase countercurrent backmixing model that takes into account vertical temperature and concentration gradients and downflow near the wall. The model for the entire Big Island reactor describes the fluid dynamics, chemistry and heat transfer in the reactor. Details of the system, such as interaction between bubbles and the pulsed heater tube bundles, are estimated from the correlations for heat exchange tubes in fluidized bed combustors. The model has been used to predict the overall performance of the Big Island system and has been a useful tool for gaining insight into system behavior. In addition to REI's in-house modeling activities, REI and the University of Utah are collaborating with DOE's National Energy Technology Laboratory (NETL) to develop a computational fluid dynamics (CFD) model of the Big Island system. Development of the fluid dynamics portion of the model, coding and and preparation associated results and visualizations are all taking place at NETL. REI and the University of Utah, as well as Georgia-Pacific and MTCI, are providing input and feedback on other aspects of the model, such as liquor injection, conversion chemistry and bed particle size development. Cold Flow Modeling of the University of Utah Fluidized Bed Steam Reformer The University of Utah has designed and constructed a Plexiglas cold flow model of the pressurized steam reformer housed in the University's Gasification Research System. Appropriate scaling conventions were followed, and the behavior of the cold flow model accurately represents the fluid dynamics of the real system when it is operating under standard conditions. Initially, the cold flow model was developed as a tool to aid in design of the real system. More recently, however, the cold flow model has been used to gather quantitative data to help validate the computational models being developed at REI and NETL. Novel experimental techniques to measure bubble frequency, average bubble voidage and heat transfer efficiency in the tube bundle region of the cold flow model have been developed and maps of these characteristics throughout the tube bundle regions have been created.