A comprehensive process model is proposed to simulate the steam gasification of biomass in a bubbling fluidized bed reactor using Aspen Plus simulator. The models are implemented external FORTRAN codes for hydrodynamic and reaction kinetic calculations. Governing equations rates char water-gas shift reactions obtained from experimental investigations literature. Experimental results at differen...

Modeling and measurement of bubble size in a rotating fluidized bed (RFB) were conducted. The model for predicting the bubble growth in RFB has been proposed based on the following concepts: (i) local centrifugal acceleration and excess gas velocity are considered as the parameters in the radial direction, and (ii) bubble volume flow locally changes depending on the radial distance. Bubbling be...

Coal is a major energy source, and on the other hand coal is a source of pollution. Some of the important environmental issues related to use of coal in energy production are the release of sulphur dioxide (SO2). SO2 is a precursor to acid rain, responsible for atmospheric pollution and damage to human health. Therefore, investigations and development of technologies promising low SO2 emission ...

Dechlorination of 2,4,6-trichlorophenol was performed within a magnetically stabilized fluidized bed (MSFB), containing a palladized iron (Pd/Fe) catalyst entrapped within alginate beads. Kinetic parameters of this multistep reaction yielding phenol as a final product were preliminarily defined in a batch system using four different intermediates as substrates for Pd/Fe catalyzed dechlorination...

Particles distributions along a conical fluidized bed were predicted by an alternative arrangement of the minimum fluidization velocity equation. The proposed approach introduces two new equations which present the particle diameter in the bed as function of: height in the bed (Z), angle of inclination of the fluidized bed wall (θ), input flow rate (Qo), and gas distributor diameter (Do, 2ro). ...

The application of an external magnetic field on a fluidized bed of ferromagnetic particles is well known in a conventional two-phase, gas–solid or liquid–solid fluidization. The external magnetic field significantly changes the fluidized bed fluid-dynamic behavior and if creatively used may enhance the bed performance. In this paper, a theoretical fluid-dynamic model describing behavior of a G...

the excellent performance of fluidized bed heat exchangers is due to the interaction between particles and heat transfer surface and to the mixing effects in the viscous sublayer. in this paper, the results of experimental investigations on heat transfer for a wide range of newtonian and non-newtonian (shear-thinning power law) fluids are presented. new design equations have been developed for ...

High-sodium lignite from the Freedom mine in North Dakota was tested in a Transport Gasifier at the Power Systems Development Facility (PSDF). The tests occurred in October 2003 and August 2004 for a total of 445 hours of operation. Due to its high sodium content, the Freedom mine lignite presented unusual challenges to gasifier operations. This paper discusses high-sodium lignite gasification ...

This paper describes an experimental study on the extent of capture efficiency in a fluidized bed system under controlled conditions. Using aerosols as tracer compound, the capture efficiency in a fluidized bed was quantitatively measured as a function of contact distance (time). The paper presents the experimental technique as well as the results relating the capture efficiency to the bed hydr...

several investigations have been devoted towards understanding the coating process in fluidized beds. most of these studies focused on spraying liquid droplets over the bed. however, due to the complexity of these systems, more investigations are still required to quantify the effect of operating conditions on the coating criteria. the present work aims at fundamentally understanding and precis...