Operating parameter effects on the solids circulation rate in the CFD simulation of a dual fluidized-bed gasification system

In this paper, a dual fluidized bed has been established. The effect of bed material build-up height and gas velocity on the solid circulation rate of CFB (circulating fluidized bed) and BFB (bubble fluidized bed) has been studied. The results show that the solid circulation rate is increased with the increasing of gas velocity Uc and the bed material build-up height. Bed material build-up height of BFB and CFB is changed with the changing of gas velocity Uc. The bed material heights of CFB and BFB have been also investigated in this experiment.

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Prediction of Solids Circulation Rate of Cork Particles in an Ambient-Pressure Pilot-Scale Circulating Fluidized Bed

Industrial & Engineering Chemistry Research ◽

10.1021/ie8001843 ◽

2009 ◽

Vol 48 (1) ◽

pp. 134-141

Author(s):

Yue Huang ◽

Richard Turton ◽

Parviz Famouri ◽

Edward J. Boyle

Keyword(s):

Fluidized Bed ◽

Circulating Fluidized Bed ◽

Ambient Pressure ◽

Pilot Scale ◽

Circulation Rate ◽

Solids Circulation Rate

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Fluid-Dynamic Investigations in a Scaled Cold Model for a Dual Fluidized Bed Biomass Steam Gasification Process: Solid Flux Measurements and Optimization of the Cyclone

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.1394 ◽

2007 ◽

Vol 5 (1) ◽

Cited By ~ 9

Author(s):

Andreas Kreuzeder ◽

Christoph Pfeifer ◽

Hermann Hofbauer

Keyword(s):

Fluidized Bed ◽

Circulating Fluidized Bed ◽

Separation Efficiency ◽

Fluid Dynamic ◽

Steam Gasification ◽

Circulation Rate ◽

Cold Model ◽

Gasification Process ◽

Dual Fluidized Bed ◽

Bed Material

Gasification of biomass is an attractive technology for combined heat and power (CHP) production. A dual fluidized bed steam gasifier is in commercial operation at the biomass CHP plant in Guessing/Austria since 2002. For circulating fluidized bed applications the bed material consumption is economically crucial. Thus, cyclones for circulating fluidized beds need to be designed properly. Some erosion and caking in the cyclone of the gasifier could be observed with increasing hours of operation. The influences of these effects as well as the influence of the solid circulation rate between the two units on the separation efficiency were investigated by fluid-dynamic investigations using a scaled cold model. The results show that due to erosion and caking elutriation rates are increased, especially for smaller particles. However, the cyclone achieves fractional separation efficiencies of more than 99.9%.

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The control of bed height and solids circulation rate in the standpipe of a cold flow circulating fluidized bed

Powder Technology ◽

10.1016/j.powtec.2005.01.002 ◽

2005 ◽

Vol 150 (3) ◽

pp. 176-184 ◽

Cited By ~ 8

Author(s):

Juchirl Park ◽

Yue Huang ◽

Richard Turton ◽

Parviz Famouri ◽

Edward J. Boyle

Keyword(s):

Fluidized Bed ◽

Circulating Fluidized Bed ◽

Circulation Rate ◽

Cold Flow ◽

Bed Height ◽

Solids Circulation Rate

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A method for estimating the solids circulation rate in a closed-loop circulating fluidized bed

Powder Technology ◽

10.1016/s0032-5910(01)00353-9 ◽

2001 ◽

Vol 121 (2-3) ◽

pp. 213-222 ◽

Cited By ~ 33

Author(s):

Shantanu Roy ◽

Abdenour Kemoun ◽

Muthanna Al-Dahhan ◽

M.P Dudukovic

Keyword(s):

Fluidized Bed ◽

Closed Loop ◽

Circulating Fluidized Bed ◽

Circulation Rate ◽

Solids Circulation Rate

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Fluidized Bed Steam Gasification of Solid Biomass - Performance Characteristics of an 8 MWth Combined Heat and Power Plant

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.1398 ◽

2007 ◽

Vol 5 (1) ◽

Cited By ~ 18

Author(s):

Tobias Pröll ◽

Reinhard Rauch ◽

Christian Aichernig ◽

Hermann Hofbauer

Keyword(s):

Power Plant ◽

Water Content ◽

Fluidized Bed ◽

Circulating Fluidized Bed ◽

Measurement Data ◽

Combined Heat And Power ◽

Steam Gasification ◽

Plant Performance ◽

Circulation Rate ◽

Dual Fluidized Bed

The work focuses on a dual fluidized bed gasification technology that is successfully operated for combined heat and power production at a scale of 8 MWth in Guessing/Austria since 2002. The reactor concept consists of a circulating fluidized bed system with a steam-fluidized bubbling bed integrated into the solids return loop. Accompanying the operation of the commercial scale plant, parameter models have been developed and validated by comparison to measured data. As the models naturally fulfill mass and energy balances, the simulation also allows the validation of measurement data. The behaviour of the plant is studied by carrying out variations of selected parameters. Evaluation of different plant operation cases yields correlations between process variables. The solids circulation rate is shown versus riser exit velocity. Fuel water content and gasification temperature significantly influence global plant performance. Simulation predicts the efficiency of the existing power plant in optimized operation. Finally, part load behaviour is investigated and performance maps of the CHP plant are presented. High fuel water content at high gas engine load results in high gas velocities in the riser (erosion limit) and higher heat ratio in the produced energy. It is concluded that CHP-concepts based on fluidized bed steam gasification can reach high electric efficiencies and high overall fuel utilization rates even at small plant capacities of about 10 MWth.

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