Hydrodynamic study of a circulating fluidized bed used for biomass gasification between 20 c and 900 c

Transcription

1 Engineering Conferences International ECI Digital Archives Fluidization XV Proceedings Hydrodynamic study of a circulating fluidized bed used for biomass gasification between 20 c and 900 c Sébastien Pecate Université de Toulouse, INPT, Laboratoire de Génie Chimique de Toulouse, 4 allée Émile Monso, Toulouse Cedex 4 - BP 84234, sebastien.pecate@ensiacet.fr Mehrdji HEMATI Université de Toulouse, INPT, Laboratoire de Génie Chimique de Toulouse, 4 allée Émile Monso, Toulouse Cedex 4 - BP Mathieu MORIN Université de Toulouse, INPT, Laboratoire de Génie Chimique de Toulouse, 4 allée Émile Monso, Toulouse Cedex 4 - BP Yilmaz KARA Centre de Recherche et d Innovation Gaz et Energies Nouvelles (CRIGEN), 361 avenue du Président Wilson BP Saint Denis la Plaine CEDEX Groupe ENGIE Sylvie VALIN CEA, LITEN, 17 rue des Martyrs F Grenoble cedex 9, France Follow this and additional works at: Part of the Chemical Engineering Commons Recommended Citation Sébastien Pecate, Mehrdji HEMATI, Mathieu MORIN, Yilmaz KARA, and Sylvie VALIN, "Hydrodynamic study of a circulating fluidized bed used for biomass gasification between 20 c and 900 c" in "Fluidization XV", Jamal Chaouki, Ecole Polytechnique de Montreal, Canada Franco Berruti, Wewstern University, Canada Xiaotao Bi, UBC, Canada Ray Cocco, PSRI Inc. USA Eds, ECI Symposium Series, (2016). This Abstract and Presentation is brought to you for free and open access by the Proceedings at ECI Digital Archives. It has been accepted for inclusion in Fluidization XV by an authorized administrator of ECI Digital Archives. For more information, please contact franco@bepress.com.

2 BIOMASS GASIFICATION IN A CIRCULATING FLUIDIZED BED: HYDRODYNAMIC STUDY BETWEEN 20 C AND 950 C Sébastien Pécate, Mathieu Morin, Mehrdji Hemati

3 GAYA PROJECT OBJECTIVES Building of an industrial process for the Synthetic Natural Gas (SNG) production from biomass Biomass 19/07/2016 Sébastien Pécate 2

4 GAYA PROJECT OBJECTIVES Building of an industrial process for the Synthetic Natural Gas (SNG) production from biomass Biomass LGC Objective : Understanding of the hydrodynamic, thermal and reactive phenomena occuring in the syngas production pilot plant Technology : CFB 19/07/2016 Sébastien Pécate 3

5 EMPLOYED TECHNOLOGY Circulating Fluidized Bed : Heat Transfer Medium Olivine Gasifier (T C) Globally endothermical biomass conversion Energy Consumption Dense Fluidized Bed - Steam Combustor (T C) Solid residue from biomass conversion combustion : Exothermical Reaction Energy Production Transported Bed - Air Heat Transfer Medium Olivine 19/07/2016 Sébastien Pécate 4

6 Circulating fluidized bed designed and built-up at the LGC Toulouse EXPERIMENTAL SETUP Biomass Feeding Gasifier / Combustor : Reactive zones - Electric furnaces 15 and 6 kw : Startup of the installation Carrying of hot hydrodynamic tests - Post-combustion chamber at the outlet Burning all combustible gas Screw feeder Cyclone Gasifier Hopper Vibrating extractor Gasifier Cyclone Combustor Combustor 5

7 Circulating fluidized bed designed and built-up at the LGC Toulouse EXPERIMENTAL SETUP Biomass Feeding Gasifier / Combustor : Reactive zones Standpipe / Dump : Solid circulation Solidflow Cyclone Gasifier Gasifier Cyclone Combustor Standpipe Combustor Solidflow : Circulating solid mass flow rate measurement Screw feeder Hopper Vibrating extractor Dump 6

8 AIR FEEDING IN THE COMBUSTOR H cane Primary Air U I Secondary Air U II U comb = U I + U II 7

9 AIR FEEDING IN THE COMBUSTOR H cane Primary Air U I Secondary Air injection cane height H cane Sets the dense fluidized bed height 15 cm Secondary Air U II U comb = U I + U II 8

10 INDUSTRIAL DEVELOPMENT ISSUES Design/simulation of industrial CFB biomass gasifiers Olivine particle size [ µm] d 3/2 = 280 µm [ µm] d 3/2 = 460 µm Dense fluidized bed hydrodynamic [ µm] d 3/2 = 690 µm properties (U mf, e mf, e) Temperature [ C] Gas nature Air / Steam Proposition of correlations 9

11 I. HYDRODYNAMIC STUDY OF THE GASIFIER MINIMUM FLUIDIZATION VELOCITY U mf T dp when U mf (Steam) => U mf (air) : ρ et µ (Steam) < ρ et µ (Air) Re mf = Ar

12 I. HYDRODYNAMIC STUDY OF THE GASIFIER POROSITY / VOIDAGE Minimum fluidization porosity ε mf : No effect of bed temperature or particle size => ε mf = 0.55 Average porosity ε : ε when But independent of : U-U mf bed temperature particle size 11

13 I. HYDRODYNAMIC STUDY OF THE GASIFIER POROSITY / VOIDAGE ε ε mf = U U mf U mf Ar

14 INDUSTRIAL DEVELOPMENT ISSUES I. Hydrodynamic study of the gasifier Syngas production efficiency Gasifier / Combustor Relative temperature difference Solid flow rate control parameters? Heat transfer medium circulation flow rate 13

15 II. HYDRODYNAMIC STUDY OF THE CFB Bed temperature CFB Solid flow rate Gas velocity in standpipe U S Solid inventory Gas velocity in gasifier U G Air velocity in combustor U comb T T ( C) m p m p (kg) (kg) U G U G (U/U (U/U mf ) mf ) U comb (U/U t ) t ) U S (U/U mf ) Reference Range [20 [20 850] [35 [35 60] 60] [1 [18] 8] [0.4 3] 3] [1 8] 14

16 II. HYDRODYNAMIC STUDY OF THE CFB Bed temperature CFB Solid flow rate Gas velocity in standpipe U S Solid inventory Gas velocity in gasifier U G Air velocity in combustor U comb T T ( C) m p m p (kg) (kg) U G U G (U/U (U/U mf ) mf ) U comb (U/U t ) t ) U S (U/U mf ) Reference Range [20 [20 850] [35 [35 60] 60] [1 [18] 8] [0.4 3] 3] [1 8] 15

17 II. HYDRODYNAMIC STUDY OF THE CFB EFFECT OF THE GAS VELOCITY U comb : 1 Dense fluidized bed 1 1 Three hydrodynamic regimes identified in the combustor : 1) Dense fluidized bed regime 1 16

18 II. HYDRODYNAMIC STUDY OF THE CFB EFFECT OF THE GAS VELOCITY U comb : 2 Turbulent bed Uc Uc Three hydrodynamic regimes identified in the combustor : 2 1) Dense fluidized bed regime 2) Turbulent (transition) bed regime 1 Uc 17

19 II. HYDRODYNAMIC STUDY OF THE CFB EFFECT OF THE GAS VELOCITY U comb : 3 Transported bed Fp max Uc Utr Uc 3Utr Three hydrodynamic regimes identified in the combustor : 2 1) Dense fluidized bed regime 3 2) Turbulent (transition) bed regime 1 3) Transported (circulating) bed regime Uc Utr 18

20 II. HYDRODYNAMIC STUDY OF THE CFB EFFECT OF THE SOLID INVENTORY : H cane = 15 cm = H comb When m p H Gasifier 19

21 II. HYDRODYNAMIC STUDY OF THE CFB EFFECT OF THE SOLID INVENTORY : H cane = 15 cm = H comb When m p H Gasifier P between A and B (driving force of the circulation) Fp max A B 20

22 II. HYDRODYNAMIC STUDY OF THE CFB EFFECT OF THE BED TEMPERATURE : C When bed temperature => Low effect on Utr Utr 21

23 II. HYDRODYNAMIC STUDY OF THE CFB EFFECT OF THE BED TEMPERATURE : C When bed temperature => Air consumption 22

24 Dense fluidized bed tests ( C) CONCLUSION T dp Gas nature Systematic experimental study U mf ε mf ε Proposition of correlations [U mf, ε mf, ε] = f(t, dp, Gas nature) => Design and simulation of industrial gasifiers 23

25 CONCLUSION Circulating fluidized bed tests ( C) Hydrodynamic regimes in the combustor : 3 between dense fluidized bed and transported bed 3 key parameters : gas velocity U comb, solid inventory and bed temperature For U comb and solid inventory Circulating solid flow rate For bed temperature Air consumption 24

26 Thank you for your attention