Catalytic ash free coal gasification in a fluidized bed thermogravimetric analyzer

Transcription

1 Engineering Conferences International ECI Digital Archives Fluidization XV Proceedings Catalytic ash free coal gasification in a fluidized bed thermogravimetric analyzer Said Samih Ecole Polytechnique Montreal, Canada, said.samih@polymtl.ca Jamal Chaouki Ecole Polytechnique Montreal, Canada Follow this and additional works at: Part of the Chemical Engineering Commons Recommended Citation Said Samih and Jamal Chaouki, "Catalytic ash free coal gasification in a fluidized bed thermogravimetric analyzer" 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 Catalytic Ash Free Coal Gasification in a Fluidized Bed Thermogravimetric Analyzer Speaker: Said Samih PEARL Group, Prof. Jamal Chaouki WORLD-CLASS ENGINEERING

3 PROBLEMATIC: KINETIC STUDY Problematic: Conventional TGA Limitations Diffusion control Temperature gradient Conventional TGA limitations Poor mixing Low heating rate Low amount of sample (mg) 2

4 CONCEPT OF THE FLUIDIZED BED TGA Scenario #1 (U g = U mf ) Bed weight ΔP Minimum fluidization Scenario #2 (U g = U mf ) Bed and distributor weight P mf 20g 0g ΔP mf P mf 20g 20g P dist. 5g P dist. 5g 25g U mf U g 25g 200g 220g According to the 2nd scenario, the weight of the fluidized bed can be measured by the balance This is how we built the first fluidized bed TGA in the world 3

5 CONCEPT OF THE PSEUDO VARIATION OF THE WEIGHT IN FBTGA The variation of the reactor weight was the same for different initial weights of the bed of 0 g and 25 g This pseudo variation of the weight is due to the pressure drop across the distributor and filter of the reactor 4 Source: Samih, S. and Chaouki, J. (2015), Development of a fluidized bed thermogravimetric analyzer. AIChE J., 61: doi: /aic.14637

6 SOLUTION: KINETIC STUDY Solution: Fluidized bed TGA No Diffusion control Different gasification medium Appropriate mixing Fluidized bed TGA advantages Uniform temperature Enough amount of solid sample (5g) Higher heating rate 5

7 SCHEMATIC OF THE FLUIDIZED BED TGA Gas to GC-FT-IR Heating rate: 50 K/min Fluidizing agent: Gas mixture (5% O2, 95 % N2) Weight measurement: Load cell Gas analyzing: GC and FT-IR Quartz reactor: Diameter: 2.5 cm Height: 15 cm Amount of coal: 5 g Bed material: Silica Sand (40 g) Catalyst: K 2 TiO 3 Differential pressure transducer Pressure transducer Filter Quartz reactor Flexibles Thermocouple Fluidized bed Distributor Flexible for fluidizing gas Furnace Electric resistance Coal particles Source: Samih, S. and Chaouki, J. (2015), Development of a fluidized bed thermogravimetric analyzer. AIChE J., 61: doi: /aic Load cell 6

8 EXPERIMENTAL VALIDATION OF THE FLUIDIZED BED TGA: CALCIUM HYDROXIDE DECOMPOSITION 20 K/min Ar atmosphere Silica Sand: 75 microns Calcium hydroxide: 40 microns Inter and intra-particle diffusion were eliminated by using 4 g in the FBTGA: Ca(OH) 2 decomposition was carried out in one stage Source: Samih, S. and Chaouki, J. (2015), Development of a fluidized bed thermogravimetric analyzer. AIChE J., 61: doi: /aic

9 OBJECTIVES Develop a fluidized bed thermogravimetric analyzer (FBTGA) Study the effect of catalyst (K 2 TiO 3 ) on ash free coal gasification is studied in the new FBTGA 8

10 WORLD ENERGY CONSUMPTION Coal will continue to be the most consumed source of energy worldwide Coal is the most polluting source of energy 9

11 ASH FREE COAL GASIFICATION IN FBTGA Yield (wt. %) Yield (wt. %) b) T = 750 C time (min) Total gas Weight (FBTGA) Temperature ( C) AFC gasification in a fluidized bed TGA: weight loss vs. total product gas 10

12 CATALYST EFFECT ON GASIFICATION HHV (Mj/Nm 3 ) 10 5 CatAFC AFC Coal Carbon conversion (wt.%) CatAFC AFC Coal Temperature ( C) Temperature ( C) Higher high heating value of the product gas at low temperature Higher carbon conversion with potassium catalyst: reaction rate was accelerated 11

13 KINETIC MODELING FROM FBTGA (MINIMUM 22 PARAMETERS) 12

14 CATALYST EFFECT ON WATER GAS SHIFT REACTION Catalyst Activation energy (kj/mol) Reference Fe 2 O 3 /ZrO A. A. Hakeem et al. (2015) Gold/ferrochro me 88.2 G. N. Vajani et al. (2011) 3.5Ni 2K/10Ce O 2 Al 2 O N. A. Pechimuthu et al. (2006) Pt@SiO2 70 Y. Wang et al. (2012) Li/MgO 158 I. Balint et al. (2000) K 2 TiO This work None This work None A. P. Watkinson et al. (1991) & B. J. C. Wurzenberger et al. (2002) 13

15 CATALYST EFFECT ON METHANE REFORMING REACTION Catalyst Activation energy (kj/mol) K-based Reference M. H. Halabi et al. (2010) & M. H. Park et al. (2015) & T. W. Kim et al. (2015) Ni/y-Al2O T. W. Kim et al. (2015) Rh/Al2O3 111 J. Wei et al. (2004) Platinum 114 K. Gosiewski et al. (1999) Ce0.9Gd0.1O2-x (CGO) 153 E. Ramirez-Cabrera et al. (2000) Ni/Mg/K/Al2O3 93 A. M. Robinson et al. (2015) Ni/La/Al2O M. H. Park et al. (2015) Ni/La-Co/Al2O M. H. Park et al. (2015) K 2 TiO This work None 108 This work None A. P. Watkinson et al. (1991) & B. J. C. Wurzenberger et al. (2002) 14

16 GAS YIELDS FROM THE CATALYTIC AFC GASIFICATION IN FBTGA CO 2 Yield (wt.%) Model Experiments CH 4 Yield (wt.%) Model Experiments time (min) time (min) H 2 Yield (wt.%) Model Experiments CO Yield (wt.%) Model Experiments time (min) time (min) Experiments and model results are in good agreement 15

17 CONCLUSION Fluidized bed TGA was developed : The unique FBTGA in the world Effect of catalyst (K 2 TiO 3 )on ash free coal gasification is studied in new FBTGA Novel kinetic parameters were found for CO shift and methane reforming reactions Model and experiments results are in good agreement 16

18 END THANKS FOR YOUR ATTENTION