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Annual Meeting October 24, 2002

CHEMICAL REACTION ENGINEERING LABORATORY Introductory Remarks Milorad P. Dudukovic and M.H. Al-Dahhan. Annual Meeting October 24, 2002. S1. CHEMICAL REACTION ENGINEERING LABORATORY. OUTLINE. Washington University (WU) and the School of Engineering and Applied Science (SEAS)

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Annual Meeting October 24, 2002

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  1. CHEMICAL REACTION ENGINEERING LABORATORYIntroductory RemarksMilorad P. Dudukovic and M.H. Al-Dahhan Annual MeetingOctober 24, 2002 S1

  2. CHEMICAL REACTION ENGINEERING LABORATORY OUTLINE • Washington University (WU) and the School of Engineering and Applied Science (SEAS) • Chemical Reaction Engineering Laboratory (CREL) • CREL Active Research Areas • Future Research Initiatives • Events for the Day S2

  3. Selected Facts • 6,509 undergraduates • 5,579 graduate and professional students, • 1,384 part-time students • Washington University offers more than 90 programs and nearly 1,500 courses in a broad spectrum of traditional and interdisciplinary majors. • $1,104,962,000 million in revenue S3

  4. CHEMICAL REACTION ENGINEERING LABORATORY Raw Materials Chemical Transformation Materials with New Properties • Petroleum & Petrochemicals • Chemicals • Materials • Biotechnology • Semiconductor • Etc. Proper Engineering of Kinetics + Transport Interactions = Increased Energy & Material Efficiency + Lower Capital Expenditure + Waste Minimization + Lower Operating Cost + Pollution Prevention + Increased Safety S4

  5. CHEMICAL REACTION ENGINEERING LABORATORY CREL Objectives • Education and Training • Advancement of reaction engineering methodology • Application and transfer of improved reaction engineering methodology to industrial practice • Assisting industry in new state-of-the-art technology development S5

  6. CHEMICAL REACTION ENGINEERING LABORATORY S6

  7. feed, Q product, Q REACTION ENGINEERING QUANTIFIES THE INTERACTIONS BETWEEN REACTION KINETICS AND TRANSPORT PHENOMENA (MOMENTUM, MASS AND HEAT TRANSFER) IN VARIOUS REACTOR TYPES. REACTOR EDDY/PARTICLE MOLECULARSCALE REACTOR PERFORMANCE = f ( input & operating variables ; rates ; mixing pattern ) MOLECULAR SCALE (RATE FORMS) Strictly Empirical Mechanism Based Fundamental Elementary Steps EDDY OR PARTICLE SCALE TRANSPORT Empirical Micromixing Models DNS / CFD Empirical Part of Rate Equation Thiele Modulus & Effectiveness Factor Rigorous Multicomponent Transport REACTOR SCALE Ideal Reactors PFR / CSTR Empirical Models Axial Dispersion Phenomenological Models CFD S7

  8. CHEMICAL REACTION ENGINEERING LABORATORY Computer Tomography (CT) • Measurement of the time-averaged cross-sectional phase holdup (volume fraction) distribution • 100 mCi Cs-137 source emitting gamma radiation • NaI(TI) detectors • 5 detectors in a 18o fan-beam (single view), with 7 projectors per detector, for the present experiment (6in. column) • 99 views • 3645 projections were used to reconstruct the solids holdup distribution at each cross-sectional plane • Estimation-Maximization (EM) algorithm used for image reconstruction • Spatial Resolution  2 mm • Density Resolution  0.04 g.cm-3 S8

  9. CHEMICAL REACTION ENGINEERING LABORATORY Devanathan (1990) S9

  10. L S S L CHEMICAL REACTION ENGINEERING LABORATORY INVESTIGATED MULTIPHASE REACTORS LIQUID-SOLID RISER BUBBLE COLUMN STIRRED TANK G G A. RAMMOHAN, V. RANADE N. DEVANATHAN, S. DEGALEESAN Y. YANG, S. KUMAR, B.C. ONG S. ROY, A. KEMOUN S10

  11. 1 U1 k 2 U2 CHEMICAL REACTION ENGINEERING LABORATORY EXAMPLES OF REACTOR SCALE MODELS FOR MULTIPHASE CONTACTING IN REACTORS WITH TWO MOVING PHASES IDEAL REACTOR CONCEPTS: A) PLUG FLOW (PFR) 1 U1 k 2 U2 B) STIRRED TANK (CSTR) • AXIAL DISPERSION MODEL • NEED MORE ACCURATE FLOW & MIXING DESCRIPTION VIA • 1) PHENOMENOLOGICAL MODELS • 2) CFD MODELS (EULER-EULER FORMULATION) • 3) MODEL VERIFICATION: HOLDUP DISTRIBUTION AND VELOCITY FIELD S11

  12. 0.4 0.35 Low Pressure Side ( <80 psi) 0.3 6 0.25 20 0.2 Z = 50 cm High Pressure Side (80-100 psi) 0.15 Z = 100 cm 15 0.1 P (a) Z = 150 cm z = 50 cm z = 100 cm 0.05 10 Axial Velocity, cm/s RECYCLE LINE z = 150 cm 0 H O P P E R R I S E R S/L = 0.10 5 P P 611" 0 0 1 2 3 4 5 6 7 911" -5 WATER TANK Radial Position, cm PUMP P EDUCTOR CHEMICAL REACTION ENGINEERING LABORATORY S/L = 0.10 Time-Averaged Solids Holdup 0 1 2 3 4 5 6 7 Radial Position, cm Deffsolids RTD Dzz, Drr  CARPT S12

  13. ks 12 CHEMICAL REACTION ENGINEERING LABORATORY MODELS FOR REACTOR FLOW PATTERN IN LIQUID-SOLID RISER Dsz UL Dsz UL UL US Us 1 Us Dz Deff US 2 kLs Dr 1 kLs kLs kLs 2 TWO ZONE 2-D CONVECTION DIFFUSION ADM S13

  14. CHEMICAL REACTION ENGINEERING LABORATORY Solids Holdup 0.4 Three-Dimensional Simulation 0.35 Ul = 20 cm/s, S/L = 0.15 0.3 0.25 Solids Holdup 0.2 0.15 Simulation: Ul = 20 cm/s; S/L = 0.15 0.1 CT Data: Ul = 20 cm/s; S/L = 0.15 0.05 0 Axial Solids Velocity 0 1 2 3 4 5 6 7 Radial Position, cm 3D Simulation 17 CARPT: Ul = 20 cm/s; S/L = 0.20 Granular Temperature 12 80 7 Axial Solids Velocity, cm/s 70 2 60 50 0 1 2 3 4 5 6 7 -3 40 Granular Temperature, cm2/s2 30 -8 Radial Position, cm 3D Simulation: Ul = 20 cm/s; S/L = 0.15 20 CARPT: Ul = 20 cm/s; S/L = 0.15 10 0 0 1 2 3 4 5 6 7 Radial Position, cm S14

  15. Lagrangian Trace (Ul = 20 cm/s; S/L = 0.15) -505 Trace over 38 s (1900 positions) Z = 125 cm Z = 100 cm t = 60 s t = 65 s t = 70 s Time Average (25 - 100 s) S15

  16. Solid flux from the hopper average time of flight obtained for number of particle visits Detectors to get RTD’s of the sections in the loop Downcomer Scintillation detectors H= 2.2 m Sc-46 radioactive particle ( 150 mm , 2.55 g.cc-3 ) Overall solids flux - Time-of-flight measurements • Solids Mass Flux (Gs) in the downcomer is : • Mean velocity can be calculated as DH = 40 cm GAS-SOLID RISER AND TIME OF FLIGHT MEASUREMENT SET-UP S16

  17. Results : Densitometry Experiments • Solids hold-up lie within the 95% confidence intervals after the modification • Radial solids hold-up profile is flat even near the wall regions • Mean value = 0.59 (with a STD = 0.001) SOLIDS HOLDUP PROFILE IN THE DOWNCOMER AS DETERMINED BY GAMMA DENSITOMETRY S17

  18. Ugriser = 3.2 m/s Ugriser = 4 m/s Number of visits 256 277 Mean RTD (sec) 2.47 1.95 Standard deviation of RTD (sec) 0.34 0.13 Velocity (mean) (m.s-1) 0.16 0.21 Standard deviation of velocity (m.s-1) 0.02 0.01 Overall Solids flux (Kg.m-2.s-1) 26.6 33.7 Standard deviation in solids flux (Kg.m-2.s-1) 1.1 0.5 Results after secondary air introduction: Time of Flight Experiments Residence Time Distribution (RTD) for Superficial Gas Velocity of 3.2 m/s Residence Time Distribution (RTD) for Superficial Gas Velocity of 4 m/s 70 60 Number of CSTR’s in Series = 225 Number of CSTR’s in Series = 53 60 50 50 40 40 Frequency Frequency 30 30 20 20 10 10 0 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Time (sec) Time (sec) SOLIDS RTD IN THE DOWNCOMER AND ESTIMATION OF SOLIDS FLUX IN THE RISER S18

  19. Gas Outlet Gas Inlet CHEMICAL REACTION ENGINEERING LABORATORY BUBBLE COLUMN REACTORS APPLICATIONS • Fischer-Tropsch Synthesis • Synthesis of methanol • Coal hydrogenation • Hydrogenation of oils • Alkylation of methanol, benzene • SO2 removal from tail gas • Effluent treatment • Wet oxidation of effluent sludge • Biotechnological processes • Production of single cell protein • Animal cell culture • Production of biomass • Oxidation • Chlorination BUBBLY FLOW UG < UG_T - low holdup - individual bubbles CHURN-TURBULENT FLOW UG > UG_T - high holdup - large voids S19

  20. 1-eL(r) Dzz uz(r) Drr -R 0 R CHEMICAL REACTION ENGINEERING LABORATORY CARPT-CT Experimental Evidence Indicates For The True Time-Averaged Flow and Backmixing Patterns Transient Convection-Diffusion Equation for Liquid Mixing Gas Holdup Profile Liquid Velocity Profile CARPT Experiments indicate Dzr , Drz ~ 0 • uz<--- Ensemble Averaged Liquid Velocity Measured from CARPT • eL <--- Time Averaged Liquid Holdup from CT Measurements • Dzz, Drr <--- Assumed to be CARPT Measured Diffusivities S20

  21. Comparison of Experimental (Liquid) Tracer Responses with 2D CDM Predictions 1 0.8 0.6 0.4 0.2 0 1 0.8 0.6 0.4 0.2 0 1 0.8 0.6 0.4 0.2 0 1 0.8 0.6 0.4 0.2 0 Detector Level 1 Detector Level 1 Detector Level 2 Detector Level 2 0 100 200 300 400 0 100 200 300 400 0 100 200 300 400 0 100 200 300 400 1 0.8 0.6 0.4 0.2 0 1 0.8 0.6 0.4 0.2 0 Detector Level 3 Detector Level 4 0 100 200 300 400 0 100 200 300 400 1 0.8 0.6 0.4 0.2 0 1 0.8 0.6 0.4 0.2 0 Detector Level 5 Detector Level 6 0 100 200 300 400 Wall Injection at N1 (Run 14.6) UG = 25 cm/s, T = 250 C, P = 5.2 MPa Experimental Model Normalized Intensity CHEMICAL REACTION ENGINEERING LABORATORY 0 100 200 300 400 S21 Time, s

  22. CHEMICAL REACTION ENGINEERING LABORATORY Comparison of Simulated & Experimental Gas Tracer Responses During Liquid Phase Methanol Synthesis Gupta et al., Catalysis Today (2000), 2253, 1-17. S22

  23. Ug = 10 cm/s Dc = 18” Dzz(cm2/s) t (sec) S23 COMPARISON OF COMPUTED (CFDLIB) AND MEASURED Dzz Ug = 12 cm/s Dc = 8” Dzz(cm2/s) t (sec) CHEMICAL REACTION ENGINEERING LABORATORY

  24. Plane including baffles Azimuthally Averaged Velocity vector plot : Particle trajectories Plane at the impeller Motor Calibration Rod Blades r (cm) Plane including baffles Disc Radioactive Particle Detector Baffles r (cm) Kinetic energy CHEMICAL REACTION ENGINEERING LABORATORY CARPT in STR : results at a glance Rammohan et al., Chem. Eng. Research & Design (2001), 79(18), 831-844. S24

  25. G G L CHEMICAL REACTION ENGINEERING LABORATORY PACKED BED WITH TWO PHASE FLOW • SIMULATION ADVANCES • Accounting for particle and reactor scale wetting effect • Prediction of the porosity distribution effect on flow field • Description of multicomponent transport • Ability to simulate periodic operation G G L L L L G G L Jiang et al., AIChE J. (2002), Jiang et al., Catalysis Today (2001) Khadilkar et al., Chem. Eng. Sci. (1999) Trickle-Bed Cocurrent Downflow Packed -Bubble Flow Cocurrent Upflow Packed-Bed Countercurrent Flow S25

  26. FLOW MODELING IN PACKED BEDS Flow Simulation using ‘Engineering Approach’ Discrete Cell Model (DCM) (Jiang et al., 1999; Holub, 1990) Computation Scheme: Non-linear multi-variable minimization Model Capabilities: Porosity distribution / Internal Obstacles / Capillary pressure (surface tension) / Distributor design / Particle initial wetting state (prewetted/nonprewetted) Sample Results: Single-phase flow system: Chem. Engrg. Sci. (2000), 55(10), 1829 Two-phase flow system: Chem. Engrg. Sci. (1999), 54(13), 2409 Flow Simulation using ‘Fundamental Approach’ (CFDLIB) (Jiang et al., 1999; Khadilkar, 1998, Kumar, 1995) Computation Scheme: Non-linear multi-variable minimization Model Capabilities: Porosity distribution / Internal Obstacles / Capillary pressure (surface tension) / Distributor design / Particle initial wetting state (prewetted/nonprewetted) Sample Results: Jiang, et al., Chem. Eng. Sci., 2001, 56(4), 1647 Jiang, et al., Catalysis Today, 2001, 66(2-4), 209 Jiang, et al., AIChE J., 2002, 48(4), 701; 716 S26

  27. CHEMICAL REACTION ENGINEERING LABORATORY CREL Research Initiativesfor which Industrial Partners are being Sought • Oxidation of Liquid Hydrocarbons (LOR) • Clean Energy from Coal • Methane Conversion • Gas-Solid Riser • Trickle Bed Reactor • Coupling Exothermic-Endothermic Reactions in Reverse Flow • Reactive and Catalytic Distillation • Miniaturization of Experimental Reactors in Multiphase Systems • Industrial Tomography and Tracer Studies • Testing of Industrial Scale Bubble Columns S27

  28. Acknowledgement of Significant Past CREL Contributions N. Devanathan - CARPT - Bubble Columns Y. Yang - CARPT - Bubble Columns B.S. Zou - CARPT - Bubble Columns S. Kumar - CT-CARPT - Bubble Columns S. Limtrakul - CT-CARPT - Ebulated Beds B. Sannaes - CARPT - Slurry Bubble Columns S. Degaleesan - CARPT - Bubble Columns J. Chen - CARPT-CT - Bubble Columns, Packed Beds S. Roy - CARPT-CT - Liquid-Solid Riser A. Kemoun - CARPT-CT - Riser, Stirred Tank CARPT-CT B.S. Zhou - Tap Reactor Model S. Pirooz - Plasma Reactors V. Kalthod - Bioreactors H. Erk - Phase Change Regenerators A. Basic - Rotating Packed Bed M. Al-Dahhan - Trickle Beds J. Turner - Fly Ash and Pollution Abatement S. Karur - Computational CRE M. Kulkarni - Reverse Flow in REGAS Z. Xu - Photocatalytic Distillation X. Balakrhishnan - Computational CRE M. Khadilkar - CFD, Models, Trickle Beds Y. Jiang - CFD, Models, Trickle Beds J-H. Lee - Models, Catalytic Distillation Y. Wu - Models (Trickle Beds, Bubble Column) Y. Pan - CFD (Bubble Columns) P. Gupta - Models (Bubble Columns) CFD, Reactor Models & Experiments S28

  29. INDUSTRIAL SPONSORS DURING 2001/2002 ABB LUMMUS AIR PRODUCTS BAYER CHEVRON CONOCO CORNING DOW CHEMICAL DUPONT ELF ATOCHEM ENI TECHNOLOGIES EXXON - MOBIL IFP INTEVEP MITSUBISHI PRAXAIR SASOL SHELL SOLUTIA STATOIL SYNETIX - ICI UOP S29

  30. Sponsors Collaborators CREL WORLD WIDE CONNECTIONS S19 S30

  31. CHEMICAL REACTION ENGINEERING LABORATORY Summary CREL’s tasks • To execute first rate technical work • To enhance reaction engineering of multiphase systems • To provide industrial participants with expertise and tools needed to deal with problems in multiphase systems • To produce first class graduates Tasks of industrial participants • To leverage resources and ensure company support of CREL • To identify areas where our skills and expertise can be used • To explore opportunities for joint research with CREL • To provide employment for our interns and graduates S31

  32. Events of the Day S32

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