2012 University of North Dakota Energy & Environmental Research Center.

Transcription

1 Coal Ash Behavior in Reducing Environments (CABRE) III Freiberg Conference May 21 24, 24, 2012 Josh Stanislowski, Kevin Galbreath, Don McCollor, Bruce Dockter, Scott Tolbert, Jason Laumb, Bob Jensen, Tyler Curran, and Daniel Schwitalla 2012 University of North Dakota Energy & Environmental Research Center.

2 CABRE III Goal Create an advanced model for the prediction of slag and ash behavior in gasification systems. Utilize EERC small pilot-scale gasifiers for the development of the data. Distribute the model in the form of stand-alone software program. Pave the way for SABRE IV (Slag and Ash Behavior in Reducing Environments).

3 Sponsors

4 Work Plan Task 1 Feedstock Characterization Completed Task 2 Laboratory Evaluation of Ash Behavior Completed Task 3 Evaluation of Ash Behavior in Bench- and Pilot- Scale Systems Completed Task 4 Ash Impacts on Gas Cleanup and CO 2 Capture Completed Task 5 Modeling of Ash Behavior Completed Task 6 Model Verification Ongoing Task 7 Reporting Ongoing

5 Summary of CABRE III Program Status Characterization of the sponsor fuels is complete. Center lignite Falkirk lignite Illinois No. 6 Petroleum coke Each fuel has been tested in the entrained-flow gasifier (EFG). Falkirk lignite has been tested in the fluid-bed gasifier (FBG). Analyses of the samples from the EFG and FBG tests have been completed. The CABRE model was completed in spreadsheet form. Development of the model interface is complete. Testing of the model beta version is ongoing.

6 CABRE III Model

7 Phase III Focus Spreadsheet Models Graphical User Interface

8 Small Pilot-Scale Gasifier Testing

9 Small Pilot-Scale Gasification Test Runs Evaluations with sponsor fuels have been completed on EERC small pilot-scale gasifiers: EFG 2750 F (1510 C) 300 psi (20 atm) High-pressure FBG 1800 F (980 C) 1000 psi (68 atm) Focus on ash behavior Nominal feed rate 8 lb/hr

10 Bench-Scale Gasification Tests Summary Fuel Type No. of Days System Run ID Comments Petcoke 5 Entrained flow EFG026 Shakedown to determine how to slag Petcoke 3 Entrained flow EFG035 Successfully completed test run Center 5 Entrained flow EFG028 Successfully completed parametric tests Falkirk 2 Entrained flow EFG027 Frozen slag in bottom of tube Falkirk 3 Entrained flow EFG030 Falkirk 5 Fluid bed FBG011 Successfully completed parametric tests Successfully completed parametric tests Illinois No. 6 2 Entrained flow EFG029 Coal feed difficulties Illinois No. 6 3 Entrained flow EFG035 Successfully completed parametric tests

11 Development of CABRE III Model

12 Model Objectives Partitioning of slag and ash Viscosity models Slag properties Vanadium Mineral transformations Ash deposition Trace element partitioning Model inputs QEMSCAN analysis

13 Model Development Partitioning Partitioning is critical to the model. Determination of partitioning: Full-scale combustion cyclone slags. Full-scale gasifier ash. Bench-scale EFG tests. Bench-scale FBG tests. Partitioning not strongly linked to process conditions. Temperature affects partitioning most.

14 Viscosity Model Test Slag Composition Calculate Viscosity Indicators (5) Slag Database Composition Viscosity (100+ slags) Calculate Viscosity Indicators (5) Calculate Differences: Composition Viscosity Indicators

15 Viscosity Model Calculate Differences: Composition Viscosity Indicators Close Match in Composition? Yes Use Database Slag Viscosity (high confidence) No Close Match in Viscosity Indicators? Yes Use Database Slag Viscosity (some confidence) Use Riboud Viscosity Model No

16 Slag Viscosity Molten slag viscosity is measured in a rotating-bob viscometer.

17 CABRE III Viscosity Model 5.0 Evaluation Falkirk Coal Ash Visco osity, log10 poise Hoy Kal Rib Sch Shaw Urb 1.5 Exp Temperature, C

18 Literature Viscosity Models Av log 10 Mean Difference Between Model and Model Measured Data Hoy Kalmanovich Novak Riboud Schobert Senior Fe 2 O Senior 50/ Senior FeO Shaw Urbain Watt Fereday Modified Watt Fereday Browning, w/s Browning, no S Based on these data, Riboud model the best.

19 Slag Properties Flow Fuel Ash Composition Wall Partitioning Solid Slag Liquid Slag T wall T 250 T surface, gas Slag Composition Gas Heat Flux Slag Properties(T) Slag Flow Viscosity Surface Tension Density Heat Capacity Liquid Solid Conductivity Liquid Solid Impaction Rate (coal + ash) Slag Flow

20 Model Comparisons

21 Partitioning Predictions Falkirk Slag Perc centage CABRE Model Test Run 0 SiO₂ Al₂O₃ Fe₂O₃ TiO₂ P₂O₅ CaO MgO Na₂O K₂O SO₃ Oxide 50 Falkirk Fly Ash 40 Percentag ge CABRE Model Test Run 0 SiO₂ Al₂O₃ Fe₂O₃ TiO₂ P₂O₅ CaO MgO Na₂O K₂O Oxide SO₃

22 Viscosity Predictions Visc cosity, Pa s Falkirk Coal CABRE Model dl CABRE/Riboud Temperature, C

23 CABRE III User Interface

24 New Session

25 Gasifier Definition

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29 Model Results Flow Sheet

30 Model Results

31 Model Results

32 Model Results

33 Deposition

34 Summary CABRE III model works to improve viscosity predictions by determining i the viscosity it of the slag produced d as opposed to using the coal ash chemistry. Viscosity is predicted using tables of experimental data when available, otherwise the Riboud model is used. The beta version of the user interface for CABRE III has been completed and beta testing is under way. This is only the beginning of program development. Many more samples and data sets are needed. Development of the SABRE IV project is under way.

35 Contact Information Energy & Environmental Research Center University of North Dakota 15 North 23rd Street, Stop 9018 Grand Forks, North Dakota World Wide Web: Telephone No. (701) Fax No. (701) Josh Stanislowski, Research Manager