Black Liquor Research in ChemCom

Transcription

1 Research in ChemCom Rainer Backman Åbo Akademi Process Chemistry Centre Combustion and Materials Chemistry Turku, Finland and Umeå University Energy Technology and Thermal Process Chemistry Umeå, Sweden

2 Research Areas in ChemCom Biomass Waste Characterisation & Conversion Inorganic Material Gas Phase & Emissions Furnace Processes Bed Processes Experiment Modelling Information

3 Research in ChemCom Post Docs PhD Students/ Post Graduates Diploma Students Rainer Backman Dan Boström (UmU) Mikko Hupa Ari Kankkunen (HUT) Bengt-Johan Skrifvars Mikael Forssén Anders Larsson (UmU) Daniel Lindberg Mathias Råberg (UmU) Pasi Miikkulainen (HUT) Gustav Lindberg (UmU)

4 Research Experimental work - Black liquor characterisation - single droplet reactor (ÅAU) - spray characterisation (HUT) - Inorganic reactions and properties - thermal analysis, cell measurements (ÅAU, UmU) Theoretical work - Modeling of melting behavior - CTD Computational ThermoDynamics - Development of thermodynamic models and databases - stand alone models (-dimensional and local models) - submodels for CFD-applications

5 Research Black liquor characterisation Modeling of melting properties Na 2 S oxidation with thermal analysis

6 Research Black liquor characterisation Modeling of melting properties Na 2 S oxidation with thermal analysis

7 Single particle reactor CO 2 CO 2 N 2 SO2 N 2 O 2 CO 2 Ventilation pump pump NO VCR SO 2 CO/CO 2 Filter NO Ventilation

8 ÅAU Database Includes totally 445 black liquors Currently background information available for 272 liquors Pulp process Liquor type Raw material Sulfate 135, sulfite 13, soda 4, Miscellanous 1, Unknown 11 As fired 76, virgin 45, Other background 44, Laboratory liquors 33, Unknown 74 Hardwood 31, softwood 55, mixed wood 16, Unknown 148, Other 22 (Eucalyptus, Bagasse, Straw, Agro, Acacia, Kenaf)

9 All liquors Sulfite Pyrolysis (s) Pyrolysis time (s) All liquors All liquors Max relative swelling (cm3/ g BLS) Pyrolysis time (s) 6 5 All liquors 4 Sulfite Max relative swelling (cm3/ g BLS) Char burning (s) Char burning time (s) All liquors All liquors Max relative swelling (cm3/ g BLS) Char burning time (s) All liquors Sulfite Max relative swelling (cm3/ g BLS) Total combsution (s) Total combustion time (s) All liquors All liquors Max relative swelling (cm3/ g BLS) Total combustion time (s) All liquors Sulfite Max relative swelling (cm3/ g BLS)

10 Sulfate Soda Pyrolysis (s) Pyrolysis time (s) 6 5 All liquors 4 Sulfate Max relative swelling (cm3/ g BLS) Pyrolysis time (s) 6 5 All liquors 4 Soda process Max relative swelling (cm3/ g BLS) Char burning (s) Char burning time (s) All liquors Sulfate Max relative swelling (cm3/ g BLS) Char burning time (s) All liquors Soda process Max relative swelling (cm3/ g BLS) Total combsution (s) Total combustion time (s) All liquors Sulfate Max relative swelling (cm3/ g BLS) Total combustion time (s) All liquors Soda process Max relative swelling (cm3/ g BLS)

11 Spray characterisation - experimental Drop size distribution Particle volume fraction vs. diameter Kankkunen et al 24 spraying temperature DT 18 C 17 C 14 C Volume fraction of particles [1/mm] Volume fraction of particles [1/mm] Volume fraction of particles [1/mm] Measured D ekv [mm] RR Normal Sqrt LogNor Measured D ekv [mm] RR Normal Sqrt LogNor Measured D ekv [mm] RR Normal Sqrt LogNor Volume fraction of particles [1/mm] Volume fraction of particles [1/mm] Volume fraction of particles [1/mm] D ekv [mm] Measured RR Normal Sqrt LogNor Measured D ekv [mm] RR Normal Sqrt LogNor Measured D ekv [mm] RR Normal Sqrt LogNor Volume fraction of particles [1/mm] Volume fraction of particles [1/mm] Volume fraction of particles [1/mm] Measured D ekv [mm] RR Normal Sqrt LogNor Measured D ekv [mm] RR Normal Sqrt LogNor Measured D ekv [mm] 4.3 kg/s 5.2 kg/s 6.1 kg/s RR Normal Sqrt LogNor HELSINKI UNIVERSITY OF TECHNOLOGY mass flow rate

12 Spray characterisation - simulation Effect of particle shape on swelling d S = 3.1 mm, 23 mg Kankkunen et al 24 3 Swelling ratio, d /d dry pyro char HELSINKI UNIVERSITY OF TECHNOLOGY Time, s

13 Research Black liquor characterisation Modeling of melting properties Na 2 S oxidation with thermal analysis

14 Detailed knowledge of melt properties needed - Deposits - superheaters, furnace walls, gasifier wall - stickiness, flow temperature - Smelt bed operation - smelt flow properties - flow temperature - Corrosion - superheaters, floor, boiler bank - first melting temperatures, composition - Release mechanisms - presence of melt - composition - Fume particle formation - condensation mechanism - surface phenomena

15 Other physical properties of suspensions needed - Heat conductivity/emissivity - deposit build up - smelt bed properties - porosity - Surface tension/wetting - fume formation - particle rebounding - Viscosity - smelt flow - furnace wall, gasifier wall - Ionic conductivity - corrosion - monitoring - Solubilities - formation of deposits - green liquor formation

16 Melting Behaviour of Inorganic Mixtures 1 Portion molten phase [wt-%] = Na2S/Na2CO3 6/4 m/m 2 = mol-% NaCl 3 = mol-% K 4 = mol-% Na2S2 5 = mol-% K Temperature [ C] 1

17 Novel method for melting studies Preparation of samples binary and complex mixtures Thermal Analysis ÅA HT X-ray diffraction Umu HT microscopy Umu Thermodynamic modeling ÅA, Umu Submodel applications Standalone programs Phase diagrams Melting curves

18 New diagrams Na 2 CO 3 -Na 2 S, Na 2 SO 4 -Na 2 S Råberg et. al 23, 25

19 Recent development of salt melting models Na, K sulfates, carbonates, chlorides, hydroxides Experimental Modeling - all binary systems fully FACT - ternary systems partly - higher order systems partly, ÅA - full model FACT, ÅA Na, K sulfides + sulfates, carbonates, chlorides -Na 2 S-Na 2 CO 3 UmU ÅA - other binaries partly ÅA - full model ÅA Plus polysulfides, pyrosulfates -Na 2 S-S UmU ÅA -K 2 S-S fully ÅA -Na 2 SO 4 -SO 3 fully ÅA -K 2 SO 4 -SO 3 partly ÅA Plus borates - binaries very little ÅA - higher order systems no ÅA Plus Ca, Mg, Pb, Zn - binaries partly, various FACT, ÅA - higher order systems little, various ÅA

20 New solution model for salts Na, K Cl, CO 3, SO 4, S, OH, BO 3, BO 2 Sublattice model (SUBM) Re-evaluation General Unified Thermodynamic Model (GUTS) Can be extended Ca, Mg, trace elements Lindberg et. al 26

21 New diagram Na-S and K-S Lindberg et. al 26

22 New diagram Na 2 S-K 2 S-S Lindberg et. al 26

23 1 Na 2 CO 3 -Na 3 BO 3 Calculated Na 2 CO 3 -Na 3 BO 3 Sublattice model Lindberg, Backman 23 9 Temperature [ C] Na 2 CO 3 Na Mol fraction Na 3 BO 3 BO 3 3

24 Na 2 CO 3 -Na 3 BO 3 -NaBO 2 Na2CO Na3BO Na4B2O5 NaBO2

25 Research Black liquor characterisation Modeling of melting properties Na 2 S oxidation with thermal analysis

26 TA-Instruments Q6

27 Kinetics Na 2 S + 2O 2 -> Na 2 SO Phase diagram Thermogravimetric program Temperature ( C) Liquid 74 Na 2 S(s) + Na 2 SO 4 (s) 884 Sample wt (mg) Sample wt Temperature O Temperature ( o C) Na 2 S mole fraction Na 2 SO Time (min) DeMartini et. al 24

28 Kinetics Na 2 S + 2O 2 -> Na 2 SO 4 Time to 9 % conversion 8 o C DeMartini et. al 24