Scale-up Method for High Temperature Black Liquor Gasification in Pressurised Entrained Flow Gasifiers

Transcription

1 Scale-up Method for High Temperature Black Liquor Gasification in Pressurised Entrained Flow Gasifiers Magnus Marklund, Rikard Gebart, Ragnar Tegman, Chemrec AB 1 BLG DRIVING FORCE Wood chips Pulp White liquor CAUSTICIZERS AND LIME KILN DIGESTER PULP MILL RECOVERY CYCLE Steam Weak black liquor EVAPORATORS Green liquor Black liquor BLACK LIQUOR GASIFIER RECOVERY BOILER MOTOR FUEL ELECTRICITY CHEMICALS HYDROGEN 1

2 BLG DRIVING FORCE 30 TWh Added Biofuels Black Liquor Energy in Swedish Pulp Mills Black Liquor energy 39 TWh 0 TWh* DME or 0 TWh Methanol or TWh Hydrogen * Corresponds to 30% Swedish market need of transport fuels year CHEMREC DP-1 PLANT

3 CHEMREC DP-1 PLANT BLACK LIQUOR OXYGEN AND ATOMIZING MEDIA COOLING WATER SHORT TIME CONTACTORS GAS COOLER WHITE LIQUOR REACTOR RAW GAS QUENCH GREEN LIQUOR CLEAN, COOL SYNTHESIS GAS WEAK WASH CONDENSATE 5 CURRENT SCALE-UP NEEDS Plant Location Process Units Capacity tds per d/ MWt Pressure (bar) Purpose DP1*) Piteå, Sweden - Gasification & BLG-Program - Gas Cooling - Gas Cleaning 0 / Verify Plant technical features. - Secure performance for DP- DP*) Kappa Kraftliner Piteå - Full BLG - Either -CC or -MF concept ~300 / Commercial Demo plant - Net prod. of10 MWe and 35 t/h of steam. or 100 tpd of MeOH *) Plant Investments Supported by a Grant from the Swedish Government of 38 MSEK, approx 5 Mill 6 3

4 CFD REACTOR SCALE-UP MODEL BASICS Based on CFX. CFD code Euler/Lagrange two phase formulation Drying, pyrolysis, char and smelt reactions k-ε turbulence model EBU/Kinetic controlled combustion model Discrete Transfer radiation model Rosin-Rammler droplet distribution 7 CFD REACTOR SCALE-UP MODEL Drying Devolatilization { { BL BLS CHEMISTRY BLS + H O( g) Volatiles( g) + Char( l, s) ( s) + O ( g) CO ( g) ( s) + CO ( g) CO( g) ( s) + H O( g) CO( g) + H ( g) C Char C conversion C (van Heiningen and Connolly 003) C C( s) + 1 ( f / ) ( ) c s Na SO s Sulphate/sulphide cycle (Wåg et al. 1995) 1 ( f / ) ( ) + / ( ) + (1 c s Na S s fc sco g f NaS( s) + O ( g) NaSO ( s) CH + 0.5O CO + H CH + H O CO + 3H Gas phase combustion (Jones and Lindstedt 1988) H + 0.5O H O CO + H O CO + H Associated swelling during conversion + c / s ) CO ( g)

5 CFD REACTOR SCALE-UP MODEL STRATEGY 9 SPRAY BURNER CHARACTERIZATION Vessel with optical access Characterization using PDA SMD 10 1 bar 5 bar d (micron) R (mm) case1 case case3 case case5 case6 10 5

6 CFD MODEL VALIDATION Main outputs from CFD model: Fluid motions Gas, droplet and wall temperatures Gas and smelt compositions at outlet 11 CFD MODEL VALIDATION GAS ANALYSES BLACK LIQUOR OXYGEN AND ATOMIZING MEDIA COOLING WATER SHORT TIME CONTACTORS GAS COOLER WHITE LIQUOR REACTOR THERMO- COUPLES QUENCH RAW GAS GREEN LIQUOR WEAK WASH GL ANALYSES CONDENSATE CLEAN, COOL SYNTHESIS GAS 1 6

7 CFD MODEL VALIDATION Considered operational condition: Liquor from Smurfit Kappa Kraftliner Piteå 8.8 tonnes BLS/h (% load) 7 % DS 15 bar at λ = 0.39 Additional N to assist atomisation 13 CFD MODEL VALIDATION Temperatures at the thermocouple locations Experimental CFD Model [ C] 106 C 899 C 1066 C 937 C 95 C 93 C 1 7

8 CFD MODEL VALIDATION Gas composition after gas cooler (CCC) Specie Experimental CFD Model CO CO CH COS H S H H O N CFD MODEL VALIDATION Performance Quantity Est. Experimental CFD Model Reduction efficiency 98.0% 99.7% C conversion 96.8% 95.5% Smelt composition Specie Est. Experimental CFD Model Na CO Na S Na SO C

9 Reasonable accurate: CONCLUSIONS In-situ measurements from the inside of the reactor are necessary before a definite conclusion about the validity of the model can be drawn Global performance parameters e.g. Carbon conversion Predicted smelt composition 17 CONCLUSIONS More/better experimental data needed: Spatially resolved temperature measurements Gas probe sampling inside reactor Smelt/char sampling for analysis 18 9