refractory developments for gasification patrick...
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TABLE OF CONTENTS
Saint-Gobain Background
Refractories Background
Refractories for Gasification
Refractory Developments
The Future of Refractories for Gasification
2
KEY FIGURES
Present inSales
countriesbn€
More than
employeesProduction sites
employees
Almost
sales outletsof saleson the habitat market
One of the world’s
most innovative companies*
*Source: Thomson Reuters3
REFRACTORY CHEMISTRY
Al2O3- high melting T, chemically inert2 3 g g ySiO2- cheap and abundant, structurally goodMgO basic steel ind strMgO- basic, steel industryCaO- good low T properties, usually mixedZrO2- high melting T, good insulatorCr O corrosion / abrasion resistantCr2O3- corrosion / abrasion resistantSiC- high heat transfer, abrasion resistant
Sourced from mined clays and minerals, or chemically derived
REFRACTORY MANUFACTURING
Pressing
Casting
Fusion Casting
ExtrusionExtrusion
processing may be similar after forming… processing may be similar after forming
REFRACTORY TYPES
Bricks and Special Shapes
Castables (Cements & Mortars)
Plastics (Ramming)
Fib (Bl k t t ) Fibers (Blankets, etc.)
Ramming Mixes and Loose Fill Powders
BRICKS & SHAPES V. CASTABLES
Bricks & Shapes CastablesShaping limits - +Shaping limits - +Size limits - +D iDensity + -Erosion ++ -Volume Stability + -Manuf. Quality + -yInstall Quality + --Drying & Curing ++ --Drying & Curing ++ --Cost - +
Process RisksFrom a refractory standpoint:
High temperature excursions High temperature excursions
Rapid thermal cycles
Chemical instability, contamination
Slagging parameters Slagging parameters
Expansion stresses
Water / steam leaks
Improper curingp p g
… can lead to forced shutdowns, expensive maintenance hot spotsexpensive maintenance, hot spots, and worse…
DEFINITION
Refractories are ceramic materials that are able to contain high temperature processes by providing thermal, structural, chemical, and corrosion barriers for a variety of industrial applications.
PROPERTY TRADE-OFFS
C O
AlAl22OO33 -- CrCr22OO33 -- ZrOZrO2 2 systemsystemCr2O3
Corrosion resistance ZC900
(slag, glass)
ZC60
ZC750
ZC60
ZC400
ZrO2Al2 O3
CC12
ZC400
ZrO2Thermal shock
resistanceHot
mechanical
Al2 O3
strength
THERMAL CYCLING
Rapid changes in operating t t ( 100 d Ctemperature (>100 degC per hour) cause increased mechanical stresses crackmechanical stresses, crack growth, and spalling.
Care must be taken when heating and cooling aheating and cooling a refractory lining. A controlled schedule must be followed.
(Source: DOE ARC presentation GTC 2002)presentation, GTC 2002)
MICROPROBE MAPPING – INFILTRATED HOT ZONE
Selective penetration of the elementselements
Deep penetration of Ca, Si, MgConcentration of V, Fe, Mg in
surface layer ~ 1 2 mmsurface layer ~ 1-2 mm
18
DENSE LAYEROPTICAL & ELECTRONIC SlagOPTICAL & ELECTRONIC MICROSCOPY
g
Dense Cr-V-Mg-O
SEM/EDS: dense layer/refractory interface
Dense Cr-V-Mg-O
Refractory
Optical microscopy: slag/dense layer/Refractory
Dense Cr V Mg O
Optical microscopy: slag/dense layer/Refractory
R f t
No sign of microcracks in the dense layer or hot face
No spallingRefractory p g
19
REFRACTORY ASSESSMENT PROGRAM –PRODUCT DEVELOPMENT
Lab performance tests II• Infiltration kinetics• Structural stability
Pilot Production • Industrial feasibility• Mix validation
(compared to lab
Test panel withcustomer• Performance in
operations
Performance evaluation• Corrosion
resistance prod
uct
mer
cial
s• Structural stability (compared to lab
results!)operations
• Several monthsresistance
• Thermal shockresistance
alua
ted
pfo
r com
mpe
ratio
ns
Fina
l eva
Rea
dyf op
F
RESEARCH & DEVELOPMENT OF NEW MATERIALS
Initial Performance Improvement
RunHours
5000
6000
7000
8000
9000
35%
1000
2000
3000
4000
5000
0
1000
1 2Old New
C.R.E.E. R&D CenterCavaillon, France
Northboro R&D Center Massachusetts, USA
,
EXAMPLES OF REFRACTORY DEVELOPMENTS
Transition from alumina monolithics to fired shapes
Saint-Gobain patents related to addition of zirconia
DOE ARC NETL development of phosphate additions to Cr2O3 DOE ARC NETL development of phosphate additions to Cr2O3
DOE ORNL studies on MgO aluminate spinels
Frauenhofer Institute studies on SiC/AlN refractories
GE Gen II Advanced Refractoryy
HEXAVALENT CHROMIUM CONCERNS
Indication in MSDS
Measurement according NF EN 689 France8h VME (mg/m3)
USA (ACGIH)8h TWA (mg/m3)
N ifi d tNon specific dust-Total dust-Respirable dust
105
103Respirable dust 5 3
Chromium (hexavalent compound) 0.05
Chromium (hexa) soluble in water 0.05( )
Chromium (hexa) insoluble 0.01
Raw Material Prices
1200
1400
Chromite1
Soda Ash2
800
1000
or T
onne
Soda Ash2
Fused Alumina3
Calcined Alumina4
400
600
SD P
er T
on o
2 per. Mov. Avg. (Chromite1)
2 per. Mov. Avg. (Soda Ash2)
200
400US
2 per. Mov. Avg. (Fused Alumina3)2 per. Mov. Avg. (Calcined Alumina4)
0May-05Mar-06Jan-07Nov-07Sep-08Jul-09May-10Feb-11Dec-11Oct-12
DateSource – Industrial Minerals magazine
RAW MATERIAL VOLATILITY
ALTERNATIVE SOLUTIONS
What else can be done in the field of thermal management?
More matching of refractory qualities to life by zone More matching of refractory qualities to life by zone
Non-chromia containing refractories
Fused cast refractories? Composites? Coatings?
Thin membrane refractory barriersy
Systems with no refractories
B tt l t t t f lid f d it Better slag treatment for solid feed units
Coal beneficiation
MAIN CONSIDERATIONS
Always weigh cost vs. performancey g p
Manufacturability
Raw material availability
Slag compatibility
CHANGES IN GASIFICATION TECHNOLOGY
Traditional Process Evolution
Hydrogen economy – smaller, distributed units
Biomass gasification/pyrolysis
Plasma gasification
Domestic waste processesDomestic waste processes
Hazardous waste processesHazardous waste processes