C23: Need for standardisation of test methods for sorbent ... septiembre/C23.pdf• Systems Analysis and Policy Consulting • Fuel Cells – Technology, Systems, Test Centre • Batteries

Ulrich Zuberbuehler

Centre for Solar Energy and Hydrogen Research (ZSW) Stuttgart, Germany

Department: Renewable Fuels and Processes

C23: Need for standardisation of test methods for sorbent/material characterisation

1st Meeting of theHigh Temperature Solid Looping Cycles Network

INCAR-CSIC, Oviedo, Spain15.-17. September 2009

Centre for Solar Energy and Hydrogen Research (ZSW): New Energy Technologies

• Applied Research & Development• Close Cooperation with Industry and Universities• 20 Million € Turnover, 150 Employees

• Photovoltaic – Thin Film Technologies (CIS) & Application Systems• Renewable Fuels and Processes• Systems Analysis and Policy Consulting• Fuel Cells – Technology, Systems, Test Centre• Batteries & Super Capacitors – Materials, Systems, Qualification

Stuttgart Widderstall Ulm

Requirements for Chemical Looping materials in Fluidized Bed Applications

Reactivity: CO2 - Absorption Capacity (gCO2 / gOxide)Reaction Rate: CO2 Absorption & Release (gCO2 / gOxide• s)Chemical and Thermal Stability (number of cycles)Mechanical Stability (amount of attrition, purge)Catalytic Effects (tar)Availability: Grain Size, Cost; Non-Toxic, Easy to Dispose

1. Common material characterisation for trading and quality control (quick, low cost)

2. Standardisation of test methods

Material Characterisation Methods

• Origin- geological information: stone quarry, age, layer, formation,morphology (thin section)

• Chemical properties- composition- capacity- reaction rate dX/dt = f(X(t), T, P, dP)

• Physical properties- grain size- density (bulk, particle, material)- treatment

grinding, fractionating, washingcalcination, sintering, impregnation

- mechanical stability definition, measurement

Carbonate quarry at Swabian Alb (South of Germany)

Upper Jurassic (Source LGRB 2006)







CO2 - Capacity (TGA)Procedure

0

100

200

300

400

500

600

700

800

900

0 100 200 300

Time [min]

Tem

pera

ture

[°C

]

28

32

36

40

44

48

52

56

60

64

Mas

s [m

g]

Calcit A3

CaCO3

CaO

CaCO3

)n(m)n(m

)n(COxid

abs,CO2=

mOxide

mCarbonate

mCO2

mStart

TGA Conditions:

d = 0.6 – 0.71 mm, m0 = 50 mg (CaCO3)m0 = 28 mg (CaO)T = 650 / 840°CΔT/Δt = 10 K/minGas: 10% CO2,

30% H2O in N2

CO2- Capacity:

Absorption Capacity with ongoing CyclesRaw and Sintered Sorbent

Absorption Capacity of raw & burnt limestonesdp = 600-710 µm, m0 = 30 mg

TGA atmosphere: 10 % CO2, 30 % H2O in N2

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 5 10 15 20 25

Cycle-No.

Abs

orpt

ion

Cap

acity

g CO

2/g O

xide

C58_1_08 (raw)

C14_1_06 (raw)

C14_3_07_005 (1200°C burnt, 3h)

C14_3_07_003 (1300°C burnt, 3h)







ZSW – Sorbent Screening: Mechanical Stability AND CO2 Sorption Reaction in FB

Raw material (200 g, 200-710µm):attrition: 3.5 w.%

0

0.001

0.002

0.003

0.004

0.005

0 100 200 300 400 500 600 700 800

Particle Size / µm

q / (

1/µm

)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Sum

Q

q raw / 1/µmq FB / 1/µmQ3 (raw)Q3 (FB)

S34_B007_C1_2_06

Particle Size Distribution Effects on “Attrition” value

0

0.001

0.002

0.003

0.004

0.005

0 100 200 300 400 500 600 700 800

Particle Size / µm

q / (

1/µm

)

0.0

0.10.2

0.3

0.4

0.5

0.6

0.70.8

0.9

1.0

Sum

Q


S31_B004_C14_1_06

0

0.001

0.002

0.003

0.004

0.005

0.006

0 100 200 300 400 500 600 700 800

Particle Size / µmq

/ (1/

µm)

0.0

0.10.2

0.3

0.4

0.5

0.6

0.70.8

0.9

1.0

Sum

Q


S24b_B001_D4_1_06

(A) bigger particles (B) smaller particles

Definition: Attrition wt% < 200µm of initial sample

Handbook of Fluidization and Fluid-Particle SystemsSources of Attrition in a FB System

tm

mr

beda Δ

Δ⋅=

1

3

2

:

:

:

urjet

urcyclone

urbed

a

a

a

≈

≈

≈

Source: Handbook of Fluidization and Fluid-Particle Systems. Dekker 2003

Handbook of Fluidization and Fluid-Particle SystemsExample of different Attrition Indexes

Source: Handbook of Fluidization and Fluid-Particle Systems. Dekker 2003

• Hardgrove Index (HGI) for the grindability of coals• Fluidized Bed Attrition Test (ASTM D-5757-95) for FCC Catalysts

Solids impaction principleDavidson jet cup

Mechanical Stability in Milling TestProcedure

MillType Fritsch pulverisette 6Grinding beaker 80 ml, steelTransmission ratio irelative 1 : -1.82Balls 5 Achate (d=20mm)Turns 440/minTime 5 minSample32 ml (volumetric dosing)Grain size 600 - 710 µm

Sieve analysis (duration 10 min, amplitude 2.5 mm)Attrition = the fraction of fines (d < 200µm) / total sample mass

Milling-Test Method (ZSW)Comparison of Attrition Values

0102030405060708090

100

Q2 Quarz

sand

X2 Oliv

ineD4 D

olomite

C1 Gree

k Limes

tone (raw

)

C1 Gree

k Limes

tone (pre-

treate

d)

C58 G

erman

Limes

tone (raw)

C58 G

erman

Limes

tone Oxide

Attr

ition

in w

t.% (<

200µ

m)

Summary Material Characterisationfor Future Trading and Quality Control

• OriginQuality control, material screening

• Chemical properties Composition, TGA, Process development, basic engineering

not every batch• Physical properties

Size distribution, density, porosity, Mechanical stability

Different individual test methodsNo reliable prediction of attrition in DFB reactorsDefine a fast, simple, and meaningful test method

C23: Need for standardisation of test methods for sorbent ... septiembre/C23.pdf• Systems Analysis and Policy Consulting • Fuel Cells – Technology, Systems, Test Centre • Batteries

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