Experimental investigation of single-particle gasification

14th of June 2016, Cologne, Germany

F. Küster1, R. Ackermann2, S. Guhl1, B. Meyer1

1IEC, TU Bergakademie Freiberg, Germany; 2IAP, Friedrich-Schiller-Universität Jena, Germany

Experimental investigation of single-particle gasification


2

Outline

8th International Freiberg Conference, 12 – 16 June 2016

1. Background and Motivation

2. The HITECOM Reactor

3. Development of a single particle holder

• Requirements / overview particle holder

• Overview adhesive-fixation

• Integration in HITECOM-System

4. Results and und Discussion

• Feedstock characterization

• Investigation of single-particle reactions

• Determination of kinetic parameters

• Further results

5. Conclusion / Outlook


3

Motivation

• Spatial and time resolved characterization of thermochemical conversion of single particles in directed

flow at T < 1400 °C and up to 40 bar for fundamental research and advanced CFD validation

• Temperature map on the particle surface

• Temperature- and concentration profiles in the boundary layer around particles

Challenges:

• High pressure

• High temperature

• reactive gases

• Integration of optical ports

• single-particle gasification

Friedrich-Schiller-Universität Jena

Institute of Applied Physics

TU Bergakademie Freiberg

Institute of Energy Process

Engineering and Chemical

Engineering

METAZIK

LIF, RAMAN,

Thermography

2. The HITECOM Reactor


The HITECOM Reactor

5

Overview


Specifications:

• Magnetic suspension balance

• Ceramic flow tube

• TMAX=1400 °C, pMAX= 40 bar

• Four optical ports

(perpendicular to the flow

direction; material: sapphire)

• Feed gases: CO, CO2, H2Og, H2,

O2, N2 and Ar

(1 – 200 l/min)

Challenging Task:

Integration of particle holder

3. Development of a single particle holder


Single particle holder

7

Demands for single particle holder


Fixation various particles (1.0 – 4.0 mm)

Temperature resistance (up to 1400 °C)

Rigidity (no natural oscillation)

Tolerance of shrinking particles

good fixation in direct flow

Minimal flow field distortion

Compatibility with magnetic suspension balance / reactor

Development of new concepts for the fixation of single-particles in direct flow

Combination with magnetic suspension balance

Modification of the HITECOM-System


8

Overview


Wire-fixation Ceramic-fixation Adhesive-fixation

Task: Realization of a vibration-free particle holder tolerant

against particle-shrinkage

Traditional particle holder with wire basket

Disadvantages:

• Disruption of the flow field

• Sensitive against direct flow (vibration)

• Problematic measurement of the boundary layer

• Not suitable for single particles

Classical:

Alternatives:


9

Particle holder type C – Adhesive-fixation


Type C.1 Type C.2

Advantages:

• suitable for direct flow

• vibration-free

• excellent reusability / easy of assembly

• temperature resistant

• low error rate

hanging standing


10

Particle holder type C – Adhesive-fixation (C.1)


Lignite I (T=900 °C, p=1.0 bar CO2)


11

Particle holder type C – Adhesive-fixation (C.2)



4. Results and discussion


Results and discussion

13

Feedstock characterization


• Characterization of single-particles of three different feedstocks (lignite and hard coal)

• Characterization of a synthetic mixture of several single-particles of the three feedstocks

(traditional methods)

• Ultimate analysis (DIN 517 24/32)

• Proximate analysis (DIN 517 18/19/20)

• particle shape (CAMSIZER)

• Reactivity (reference thermobalance, 1bar CO2, 800-1000°C)

• Challenges:

• Hypothesis: „each particle is different“ (Influence of feedstock)

• Non-destructive analysis methods (difficult / impossible)

• Ultimate- and proximate analysis of the same particle: impossible

• Ultimate analysis according to DIN

• Proximate analysis in accordance with DIN

Results and discussion

14

Feedstock characterization – single-particles

20

30

40

50

60

70

80

90

100

Car

bo

n c

on

ten

t[w

t.-%

]

Hard coal (x=1.6-2.0 mm)

20

30

40

50

60

70

80

90

100

Car

bo

n c

on

ten

t[w

t.-%

]Central German lignite (lignite I; x=0.5-3.0 mm)

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9

0

10

20

30

40

50

60

70

80

w A (wf) FB (wf) CFIX (wf)

wt.

-%

Central German lignite (lignite I; x=0.5-3.0 mm)

BK2820_4,85

BK2820_4,86

BK2820_4,88

MAX

Min

0

10

20

30

40

50

60

w A (wf) FB (wf) CFIX (wf)

wt.

-%

Hard coal (x=1.6-2.0 mm)

SK3010_5,60

SK3010_5,62

SK3010_5,64

MAX

Min

moisture ash (wf) volatile (wf) fixed carbon

(wf)

moisture ash (wf) volatile (wf) fixed carbon

(wf)

Ultimate

analysis

Proximate

analysis

Results and discussion – feedstock characterization

15

Reactivity – single-particles

0

2

4

6

8

10

12

14

16

18

BK3037 BK2820 SK3010

Rea

cti

vit

y i

nd

ex

R [

1/h

]

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

SK3010

0.0000

0.0005

0.0010

0.0015

0.0020

0.0025

0.0030

0.0035

0.0040

0.0045

BK3037 BK2820 SK3010

Rea

cti

on

rate

r [

1/s

]

0.00000

0.00003

0.00005

0.00008

0.00010

0.00013

0.00015

0.00018

0.00020

SK3010

0.0000

0.0005

0.0010

0.0015

0.0020

0.0025

0.0030

0.0035

0.0040

0.0045

0% 20% 40% 60% 80% 100%

Rea

cti

on

rate

r

[1/s

]

Carbon conversion Xc

Lignite I (7.52<m<10.36 mg)

10,36 7,52 8,25 8,33 8,35 8,76 9,01 9,06

Reaction rate r:

𝑟 =1

𝑚𝐶,0∙𝑑𝑚𝐶

𝑑𝑡=𝑑𝑋𝐶𝑑𝑡

reactivity index RS (Carbon conversion Xc=50%):

𝑅𝑆 0.5 =0.5

𝑡1/2

Influence of feedstock

Carbon conversion Xc=50%

Lignite I Lignite II Hard coal Lignite I Lignite II Hard coal

Results and discussion – single-particle reactions

16

Single-particle reactions in HITECOM reactor (I)


0

1

2

3

4

0 500 1000 1500 2000 2500 3000 3500 4000

Par

ticl

em

ass

m [

mg]

time [s]

0

1

2

3

4

5

0 100 200 300 400 500 600 700

Par

ticl

em

ass

m [

mg]

time [s]

Lignite I (T=1000 °C, p=1.0 bar CO2) Hard coal (T=1000 °C, p=1.0 bar CO2)


17

Single-particle reactions in HITECOM reactor (II)


0

5

10

15

20

25

0 100 200 300 400 500 600 700 800

Pa

rtic

lem

as

sm

[m

g]

time [s]

Lignite II (T=1000 °C, p=1.0 bar CO2)


18

Single-particle reactions in HITECOM reactor (II)


0

5

10

15

20

25

0 100 200 300 400 500 600 700 800

Pa

rtic

lem

as

sm

[m

g]

time [s]

IEC-Nr.: 2820 (T=1000 °C, p=1.0 bar)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 0.2 0.4 0.6 0.8 1

Carb

on

co

nve

rsio

nX

c

time τ [-]

• Performing single-particle gasification

is possible


0.000

0.001

0.001

0.002

0.002

0.003

0.003

0.004

0% 20% 40% 60% 80% 100%

Re

acti

on

rat

e r

[1

/s]


r(BK2820)0.000

0.001

0.001

0.002

0.002

0.003

0.003

0.004

0% 20% 40% 60% 80% 100%

Re

acti

on

rat

e r

[1

/s]


r(BK2820) r(SCM)


19

Validating the HITECOM results – experimental design


IEC-Nr.: 2820 (T=1000 °C, p=1.0 bar)• Preliminary tests using reference thermobalance

• Characterization of single-particles (lignite and hard coal)

• Characterization of powdered samples (homogeneous)

• Ceramic crucible (particle container, 10µl)

• Experimental conditions:• Temperature range: 800-1000 °C (50K-steps)

• Pressure: 1bar CO2

• Experiments in HITECOM-reactor

• Characterization of single-particles (lignite and hard coal)

• Adhesive-fixation (hanging)

• Experimental conditions:• Temperature range: 800-1000°C (50K-steps)

• Pressure: 1bar CO2

• Comparison of the results

-7.0

-6.5

-6.0

-5.5

-5.0

-4.5

-4.0

0.78 0.83 0.88 0.93

ln(k

) [1

/s]

1/T [103 K]


20

Validating the HITECOM results – determination of kinetic parameters

-7.0

-6.5

-6.0

-5.5

-5.0

-4.5

-4.0

0.78 0.83 0.88 0.93

ln(k

) [1

/s]

1/T [103 K]

BK3037_0,5-3,0_xmg ( 4 ) HITECOM


successful (Arrhenius plot)

• Validation with data from the reference

thermobalance successful

• Influence of the feedstock confirmed Possible solution: synthetic particles

-11.5

-10.5

-9.5

-8.5

-7.5

-6.5

-5.5

-4.5

0.78 0.83 0.88 0.93

ln (

k)

[1/s

]

1/T [103 K]

-11.5

-10.5

-9.5

-8.5

-7.5

-6.5

-5.5

-4.5

0.78 0.83 0.88 0.93

ln (

k)

[1/s

]

1/T [103 K]

SK3010_1,6-2,0_xmg ( 3 ) HITECOM

Hard coal (XC=0.5, p=1.0 bar CO2)

Temperature range:

800-1000 °C

Lignite I (XC=0.5, p=1.0 bar CO2)


21

Further results – synthetic particles


• Idea: Minimization the influence of the feedstock with „ideal“ particles

Known and homogeneous composition

Known (ideal) particle shape

Known reactivity

Known and well defined properties

comparative measurements

0

1

2

3

4

5

6

0 100 200 300 400 500

Part

icle

mass m

[m

g]

Time [s]

Synthetic particle (T=1000 °C, p=1.0 bar CO2)


22

Further results – thermal camera


• Task: Integration of the thermal camera in the HITECOM reactor

• Calibration of the thermal camera under real conditions

• Visual observation of single-particles during gasification

Temperature map on the particle surface under gasification conditions

Compare with simulation


5. Conclusion / Outlook



24

Conclusion


• Development, construction and commissioning of the HITECOM-Reactor finished• Software and hardware improvements

• Integration of particle holder into the TG• Further development of the particle holder / adhesive composition

• Combination of the particle holder with TG interface

• Performing single-particle gasification is possible• Adjustment to models is possible

• Determination of kinetic parameters• Validation with data from the reference thermobalance successful

• Influence of feedstock not negligible!• the differences in reactivity between particles from the hard coal are larger than the

differences between particles of two central German brown coals

• „each particle is different“

• “Avoid” the influence of the feedstock• Possible solution: synthetic particles


25

Outlook


• Expansion of the experimental design (CO2-gasification)

• Test other single-particle holder (e.g. ceramic-fixation)

• Variation of the flow conditions

• Variation of the pressure conditions (partial pressure / total pressure)

Expanding applicability of kinetic parameters

• Investigation of the influence of the adhesive

• Water steam gasification

T=1000 °C, p=1.0 bar

Thank you for your attention


This research has been funded by the Federal Ministry of Education and Research of Germany

in the framework of Virtuhcon (Project Number 03Z2F512).

Documents

Experimental investigation of single-particle gasification