Chemometric modelling of experimental data on co-gasification of bituminous coal and biomass

to hydrogen-rich gas

Adam Smoliński, Natalia Howaniec

Central Mining InstituteDepartment of Energy Saving and Air Protection

Plac Gwarków 1, 40-166 Katowice, PolandE-mail: asmolinski@gig.katowice.pl

Objective

Chemometrics study of the experimental data set of co-gasification

of bituminous coal and biomassto H2-rich gas

Outline

1. Role of coal in energy security

2. Biomass as a „zero-emission” energy source

3. Thermal utilization of biomass in steam co-gasification with coal to H2-rich gas

4. Application of chemometric methods in effective exploration of the experimental data sets: PCA and HCA

World marketed energy consumption 1990-2035

0

200

400

600

800

1990 1995 2000 2007 2015 2020 2025 2030 2035

quadrillion Btu

ProjectionsHistory

355374

406

495

1 Btu (British thermal unit) =1055.0559 J U.S. DOE, International Energy Outlook 2013. Washington, IEA.

Electricity generation by fuel 1990-2040

U.S. DOE, International Energy Outlook 2013. Washington, IEA.

World net electricity generation is expected to increase by 94%from 20.2 trillion kWh in 2010 to 39.0 trillion kWh in 2040.

Total world electricity generation from coal in 2040 is expected to be 73% higher than in 2010.

Coal-fired electricity generation is assumed to increase by 1.3% per year in the period 2010 –2040.

Coal resources

Diversification of coal applications

Is coal a clean fuel?

Coal processing

8

Clean Coal Technologies +

CO2 Sequestration

Green energy from coal

Biomass as a „zero-emission”energy source

• Biomass and biowaste is a group of fuels of varied composition and physical properties.

• Biomass/biowaste can be classified according to origin (plant, animal) or structures which are dominant (cellulose, lignin, fats, wax or albumens).

• Biomass wood waste (sawdust, shaving), straw and paper industry waste, in which cellulose structures are dominant, are also recognized as fuel.

10

Main trends in coal/biomass processing

• Combustion

• Gasification

• Polygeneration

• Hydrogenation

11

Products of coal processing

Coal/biomass

Gasification Hydrogenation

Fischer-Tropsch

synthesis

Methanol Synthesis

Methanation Refinery Treatment

Liquid Fuels

Chemicals Methanol SNG Liquid Fuels

Combustion

Gas combustion

Power and Thermal energy

Separation

Hydrogen

Coking

Coke

Coal/biomass

Coal/biomass

Oxygen

Gasification with Oxygen

C+1/2O2=CO

C + O2 = CO2

Gasification with Carbon Dioxide

C+CO2=2CO

Exothermic reaction

Endothermic reaction

Gasification process

Steam

Gasification with Steam

C + H2O = CO + H2

Water-Gas Shift

CO + H2O = H2 + CO2 Exothermic reaction

Endothermic reaction

Gasification process

Coal/biomass

Hydrogen

Gasification with Hydrogen

C + 2H2 = CH4

Gasification with Hydrogen

CO + 3H2 = CH4 + H2O Exothermic reaction

Exothermic reaction

Gasification process

Coal/biomass

(volume %)H2 25-30CO 30-60CO2 5-15H2O 2-30CH4 0-5

H2S 0,2-1COS 0-0,1

N2 0,5-0,4Ar 0,2-1NH3 0-0,3

Ash/Slag

Gas

ifica

tion

of c

oal/b

iom

ass

Further Processing

Typical gasifier gas composition

Gasification methods

• In a fixed bed (quasi-stationary)Sasol - Lurgi FBDB

• In a fluidized bedHigh Temperature Winkler (HTW) gasification technology

• In a stream reactorSHELL, GE-TEXACO

Industrial gasification plantscapacities by fuel type

NETL: 2010 Worldwide Gasification Database

Coal

Resources

Gasification technology

Environmental aspects of coal processing

Biomass

Resources

Gasification technologies

Environmental aspects of biomass processing

Coal & sewage sludgeco-gasification:

Resources

Co-gasification technologies

Environmental aspects

Area of research activities in the field of coal and biomass gasification and co-gasification

R&D activities in the field of gasification

Thermodynamic analysis, optimization: influence of various operating parameters on the yield and

composition of gas: various gasification agents, temperature, pressure, metal oxides as catalysts

and various reactor types.

Carbonaceous fuel:

coal and biomass

Syngas

Electricity and thermal energy

Chemical synthesis: SNG, methanol, ammonia, liquid fuel

Fuel cellsPetrochemical industry

Chemical industry

Hydrogen

Coal & biomass co-gasification

Synergy effect in co-gasification

Area of research activities in the field of coal and biomass/sewage sludgegasification and co-gasification

Coal & biomass co-gasification

Thermal utilization of biomass in steam co-gasification with coal to H2-rich gas production

Fig.1 Fixed-bed reactor experimental stand with gasification agents pre-heating system (1 – gas inlets, 2 – water pump with a steam generator, 3 – gasification agents pre-heating system, 4 – fixed bed reactor with resistance furnace, 5 – flowmeter and 6 – gas chromatograph Agilent 3000A)

Fuel samples (10g) (hard coal or hard coal blends with 20,40%w/w MXG or SH) of a grain size below 0.2 mm, inanalytical state, were placed at the bottom of the reactorbetween two layers of a quartz wool for better temperaturedistribution and avoidance of the entrainment of fuelparticles by the gasification agents.

The reactor containing the studied fuel sample was firstheated up with a resistance furnace with a heating rate of1.33oC/s to the set temperature (700 or 900oC) in a nitrogenatmosphere.

After temperature stabilization steam as a gasificationagent was injected with a flow rate of approximately 5·10-2

cm3·s-1.

Experimental procedure

Materials

Table 1: Proximate and ultimate analyses of studied fuels

Studied coal and biomass samples were dried, grinded and sieved to the fractions ofparticle size below 0.2 mm for coal and below 3 mm for biomass.

No. Parameter Unit HC1 HC2 HC3 MXG SH

1 Moisture, W %w/w 6.02 6.50 11.05 6.78 8.76

2 Ash, A %w/w 5.69 28.73 10.40 1.60 2.63

3 Volatiles, V %w/w 32.12 25.29 31.82 76.00 71.47

4

Heat of

combustion,

Qs

kJ/kg 28,805 20,043 24,515 16,546 16,484

5Calorific

value, Qi

kJ/kg 27,616 19,120 23,318 14,942 15,030

6 Sulfur, S %w/w 0.5 0.82 1.85 0.05 0.04

7 Carbon, C %w/w 70.64 49.62 60.47 53.71 47.18

8 Hydrogen, H %w/w 4.08 3.46 3.46 6.59 5.68

9 Nitrogen, N %w/w 0.98 0.89 0.54 0.00 0.00

10 Fixed carbon %w/w 57.17 39.48 46.73 15.62 17.14

Miscanthus X Giganteus (MXG) provided by plantation in Főhren (Germany)

Coal mines located in the Upper Silesian Coal Basin (Poland)

Sida Hermaphrodita (SH) provided from the plantation of the Department of Agricultural Sciences in Zamość of University of Life Sciences in Lublin (Poland)

Materials

No. Parameter

1 Total moisture, M2 Ash, A3 Volatiles, V4 Heat of combustion, Qs

5 Calorific value, Qi

6 Sulfur, S7 Carbon, C8 Hydrogen, H9 Nitrogen, N10 Fixed carbon11 Total gas yield at 700oC12 H2 yield at 700oC13 CO yield at 700oC14 CO2 yield at 700oC15 CH4 yield at 700oC16 Total gas yield at 900oC17 H2 yield at 900oC18 CO yield at 900oC19 CO2 yield at 900oC20 CH4 yield at 900oC

No. Object1 HC12 HC23 HC34 MXG5 SH6 HC1+20MXG7 HC1+20SH8 HC1+40MXG9 HC1+40SH

10 HC2+20MXG11 HC2+20SH12 HC2+40MXG13 HC2+40SH14 HC3+20MXG15 HC3+20SH16 HC3+40MXG17 HC3+40SH

Table 2 List of objects applied in PCA and HCA

Table 3 List of parameters applied in PCA and HCA

X1

20

17

parameters

Objects (studied samples)

0

5000

10000

15000

20000

25000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Volume of gas com

pone

nts, cm

3

Object no

H2

CO

CO2

CH4

a)

0

5000

10000

15000

20000

25000

30000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Volume of gas com

pone

nts, cm

3

Object no

H2

CO

CO2

CH4

b)

Fig.2 Total volume of the main gas components generated in the gasification and co-gasification of coal and biomass at (a) 700oC and (b) 900oC, respectively

Experimental results

No. Object

1 HC1

2 HC2

3 HC3

4 MXG

5 SH

6 HC1+20MXG

7 HC1+20SH

8 HC1+40MXG

9 HC1+40SH

10 HC2+20MXG

11 HC2+20SH

12 HC2+40MXG

13 HC2+40SH

14 HC3+20MXG

15 HC3+20SH

16 HC3+40MXG

17 HC3+40SH

0

1

2

3

4

5

6

7

8

7 9 11 13 15 17

Relativ

e chan

ge in

 the total gas volum

e, %

Object no

700C

900C

b)

Fig.3 Relative change in the total gas volume generated in co-gasification of coal and (a) MXG and (b) SH biomass and gasification of coal and biomass separately at 700 and 900oC

Experimental results

0

0,5

1

1,5

2

2,5

6 8 10 12 14 16

Relativ

e chan

ge in

 the total gas volum

e, %

Object no

700C

900C

a)

No. Object

1 HC1

2 HC2

3 HC3

4 MXG

5 SH

6 HC1+20MXG

7 HC1+20SH

8 HC1+40MXG

9 HC1+40SH

10 HC2+20MXG

11 HC2+20SH

12 HC2+40MXG

13 HC2+40SH

14 HC3+20MXG

15 HC3+20SH

16 HC3+40MXG

17 HC3+40SH

Parametr 1

Parametr 2

A

B

C

Parameter 1

Parameter 2

Visualization of the data

Principal component analysis (PCA)

Goals:- dimensionality reduction- reduction of experimental error- data visualization and interpretation

X = SD’

n

m

fn

fn

n

+m

n

ESamples(objects)

m

parameters

PCA results

MXG

SH

content of volatiles and hydrogen in a sample

heat of combustion, calorific value, content of nitrogen and fixed carbon, total gas, hydrogen, carbon monoxide and carbon dioxide yields at 700 and 900oC

HC2 blends with 40%w/w of MXG and SH biomass, and HC3 blends with 40%w/w of MXG and SH biomass

HC1 blends with 40%w/w of MXG and SH biomass, HC2 blends with 20%w/w MXG and SH, and HC3 blends with 20%w/w of MXG and SH biomass

HC2, HC3 and HC1 blends with 20%w/w of MXG and SH biomass

uniqueness of HC1

PCA resultsHC1 and HC1 blends of 20

and 40%w/w of MXG and SH biomass content

carbon content

heat of combustion, calorific value, content of nitrogen and fixed carbon, total gas, hydrogen, carbon monoxide and carbon dioxide yields at 700 and 900oC

HC2

PCA resultsHC3 and HC3

blends of 20%w/w of MXG biomass

Moisture content in a sample

content of ash and nitrogen in a sample

PCA resultsHC3 blend of

40%w/w of MXG biomass content

HC1 blends of 40%w/w of SH biomass and HC2 blends of 20%w/w of MXG biomass content

content of the total moisture, and sulfur in a sample, high volume of carbon monoxide produced at 900oC

yield of methane generated in co-gasification at 900oC

Hierarchical clustering can be applied to multidimensional data sets, in order to study similarities (or dissimilarities) of objects in the variables space, or similarities of variables in the objects space.

Any agglomerative hierarchical clustering method is characterized by:

- the similarity measure used, and

- the way the resulting sub-clusters are merged (linked).

Hierarchical clustering analysis (HCA)

Among the linkage methods, the most popular ones are:

SINGLE LINKAGE

COMPLETE LINKAGE

AVERAGE LINKAGE

CENTROID LINKAGE

WARD LINKAGE.

Hierarchical clustering analysis (HCA)

12 13 2 10 11 15 3 14 16 17 1 6 7 8 9 4 5

2

4

6

8

10

12

objects

diss

imila

rity

4 5 10 14 19 7 2 9 17 11 12 16 13 18 1 6 15 20 3 80

1

2

3

4

5

6

7

8

9

objects

diss

imila

rity

parameters

12 13 2 10 11 15 3 14 16 17 1 6 7 8 9 4 5

45

101419

729

171112161318

16

1520

38 -2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

A B C

A1 A2

A B C D

para

met

ers

objects

objects parameters

diss

imila

rity

diss

imila

rity

a) b)

c)

HCA results

12 13 2 10 11 15 3 14 16 17 1 6 7 8 9 4 5

2

4

6

8

10

12

objects

diss

imila

rity

4 5 10 14 19 7 2 9 17 11 12 16 13 18 1 6 15 20 3 80

1

2

3

4

5

6

7

8

9

objects

diss

imila

rity

parameters

12 13 2 10 11 15 3 14 16 17 1 6 7 8 9 4 5

45

101419

729

171112161318

16

1520

38 -2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

A B C

A1 A2

A B C D

para

met

ers

objects

objects parameters

diss

imila

rity

diss

imila

rity

a) b)

c)

Cluster A: coal samples HC2, and HC3, blends of HC2 with 20 and 40%w/w of MXG and SH biomass; HC3 blends of 20 and 40%w/w of MXG and SH biomass (objects nos 2, 3, 10-17)

Cluster B: coal sample HC1; HC1 blends of 20 and 40%w/w of MXG and SH biomass (objects nos 1 and 6-9)

Cluster C: MXG and SH biomass samples (objects nos 4 and 5)

sub-cluster A1:coal sample HC2, blends of HC2 with 20 and 40%w/w of MXG and SH biomass, and blends of HC3 with 20%w/w of SH biomass (objects nos 2, 10-13 and 15)

sub-cluster A2: coal sample HC3; HC3blends of 20%w/w of MXG biomass, and HC3 blends of 40%w/w of MXG and SH biomass (objects nos 3, 14, 16 and 17)

HCA results

12 13 2 10 11 15 3 14 16 17 1 6 7 8 9 4 5

2

4

6

8

10

12

objects

diss

imila

rity

4 5 10 14 19 7 2 9 17 11 12 16 13 18 1 6 15 20 3 80

1

2

3

4

5

6

7

8

9

objects

diss

imila

rity

parameters

12 13 2 10 11 15 3 14 16 17 1 6 7 8 9 4 5

45

101419

729

171112161318

16

1520

38 -2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

A B C

A1 A2

A B C D

para

met

ers

objects

objects parameters

diss

imila

rity

diss

imila

rity

a) b)

c)

group A: heat of combustion, calorific value, carbon and fixed carbon content in a sample, and carbon dioxide yield at 700 and 900oC (parameters nos 4, 5, 7, 10, 14 and 19)group B: content of ash, and nitrogen in a sample, as well as the total gas, hydrogen and carbon monoxide yield at 700 and 900oC (parameters nos 2, 9, 11, 12, 13, 16, 17 and 18)group C: total moisture and sulfur content in a sample, and methane yield at 700 and 900oC (parameters nos 1, 6, 15 and 20)group D: volatiles and hydrogen content in a sample (parameters nos 3 and 8)

HCA results

The dendrograms present the data structure, but did not allow the investigation of the observed patterns in terms of studied parameters. To solve this problem the HCA was complemented with a color map of experimental data sorted according to the specific order of the studied fuel samples (objects) and parameters.

12 13 2 10 11 15 3 14 16 17 1 6 7 8 9 4 5

2

4

6

8

10

12

objects

diss

imila

rity

4 5 10 14 19 7 2 9 17 11 12 16 13 18 1 6 15 20 3 80

1

2

3

4

5

6

7

8

9

objects

diss

imila

rity

parameters

12 13 2 10 11 15 3 14 16 17 1 6 7 8 9 4 5

45

101419

729

171112161318

16

1520

38 -2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

A B C

A1 A2

A B C D

para

met

ers

objects

objects parameters

diss

imila

rity

diss

imila

rity

a) b)

c)

HCA resultsCoal samples HC2 and HC3, blends of HC2 with 20 and 40%w/w of MXG and SH biomass, as well as blends of HC3 with 20 and 40%w/w MXG and SH biomass were characterized by low volatiles and hydrogen content in a sample.

The uniqueness of fuels grouped into sub-cluster A1 was attributed to high ash content in a fuel sample, low heat of combustion, calorific value, fixed carbon content, and carbon dioxide yield at 700 and 900oC and the lowest carbon content in a sample.

Furthermore, the distinctiveness of coal sample HC2 was reported resulting from the highest ash content, relatively high nitrogen content in a sample, as well as high total gas, hydrogen, carbon monoxide and carbon dioxide yields at 700 and 900oC.

12 13 2 10 11 15 3 14 16 17 1 6 7 8 9 4 5

2

4

6

8

10

12

objects

diss

imila

rity

4 5 10 14 19 7 2 9 17 11 12 16 13 18 1 6 15 20 3 80

1

2

3

4

5

6

7

8

9

objects

diss

imila

rity

parameters

12 13 2 10 11 15 3 14 16 17 1 6 7 8 9 4 5

45

101419

729

171112161318

16

1520

38 -2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

A B C

A1 A2

A B C D

para

met

ers

objects

objects parameters

diss

imila

rity

diss

imila

rity

a) b)

c)

HCA resultsCoal sample HC3, blends of HC3 with 20%w/w of MXG biomass, and blends of HC3 with 40%w/w of MXG and SH biomass (objects nos 3, 14, 16 and 17) were characterized by high total moisture and sulfur content in a fuel sample as well as methane yield at 700oC.

Coal sample HC3 (object no. 3) was characterized by the highest total moisture and sulfur content in a sample and high heat of combustion, calorific value and fixed carbon content in a sample.

HC3 blend of 20%w/w of MXG (object no. 14) was unique due to the highest methane yield at 700oC.

12 13 2 10 11 15 3 14 16 17 1 6 7 8 9 4 5

2

4

6

8

10

12

objects

diss

imila

rity

4 5 10 14 19 7 2 9 17 11 12 16 13 18 1 6 15 20 3 80

1

2

3

4

5

6

7

8

9

objects

diss

imila

rity

parameters

12 13 2 10 11 15 3 14 16 17 1 6 7 8 9 4 5

45

101419

729

171112161318

16

1520

38 -2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

2.5

A B C

A1 A2

A B C D

para

met

ers

objects

objects parameters

diss

imila

rity

diss

imila

rity

a) b)

c)

HCA resultsCoal sample HC1; HC1 blends of 20 and 40% of MXG and SH biomass were characterized by high heat of combustion, calorific value, carbon and fixed carbon content in a sample, and carbon dioxide yield at 700 and 900oC as well as low total moisture and sulfur content in a sample and methane yield at 700oC.

MXG and SH biomass samples differed from the remaining studied samples largely because of the lowest ash, nitrogen and fixed carbon content in a sample, the lowest heat of combustion and calorific value and the total gas, hydrogen, carbon monoxide and carbon dioxide yields at 700 and 900oC, as well as the highest volatiles and hydrogen content in a fuel sample.

The average total gas yields produced in coal and biomass steam gasification and co-gasification at 900oC was approximately of approx. 12% higher than the respective values reported at 700oC.

The increase in the total gas yields in co-gasification of coal with 20 and 40%w/w of biomass was observed in comparison with the gasification of coal and biomass separately. The significant differences between studied biomass samples were observed, reflected in the stronger synergy effect reported in co-gasification of blends of coal and Sida Hermaphrodita biomass than for blends of coal and Miscanthus Giganteus biomass.

More pronounced synergy effects were observed in co-gasification of coal blends with Sida Hermaphrodita biomass at 700oC than at 900oC. These differences may be attributed to various content of selected metals in samples tested.

Conclusions

Thank you for your attention

ACKNOWLEDGEMENTS This work was supported by the Ministry of Science and Higher Education, Poland, under Grant No. 11310046