Ni CATALYSTS FOR CO 2 CONVERSION USING

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The solid with 15% of Ni and 0,5% of Ru (S_0,5Ru) showed the best catalytic behaviour in all the studied compositions and also the lowest amount of carbon ...
Ru – Ni CATALYSTS FOR CO2 CONVERSION USING METHANE REFORMING REACTIONS

Andrea Álvarez, Miguel Ángel Centeno, José Antonio Odriozola Instituto de Ciencia de Materiales de Sevilla, Centro Mixto Universidad de Sevilla - CSIC. Avenida Americo Vespucio 49, 41092, Sevilla, Spain

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H2/CO=1 HOW TO PRODUCE SYNGAS WITH A H2/CO 2 ?

H2O ADDITION !!

Catalysts design

Catalyst Characterization

Calcined samples

THE PROGRAMMING ! -Al2O3

Formation of MgAl2O4 spinel:

Ruº

NiMAlu 2%Ru/MgAl2O4

[101] [111]

[200]

Niº MgAl2O4

Niº

[400]

S_2Ru

#"N No evidence of Ru as (RuO2) or (Ruº)) in the sample S_0,5Ru. !

S_0,5Ru NiMAlu 2%Ru/MgAl2O4

Suggests highly disperses Ru!

0,5%Ru/MgAl2O4

!" Increases H2O and CO2 adsorption. !" Increases basicity. !" Increases Ni dispersion.

[002]

XRD

S_0,5Ru

Intensity (a.u)

-Al2O3

Reduced samples

Ruº

S_2Ru

MgAl2O4

Syntheti ze activ e and stabl e Ni base d catalysts for severa l C O2 c o nversio n reactions

SYNGAS

Among the many human activities that produce green house gases (GHG) the use of energy represents by far the largest source of emissions. Within the energy sector, CO2 resulting from the oxidation of carbon in fuels during combustion, correspond to the 90% of produced GHG.

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CH4 + CO2 ! 2 CO + 2 H2

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69%

PURPOSE

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Energy

14%

0,5%Ru/MgAl2O4 MgAl2O4

MgAl2O4 20

25

30

35

40

45

50

55

º2!

60

65

70

75

40

42

44

46

48

º2!

50

52

54

LO TO

RAMAN STUDY

S_0,5Ru

S_2Ru S_0,5Ru NiMAlu 2%Ru/MgAl2O4

#" Suggests higher Ru-Ni interaction

S_2Ru

200

300

THERMODYNAMIC ANALYSIS

2,0

80

Thermodynamic Eq.

S_0,5Ru

70

S_2Ru

60

NiMAlu

50 40 30

POST-REACTION ANALYSIS

1,8

900 800 700

80

0,3

H2O CO2/CH4 : 0,6

0

10

20

30

Time (h)

40

80

60

70

50 40 30

50

NiMAlu

0

Thermodynamic Eq.

S_2Ru

70

S_2Ru

S_0,5Ru

S_0,5Ru

NiMAlu

50 40 30 20 10

20

30

40

50

10

15

20

Time (h)

50

50 S_2Ru

30

S_0,5Ru

30

10

30

Time (h)

500 NiMAlu

S_0,5Ru

40

50

400

60

70

300

80

Time (min)

0

20

+

40

60

80

900

9% H 2O

13% H 2O

800

20% H 2O

28% H2O

70

700 600

S_0,5Ru

500

S_2Ru

NiMAlu

400

S_0,5Ru

56

60

63 Time (min)

300 77

70

900

50

800

40

S_2Ru

30

10

20

S_2Ru

50

NiMAlu

20

NiMAlu

0

600

S_2Ru

40

90

60

800 700

Time (h)

70

10

S_0,5Ru

80

40

28% H 2O

60

10

25

80

20 0

5

20% H2O

662ºC

569ºC

20

Thermodynamic Eq.

90

60

10

70

13% H2O

9% H 2O

595ºC

NiMAlu

0

20

40 Time (h)

60

80

S_0,5Ru

700 600

NiMAlu

500 S_2Ru

400

50

60

70

Time (min)

Conclusions "" The solid with 15% of Ni and 0,5% of Ru (S_0,5Ru) showed the best catalytic behaviour in all the studied compositions and also the lowest amount of carbon deposits after 100h of reaction. "" Water addition to the reaction not only helped the carbon gasification, and therefore the activity, but also was very useful to modulate the final H2/CO ratio obtained. "" An optimum molar ratio of 1-0,56-0,4 of CH4-H2O-CO2 was found to achieve the production of syngas with H2/CO ratio of 2, a feedstock very useful in Fisher-Tropsch reaction for the manufacture of synthetic fuels.

80

300

Temperature (ºC)

CO2 conversion (%)

1,4

90

90

900

Temperature (ºC)

CO2/CH4 : 0,4

Molar Ratio CO2/CH4: 0,4 +

10

CO2 conversion (%)

10

0,5

Temperature (ºC)

900

Thermodynamic Eq.

20

20

0,6

800

Molar Ratio CO2/CH4: 0,4

90

CH4 conversion (%)

CH4 conversion (%)

80

2,2

0,7

400 500 600 700 -1 Raman Shift (cm )

100 200 300 400 500 600 700 800 900

Temperature (ºC)

H2/CO

Molar Ratio CO2/CH4: 1

90

2,4

0,8

2%Ru/MgAl2O4

CATALYTIC RESULTS

CO2/CH4: 0,2

0,4

NiMAlu

0,5%Ru/MgAl2O4

MgAl2O4

1,6

S_0,5Ru

0,5%Ru/MgAl2O4

Calcined at 500ºC for 3h!

2,50 2,35 2,20 2,05 1,90 1,75 1,60 1,45 1,30

S_2Ru

CO2 --> m/z=44 signal (a.u)

NiMAlu

#

#"R Ru O 2 l a t t i c e seems to b e a ff e c t e d b y NiO presence.!

#"T The presence of Ru increases the reducibility of Ni and decreases the temp erature of reduction.!

O2 --> m/z=32 signal (a.u)

!"

!" #

TP R – H 2

CO --> m/z=28 signal (a.u)

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A1g B2g

CH4 conversion (%)

!" #

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Eg

CO2 conversion (%)

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T (ºC)

Others

COULD WE USE CO2 AS A FEEDSTOCK ?

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Intensity (a.u)

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