Encyclopedie de la recherche sur l'aluminium au Quebec - Edition 2014 | Page 32

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Characterization and
PRODUCTION D’ALUMINIUM // ALUMINIUM PRODUCTION

Thermal
Desulfurization of High Sulfur Petroleum
CARACTÉRISATION ET DÉSULFURISATION THERMIQUE DE COKE DE PÉTROLE
Coke for Carbon Anode Production
AVEC HAUTE TENEUR EN SOUFRE POUR LA PRODUCTION D'ANODES EN CARBONE

Caractérisation et désulfurisation thermique

CHARACTERIZATION AND THERMAL DESULFURIZATION OF HIGH
de coke de pétrole avec haute teneur en soufre
SULFUR PETROLEUM COKE FOR CARBON ANODE PRODUCTION

pour la production d’anodes en carbone

Meltem

KILIC1,

Duygu KOCAEFE1 , Yasar KOCAEFE1, Dipankar BHATTACHARYAY1, Brigitte MORAIS2

CHAIRE DE RECHERCHE UQAC /
AAI SUR LE CARBONE

Université du Québec à Chicoutimi. 555, Boul. De l’Université, Chicoutimi (Québec), Canada G7H 2B1
Aluminerie Alouette Inc. 400, Chemin de la Pointe-Noire, P. O. Box 1650, Sept-Îles (Québec) Canada G4R 5M9
1

2

CHAIRE DE RECHERCHE UQAC/AAI SUR LE CARBONE

Introduction

Experimental Procedure

Problem Statement

Coal tar pitch

Mixing of raw
materials

Butts and recycled anodes

Vibration
Forming

Baking

High sulfur

Rodding

1. Characterization of Green Petroleum Coke (GPC)

Anode-grade
petroleum
coke

Sulfur analysis
Low sulfur

Process conditions

Raw material quality

GPC

Availability
decreasing

Environment
Anode quality

XPS

Calcined
coke

Elemental Analysis

•Characterization of several green petroleum cokes with
different sulfur contents

Sulfur content
of green coke

Green coke

C

S

H

•Study of sulfur removal by thermal desulfurization
during calcination of green cokes with different sulfur
contents

Results

N

(wt%) (wt%) (wt%) (wt%)
Elemental analysis of three green
petroleum coke samples from the
Coke A 88.74 6.44 3.85 1.00
same source (these results will be
compared with those of the
Coke B 88.80 5.64 3.77 1.42
thermodesulfurized and calcined
samples)
Coke C 88.68 5.03 3.75 1.45

FT-IR Analyses

Fig 1. Green
petroleum coke

Thermal Desulfurization
1.00

(a)

(b)

(c)

1.00

Coke A

0.95
0.90
0.85

1200⁰C
1300⁰C

0.80

1400⁰C

0.75

XPS Analyses

PRIX // AWARD

• With TGA induction furnace
• 3 different coke samples from
the same source (different in
terms of S content)
• Measurement of weight loss
• Up to 3 maximum temperatures:
1200ºC-1300ºC-1400ºC
• Constant heating rate
TGA Induction furnace

Objectives

Production of good quality
carbon anodes

Dimensionless Weight

More stable cell operation
Reduced environmental emissions
More efficient energy use

SEM

2. Thermal Desulfurization of Green Petroleum Coke

Desulfurization

The quality
of carbon
anode

FT-IR

0

10

20

0.90

50

60

CN/C C=O/
COO
O/CS CSO2

O
(%)

N
(%)

3.05

1.43

6.96

0.00

95.5

0.85

1200⁰C
1300⁰C
1400⁰C

0.80
0.75

0

10

20
30
40
Process time (min)

(a)

85.99

9.48

2.11

0.88

1.54

2.52

0.00

1.98

Coke
93.71 84.56
C

FT-IR Spectra of green petroleum cokes
reported by Menéndez et al.*

7.91

4.44

1.56

1.53

4.47

0.01

1.81

(* Menéndez, J.A., J.J. Pis, R. Alvarez, C. Barriocanal,
E. Fuente and M.A. Díez, Characterization of Petroleum
Coke as an Additive in Metallurgical Cokemaking.
Modification of Thermoplastic Properties of Coal. Energy
& Fuels, 1996. 10(6): p. 1262-1268.)

Atomic percentages of green petroleum cokes

%S of Coke /
%S of Green Coke A

Dimensionless weight

0.90

1.96

Coke
B

50

60

50

0.8

1200C
0.4

1300C
1400C

0.2
0.0

60

initial

0.6

Coke A

Coke B

Coke C

Sulfur content of 3 petroleum cokes before
and after thermal desulfurization

SEM Analyses

S
(%)

Coke
91.08 78.83 10.43 6.26
A

30
40
Time (min)

Green

C-C

20

(b)

(c)

Thermodesulfurized

Brigitte Morais
Aluminerie Alouette Inc.

Carbon Components
C=C

10

1.0

Coke C

0.95

Deconvoluted high resolution spectra of C1s peak for (a) green coke A (b) green coke B
(c) green coke C

C
(%)

0

Weight loss of petroleum cokes A-B-C with thermal desulfurization up to 1200-1300-1400ºC

FT-IR Spectra of 3 different green
petroleum coke samples by DRIFT
technique

Coke
Type

1300⁰C
1400⁰C

0.80

1.00

Saliha Meltem Kilic
Duygu Kocaefe
Yasar Kocaefe
Dipankar Bhattacharyay
Université du Québec
à Chicoutimi

1200⁰C

0.85

0.75
30
40
Time (min)

Coke B

0.95

Dimensionless weight

Calcined
petroleum coke

Results of the SEM analysis for green and thermodesulfurized (a) Coke A ,
(b) Coke B, and (c) Coke C

Conclusions and Future Work
•The sulfur contents of the cokes decrease after thermal desulfurization as expected. One would expect higher sulfur removal with increasing
temperature. The overall tendency seems to follow this trend; however, the data show significant scatter. This is likely due to the
non-homogeneous nature of the petroleum coke.
•FT-IR analysis was used to identify the chemical functionality of the coke samples. The results show that qualitatively the three coke samples have the
same types of functional groups.
•XPS analysis indicates the differences in the quantity of the surface functional groups of the three petroleum cokes.
•SEM results clearly show the changes in the physical structure of the three coke samples after thermal desulfurization at high temperature.
•Future work will focus on the removal of sulfur via hydrodesulfurization. The results of the thermal desulfurization (some of which are presented
here) will be compared with those of the hydrodesulfurization to assess the effectiveness of sulfur removal by each method.

Acknowledgment
The technical and financial support of Aluminerie
Alouette Inc. as well as the financial support of the
Natural Sciences and Engineering Research