Performance of cycloalkane and paraffinic solvent mixtures for non-aqueous extraction of Alberta oil sands.

1. 1
Performance of cycloalkane and paraffinic
solvent mixtures for non-aqueous
extraction of Alberta oil sands
Krupal Pal, Ph.D.
Lucas da Paz Nogueira Branco2, Annabell Heintz1, Phillip Choi1,
Qi Liu1, Peter R Seidl2, and Murray R Gray1
1. Institute for Oil Sands Innovation (IOSI), Department of Chemical and Materials
Engineering, University of Alberta, Edmonton, Alberta
2.Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.

2. Outline
2
• Introduction
• Motivation
• Objective Study of oil sand extraction using
pure solvents and mixture of solvents
(cycloalkanes and paraffinic)
• Methodology IOSI oilsand extraction process
• Results
• Conclusions

3. Motivation
3
 Increases Tailings ponds
 Excess withdrawal of
fresh water
 High energy consumption
 Ecological imbalance
Aqueous
Extraction
(Hot water)
Commercial
Process for
Bitumen
recovery
Disadvantages
Oil sand Ore
Solvent
Extracted
gangue
BitumenNon-Aqueous
Extraction
Solvent Recovery
• Eliminate use of
water
• No tailing ponds
• Solvent recovered
and recycled

4. Objective
4
High bitumen recovery
Low fine solids content in bitumen
Release little solvent in environment
Non aqueous
extraction process
is feasible if….
Ideal solvent
for extraction
Strong bitumen solubility
Low boiling point = Easy solvent recovery
Study of oil sand extraction using mixture of solvents for rich grade ores.
 Solvents: Mixtures of cyclohexane and paraffinic solvents (Heptane, Hexane,
Pentane)
 Evaluated parameters: (i) Bitumen recovery
(ii) Fine solids in extracted bitumen

5. Methodology
5

6. Sample Analysis and Bitumen Recovery
• Dean Stark analysis: Analyze bitumen content in ore
– Bitumen, water and fine solids
• Carbon content analysis: Calculate bitumen recovery
– Vacuum dried gangue samples
– Vacuum dried fine solid samples
• Bitumen recovery calculation:
6

7. 7
Results
Comparison of pure solvents: Bitumen recovery
Boiling Point (0C) Density (g.cm-3) Solubility
Parameter (MPa)1/2
Cyclohexane 80.7 0.78 16.8
Cyclopentane 49 0.75 16.6
Methylcyclopentane 71.8 0.75 16.2

8. Solvent blends: Cyclohexane/heptane mixture solvent
8
Cyclohexane
(%)
Mass of
centrifuged
solids (g)
Carbon %
2nd gangue
Bitumen
Recovery
100 4.0 0.3 99.2
97.5 3.8 0.6 97
95 1.7 0.6 97
92.5 1.3 0.6 97
90 2.7 0.8 96
80 2.6 0.6 97
70 2.8 0.7 96
0 7.2 0.7 96
 Bitumen recovery > 95%
 Lowest amount of centrifuged fines released using solvent mixture of 92.5%
cyclohexane/7.5% heptane.

9. Behavior of released centrifuge solids in bitumen
(Cyclohexane/n-heptane)
9
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
60 70 80 90 100
Amountofcentrifugedsolids(g)
% of Cyclohexane in the mixture of Heptane
 Migration of fines in bitumen
product - lowest for 92.5%
cyclohexane/7.5% heptane
 Solubility parameter was
selected as a parameter for
comparison
 Solubility parameter was
measured for
1. 92.5% CH/7.5% Heptane
2. 80% CH/20% Heptane
 At similar solubility coefficients
cyclohexane/hexane and
cyclohexane/pentane mixtures
were studied

10. 10
Solubility parameter of mixtures
𝛿𝑚𝑖𝑥 =
𝑖=1
𝑛
𝛾𝑖 ∗ 𝛿𝑖
𝛾𝑖 = Volumetric fraction of solvent ‘i’
𝛿𝑖 = Solubility parameter of solvent ‘i’
𝛿𝑚𝑖𝑥 =
100 ∗ 𝜃1
𝜌1
𝑚1
𝜌1 +
𝑚2
𝜌2
∗ 𝛿1 +
100 ∗ 𝜃2
𝜌2
𝑚1
𝜌1 +
𝑚2
𝜌2
∗ 𝛿2
Solubility parameter calculated for data points of interest
= 16.65 (MPa)1/2 and 16.45 (MPa)1/2
 Cyclohexane/n-hexane and Cyclohexane/n-pentane mixtures were
studied at solubility parameter 16.65 (MPa)1/2 and 16.45 (MPa)1/2
 Cyclopentane and paraffinic solvents were studied further

11. Cyclohexane/paraffinic solvent mixtures
11
Experimental set 1 mix
(MPa)1/2
92.5% Cyclohexane/ 7.5% n-Heptane 16.65
94.5% Cyclohexane/ 5.5% n-Hexane 16.65
96% Cyclohexane/ 4% n-Pentane 16.65
0.000
0.002
0.004
0.006
0.008
0.010
0.012
0.014
0.016
0.018
0.020
75 80 85 90 95 100
Massoffinesreleased/Massof
initialoilsands
% of Cyclohexane
Heptane
Hexane
Pentane
Set 2
Set 1
Experimental set 2 mix
(MPa)1/2
80% Cyclohexane/ 20% n-Heptane 16.45
85% Cyclohexane/ 15% n-Hexane 16.45
89.2% Cyclohexane/ 10.8% n-Pentane 16.45

12. Summary of Cyclohexane/paraffinic solvent mixtures
12
Total
centrifuged
solids (g)
Bitumen
recovery (%)
92.5% Cyclohexane/ 7.5% Heptane 1.7 97
94.5 Cyclohexane/ 5.5% Hexane 0.8 98
96% Cyclohexane/ 4% Pentane 0.6 96
Total
centrifuged
solids (g)
Bitumen
recovery (%)
80% Cyclohexane/ 20% Heptane 2.4 97
85% Cyclohexane/ 15% Hexane 1.6 99.7
89.2% Cyclohexane/ 10.8%Pentane 0.9 96
 Cyclohexane/
Hexane solvent
mixtures gives high
Bitumen recovery
compared to
cyclohexane/
heptane &
cyclohexane/
pentane
 Carbon% increases
with cyclohexane/
pentane solvent
mixture.
 Cyclopentane
mixtures were
studied at 16.45

13. 13
Summary of cyclopentane/paraffinic solvent mixtures
Total
centrifuged
solids (g)
Bitumen
recovery (%)
90.2% Cyclopentane/ 9.8% n-Heptane 2.4 93
92.6% Cyclohexane/ 7.4% n-Hexane 1.7 97
94.5% Cyclohexane/ 5.5% n-Pentane 1.3 89
 Bitumen recovery decreased
 Cyclopentane/n-hexane gives better results as compared to other blends.
 Asphaltene precipitation was observed

14. 14
Comparison of Cyclopentane/paraffinic mixtures using
solubility parameter
n-hexane gives better results in
cycloalkane

15. Conclusion
Pure solvents:
• Pure cyclohexane has the best potential for non-aqueous process
• For pure solvents, bitumen recovery increased with increase in solubility
parameter of pure solvents.
Solvent mixtures:
• Bitumen recovery was highest for cyclohexane/hexane mixtures.
• Cyclohexane/pentane solvent mixtures released lowest amount of
centrifuged fines.
• Amount of released centrifuged solids followed the order cycloalkane/n-
heptane > cycloalkane/n-hexane > cycloalkane/n-pentane blends.
15