EXPERIMENTAL STUDY OF SOLUBILITY OF ELEMENTAL
SULPHUR
IN
METHANE
Eric CLOAREC, Pierre CEZAC, Jean Paul SERIN, Jacques MERCADIER
Laboratoire de Thermique, Énergétique et Procédés (LaTEP) Rue Jules Ferry BP 7511 Pau Cedex, FRANCE
Project sponsored by GERG 1.66
LaTEP
Ea 1932
GERG ACADEMIC NETWORK EVENT 2012
OUTLINE
1. Sulphur deposition in transmission network
1. Problematic
2. Existing data
2. Experimental work
1. Gas saturation in sulphur
2. Trapping of sulphur
3. Analysis by gas chromatography
3. Results
4. Conclusions and outlooks
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1 SULPHUR DEPOSITION IN
TRANSMISSION NETWORK
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1 SULPHUR DEPOSITION IN
TRANSMISSION NETWORK
 Transmission conditions
 2 MPa < P < 8 MPa
 Distribution conditions
P = 0,5 MPa
solid sulphur
deposit
 Sulphur deposition implies
 Safety problems
 Maintenance actions
Cost
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1.1 PROBLEMATIC
 Sulphur desublimation
• Modelling thermodynamic approach [1]
Desublimation
• Only few available data in a range of pressure and temperature
473.15
T (K)
GAS FIELD
373.15
TRANSPORT
273.15
0
10
P (MPa)
[1] Cézac P., Serin J.-P., Reneaume J.-M., Mercadier J., Mouton G., J. Supercritical Fluids,
vol. 44, 2, 2008, p. 115
20
30
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1.2 EXISTING DATA
 Sulphur solubility in Carbon dioxyde
Solubility (mg/Nm3)
2500
2000
Serin 333.15K
Kennedy 338.71K
Serin 363.15K
Gu 363.2K
Kennedy 366.48K
Gu 383.2K
1500
1000
500
0
0
10
20
30
40
50
Pressure (MPa)
[2] Kennedy H. T., Wieland D. R., Equilibrium in the methane-carbon dioxide-hydrogen sulfide-sulfur system, Petroleum Transaction
AIME 219, 1960, p. 166-169
[3] Gu M-X. et al., Experimental and modeling studies on the phase
behavior of high H2S-content natural gas mixtures, Fluid Phase Equilib. 82, 1993, p. 173-182
[4] Serin et al The Journal of Supercritical Fluids, Volume 53, Issues 1-3, June 2010, Pages 12-16
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1.2 EXISTING DATA (II)
 Sulphur solubility in Methane
500
Solubility (mg/Nm3)
450
400
350
300
Kennedy 338.71K
Kennedy 366.48K
Gu 383.2K
250
200
150
100
50
0
0
10
20
30
40
50
60
Pressure (MPa)
[2] Kennedy H. T., Wieland D. R., Equilibrium in the methane-carbon dioxide-hydrogen sulfide-sulfur system, Petroleum Transaction
AIME 219, 1960, p. 166-169
[3] Gu M-X. et al., Experimental and modeling studies on the phase
behavior of high H2S-content natural gas mixtures, Fluid Phase Equilib. 82, 1993, p. 173-182
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2 EXPERIMENTAL WORK
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2 EXPERIMENTAL WORK
 Experimental
•
•
•
procedure consists in 3 major steps:
Gas saturation in sulphur
Trapping of sulphur
Analysis by gas chromatography
N2
Equilibrium
cell
Booster
Pmax = 500 bar
Atmospheric
Separators
CO
CO22,orCHCH
4, 4
N2, etc…
Saturated
gas
Pressure
drop
Pressurised
separator
Mass
flowmeter
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Analysis
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2.1 GAS SATURATION IN SULPHUR
 Gas saturation procedure
•
•
•
•
Excess sulphur introduced
Introduction of Gas
Reactor isolated and stirring for 15 h to establish gas-solid equilibrium
Saturated gas is flowed out
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2.2 TRAPPING OF SULPHUR
 Trapping of sulphur procedure
•
•
•
Pressurised reactive absorption
Pressure reduction
Atmospheric reactive absorption
Atmospheric
Separators
Saturated
gas
Pressurised
separator
Mass
flowmeter
Pressure
drop
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2.3 ANALISYS BY GAS
CHROMATOGRAPHY
 The chemical reaction developed by Bartlett and Mergurian [5], is the basis of the
analytical method used:
 Elemental sulphur (S8) contained in saturated gas reacts in solution with
triphenylphosphine (TPP) to form sulphur triphenylphosphine (TPPS).
[5] P. D. Bartlett, G. Mergurian G., J. Am. Chem. Soc., vol. 78, 1956, p. 3710
[6]K.L. Lesage, P.D. Clark, Quantitative determination of elemental sulfur in hydrocarbons, soils, and other materials, J. Chromatogr. Sci.
27 (1989) 259– 271.
[7] P.M. Davis, K.L. Lesage, P.D. Clarck, An analytical strategy and test protocol for the determination of low levels of elemental sulfur in
natural gas, in: Conference on Natural Gas Odorization, Quality & Energy Measurement, Chicago, IL, 1999.
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Analysis
2.3 ANALISYS BY GAS
CHROMATOGRAPHY
by GC coupled with FPD Detector in phosphorus mode allows the
quantification of solubilised products
• toluene
• triphenylphosphine (TPP)
• triphenylphosphate (TPPO4),
• triphenylphosphine oxide (TPPO)
• sulphur triphenylphosphine
(TPPS)
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3 RESULTS
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3 RESULTS
 Sulphur solubility in carbon dioxyde at 363.15K
Solubility (mg/Nm3)
2
1,6
Pilot and Protocol
validation
1,2
0,8
0,4
0
0
5
10
15
20
25
Pressure (MPa)
30
35
40
45
, Serin and al [1] ; , Kennedy and Wieland [2] ; , Gu and al [3].
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This work
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3 RESULTS (II)
 Sulphur solubility in Methane
8
Solubility (mg/Nm3)
7
6
5
This work 363.15K
This work 333.15K
This work 303.15K
4
3
2
1
0
0
2
4
6
Pressure (MPa)
8
10
12
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3 RESULTS (III)
 Sulphur solubility in Methane
500
450
Solubility (mg/Nm3)
400
350
This work 333.15K
Kennedy 338.71K
This work 363.15K
Kennedy 366.48K
Gu 383.2K
This work 303.15K
300
250
200
150
100
50
0
0
10
20
30
Pressure (MPa)
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40
50
60
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3 RESULTS (IV)
 Sulphur solubility in Methane
20
18
Solubility (mg/Nm3)
16
14
This work 333.15K
Kennedy 338.71K
This work 363.15K
Kennedy 366.48K
This work 303.15K
12
10
8
6
4
2
0
0
5
10
Pressure (MPa)
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4 CONCLUSIONS
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4 CONCLUSIONS

Experimental procedure validated:
.
Isothermal evolution of solubility of sulphur in CH4 at 363.15K,
333.15K, 303.15K,
 Still many studies to come:

•
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Study solubility in LNG, Gas mixture and Natural gas
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Many thanks….
Questions ?
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