EXPERIMENTAL STUDY OF SOLUBILITY OF ELEMENTAL SULPHUR IN METHANE

Transcription

1 EXPERIMENTAL STUDY OF SOLUBILITY OF ELEMENTAL SULPHUR IN METHANE Eric CLOAREC, Pierre CEZAC, Jean Paul SERIN, Jacques MERCADIER Laboratoire de Thermique, Énergétique et Procédés () Rue Jules Ferry BP 7511 Pau Cedex, FRANCE Project sponsored by GERG 1.66 GERG ACADEMIC NETWORK EVENT 2012

2 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 2

3 1 SULPHUR DEPOSITION IN TRANSMISSION NETWORK 3

4 1 SULPHUR DEPOSITION IN Transmission conditions 2 MPa < P < 8 MPa TRANSMISSION NETWORK Distribution conditions P = 0,5 MPa solid sulphur deposit Sulphur deposition implies Safety problems Maintenance actions Cost 4

5 Sulphur desublimation 1.1 PROBLEMATIC Modelling thermodynamic approach [1] Desublimation Only few available data in a range of pressure and temperature GAS FIELD T (K) TRANSPORT P (MPa) [1] Cézac P., Serin J.-P., Reneaume J.-M., Mercadier J., Mouton G., J. Supercritical Fluids, vol. 44, 2, 2008, p

6 1.2 EXISTING DATA 2500 Sulphur solubility in Carbon dioxyde Solubility (mg/nm3) Serin K Kennedy K Serin K Gu 363.2K Kennedy K Gu 383.2K 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 [3] Gu M-X. et al., Experimental and modeling studies on the phase behavior of high H 2 S-content natural gas mixtures, Fluid Phase Equilib. 82, 1993, p [4] Serin et al The Journal of Supercritical Fluids, Volume 53, Issues 1-3, June 2010, Pages

7 1.2 EXISTING DATA (II) Solubility (mg/nm3) Sulphur solubility in Methane 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 [3] Gu M-X. et al., Experimental and modeling studies on the phase behavior of high H 2 S-content natural gas mixtures, Fluid Phase Equilib. 82, 1993, p Kennedy K Kennedy K Gu 383.2K 7

8 2 EXPERIMENTAL WORK 8

9 2 EXPERIMENTAL WORK Experimental procedure consists in 3 major steps: Gas saturation in sulphur Trapping of sulphur Analysis by gas chromatography N 2 Booster P max = 500 bar CO 2, or CH CH 4, 4 N 2, etc Saturated gas Equilibrium cell Pressure drop Atmospheric Separators Mass flowmeter Pressurised separator Analysis 9

10 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 10

11 2.2 TRAPPING OF SULPHUR Trapping of sulphur procedure Pressurised reactive absorption Pressure reduction Atmospheric reactive absorption Saturated gas Pressurised separator Pressure drop Atmospheric Separators Mass flowmeter 11

12 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 (S 8 ) 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 [6]K.L. Lesage, P.D. Clark, Quantitative determination of elemental sulfur in hydrocarbons, soils, and other materials, J. Chromatogr. Sci. 27 (1989) [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,

13 2.3 ANALISYS BY GAS CHROMATOGRAPHY Analysis by GC coupled with FPD Detector in phosphorus mode allows the quantification of solubilised products toluene triphenylphosphine (TPP) triphenylphosphate (TPPO 4 ), triphenylphosphine oxide (TPPO) sulphur triphenylphosphine (TPPS) 13

14 3 RESULTS 14

15 Sulphur solubility in carbon dioxyde at K 2 3 RESULTS Solubility (mg/nm 3 ) 1,6 1,2 0,8 0,4 Pilot and Protocol validation Pressure (MPa), Serin and al [1] ;, Kennedy and Wieland [2] ;, Gu and al [3]. This work 15

16 Sulphur solubility in Methane 3 RESULTS (II) Solubility (mg/nm3) This work K This work K This work K Pressure (MPa) 16

17 Sulphur solubility in Methane 3 RESULTS (III) Solubility (mg/nm3) Pressure (MPa) This work K Kennedy K This work K Kennedy K Gu 383.2K This work K 17

18 Solubility (mg/nm3) Sulphur solubility in Methane Pressure (MPa) 3 RESULTS (IV) This work K Kennedy K This work K Kennedy K This work K 18

19 4 CONCLUSIONS 19

20 4 CONCLUSIONS Experimental procedure validated:. Isothermal evolution of solubility of sulphur in CH 4 at K, K, K, Still many studies to come: Study solubility in LNG, Gas mixture and Natural gas 20

21 Many thanks. Questions? 21