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Optical cells with fused silica windows for the study of geological fluids
I-Ming Chou
U.S. Geological SurveyReston, Virginia
USA
Outline• HDAC vs FSCC• Two types of optical cells with fused silica windows for
the study of geologic fluids (C-O-H-N-S-salts) at P-T conditions up to 100 MPa and 600 ºC:– (1) High pressure optical cell ( HPOC) for samples
with known compositions and adjustable pressures for in-situ experiments
– (2) Fused silica capillary capsule (FSCC) for samples with mostly uncertain composition and pressure, and suitable for long term (days or weeks) experiments
• Constructions of these optical cells and applications• Summary
April 17, 2005At APS
Argonne National Lab
Bassett et al. (1993)
HDAC type V
Kenji MibeEarthquake Research Institute
University of Tokyo, Japan
Raman study of synthetic subduction-zone fluids
(KAlSi3O8-H2O) system
SCF: supercritical fluidF: aqueous fluidSa: sanidineM: hydrous meltMs: muscoviteC: corundum
Dec. 6, 2006at USGS
Mibe, Chou, & BassettJGR, 113 (2008)
SanidineKAlSi3O8
MuscoviteKAl2(Si3Al)O10(OH)2
Some mineralsin the system:
KAlSi3O8 - H2O
CorundumAl2O3
Mibe, Chou, & BassettJGR, 113 (2008)
Mibe, Chou, & BassettJGR, 113 (2008)
Moleculea Frequency (cm-1)b Motionj
H4SiO4 (Mo) 783 (calc)c, 785 (exp)d, 788 (calc)e n(Si-O)
KH3SiO4 (Mo) 748 (calc)f n(Si-O)
H6Si2O7 (D) 620 (calc)e, 631 (calc)c, 638 (calc)g n(Si-O), d(Si-O-Si)
H6SiAlO71- (D) 585 (calc)g n(Tk-O), d(Si-O-Al)
H4SiAlO73- (D) 574 (exp)d n(T-O), d(Si-O-Al)
H6Si3O9 (3R) 629 (calc)e n(Si-O-Si)H6Si2AlO9
1- (3R) 574 (calc)h n(T-O-T)H8Si4O12 (4R) 490 (calc)h n(Si-O-Si)
H8Si3AlO121- (4R) 488 (calc)h n(T-O-T)
Al(OH)41- 616 (calc)i, 620 (exp)d n(Al-O)
KAl(OH)4 619 (calc)f n(Al-O)KH2AlO3 691 (calc)f n(Al-O)Al(OH)3H2O 438 (calc)i n(Al-OH2)
KOH 361 (calc)f d(K-O-H)
Mibe, Chou, & Bassett
JGR, 113 (2008)
Jan. 16, 2008at USGS
Wanjun LuChina Univ. of Geosci.
Zhiyan PanZhejiang Univ.
of Tech. Xiaochun XuHefei Univ.
of Tech.
Synthetic Fluid Inclusionsin Quartz
(Sterner & Bodnar, 1984)
• Pre-fractured quartz core or prism, together with sample fluid and silica powder, were sealed in a precious-metal capsule.
• The fractures in quartz were healed at a fixed P-T condition in a pressure vessel and captured sample fluid as inclusions.
• To heal the fractures requires high T (> 300 ºC) and time (days and weeks).
Lin (2005)
• Synthesized CH4-H2O fluid inclusions in quartz in Pt capsules at 300 to 700 C and 1, 3, and 5 kbars
• Al4C3 +12 H2O = 3 CH4 + 4 Al(OH)3
• All inclusions formed at and above 600 C contain CO2
CH4+ H2O = CO2 + H2
Polymicro Technologies, LLC(www.polymicro.com).
Fused Silica Capillary Tube
Square-sectioned tubeRound-sectioned tube
HPOCChou et al. (2005)
GlandSleeve
Valve Fused silicaHP tube
Chou, Burruss, Lu (2005)Chapter 24 in
Advances in High-Pressure Technologyfor Geophysical Applications
Raman Spectra for CH4 in Different Phases
2911
.3
Dissolved CH4(31.7 MPa)
Gas phase @ 3.4 MPa2917.3 cm-1
2880 2890 2900 2910 2920 2930 2940Wavenumbers (cm-1)
Inte
nsit
y (a
.u.)
Large cage Small cage
2904.8 cm-1
2915 cm-1
CH4 sI Hydrate
P (MPa)0 20 40 60 80
-8
-6
-4
-2
0
D =
n -
n o (cm
-1)
P (MPa)0 20 40 60 80
CH
4 1 p
eak
posi
tion
(cm
-1)
2910
2912
2914
2916
2918
Thieu et al. (2000)
Hansen et al. (2001)
Thieu (1998)
Seitz et al. (1996)Fabre & Couty (1986)
Hester (2002)
Jager (1998)
Lin (2005) This study
Lu, Chou, Burruss, Song GCA (2007)
no = p.p. near 0 Pn = p.p. at high P
P (MPa) = - 0.0148 D5 - 0.1791 D4
- 0.8479 D3 - 1.765 D2 - 5.876 D
What Are Gas Hydrates ?
136 H2O
46 H2O
34 H2O
2
16
3
6
8
2 1
51264
51268
51262
512
435663
Structure I
Structure II
Structure H
Methane, Ethane, Carbon dioxide, etc.
Cavity Types Hydrate Structure ‘Guest’ Molecules
Propane, Iso-butane, etc.
Methane + Neohexane,Methane + Cycloheptane,
etc.
Chou et al. (2000) PNAS, v. 97, 13484-13487
SH
SII
SI G
35.3 C137 MPa
[X(CH4)] = 1.0563 [A(CH4)aq/A(H2O)]r2 = 0.9962
Lu, Chou, Burruss, Yang (2006)Applied Spectroscopy
115 minutes after being pressurized by CH4 at 24.47 MPa
Y = 0.70 mm
Y = 4.12 mm
[X(CH4)] = 1.0563 [A(CH4)aq/A(H2O)]
Ymax. = 12.2 mm
Diffusion of Methane in Water
D = 1.66 x 10–9 m2s-1Lu, Chou, Burruss, & Yang (J. Applied Spectroscopy; 2006)
Keith Kvenvolden
Davie et al. (2004)
This studyLu, Chou, Burruss
GCA (2008)
Yang et al. (2001)
Servio & Englezos (2002)
Kim et al. (2003)
Previous studies
CH4 conc. in equilib. with
methane hydrate
Lu, Chou, & Burruss(GCA, 2008)
Growth of methane hydrate in 2 wt% Na2SO4 aqueous solution
near room temperature
T dropped from ~23oC to ~22oC in one hour
CH4 tank
Vacuum line
Immersed in liquid N2
Sample loading systemfor a capillary capsule
~ 11 mm
Methane Hydrate
Smackover Oil(50 μm ID)
Room T(50 μm ID)
H2O CO2 (L) CO2 (V)CO2-H2O
m
Methane hydrateat 22oC
~ 40 MPa
Chou, Song, Burruss (GCA, 2008)
Cracking of octadecane (C18H38) with various densities at 350, 375, and 400
Methane
Ethane
Propane + n-butane
350 C
Duration (hrs)
Peak
Are
a Fr
actio
n
• Our understanding of the reaction pathways and decomposition of organic compounds in the
presence of water is limited. • Raman spectroscopic analysis for the following
reactions at 206 °C for 41 hours:
– CH4 + H2O = CH3OH + H2
– C2H6 + H2O = C2H5OH + H2
– C2H6 + 2 H2O = CH3CO2H + 3 H2
Shang et al. (GCA, 2009)
(1963)(1941)
r2 = 0.99991
Modified from: Williamson & Rimstidt (1992)
Number of Sulfur AtomsAv
erag
e Fo
rmal
Cha
rge
on S
ulfu
r -2
+1
-1
+4
+2
0
+3
+5
+6
+7
1 32 4 765
S2-
S22-
S2O32-
S32-
S52-S4
2-S6
2- S72-
S3O32-
S4O32- S5O3
2- S6O32- S7O3
2-
SO42-
S2O42-
SO32-
S2O62-
S2O72-
S2O82-
S3O62-
S4O62-
S5O62-
S2O52-
S6O62- S7O6
2-
S8
8
TSR by H2
300 oC107 MPa10 days
300 oC (v)
In-situ Ramanin USGS heating stage
TSR by CH4
In-situ Ramanin USGS heating stage TSR by CH4
Stretching frenquency of water dissolved in CO2
at 32 ºCas a function of
CO2 density
Berkesi et al.(2009)
Uranyl chloride complexes in LiCl solution (1.5 molal) at 200 ºC at vapor satrated (Dargent et al., 2012)
C
CH3
CH3
O CO
O H2O C
CH3
CH3
HO OH CO2nn nn
Polycarbonate Bisphenol A
Hydrolysis of Polycarbonate in sub-critical water (280 oC)
Pan, Chou & Burruss (Green Chem., 2009)
0 10 20 30 40 50 600
1
2
3
4
5
0
20
40
60
80
100
Peak area
Reaction time / min
R2=0.996
Peak area
×104
Depolymerization yeild / %
Depolymerization yeild
INSTEC Heating-Cooling Stage
FSCC (0.1 mm ID)
CO2
Linkam 500Capillary Pressure Stage
7: Capillary sample holder8: Capillary movement mechanism9: Silver block heater & cover10: Pt sensor protection plate11: 16 mm glass cover slip
Linkam 500Capillary Pressure Stage
1: Qtz sample carrier for FSCC(25 mm movement)
2: Silver cover
Linkam 500Capillary Pressure Stage
Error band over 30 mm of movement
Summary
• Optical cells with fused silica windows, such as HPOC and FSCC, were designed for experiments at pressures up to 100 MPa and temperatures up to 600 ºC, such as the P-T conditions of sedimentary basins, hydrothermal systems, and low-grade metamorphism.
• These types of cells are particularly suitable for the study of organic compounds and also for the systems containing S.
Summary• When compared with the conventional synthetic fluid
inclusion method, in which fluid inclusions were formed by healing fractures in quartz chips at elevated P-T conditions, the new FSCC method has the following advantages: (1) simple; (2) large and uniform inclusions can be formed; (3) suitable for the studies of organic material and/or S with/without water, and (5) allowing redox control when needed, especially for TSR experiments.
• The HPOC & FSCC have a great potential for studying geologic fluids at various P-T conditions, as demonstrated by many examples.
