Transcript Document

IAPWS MEETING MARCH 14th
2005
Supercritical Properties and
Geothermal Energy, Hydrogen,
Methanol and Metals/Minerals
From Near Surface Magmatic
Systems
Dr. Daniel W.H. Fraser
Department of Mechanical and Industrial
Engineering, University of Manitoba
[email protected]
The whole concept of a hydrogen
economy, to counter climate
change, requires finding large
sources of clean energy to
create hydrogen. An enormous
amount of geothermal energy
and additional methane,
hydrogen and metals/minerals
exist in hydrothermal fluids that
originate from high temperature
magmatically heated reaction
zones.
Tectonic Plate Spreading
We are now in a major
discovery period with
regard to the earth
The
Pacific
Rim Of
Fire
Hydrothermal
Ocean Ridge
Formation
Spreading
Center-Iceland
• Mid-Ocean Ridges are places where the Earth's
tectonic plates are gradually moving apart:
– magma rises up to fill the gap
– magma provides an enormous heat source that
creates many seafloor hotsprings (black
smokers etc.) along these ridges undersea
– thermal capacity is orders of magnitude greater
than conventional land based systems
– transports heat and chemicals into the ocean
Mid-Atlantic Ridge - Iceland
Drill Site
Sub
Continental
Spreading
Region
Active
Volcanoes
Glacier
• Plates are moving apart at a rate of only 2
cm/year
• Mid-Atlantic Ridge occurs on the island
• These systems bring the Magma close to the
surface such as what occurs in an Island Arc
System (Aleutians)
Makushin
Proximity to the Ocean for
Saline Fluids?
3-D Modelling – AECL,
Iceland, USNRC, U of
M etc.
Saline Hydrothermal Systems
• Seawater penetrates the ocean floor or land
mass (e.g. Iceland and the Aleutians or
Coastal Alaska?) through highly fractured
zones
• Very different chemistry than conventional
land based hydrothermal convection cells
• Much greater energy content and maximum
temperature potential than conventional land
based systems
• Can be highly permeable with no possible loss
of water or pressure over time as occurs with
conventional land based systems
To
plant
Reykjanes Drill Site
Injection
For corrosion
and plugging
prevention
Patent
Pending
Not to scale
Highly fractured basalt
magma
Saline Hydrothermal Systems
# NOTE SCALE #
 100 km
Ocean
P=gh
 4000C
Black Smoker
• Laden with metal
sulfides that precipitate
into suspended
particulates on contact
with the cold seawater
• Fluids also contain H2,
CH4 and CO2
• Raw materials for
Methanol Synthesis
• Similar fluids come
from the Icelandic land
based plant and many
other worldwide
locations (e.g Alaska,
Africa etc.)
Alvin
Papua New Guinea
Back Arc Spreading Centre
Steve Scott
(U of T)
Sub-Sea
Mining
Strategies
VENT CHIMNEY/SUFIDE DEPOSIT COMPOSITION
11 wt% Cu, 27 wt% Zn, 230 ppm Ag and 200 ppm Au
GASES, METALS AND MINERALS
SOURCES SUPERCRITICAL
SOLUTIONS
LAND BASED VERSUS OCEAN/SALINE BASED
• Meteoric Water (Conventional Plants)
• Fluids contain silicon, aluminum salts, potassium,
trace minerals, CO2, H2 & H2S
• Oceanic Water (Iceland Pilot Plant - First worldwide)
• Complex process – Supercritical aqueous chloride
fluids strip metals, minerals and create gases (H2
and H2S) in an interaction with magma at high T?
• As yet undetermined, juvenile fluids may
contribute substantially to gas and mineral
content
HYDROGEN SOURCES
• Hydrogen may occur naturally in vent fluids
– water gas reaction using coke & water ( >600º C )
C(s) + H2O(g)
CO(g) + H2(g)
– C present in rock formations such as Basalt
– steam reforming process using natural gas and water
( >600º C ) which could occur near the magma source
CH4(g) + H2O(g)
CO(g) + 3 H2(g)
– possibly accounts for some of the dissolved hydrogen present in vent fluids
(solubility increases with increasing pressure)
HYDROGEN SOURCES - CONT.
• Water gas shift may also occur
H2O + CO
H2 + CO2
• H2 + CO2
Methanol (high T Catalytic)
• Many teams are researching H2 and CH4
concentrations in vent fluids and will also
investigate the similar content in land based
systems
• Very similar fluids exist in Oceanic source
wells in Iceland, Alaska? and hydrothermal
vents
• 101 ways to produce hydrogen or methanol!
• SWPO using cheap available thermal energy in
Iceland or Alaska General Atomics (USA) is
leading SWPO processes for H2 production
Current H2 Production Processes
SMR of Natural Gas
Partial Oxidation
Coal Gasification
SCW Process
Water Electrolysis
Thermochemical
Photo Chemical Process
Photo Electric
Photo Biological
Fermentative
Thermal Splitting etc.
Status
Mature
Mature
R&D/Mature
R&D/Mature
Mature
R&D
R&D
R&D
R&D
R&D
R&D
Clean? Coal to Methanol
Advanced CANDU-X Reactors
University of Manitoba Research
-Safety Issues (LOCA) Modelling Critical two-phase
flow.
-Heat Transfer To Supercritical Water(D. Fraser,
UBC,U of M).
-Natural Convection Loop SC CO2 and SCW (V.
Chatoorgan and D. Fraser)
-Experimental Critical Flow with SCW at
stagnation- funding?
-Collaboration with IDDP to test SCW power cycle
components?
Enhancement of heat transfer coefficients at and near the
critical region, G=662 kg/m2.s, P=24.4 MPa, q=195 kW/m2
Buoyancy/Natural Convection Effects of SCW
Varying heat transfer coefficients at both top and bottom surfaces
P=24.4 MPa, G=340 kg/m2.s, q=300 kW/m2
Economic Potential Of Metals
Samples of material that scale the high
temperature geothermal wells in Iceland and the
Salton Sea contain bonanza values of gold, copper,
zinc and other valuable metals. Such deposits
were produced over time from wells whose
temperatures and pressures were well below
supercritical. Under such conditions, the
solubilities of the metals/minerals are low
compared to supercritical conditions. Hence,
under supercritical conditions the metal sulfide
yields should increase dramatically.
Land Bases Extraction Methods. Environmentally
Safe Compared to, For Example - Dow Process
SCW PROPERTIES
• Accounts for
solubility variation
• May account for
some self sealing
mechanisms – may
cause increased
pressures below such
a formation
• Low density permits
high wellhead
pressures (at 5000C
the density is around
1/5 of seawater)
P=23.5 MPa
Accounts for high
enthalpies
300
500
Tpc400
Variation of Water Properties
PH ~ 3
P > 22 MPa
4000C
0.00C ambient
temperature
Typical Metal/Salt Solubility
Binary
System H2O
+ Metal or
Salt
~420°C
Temperature
High pressure
oxidation
leaching type region for
extractive metallurgy
H2O + Metal
+ Cl
~420°C
~420°C
Cl dramatically
improves solubility
Supercritical
Pressure
very high
solubility
region
Pseudo - critical
temperature
line,PCTL
Regions where
solubility can
vary. Varying
minerals/metals
behave
differently
Conventional
nuclear and
geothermal
Fluid states within the very high solubility region will
transport minerals/metals dissolved in solution and
also suspended/dissolved in a brine phase. The blue
line represents the path a black smoker fluid takes
when exiting the chimney (shock precipitation).
Supercritical
Pressure
very high
solubility
region
Pseudo - critical
temperature line,PCTL
Drive the thermodynamic
properties of the solution
along this path (blue).
Regions where
solubility can
vary. Varying
minerals/metals
behave
differently
Conventional
nuclear and
geothermal
As long as the fluid state is within the very high solubility region it will transport
the minerals and metals dissolved in solution and suspended/dissolved in the brine
phase (some precipitation may occur - see later slide). Moving outside of this
region will cause the metals/minerals to precipitate out of solution. The faster the
fluid is brought out of this region the more rapid the precipitation (shock
precipitation). This will occur most rapidly along the blue path - across the PCTL.
Solubility can vary by orders of magnitude across the pseudo-critical line.
very high
solubility
region
Supercritical
Fluid
Blue Path.Drive the
thermodynamic
properties of the
solution along this
path. This is identical
to what occurs at or
near the exit section of
black smokers. Shock
precipitation occurs
while crossing the
pseudo-critical
temperature line.
Red Path. Path the fluid follows in a normal well. Note that decreasing solubility
is not well demarcated (occurs over a wider variation of properties). Hence,
precipitation will occur over a longer length of pipeline. This was seen in
Reykjanes well #9 although the starting point is below supercritical. Solubility
variation within the superheated region, as one drops below the critical pressure,
is very poorly understood.
Global Resource Potential
Tectonic Plate Boundaries
Japan
Hawaii
Mid-Atlantic
Ridge
Andes
East Africa
Rift
WORLD-WIDE SITES
East Africa Rift
Erta Ale
MIDDLE EAST
ISRAEL
JORDAN
EGYPT
RED
SEA
A satellite view of the Sinai showing two arms of the
Red Sea spreading ridge, exposed on land.
WORLD WIDE
COLLABORATION
NEPTUNE –Canada, USA
And Partners (Orion)
ACKNOWLEDGEMENTS
The author wishes to acknowledge the permission of
John Madden the former director of Neptune (and its
affiliates) as well as all the people from the Icelandic
consortium for the use of some of their graphics in
this presentation.
IDDP, NEPTUNE, ORION and ALASKA
•Iceland or Alaska (Unalaska?) pilot plant will provide an
unprecedented opportunity to access saline based
hydrothermal resources from land and potentially extract
valuable metals/minerals and enormous energy potential.
Understand the geochemistry of supercritical aqueous
chloride solutions (e.g. black smokers). We can expect similar
fluids from the land based saline wells.
Understand the behavior of thermal convection cells- heat and
mass transfer (modeling etc.)using state of the art 3-D codes.
Quantify the material flux and composition from black
smokers and wells in Iceland and Alaska.
On land, use efficient SCW processes to produce H2 and
Methanol or combine H2 and CO2 to methanol (high T catalytic)
etc.
Investigate other possible H2 carriers such as Ammonia NH3
CO2 sources to produce methanol (high T catalytic reaction).
Mining interests may predominate at first but lay the
infrastructure for energy/hydrogen/ methanol? production.
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