IAPWS MEETING MARCH 14th 2005

Supercritical Properties and Geothermal Energy, Hydrogen, Methanol and Metals/Minerals From Near Surface Magmatic

SystemsDr. Daniel W.H. Fraser

Department of Mechanical and Industrial Engineering, University of Manitoba

fraserdw@cc.umanitoba.ca

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.

We are now in a major discovery period with regard to the earth

The Pacific Rim Of Fire

Tectonic Plate Spreading

Hydrothermal Ocean Ridge

FormationSpreading

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

• 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)

Sub Continental Spreading Region

Active VolcanoesGlacier

Drill Site

MakushiMakushinn

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

Reykjanes Drill Site

magma

Not to scale

Highly fractured basalt

To plant

Injection

For corrosion and plugging prevention

Patent Pending

Saline Hydrothermal SystemsSaline Hydrothermal Systems

Ocean

P=gh

100 km

4000C

# NOTE SCALE ## NOTE SCALE #

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

VENT CHIMNEY/SUFIDE DEPOSIT COMPOSITION

11 wt% Cu, 27 wt% Zn, 230 ppm Ag and 200 ppm Au

Steve Scott (U of T)

Sub-Sea

Mining

Strategies

Papua New GuineaBack Arc Spreading Centre

• 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

GASES, METALS AND MINERALS SOURCES SUPERCRITICAL

SOLUTIONS LAND BASED VERSUS OCEAN/SALINE BASED

C(s) + H2O(g)            CO(g) + H2(g)

CH4(g) + H2O(g)            CO(g) + 3 H2(g)

HYDROGEN SOURCES

• Hydrogen may occur naturally in vent fluids – water gas reaction using coke & water ( >600º C )

– 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

– 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 Status

SMR of Natural Gas Mature

Partial Oxidation Mature

Coal Gasification R&D/Mature

SCW Process R&D/Mature

Water Electrolysis Mature

Thermochemical R&D

Photo Chemical Process R&D

Photo Electric R&D

Photo Biological R&D

Fermentative R&D

Thermal Splitting etc. R&D

Clean? Coal to Methanol

Advanced CANDU-X ReactorsUniversity 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

Varying heat transfer coefficients at both top and bottom surfaces,

P=24.4 MPa, G=340 kg/m2.s, q=300 kW/m2

 

Buoyancy/Natural Convection Effects of SCW

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

Economic Potential Of Metals

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

300 Tpc400

500

Variation of Water Properties

Accounts for high enthalpies

P > 22 MPa0.00C ambient temperature

4000C

PH ~ 3

Temperature~420°C

Typical Metal/Salt Solubility

~420°C

Solu

bi li

ty

Solu

bi li

ty

Binary System H2O + Metal or

Salt

H2O + Metal + Cl

High pressure oxidation leaching type region for extractive metallurgy

Cl dramatically improves solubility

~420°C

SupercriticalPressure

Pseudo - critical temperature line,PCTL

Regions where solubility can vary. Varying

minerals/metals behave

differently

very high solubility

region

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).

Conventional nuclear and geothermal

SupercriticalPressure

Pseudo - critical temperature line,PCTL

Regions where solubility can vary. Varying

minerals/metals behave

differently

very high solubility

region

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.

Drive the thermodynamic properties of the solution along this path (blue).

Conventional nuclear and geothermal

SupercriticalFluid

very high solubility

region

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

JapanHawaii

Mid-Atlantic Ridge

Andes

East AfricaRift

Tectonic Plate Boundaries

WORLD-WIDE SITES

                       

East Africa Rift

Erta Ale

A satellite view of the Sinai showing two arms of the Red

Sea spreading ridge, exposed on land.

MIDDLE EAST

JORDANISRAEL

EGYPT

RED

SEA

WORLD WIDE COLLABORATION

NEPTUNE –Canada, USA And Partners (Orion)

ACKNOWLEDGEMENTSThe 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.

•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.

IDDP, NEPTUNE, ORION and ALASKA