Presentation on theme: "IAPWS MEETING MARCH 14 th 2005 Supercritical Properties and Geothermal Energy, Hydrogen, Methanol and Metals/Minerals From Near Surface Magmatic Systems."— Presentation transcript:
IAPWS MEETING MARCH 14 th 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@example.com
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.
The Pacific Rim Of Fire Tectonic Plate Spreading
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 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 Volcanoes Glacier Drill Site
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
Reykjanes Drill Site magma Not to scale Highly fractured basalt To plant Injection For corrosion and plugging prevention Patent Pending
Saline Hydrothermal Systems Ocean P= gh 100 km 400 0 C # NOTE SCALE #
Black Smoker Laden with metal sulfides that precipitate into suspended particulates on contact with the cold seawater Fluids also contain H 2, CH 4 and CO 2 Raw materials for Methanol Synthesis Similar fluids come from the Icelandic land based plant and many other worldwide locations (e.g Alaska, Africa etc.)
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 Guinea Back Arc Spreading Centre
Meteoric Water (Conventional Plants) Fluids contain silicon, aluminum salts, potassium, trace minerals, CO 2, H 2 & H 2 S Oceanic Water (Iceland Pilot Plant - First worldwide) Complex process – Supercritical aqueous chloride fluids strip metals, minerals and create gases (H 2 and H 2 S) 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) + H 2 O(g) CO(g) + H 2 (g) CH 4 (g) + H 2 O(g) CO(g) + 3 H 2 (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 H 2 O + CO H 2 + CO 2 H 2 + CO 2 Methanol (high T Catalytic) Many teams are researching H 2 and CH 4 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 H 2 production
Current H 2 Production ProcessesStatus SMR of Natural GasMature Partial OxidationMature Coal GasificationR&D/Mature SCW ProcessR&D/Mature Water ElectrolysisMature ThermochemicalR&D Photo Chemical ProcessR&D Photo ElectricR&D Photo BiologicalR&D FermentativeR&D Thermal Splitting etc.R&D
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/m 2.s, P=24.4 MPa, q =195 kW/m 2
Varying heat transfer coefficients at both top and bottom surfaces, P=24.4 MPa, G=340 kg/m 2.s, q =300 kW/m 2 Buoyancy/Natural Convection Effects of SCW
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 500 0 C the density is around 1/5 of seawater) P=23.5 MPa 300 T pc 400 500 Variation of Water Properties Accounts for high enthalpies
P > 22 MPa 0.0 0 C ambient temperature 400 0 C PH ~ 3
Temperature ~420°C Typical Metal/Salt Solubility ~420°C Solubility Binary System H 2 O + Metal or Salt H 2 O + Metal + Cl High pressure oxidation leaching type region for extractive metallurgy Cl dramatically improves solubility ~420°C
Supercritical Pressure 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
Supercritical Pressure 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
Supercritical Fluid 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.
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.
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 H 2 and Methanol or combine H 2 and CO 2 to methanol (high T catalytic) etc. Investigate other possible H 2 carriers such as Ammonia NH 3 CO 2 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