Oxygen Production in the Moon-Powerpoint presentation

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Unformatted text preview: Oxygen on the Moon Oxygen Group 3 Tyler Watt Brian Pack Ross Allen Michelle Rose Mariana Dionisio Blair Apple Presentation Outline Presentation Background Background Overview of logistics Overview Process options Process General process information General Reaction kinetics Reaction Operating conditions optimization Operating Diffusion model Diffusion Equipment design Equipment Cost estimation Cost Conclusions Conclusions Mystery bonus material Mystery Background Background President Bush announces plan for lunar exploration on President January 15th, 2004 Stepping stone to future Mars exploration Stepping Previously proposed by Bush, Sr. Previously 2003 Senate hearing: lunar exploration for potential 2003 energy resources Lunar Helium-3, Solar Power Satellites (SPS) Lunar President’s Commission on Moon, Mars, and Beyond President Commissioned to implement new exploration strategy Commissioned Report findings in August 2004 Report Project Time Line Problem Description Determine the feasibility of Determine running a self-sufficient process to produce O2 for 10 people on the Moon by 2015 Biological Considerations Biological Oxygen production requirements Oxygen Average human consumes 305 kg O2/year Average Total oxygen production goals: Total 8.4 kg/day or 20 moles/hr 8.4 6 month back-up oxygen supply for month emergency use Adequate for survival until rescue mission Adequate Overview of Logistics Overview Primary Concern Primary Each launch costs $200 Each million Maximum lift per launch: Maximum 220,200 lbs Minimize necessary Minimize launches Secondary Concerns Secondary Minimize process energy Minimize requirements Operate within budget Operate (non-profit project) NASA budget: $16 billion/yr NASA $12 billion/yr dedicated to $12 lunar exploration Process Options Process Process rankings Process Evaluated for very large scale O2 production Evaluated 1000 tons per year 1000 Process Technology No. of Steps Process Conditions Ilmenite Red. with H2 8 9 7 Ilmenitre Red with CH4 7 8 7 Glass reduction with H2 7 9 7 Reduction with H2S Vapor Pyrolysis Molten silicon Electrolysis HF acid dissolution 7 6 6 5 8 8 8 1 7 6 5 2 (Taylor, Carrier 1992) H2 Reduction of Ilmenite Reaction FeOTiO2(s) + H2(g) Fe(s) + TiO2(s) + H2O(g) Previous experimentation has shown: Previous Iron oxide in ilmenite is completely reduced Iron Reaction temperature <1000°C Reaction At these conditions, 3.2-4.6% O2 yields by mass 3.2 At these 35 kg of lunar soil per hour must be processed 35 Process Location Process Oxygen production correlates to Fe content in Oxygen lunar soil Plant location must have adequate Fe reserves Plant N S South Pole also provides maximum amount of monthly sunlight at ~90% S N Solids added to reactor; Solids then H2 gas After reaction, After H2/H2O goes to condenser; spent solids removed From condenser, From H2O liquid to electrolysis; H2 gas to storage Block PFD Block Mining & Solids Transportation Hydrogen Storage Reactor Condenser Spent Solids From electrolysis, From O2 is liquefied and stored; H2 gas to storage for recycle Electrolysis Chamber LLOX O2 Storage Obtaining Raw Materials Obtaining Automatic miner provides lunar soil to process Automatic Miner must provide 840 kg / day Annual area mined 4000 m2 (2.54 cm mining depth) Annual Initial hydrogen charge delivered as liquid water Initial Reduction of Ilmenite Reaction Reduction FeOTiO2(s) + H2(g) Fe(s) + TiO2(s) + H2O(g) Previous experimentation has shown: Previous Rxn is 0.15 order in H2 Rxn 0.15 ∆Hrxn=9.7 kcal/g-mol Particle radius is 0.012 cm (240 microns) Particle Complete reduction of ilmenite in 20-25 min. Complete T=900 °C, P =150 psia T=900 At these conditions, 3.2-4.6% O2 yields by mass At these 3.2 Reaction neither diffusion controlled nor Reaction reaction control: combination of both resistances accounted for in reaction model Unreacted Shrinking Core Model Unreacted •Diffusion Limited [H2] s [H2 ]bulk [H2 ]i Time Solid Reactant Time Shrinking Unreacted Core Ash Ash Gas Film 0 Gas Film Ri R Rg Homogenous Model Homogenous •Reaction Limited Time Solid Reactant Ash Gas Film Intermediate Model Intermediate •Reaction-Diffusion Control Combined [H 2]s [H 2]bulk [H 2] i Solid Reactant Time Time Unreacted Shrinking Core Reaction Ash Ash Gas Film 0 Gas Film R i R i0 R Rg Reaction Model Reaction n dη c dη c 2 2 + 1 − 6σ s (η c − η c ) =0 dt dt where: B.C. ηc =1 @ t =0 σs2 = reaction modulus = kCn-1H2 (particle radius)/[6(effective diffusivity)] ηc = dimensionless radial coordinate of shrinking core = core radius/particle radius t = dimensionless time =(time)(kCnH2)/[(solid molar density)(particle radius)] n = reaction order, found to be 0.15 CH2 = constant H2 concentration, gm-mol/cm3 kCnH2 = rate expression, 0.15 order in CH2 = reaction rate, mole H2/sec-cm2, k= rate constant (Gibson et. al, 1994) Solution Method Solution DE numerically solved for rate change of DE shrinking core (dnc/dt) Reaction modulus, σs, used as parameter Reaction σs varied until project results compared respectably with prior experimental results Reaction rate constant, k, then was determined Reaction from the value of σs RECALL: RECALL: σs = (kCn-1H2 (particle radius)/[6(effective diffusivity)])0.5 Result Comparison Result 0.006 0.000000045 0.00000004 0.005 0.000000035 0.004 0.00000003 Experiment M oles H2 Project Results Moles H2 0.000000025 Poly. (Experiment) 0.003 Poly. (Project Results) 0.00000002 0.000000015 0.002 2 2 R = 0.9989 R = 0.9953 0.00000001 0.001 0.000000005 0 0 0 2 4 6 Time (min) 8 10 12 0 2 4 6 Time (min) 8 10 12 Project Results Project Reaction modulus Reaction σ = 3.52 3.52 NOTE: σ <10 – Intermediate (reaction and diffusion control) Rate constant Rate k = 4.57 x 10-4 M0.85/min 4.57 Reaction time of experimental model Reaction t = 22 min for a particle radius of 0.012 cm (dp=240 microns) Shrinking Core Shrinking Radius of particle 0.012 cm Radius 150 PSIA 0.014 0.012 Inner Core (cm) 0.01 0.008 R=0.012 Poly. (R=0.012) 0.006 R2 = 0.9985 0.004 0.002 0 0 5 10 15 Time (min) 20 25 Water Production Water 78 moles produced in 22 minutes 78 90 80 70 Moles H2O 60 50 40 Mole H2O Production/time 30 20 10 0 0 5 10 15 Time (min) 20 25 Using the Model Using Reactor Design Reactor Pressure optimization Pressure Volume optimization Volume Usable particle size Usable Operating Conditions Optimization Operating 140 120 25 atm 100 time (minutes) 10 atm 15 atm 80 20 atm 60 40 1250 liters @ 20 atm 20 0 0 2000 4000 6000 Volume (liters) 8000 10000 12000 Effect of Particle Diameter Effect 300 PSIA 0.12 0.1 R=0.012cm R=0.024cm Radius (cm) 0.08 R=0.048cm 0.06 R=0.096cm 0.04 0.02 0 0 100 200 300 400 500 Time (min) 600 700 800 900 Optimal Operating Conditions Optimal Pressure of reactor: 300 psi Pressure Volume of reactor: 1250 liters Volume Number of batches per day: 12 Number Mean particle diameter: 240 µm Mean 80% of lunar soil less than 960 µm 80% Reaction complete in <15 minutes Reaction Reactor Diffusion Model Reactor Must use fixed bed reactor Must Fluidized particles highly erosive Fluidized Analyze diffusion to determine bed depth, Analyze reactor dimensions and possible effect on batch time Bed Depth Bed Thin if diffusion is slow Thin Thick if diffusion is fast Thick Reactor Dimensions Reactor Volume fixed Volume Affects diameter and height Affects Batch Time Batch May need to factor in time for diffusion May Reactor Design Considerations Reactor Complicates reactor design Complicates Facilitates diffusion Facilitates •Simpler reactor design •Possible diffusion complications Diffusion in Reactor Diffusion Model using simplified continuity equation Model General Continuity Equation General ∂C H 2 + ∇N H 2 − RH 2 = 0 ∂t For a one dimensional system For ∂C H 2 ∂t ∂ CH 2 2 + DH 2 , H 2 O ∂x 2 − RH 2 = 0 Conditions and Assumptions Conditions Assume RH2 is constant Assume Initial Condition Initial C(x,0) = CH2,o = 0.21 M C(x,0) Boundary Conditions Boundary ∂C ∂x =0 x =0 C (l,t) = C* = CH2,o – RH2t Hydrogen Concentration vs. Bed Depth 40 Top of Bed 35 t = 40 s Bed Depth (cm) 30 t = 80 s 25 20 t = 120 s 15 10 t = 13.25 min Cf = .14 M 5 Bottom of Bed 0 0.14 0.15 0.16 0.17 0.18 [H2] 0.19 0.2 0.21 Diffusion Conclusions Diffusion Hydrogen diffuses very fast through the Hydrogen bed Water diffuses very fast through the Water hydrogen above the bed Diffusion is not a problem in the reactor Diffusion Reactor Design Considerations Reactor Fast diffusion facilitates design: Fast Not necessary to agitate H2 Not Not necessary to have an even layer of Not ilmenite Can use hopper bottom to facilitate discharge of Can solids Smoothing mechanism unnecessary Smoothing Must feed and remove reactants and Must products in an order that will minimize H2 loss Initial Reactor Design Initial •Smoothing blades and flat bed bottom create even layer of ilmenite “Trap door” bottom opens to remove solids **Note considerable complications with moving parts Solids fed first to avoid opening valve 1 while H2 is in reactor Screw Conveyer Hopper H2vacuumed out before removing solids to prevent H2 loss Valve 1 Solid Inlet (70 kg Ilmenite/batch) Hydrogen Inlet (257 mol/batch) To Condenser Valve 2 Line Heater Valve 3 Fixed Bed Batch Reactor 0.3 m 1.2 m Hydrogen and Water Outlet Vacuum Pump 1m E-12 Diffusion fast enough to eliminate need for even layer of particles No smoothing blade Hopper bottom Valve 4 Solids Outlet Reactant Preheat Reactant Reaction T=900°C Reaction Ilmenite enters at -30°C Ilmenite H2 enters at 89°C Heating Options: Heating Heat inside reactor (heating coils) Heat Difficult to repair Difficult Very slow heating due to low convection (stagnant H2) Very Preheat H2, heat ilmenite with H2 Preheat Complex solid-gas heat exchanger (rotating parts) Complex Flowing hot H2 over ilmenite in the reactor causes dust Flowing levitation Preheat H2 with a line heater; preheat ilmenite in Preheat hopper by induction heating Reactant Preheat Reactant •Ilmenite heated from -30°C to 955°C by induction heating •Copper induction coils in hopper •Coils isolated from hopper walls with non-conductive ceramic •15 minute heating time •50 kW heating source needed (assumes 50% efficiency) Hydrogen Preheat: •Line heater: L = 3 m, D = 2” •H2 inlet gas heated from 89°C to 930°C in 5 minutes •6.5 kJ required Block PFD Block After After reaction, H2/H2O goes to condenser; spent solids removed Mining & Solids Transportation Hydrogen Storage Reactor Condenser Spent Solids Electrolysis Chamber LLOX O2 Storage Condenser System Condenser H2/H2O Reactor Effluent 900°C S S FT Condensing Heat Exchanger A = 10 ft2 H2/H2O to Electrolysis • 98°C Hot Liquid Ammonia to Radiator •300 psia •3000 mol/batch •30 mol% liquid H2O • 4°C Radiant Heat to Space Recycled cold Ammonia Aluminum honeycomb radiator – 2 panels, ea. 9 ft x 11 ft Ammonia cooled to -30°C, ~90min Why use Ammonia? Why Why not use something on site (i.e. H2O or cold Why rock)? Advantageous properties of Ammonia: Advantageous Very low freezing temperature (-77°C) Very Lowest fouling rate (0.2286 J m K/s) Lowest Most efficient of commonly used refrigerants Most (C.O.P. is ~3% better than R-22; 10% better than R-502) High heat transfer characteristics (CP, latent heat High latent of vaporization, k) Condensing System Condensing Aluminum Aluminum honeycomb radiator panels (ISS) Each panel 9 ft x11 ft Each and rejects 1.5 kW 2.3 kW must be 2.3 rejected per batch Two panels used; one Two ammonia batch needs ~90 minutes Two panels hold Two nearly 5 batches of ammonia Block PFD Block From From condenser, H2O liquid to electrolysis; H2 gas to storage Mining & Solids Transportation Hydrogen Storage Reactor Condenser Spent Solids Electrolysis Chamber LLOX O2 Storage Electrolysis Chamber Electrolysis Recycle H gas to storage H2 (g) + H2O (l) from Condenser 2 •300 psia •89 °C Nominal H2O level H2O LT •Overall reaction 1 H 2 O → H 2 + O2 2 •Runs continuously •20 L volume •3.5 kW power required •2090 A current required Constant H2O Level: corresponds to 17 L O2 gas to LLOX LC Cathode rxn + - + Pt •300 psia Pt •89 °C − 2 H + 2e → H 2 Anode rxn 1 H 2 O → 2 H + + 2e − + O2 2 Overview: Process Timeline Overview: E le c tro ly s is ( C o nt in ou s ) R e m o v e S o lid s 5 m in A irlo c k R e a c t o r 5 m in P r e -H e a t Ilm e n ite 1 5 m in A irlo c k H o p p e r 5 m in C o n d e n s e W a te r 1 0 m in Lo a d R e a c to r a n d R e a c tio n T im e 6 0 m in H y d ro g e n P r e -H e a t 5 m in Load Hopper -4 0 -3 0 -2 0 -1 0 5 m in 0 10 20 30 40 50 60 70 80 90 100 110 T i m e ( m in ) TOTAL BATCH TIME: 90 minutes 120 Block PFD Block From From electrolysis, O2 gas is liquefied and stored Mining & Solids Transportation Hydrogen Storage Reactor Condenser Spent Solids Electrolysis Chamber LLOX O2 Storage Oxygen Storage Oxygen Necessary Capabilities Necessary Collection of six month emergency supply Collection Collection of occasional excess oxygen Collection Restore emergency supply Restore Options Options Compress and store as gas Compress Implement liquefaction process Implement Liquefaction Process Liquefaction Modified Claude Cycle Floor Plan Floor Habitat Structure Habitat Geodesic Dome Maximum volume for a Maximum given surface area Structurally sound Structurally Easily constructed Easily Necessary layers **Required for permanent habitation Habitat Energy Requirements Habitat Energy Needs (max. energy consumption) Energy 840 kW 840 Energy will be input through electrical heating Energy from solar panels Total solar panel area required Total 5440 m2 (based on 12% efficiency) 5440 (based Less than 1 launch necessary Less Cost Estimates Cost Cost of project before Cost delivery Construction material: Construction $32 million Solar Panels: $8 million Solar Process: $3.4 million Process: 8% 18% 74% Construction Material Solar Panels Process Cost Estimates Cost Cost of Shuttle Cost Launches 1% 23 shuttle launches 23 necessary 13 Launches for habitat 13 5 Exploratory launches Exploratory 3 Launches for astronauts Launches 1 Launch for solar panels Launch 1 Launch for process Launch Total cost of $4.6 billion Total 99% Launches Solar Panels Process Construction Material Conclusions Conclusions Process Process Design for simplicity and safety Design Safety should be primary concern Safety Simplicity reduces unknowns with lunar Simplicity enviornment Economics Economics Minimize shuttle launches to minimize cost Minimize Habitat will be majority of shuttle launches Habitat QUESTIONS? QUESTIONS? *Mystery Bonus Material* *Mystery In Response To… In Email sent to Mr. Carlton Allen, head procurator of astro-materials at NASA’s Johnson Space Center (shown at right at ilmenite testing facility?) inquiring about our final reactor design “Your design looks reasonable to me.” Carlton Allen Head Procurator of Astro-Materials In Response To… In Email sent to [email protected]: Email “Hello NASA, I have heard a lot about President Bush's new plan for permanent colonies on the moon. It seems like it would be really hard to produce enough oxygen to support a reasonable number of people. I know a lot of research has been done on ilmenite. Is this the most likely way that NASA plans to produce oxygen? It seems like a good idea, but could you all fill me in on the physical properties of ilmenite. Thanks a lot, Stevie Hernandez Ms. Jagajewicz 4th Grade Class President” “Nasa is nowhere near making oxygen on the moon.” [email protected] Batch Number Optimization Batch 1 0.9 0.8 5 Batches per day 0.7 9 Batches per day 11 Batches per day 0.6 13 Batches per day 0.5 17 Batches per day 0.4 24 Batches per day 0.3 0.2 0.1 0 0 0.005 0.01 0.015 t/vol 0.02 0.025 0.03 Electrolysis Reactions (backup) Electrolysis H2O H+ + OHH+ picks up an electron from the cathode: H+ + eH H+H H2 Anode removes the e- that the OH- ion Anode “stole” from the hydrogen initially OH- combines with 3 others OH 4OHO2 + 4H2O + 4e4OH O2 molecule is very stable-bubbles to the surface A closed circuit is created in a way, closed involving e-’s in the wire, OH- ions in the liquid Energy delivered by the battery is Energy stored in the production of H2 Back up – Calculations for Back Electrolysis Nernst Equation Nernst 1/ 2 RT a H 2 aO2 E = Eo − ln nℑ a H 2O Gibbs electrochemical energy Gibbs ∆G = − Enℑ Work Work W = −∆G Equipment Equipment Compressor Compressor 217 hp 217 Heat Exchangers Heat E1 requires 100 ft2 E1 E2 requires 120 ft2 E2 All equipment will be vacuum jacketed All and a multilayer insulation systems will be implemented ...
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This note was uploaded on 08/31/2011 for the course CHE 4273 taught by Professor Staff during the Spring '10 term at Oklahoma State.

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