Oxygen on the Moon Oxygen on the Moon Group 3 Group 3 Tyler Watt Tyler Watt Brian Pack Brian Pack Ross Allen Ross Allen Michelle Rose Michelle Rose Mariana Dionisio Dionisio Mariana Blair Apple Blair Apple
Presentation Outline Presentation Outline � Background Background � � Overview of logistics Overview of logistics � � Process options Process options � � General process information General process information � � Reaction kinetics Reaction kinetics � � Operating conditions optimization Operating conditions optimization � � Diffusion model Diffusion model � � Equipment design Equipment design � � Cost estimation Cost estimation � � Conclusions Conclusions � � Mystery bonus material Mystery bonus material �
Background Background � President Bush announces plan for lunar exploration on President Bush announces plan for lunar exploration on � January 15th, 2004 January 15th, 2004 � Stepping stone to future Mars exploration Stepping stone to future Mars exploration � � Previously proposed by Bush, Sr. Previously proposed by Bush, Sr. � � 2003 Senate hearing: lunar exploration for potential 2003 Senate hearing: lunar exploration for potential � energy resources energy resources � Lunar Helium Lunar Helium- -3, Solar Power Satellites (SPS) 3, Solar Power Satellites (SPS) � � President President’ ’s Commission on Moon, Mars, and Beyond s Commission on Moon, Mars, and Beyond � � Commissioned to implement new exploration strategy Commissioned to implement new exploration strategy � � Report findings in August 2004 Report findings in August 2004 �
Project Time Line Problem Description Problem Description Determine the feasibility of Determine the feasibility of running a self- -sufficient sufficient running a self process to produce O 2 for process to produce O 2 for 10 people on the Moon by 10 people on the Moon by 2015 2015
Biological Considerations Biological Considerations � Oxygen production requirements Oxygen production requirements � � Average human consumes 305 kg O Average human consumes 305 kg O 2 /year 2 /year � � Total oxygen production goals: Total oxygen production goals: � � 8.4 kg/day or 20 moles/hr 8.4 kg/day or 20 moles/hr � � 6 month back 6 month back- -up oxygen supply for up oxygen supply for � emergency use emergency use � Adequate for survival until rescue mission Adequate for survival until rescue mission �
Overview of Logistics Overview of Logistics � Primary Concern Primary Concern � � Each launch costs $200 Each launch costs $200 � million million � Maximum lift per launch: Maximum lift per launch: � 220,200 lbs 220,200 lbs � Minimize necessary Minimize necessary � launches launches � Secondary Concerns Secondary Concerns � � Minimize process energy Minimize process energy � requirements requirements � Operate within budget Operate within budget � (non- (non -profit project) profit project) � NASA budget: $16 billion/yr NASA budget: $16 billion/yr � � $12 billion/yr dedicated to $12 billion/yr dedicated to � lunar exploration lunar exploration
Process Options Process Options � Process rankings Process rankings � � Evaluated for very large scale O Evaluated for very large scale O 2 production 2 production � � 1000 tons per year 1000 tons per year � Process Technology No. of Steps Process Conditions Ilmenite Red. with H 2 8 9 7 Ilmenitre Red with CH 4 7 8 7 Glass reduction with H 2 7 9 7 Reduction with H 2 S 7 8 7 Vapor Pyrolysis 6 8 6 Molten silicon Electrolysis 6 8 5 HF acid dissolution 5 1 2 (Taylor, Carrier 1992)
H 2 Reduction of Ilmenite H 2 Reduction of Ilmenite Reaction Reaction FeOTiO 2 (s) + H 2 (g) Fe(s) + TiO ) + TiO 2 (s) + H + H 2 O(g) FeOTiO 2 (s) + H 2 (g) Fe(s 2 (s) 2 O(g) � Previous experimentation has shown: Previous experimentation has shown: � � Iron oxide in Iron oxide in ilmenite ilmenite is completely reduced is completely reduced � � Reaction temperature <1000 Reaction temperature <1000° °C C � � At At these conditions, these conditions, 3.2 3.2- -4.6% 4.6% O O 2 2 yields by mass yields by mass � � 35 kg of lunar soil per hour must be processed 35 kg of lunar soil per hour must be processed �
Process Location Process Location � Oxygen production correlates to Fe content in Oxygen production correlates to Fe content in � lunar soil lunar soil � Plant location must have adequate Fe reserves Plant location must have adequate Fe reserves � N S South Pole also provides maximum amount of monthly sunlight at ~90% S N
Block PFD Block PFD Mining & Solids Solids added to reactor; � Solids added to reactor; � Transportation then H2 gas then H2 gas After reaction, � After reaction, � Hydrogen H 2 H 2 /H /H 2 2 O goes to O goes to Storage condenser; condenser; spent solids spent solids removed removed Reactor From condenser, � From condenser, � H H 2 2 O liquid to O liquid to electrolysis; H electrolysis; H 2 2 gas gas to storage to storage Condenser Spent From electrolysis, � From electrolysis, � Solids O O 2 2 is liquefied and is liquefied and stored; H stored; H 2 2 gas to gas to storage for recycle storage for recycle Electrolysis Chamber O 2 LLOX Storage
Obtaining Raw Materials Obtaining Raw Materials � Automatic miner provides lunar soil to process Automatic miner provides lunar soil to process � � Miner must provide 840 kg / day 2 (2.54 cm mining depth) � Annual area mined 4000 m Annual area mined 4000 m 2 (2.54 cm mining depth) � � Initial hydrogen charge delivered as liquid water Initial hydrogen charge delivered as liquid water �
Reduction of Ilmenite Reaction Reduction of Ilmenite Reaction FeOTiO 2 (s) + H 2 (g) Fe(s) + TiO ) + TiO 2 (s) + H + H 2 O(g) FeOTiO 2 (s) + H 2 (g) Fe(s 2 (s) 2 O(g) � Previous experimentation has shown: Previous experimentation has shown: � � Rxn Rxn is is 0.15 0.15 order in H order in H 2 � 2 � ∆ ∆ H H rxn =9.7 kcal/g- -mol mol rxn =9.7 kcal/g � � Particle radius is 0.012 cm (240 microns) Particle radius is 0.012 cm (240 microns) � � Complete reduction of ilmenite in 20 Complete reduction of ilmenite in 20- -25 min. 25 min. � � T=900 T=900 ° °C, P =150 C, P =150 psia psia � these conditions, 3.2 3.2- -4.6% 4.6% O O 2 yields by mass At these conditions, 2 yields by mass � At � � Reaction neither diffusion controlled nor Reaction neither diffusion controlled nor � reaction control: combination combination of both of both reaction control: resistances accounted for in reaction model resistances accounted for in reaction model
Unreacted Shrinking Core Model Unreacted Shrinking Core Model • Diffusion Limited [H 2 ] s [H 2 ] bulk [H 2 ] i Time Time Shrinking Solid Reactant Unreacted Core Ash Ash Gas Film Gas Film 0 R i R R g
Homogenous Model Homogenous Model • Reaction Limited Time Solid Reactant Ash Gas Film
Intermediate Model Intermediate Model • Reaction-Diffusion Control Combined [H 2 ] s [H 2 ] bulk [H 2 ] i Time Time Unreacted Solid Reactant Shrinking Core Reaction Ash Ash Gas Film Gas Film R i R i0 R R g 0
Reaction Model Reaction Model n η η d d + − σ η − η = 2 2 c 1 6 ( ) c 0 s c c dt dt B.C. η η c where: =1 @ t t =0 =0 where: B.C. c =1 @ σ s σ 2 s2 = reaction modulus = reaction modulus 2 (particle radius)/[6(effective diffusivity)] n- -1 1 H = kC n = kC H 2 (particle radius)/[6(effective diffusivity)] η c η = dimensionless radial coordinate of shrinking core = dimensionless radial coordinate of shrinking core c = core radius/particle radius = core radius/particle radius t = dimensionless time t = dimensionless time n =(time)(kC n =(time)(kC H2 )/[(solid molar )/[(solid molar density)(particle density)(particle radius)] radius)] H2 n = reaction order, found to be 0.15 n = reaction order, found to be 0.15 CH 2 = constant H 2 concentration, gm- -mol/cm mol/cm 3 3 CH = constant H 2 concentration, gm 2 kC n n H H 2 = rate expression, 0.15 order in CH 2 kC 2 = rate expression, 0.15 order in CH 2 = reaction rate, mole H 2 /sec- -cm cm 2 2 , k= rate constant , k= rate constant = reaction rate, mole H 2 /sec (Gibson et. al, 1994) (Gibson et. al, 1994)
Solution Method Solution Method � DE numerically solved for rate change of DE numerically solved for rate change of � shrinking core ( ( dn dn c /dt ) ) shrinking core c /dt σ s Reaction modulus, σ � Reaction modulus, , used as parameter s , used as parameter � � σ σ s varied until project results compared s varied until project results compared � respectably with prior experimental results respectably with prior experimental results � Reaction rate constant, Reaction rate constant, k k , then was determined , then was determined � σ s from the value of σ from the value of s � RECALL: RECALL: � 2 (particle radius)/[6(effective diffusivity)]) � σ σ s = (kC n n- -1 1 H H 2 (particle radius)/[6(effective diffusivity)]) 0.5 0.5 s = (kC �
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