Carbon Dioxide and Moisture Removal System

Carbon Dioxide and Moisture Carbon Dioxide and Moisture Removal SystemRemoval System

08-14-0208-14-02 Coeus EngineeringCoeus Engineering 22

Team OrganizationTeam Organization

• Jessica BadgerJessica Badger – Project CoordinatorProject Coordinator– AerogelsAerogels

• April SnowdenApril Snowden– Researcher Researcher – Carbon nanotubesCarbon nanotubes

• Dennis ArnoldDennis Arnold – Team LeaderTeam Leader– AerogelsAerogels

• Julia ThompsonJulia Thompson– ResearcherResearcher– Honeycomb structuresHoneycomb structures

• Advisor:Advisor: Dr. John Graf, NASA ECLSS Dr. John Graf, NASA ECLSS


OverviewOverview

• Space Launch Initiative ProgramSpace Launch Initiative Program• Current RCRS Design (Recap) Current RCRS Design (Recap) • Carbon Dioxide/Moisture Removal Carbon Dioxide/Moisture Removal

System (CMRS) Design RequirementsSystem (CMRS) Design Requirements• Materials ResearchedMaterials Researched

– Honeycomb structuresHoneycomb structures– Carbon nanotubesCarbon nanotubes– AerogelsAerogels

• Project SpecializationProject Specialization– Pressure drop Analysis through aerogelPressure drop Analysis through aerogel

• Summary/ConclusionsSummary/Conclusions


Space Launch Initiative Space Launch Initiative ProgramProgram

• FFocuses on the future ocuses on the future of exploration and of exploration and development of spacedevelopment of space

• Creation of 2Creation of 2nd nd

Generation Reusable Generation Reusable Launch Vehicle (RLV)Launch Vehicle (RLV) – Lower payload cost to Lower payload cost to

less than $1,000 per less than $1,000 per poundpound

– Incorporate latest Incorporate latest technology for COtechnology for CO22 removalremoval


Current RCRS DesignCurrent RCRS Design

• 12 layered CO12 layered CO22 adsorbent “beds” adsorbent “beds”

– 6 layers per bed6 layers per bed

• Alternating active and inactive Alternating active and inactive layerslayers

– Active layers remove COActive layers remove CO22

– Inactive layers exposed to Inactive layers exposed to vacuum to release COvacuum to release CO22

• Dimensions: 3 ft x 1 ft x 1.5 ft Dimensions: 3 ft x 1 ft x 1.5 ft

• Removes Removes ≈ 0.62 lbs CO≈ 0.62 lbs CO22/hour/hour

– 7 member crew7 member crew

– Requires 26 lbs of solid amine Requires 26 lbs of solid amine chemicalchemical

– Requires flow rates of 20 - 40 cfm Requires flow rates of 20 - 40 cfm


Airflow Diagram of RCRS Airflow Diagram of RCRS LayerLayer

• 4 bead-filled foam 4 bead-filled foam chambers per layerchambers per layer

• Retaining screensRetaining screens– Prevent beads from Prevent beads from

entering main air entering main air streamstream

– 8 screens per layer8 screens per layer– Inlet and outletInlet and outlet

– Create large Create large pressure drop due pressure drop due to blockage at to blockage at outletsoutlets


Specific RCRS Specific RCRS ComponentsComponents

• Ion-Resin BeadsIon-Resin Beads– Copolymer of polystyrene Copolymer of polystyrene

and divinylbenzeneand divinylbenzene– ≈ ≈ .3mm diameter.3mm diameter– Extremely porousExtremely porous– Coated surface area:Coated surface area:

250-350 m250-350 m22/cm/cm33

• Aluminum Puffed Duocell Aluminum Puffed Duocell FoamFoam

– Houses ion-resin bedsHouses ion-resin beds

– Structural rigidity Structural rigidity

– Heat transfer propertiesHeat transfer properties


Solid-Amine ChemicalsSolid-Amine Chemicals

• COCO22 and H and H22O “loosely” bond to solid-O “loosely” bond to solid-aminesamines

• Can be “coated” onto certain materialsCan be “coated” onto certain materials• Air + solid-amine reaction produces Air + solid-amine reaction produces

heatheat

• Common alkanolamine COCommon alkanolamine CO22 adsorbents: adsorbents:– monoethanolamine (MEA)monoethanolamine (MEA)– diethanolamine (DEA)diethanolamine (DEA)– methyldiethanolamine (MDEA)methyldiethanolamine (MDEA)


Julia ThompsonJulia Thompson

CMRS RequirmentsCMRS Requirments

Honeycomb StructuresHoneycomb Structures


CMRS Design CMRS Design RequirementsRequirements

• Maximize solid-amine Maximize solid-amine surface areasurface area• Maximize Maximize structural rigiditystructural rigidity • Maximize Maximize heat transferheat transfer from active from active

to inactive bedsto inactive beds• Minimize Minimize pressure droppressure drop through through

each bedeach bed


Materials ResearchedMaterials Researched

Surface Area&

Pressure Drop

Carbon Nanotubes&

Aerogels

Structural Rigidity&

Heat Transfer

AluminumHoneycomb


Overview of Overview of HoneycombsHoneycombs

• Packed or joined Packed or joined together in together in hexagonal mannerhexagonal manner

• High strength and High strength and rigidity to weight rigidity to weight ratiosratios

• Commonly used in Commonly used in sandwiched sandwiched structuresstructures– Airliner floorsAirliner floors– Airplane wingsAirplane wings– Motorcycle helmetsMotorcycle helmets


Use of Honeycomb in Use of Honeycomb in CMRS CMRS

• Applied in directional Applied in directional air/fluid flow control air/fluid flow control and/or energy and/or energy absorptionabsorption

• Available in various Available in various Aluminum alloysAluminum alloys– 2024-T81P2024-T81P

• Varied cell sizesVaried cell sizes– 1/4”1/4”

• PerforatedPerforated– Allows three-Allows three-

dimensional air flowdimensional air flow– Improves heat removalImproves heat removal


Use of Honeycomb in Use of Honeycomb in CMRSCMRS

• Grade C: Alloy 2024-T81PGrade C: Alloy 2024-T81P– PerforatedPerforated– HardenedHardened– Chemically treated for erosion protectionChemically treated for erosion protection

• 3 lbs/ft3 lbs/ft33

• Total weight of honeycomb in system = Total weight of honeycomb in system = 5 lbs5 lbs

• 30 in30 in22 surface area per cubic inch surface area per cubic inch– more surface area = more heat removedmore surface area = more heat removed


Use of Honeycomb in Use of Honeycomb in CMRSCMRS

• Structural RigidityStructural Rigidity– Grade C honeycomb Grade C honeycomb

provides more provides more structural rigidity than structural rigidity than Grade B.Grade B.

– T81 more rigid than T3T81 more rigid than T3

• AirflowAirflow– 3 dimensional3 dimensional– More air in contact More air in contact

with solid aminewith solid amine


Honeycomb vs. Duocell Honeycomb vs. Duocell FoamFoam

• Heat transfer not a Heat transfer not a problemproblem

• Strength tests Strength tests – Layers must be built, Layers must be built,

pressurized.pressurized.

• Manufacturing of Manufacturing of layerslayers– Weld/Bond plates to Weld/Bond plates to

corecore– Filling with chemicalFilling with chemical

• Less area taken up Less area taken up by aluminum by aluminum structurestructure


April SnowdenApril Snowden

Carbon NanotubesCarbon Nanotubes

AerogelsAerogels


Carbon Nanotube Carbon Nanotube AttributesAttributes

• DiameterDiameter– Size of nanometersSize of nanometers– 1/50,0001/50,000thth of a human of a human

hairhair

• LengthLength– Several micrometersSeveral micrometers– Largest is ~ 2 mmLargest is ~ 2 mm

• Each nanotube is a Each nanotube is a single moleculesingle molecule– Hexagonal network of Hexagonal network of

covalently bonded covalently bonded carbon atoms carbon atoms

• Super strengthSuper strength• Low weightLow weight• StabilityStability• FlexibilityFlexibility• Good heat Good heat

conductanceconductance• Large surface areaLarge surface area

– 300-800 m300-800 m22/cm/cm33


Carbon NanotubeCarbon NanotubeMechanical PropertiesMechanical Properties

• Extremely strongExtremely strong– 10-100 times stronger than 10-100 times stronger than

steel per unit weightsteel per unit weight

• High elastic moduliHigh elastic moduli– About 1 TPaAbout 1 TPa

• FlexibleFlexible– Can be flattened, twisted, or Can be flattened, twisted, or

bent around sharp bends bent around sharp bends without breakingwithout breaking

• Great performance under Great performance under compressioncompression

• High thermal conductivityHigh thermal conductivity


Carbon Nanotube Possible Carbon Nanotube Possible UsesUses

• Transistors & diodesTransistors & diodes• Field emitters for flat-Field emitters for flat-

panel displayspanel displays• Cellular-phone signal Cellular-phone signal

amplifiersamplifiers• Ion storage for Ion storage for

batteriesbatteries• Materials strengthenerMaterials strengthener

– Polymer compositesPolymer composites– Low-viscosity compositeLow-viscosity composite


Potential Use for CMRSPotential Use for CMRS

• Coat nanotubes with solid amineCoat nanotubes with solid amine– Maximize surface areaMaximize surface area

• Eliminate mesh retaining screenEliminate mesh retaining screen– Carbon nanotubes fixed to housing structureCarbon nanotubes fixed to housing structure– No need for beads No need for beads – Minimize pressure dropMinimize pressure drop

• Nanotube structureNanotube structure– Replace aluminum Duocell foam with Replace aluminum Duocell foam with

aluminum/carbon nanotube compositealuminum/carbon nanotube composite


Aerogel AttributesAerogel Attributes

• Critically evaporated gelCritically evaporated gel• Lightest solid knownLightest solid known• Almost transparent Almost transparent

solidsolid


Aerogels as Support Aerogels as Support StructuresStructures

• Young’s modulus: Young’s modulus: 101066 – 10 – 1077 N/m N/m22

• Tensile strength:Tensile strength: 16 Kpa16 Kpa• Density: Density: ≥≥ 0.003 g/m 0.003 g/m33

• Support 1500 timesSupport 1500 times

their own weighttheir own weight


Aerogels as High Aerogels as High Surface Surface Area MaterialsArea Materials

• Up to 99% airUp to 99% air• Pore sizePore size

– Range from Range from

3 nm to 50 nm3 nm to 50 nm– Average about 20 nmAverage about 20 nm

– Allows OAllows O22 and N and N22 molecules to flow through molecules to flow through

• Effective surface area: 300 – 400 mEffective surface area: 300 – 400 m22/cm/cm33

• Possible UsePossible Use

– Replace ion resin beadsReplace ion resin beads


Ion-Resin Beads / Ion-Resin Beads / Carbon Nanotubes / Carbon Nanotubes / AerogelsAerogels

PropertiePropertiess

Ion Resin Ion Resin BeadsBeads

Carbon Carbon NanotubNanotub

eses

AerogelsAerogels

Surface AreaSurface Area 250-350 250-350 mm22/cm/cm33

300-800 300-800 mm22/cm/cm33

300-400 300-400 mm22/cm/cm33

Young's Young's ModulusModulus

N/AN/A 11 TPaTPa 101066-10-1077 Pa Pa

Tensile Tensile StrengthStrength

N/AN/A 30 GPa30 GPa (max)(max)

16 kPa16 kPa


Dennis ArnoldDennis Arnold

New Design Plan New Design Plan

Analysis of New DesignAnalysis of New Design


Project SpecializationProject Specialization

• Focused on use of aerogels in CMRSFocused on use of aerogels in CMRS– Time constraintsTime constraints– Amount of readily available informationAmount of readily available information– Nanotubes are in early development Nanotubes are in early development

stagesstages– NASA currently researching nanotubesNASA currently researching nanotubes


Aerogels Replacing Aerogels Replacing BeadsBeads

• Issue of pressure drop through chambers Issue of pressure drop through chambers full of aerogelfull of aerogel

• Discussed issue with Dr. Noel ClemensDiscussed issue with Dr. Noel Clemens– Aerogels would result in lack of sufficient airflowAerogels would result in lack of sufficient airflow– Decided NOT to replace the beads with aerogelDecided NOT to replace the beads with aerogel

• Decided to keep the beads, replace screenDecided to keep the beads, replace screen• Concluded to research replacing the mesh Concluded to research replacing the mesh

screen with a thin slice of aerogelscreen with a thin slice of aerogel


Aerogels Replacing Mesh Aerogels Replacing Mesh ScreenScreen

Retaining Screen

Solid Amine Ion Resin Beads

Airflow Inlet

Choked Airflow Outlet

Choked Airflow Outlet

Retaining Screen

Solid Amine Beads

• Air flow is choked by Air flow is choked by the beads at the the beads at the outlet retaining screenoutlet retaining screen


Aerogels Replacing Mesh Aerogels Replacing Mesh ScreenScreen

Solid Amine Ion Resin Beads

Airflow Through Screen at Inlet

Aerogel

Airflow Through Aerogel at Outlet

• Theoretically, air flows around the beads Theoretically, air flows around the beads and through the aerogel slice without and through the aerogel slice without blockageblockage


Aerogel Pressure Drop Aerogel Pressure Drop AnalysisAnalysis

• Start with Darcy’s Law:Start with Darcy’s Law:

Q = volumetric flow rateQ = volumetric flow rate

K = permeabilityK = permeability

A = area perpendicular to flowA = area perpendicular to flow

L = length of flow across mediumL = length of flow across medium

∆∆P = Change in pressure across mediumP = Change in pressure across medium

L

PAKQ


Pressure Drop Analysis Pressure Drop Analysis (Cont)(Cont)

• Rearranged into slope-intercept Rearranged into slope-intercept form: form:

• Which resemblesWhich resemblesm = slope m = slope

b = y-interceptb = y-intercept

A

Q

K

1

L

P

bmxy



• EstimatedEstimated

slope fromslope from

figurefigure

• Slope = 1/KSlope = 1/K



• Solving Darcy’s law for Solving Darcy’s law for ∆P:∆P:

Q = 20 cfmQ = 20 cfmL = 0.15 x 2L = 0.15 x 21/21/2 in. in.A = 3 ft. x 1.25 in. x Cosine 45A = 3 ft. x 1.25 in. x Cosine 45 ⃘⃘K = 1.8 x 10K = 1.8 x 1066 g/cm g/cm33 – s – s22

∆∆P = 3.7 in HP = 3.7 in H22OO

KA

QLP



Pressure Drop Through Bed and Headers

0

2

4

6

8

10

12

0.0 10.0 20.0 30.0 40.0

Flow Rate (CFM)

Pre

ss

ure

Dro

p (

in H

2O

)

Bed A Data

Bed B Data


Jessica BadgerJessica Badger

SummarySummary

ConclusionsConclusions


Summary Summary

• Heat Transfer and Structural RigidityHeat Transfer and Structural Rigidity– Replace aluminum puffed foam with Replace aluminum puffed foam with

perforated honeycomb (2024 - T81P)perforated honeycomb (2024 - T81P)– Cell size = 0.25”Cell size = 0.25”– Provides 3-D airflow through bedProvides 3-D airflow through bed– Adds strength and rigidity due to high strength-to-Adds strength and rigidity due to high strength-to-

weight ratiosweight ratios– Allows the beads to be more densely packed into Allows the beads to be more densely packed into

the structurethe structure

– Heat removed via radiation Heat removed via radiation – Rate at which heat is removed is comparable for Rate at which heat is removed is comparable for

both perforated honeycomb and puffed foamboth perforated honeycomb and puffed foam


Summary (cont)Summary (cont)

• Surface Area & Pressure DropSurface Area & Pressure Drop– Studied carbon nanotubes and aerogels for Studied carbon nanotubes and aerogels for

ways to replace ion resin beadsways to replace ion resin beads– Considered filling each perforated honeycomb Considered filling each perforated honeycomb

cell with solid-amine coated aerogelcell with solid-amine coated aerogel– Air would not be able to flow throughAir would not be able to flow through– Needed a new design strategyNeeded a new design strategy

– Decided to use thin slice of aerogel to replace Decided to use thin slice of aerogel to replace outlet retaining screens outlet retaining screens – Pressure drop for single slice of aerogel was Pressure drop for single slice of aerogel was

comparable to entire RCRS bedcomparable to entire RCRS bed– Needed more recent aerogel permeability dataNeeded more recent aerogel permeability data


ConclusionsConclusions

• Replace aluminum puffed foam Replace aluminum puffed foam with perforated honeycombwith perforated honeycomb

• Further investigate aerogel Further investigate aerogel properties and possible useproperties and possible use

• Research previous option of carbon Research previous option of carbon nanotubes for solid-amine housingnanotubes for solid-amine housing


Special Thanks!!Special Thanks!!

• Dr. John GrafDr. John Graf• Dr. Ronald O. StearmanDr. Ronald O. Stearman• Dr. Noel ClemensDr. Noel Clemens• Dr. Arlon Hunt & Dr. Ulrich Dr. Arlon Hunt & Dr. Ulrich

SchubertSchubert• Marcus KrugerMarcus Kruger


Questions?Questions?

• Preguntas?Preguntas?• Questionne?Questionne?• Bопрос?Bопрос?• Kwestie?Kwestie?• Ninau?Ninau?• Swali?Swali?• Spørsmål?Spørsmål?• Förhöra?Förhöra?

Please visit our website at www.ae.utexas.edu/~juliatPlease visit our website at www.ae.utexas.edu/~juliat

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Carbon Dioxide and Moisture Removal System