aiaa 6034 2010 presentation

8/6/2019 AIAA 6034 2010 Presentation

1/23

Solid Waste Streams

James A. Nabity, Erik W. Andersen & Jeffrey R. Engel

TDA Research, Inc.

John W. Fisher

NASA Ames Research Center

40th International Conference on Environmental Systems

Barcelona, Spain

July 12, 2010

TDA

R e s e a r c h


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3/23


4/23

Summary of Current Methods Used

Strategy depends on mission duration

Short term missions can store, compact, orencapsulate waste and do not need to recoverresources

Long term missions must process the waste andrecycle resources especially water and O

2 Oxidation is an excellent choice, since ~0.67 gH2O can be produced per gram of mixed wastes

However, current methods for oxidation still havedisadvanta es

There is a need for an effective oxidationrocess that is ra id and safe


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TDA Approach

Use ozone to convert waste to CO and H O

at moderate temperature The rocess has several advanta es over

other methods

Ozone will rapidly oxidize a wide range ofy rocar ons

Eliminates many hazardsdoes not require high temperatures

does not produce high concentrations of NOX It is safe and easy to use Theoretically, no net consumables are needed


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Closing the Loop on Consumables

6 H2O

OzoneGeneration

OzoneOxidation

4 O3C6H10O5 + H2OModel Waste

O26 CO2

Electrolysis Pyrolysis6 CH412 H2O

Sabatier12 H2 12 H2 6 C

Global System Equation:

C6H10O5 + H2O + energy 6 C + 6 H2O


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Ozone Oxidation

Fr m Thi

To This

WWW.NASA.GOV

Automated WasteOxidation Apparatus


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Wet Oxidation Process to Handle

Low tem erature rocess ~100 to 135C

Stable175

200

175

200 WaterBoiling Pt

100

125

150

rature(C)

Reactor Operating

125

150

100ratu

re(C)

50

75Tempe

Pressure ~ 4.4 atmabsolute (65 psia)75

50Tempe

0

25

0 25 50 75 100 125 150 175 200

Pressure sia500 25 75 100 125 150 175 200

0

25

ressure ps a


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Pilot Scale Reactor Design15.24 cm Diameter, 60.96 cm Length 11.1 LiterVolume316 Stainless Steel

Fabricated using 3A sanitary tubing, fittings andclamps13.6 atm max pressure @ 121C

3 diffusers forenhanced mixing and

O3/waste contact

Split PTFE bottom forease of installation

Holes tapped for easydiffuser installation

O3/O2 inlet feed (one

for each diffuser)


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Pilot Scale Wet Oxidation System

ReactorCondenser

CondensableTrap

Recycleow ump


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Conditions for the Experiment

Reactor ressure: 4.4 atm 65 sia

Reactor temperature: 125C

2

O3 flow into the reactor: 1.6 to 4.3 mol/h Recycle flow: 20 slpm

Waste: 100 g of fecal simulant in 5 L of distilled

water


12/23

Fecal Simulant Breakdown

Yeast* (30%)Peanut Oil

(20%)

*substituted for E Coli

PolyethyleneGroundPs llium Husk

(20%)

Ref: Wignarajah, Kanapathipillai, Eric Litwiller, John W. Fisher and John Hogan, SimulatedHuman Feces for Testing Human Waste Processing Technologies in Space Systems,

ICES 2006-01-2180.


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Effect of Ozone Flow on Oxidation of

25

20

te,g/h

15

sum

ptionR

5WasteCo

0

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

zone ow to t e eactor, mo /


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100 gm of Mixed Wastes

No Pre-processing Cut into Strips


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Ozone Oxidation Results

25

20

e,g/h

100 gm sample not

fully oxidized

eca s mu antUnprocessed mixed solid wastes

Pre-processed mixed solid wastes

15

umptionRat

Complete oxidationof 100 m

10

WasteCon

0

re-process ng

. . . . .

Ozone Flow to the Reactor, mol/h


17/23

Power Budget

Heat Tapes 62.3%Recycle Pump 7.1%

Ozone Generator 19.0%

Water Transfer Pump 1.5%Computer 1.2%

Gas Analyzers 8.8%

Total 100%


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Summary of Experimental Results

Ozone can rapidly oxidize wastes at temperatures

below 150C with very high selectivity to CO2 andH2O..

8.5 g/h for cut up mixed wastes

<


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Projected Performance of an

Waste oxidation performance: 36 g/h @ 99.7% destruction removal efficiency 860 g/day

. . 2 from Wignarajah fecal simulant (8.4 wt% H)

-scale for 6 crew members 0.1 m3 box size and 139 kg

Consumables: Only the wastes in a closed loop


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System Benefits

Solid waste destruction: 99.7% based on gasanalysis

Water recovery and production: up to 1.1 kgper crewmem er- ay assum ng m xewastes w/ 11% water & 6% H content

and viruses Typically less than 10 minute contact times with

between 0.01 10 mg O3 per Liter of water (


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Conceptual Waste Oxidation SystemCooling

ys em

COOxidation

Ozone Oxidation System

Oxygen

ReactorCondenser +

Separator

NOx

Feed forstart-up only

ater ecyc eCircuit

O3, CO2, CO,NOx Analyzers

O

Scrubber

Water

Ozone Generator Ozone RecycleCircuitO3

Destruction

CO2Recovery

rea men


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Summary and Conclusions

Stable and reliable ozone oxidation of waste

streams

Capable of 0.3 to 0.86 kg / day with high

capacity ozone generator

Generates and recovers water 1.1 k er crewmember-da assumin mixed wastes

w/ 11% water & 6% H content

Inactivates microbial or anisms and viruses


23/23

Acknowledgements

Mr. hn Fi h r TR f r NA A AR

Contract # NA06CA57C

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