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WALNUT SHELL FILTERS

SAIDU BALDE

JOSEPH PECSENYICKI

KORKU TETTEY

NAVJIWAN TINJAN

Chem 260 Project: 2013Produced by:

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INTRODUCTION

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Walnut shell filtration where sand filters formerly used:

more suitable for filtering free oil and suspended solidstreat oil field produced waterrefinery wastewatersteel mill direct spray and caster

waterethylene plant quench watercopper concentrate decant cooling water

(Slide information from [6])

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Reduces:

•Backwash water volume•Weight•Footprint

Suitable for off-shore oil production

(Slide information from [2])

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• mechanically separate solids (or free droplets) from solution

Filters

(Slide information from [3])

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Filter Type A

Surface filters – sieves (size exclusion)

Eg: cheesecloth, coffee filters

Image: http://www.bravilor.com/en-IN/product/filter-cups/110

(Slide information from [3])

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Deep Bed (or Depth) filters

• droplets slowed in tortuous channels

• droplets attach to filter by some mechanism

Filter Type B

Image: http://www.nuts.com/nuts/black-walnuts/in-shell.html

Eg: black walnut shell filter

(Slide information from [3])

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Filter media

granules

Clear Path Tortuous Path

Flow

(Image: Joseph Pecsenyicki)

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Droplets slowed in tortuous channels

Droplets captured on walnut shell media via:• Direct collision• Diffusion

• London force attraction• Surface charge attraction /

repulsion(Slide information from [3])

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Link to Flash Animation

http://chou-seh-fu.com/presentations/chem260/walnutShellFilterAnimation.html

1. Click on link.2. Animation will load onto your default browser.3. Control+ or Control– to adjust screen size.4. Click anywhere on Flash screen to advance to next

animation sequence.5. Click green back button to play previous animation

sequence.6. Close browser when finished.

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ADVANTAGES OF WALNUT SHELL FILTERSI

• Lightweight media

• Strong & elastic less fracturing than sand less flaking than anthracite

• Non-abrasive less frictional damage to

media than sand / anthracite

(Slide information from [3])

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ADVANTAGES OF WALNUT SHELL FILTERS II

• Can be ground into optimal size

sand grains are a little too small – require higher flow pressure

• Coalesces oil easy to clean via water

backwash(Slide information from [3])

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CONCLUSION

Walnut shell filters:

• Saw adoption during early 1970s

• Widespread due to: Easy oil coalescence Mechanical properties Easy & chemical-free backwash properties

(Slide information from [3])

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Supplemental

Information(Skimmed through in original presentation due to time constraints)

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COMPARISON OF MEDIA

Media Oil affinity quotientPolyvinyl chloride 0.212Anthracite 0.042Silica sand 0.043Black walnut shells 0.033

g of oil retained by cm3 of media

(Slide information from [3])

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BLACK WALNUT SHELLS

(Slide images from [2])

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MEDIA GRANULES

(Slide images from [2])

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OIL-COATED WALNUT SHELL GRANULES

(Slide images from [2])

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INDUSTRIAL-SIZED WALNUT SHELL FILTER

• Vertical vessel: 48 – 66 inch walnut shell media depth

(Slide images & information from [2])

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Longer run times

Longer media lifetime

Fewer suspended solids escape downstream

VERTICAL FILTRATION

(Slide image & information from [2])

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OIL REMOVAL

• 100 PPM oil enters

•Oil droplets > 2 μm ≈ 95% removal

•Oil droplets > 5 μm ≈ 98% removal

•< 5 PPM oil exits

(Slide image & information from [2])

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Media requires aqueous wetting before use.

Backwash:

• Once per day

• Water backwash – no chemicals

• 20-30 min. process

• 1% to wastewater

Media attrition: 5% per year. (Slide images & information from [2])

SOURCES[1] Abdallah, W., et al. (2007). Fundamentals of

Wettability. Oilfield Review. Summer. pp. 44, 49.

[2] Howdeshell, M., Catalanotto, C. and Lorge, E. (Siemens) .“Walnut Shell Filter Reuse Potential.” 2011. Retrieved October 15, 2013 from http://www.sawea.org/pdf/Mike_Howdeshell.pdf

[3] Kashaev, S. and Lee, D. (2010). Deep Bed Nutshell Filter Evolution. Retrieved October 27, 2013 from: http://www.exterran.com/Content/Docs/Products/Deep-Bed-Nutshell-Filter-Evolution-English-Letter.pdf

[4] Ian Mackay. Instructor, SAIT. Interview. Calgary, AB. November 4, 2013

[5] Kari McDonald. Instructor, SAIT. Interview. Calgary, AB. November 8, 2013

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SOURCES[6] Siemens. “Auto-Shell™ Filter: Walnut Shell

Filtration.” 2009. [Online]. Retrieved October 15, 2013 from http://www.water.siemens.com/SiteCollectionDocuments/Product_Lines/Monosep/Brochures/ZP-AUSH-DS-0310.pdf

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ADDITIONAL REFERENCES

Filtra Systems Technology. “Deep Bed Media Filter.” n.d. [Online]. Retrieved October 15, 2013 from: http://filtrasystems.com/products/deep-bed-media-filter/