Crown Iron Works Company

Transcription

1 Crown Iron Works Company AOCS FUNDAMENTALS OF OILSEED AND EDIBLE OIL PROCESSING AND REFINING Bleaching Basics and Practical Optimization Shanghai, China November 2014 Greg Waranica 1

2 Crown Contacts USA Greg Waranica or Derek Masterson Crown Iron Works Company Phone: Web: 2

3 Crown Contacts China Crown Asia Engineering (Wuhan) Co., Ltd Phone: +86 (27) Web: 3

4 Oils & Fats Refining Roadmap 4

5 Purpose of Bleaching Remove contaminants from crude oil prior to deodorizing or other refining processes: Residual gums from Degumming or Neutralizing Residual soaps from Degumming or Neutralizing Color bodies or pigments, primarily chlorophyll A and carotene Metals and other pro-oxidants (Cu, Ca, Fe, Mg and P) Oxidation byproducts (PV and AV) 5

6 Target Oil Quality Chlorophyll: <50 ppb PV: <0.5 meq/kg Phosphorus (P): <5 ppm but <2 ppm typical Soaps & Gums: nil Iron (Fe): <0.2 ppm Moisture: <0.1% 6

7 Bleaching Process Options Precoat Bleaching Clay vs. Filter Aid (equipment) Filter Aid vs. Cellulose (filter screens) Adsorption vs. Water Washing Silica/Silicates: Combine with bleaching clay vs. separate reaction (equipment) Bleaching Clay Addition: Slurry tank vs. Bleacher (equipment) Filters: Vertical vs. Horizontal (space and labor) 7

8 Adsorbents/Absorbents Adsorbents Remove residual gums and soap Remove metals Typically used only if oil is not water washed in Degumming or Neutralizing Bleaching Clay/Earth Remove residual gums and soap Remove metals and other pro-oxidants, chlorophyll, some red color pigments (carotenes) and oxidation byproducts 8

9 Adsorbents/Absorbents Filter Aid Precoat filters for longer filter cycle time than bleaching clay only Improved cake release over bleaching clay only Sometimes added as a body feed in silica adsorption step to improve filtration rate or extend filter cycle time Activated Carbon Remove PAH, PCB, dioxin and furan Sometimes blended with bleaching clay 9

10 Affect of Temperature As temperature increases Chlorophyll removal increases Bleached oil color improves Filtration rate increases But Oxidation reactions increase Deodorized oil color deteriorates 10

11 Affect of Time As time increases Chlorophyll removal increases slightly Bleached oil color improves But Oxidation byproducts increase Deodorized oil color deteriorates 11

12 Affect of Vacuum As vacuum increases (<50 mmhg) Oil drying increases As vacuum decreases (>100 mmhg) Oxidation reactions increase Oil drying decreases Filtration decreases 12

13 Affect of Moisture Acid activated bleaching clay needs moisture in the oil for optimal performance As moisture increases (>0.5%) Filtration decreases Bleaching efficiency decreases As moisture decreases (<0.1%) Bleaching efficiency decreases 13

14 Operating Conditions Condition Range Typical Temperature Up to 125C/260F C F Time Up to 240 min min Vacuum mmhg Moisture % % Operating conditions depend on bleaching clay 14

15 Classic Bleaching Process Water Wash Centrifuge Degumming or Neutralizing Dryer Slurry Tank (Optional) Bleaching Clay Bleacher Filter(s) 1 or 2 15

16 Tri-clear, DoublePass, Combiclean, Lead Lag Bleaching Process Primary Centrifuge Degumming or Neutralizing Slurry Tank Silica Dryer Silica filtered and oil pre-bleached on bed of spent bleaching clay Slurry Tank (Optional) Bleaching Clay Silica may be filtered on clean filter but a 4 th filter is recommended Bleacher Filters 3 16

17 Pre-Bleached Oil Color Color after pre-bleaching (zero B.E. consumption) 17

18 Filter Cake Filter cake Solid 25 mm cake Less than 30% oil Silica Bleaching Earth Filter Aid 18

19 Packed Bed Bleaching Process Primary or Water Wash Centrifuge Degumming or Neutralizing Slurry Tank (Optional) Silica (optional) Dryer Silica Filter(s) 1 or 2 (optional) Packed Bed Filters 2 Bleaching Clay 19

20 Pre-Bleaching Bleaching Process Water Wash Centrifuge Degumming or Neutralizing Dryer Body feed (optional) Oil pre-bleached on bed of spent bleaching clay Slurry Tank (Optional) Bleacher Bleaching Clay Silica optional Filters 3 20

21 Counter Current Bleaching Process (Ӧhmi) Primary or Water Wash Centrifuge Degumming or Neutralizing Slurry Tank (Optional) Silica (optional) Bleacher No. 1 Slurry Tank (Optional) Bleacher No. 2 Fresh Bleaching Clay Filters 3 Spent Bleaching Clay 21

22 Recent Trends in Bleaching Improved bleaching clay activity while maintaining fast filtration Inline color and turbidity measurement Pulse tube filter replacing bag filters as the polish filter (most useful for stock changes) 22

23 THANK YOU FOR YOUR ATTENTION 23