Potentials in Bleaching Earth Reduction Theoretical Background Industrial Results

Transcription

1 Potentials in Bleaching Earth Reduction Theoretical Background Industrial Results Gunter Börner Matthias Schneider ÖHMI Engineering GmbH Berliner Chaussee 66 D Magdeburg

2 Bleaching Mechanism for Removal of Impurities 1. Physic: (adsorption) dyestuffs, phospholipids, soaps pesticides, metals traces, PAH, oxidation products, glucolipids 2. Chemical: (catalyst reaction, ion exchange) phospholipids, soaps metals traces, pesticides, oxidation products 3. Mechanical: (filtration) phospholipids, soaps Adsorption on a grain

3 Bleaching Process Phase Diagram 1 st Publication 1986 by P. Transfeld Equilibrium line for certain oil-be system c particle concentration in the oil q 1 q load of bleaching earth q = (c 2 -c 1 )/m B Co-current operating line c 1 α c 2 α tan α = q/ c, rise of working line small α high BE consumption

4 Bleaching Processes 1. Standard process, Co-current bleaching 2. Filter-press - bleaching 3. Tri-Clear Filter-press -bleaching with Silica-pre-treatment 4. Counter-current-bleaching, ÖHMI bleach, 2-stages 5. Bleaching with superfine bleaching earth, ÖHMI filtration

5 Filter-Press - Bleaching More than 49 years old bleaching earth unbleached bleached filtration 1 oil across filter cake bleaching filtration 2

6 Filter-Press - Bleaching α P > α q 1P > q 1 q 1P q 1 α P Less bleaching earth α P α c 1 c 2 Co-current operating line Filter-press operating line Mainly mechanical effect (filtration) Pre- bleaching time in filter cake approx. 1 s

7 Tri-Clear Process By Grace Davison silica bleaching earth unbleached bleached pre-treatment filtration 1 oil across filter cake bleaching filtration 2

8 Tri-Clear Process α T > α P > α q 1T > q 1 q 1T α T Less bleaching earth q 1 α T α c 1 c 2 Co-current operating line Tri-Clear operating line 1 st physical+chemical effect 2 nd mechanical effect (filtration)

9 Counter-Current Bleaching bleaching earth pre-bleaching filtration 1 filtration 2 unbleached bleached final bleaching re-use of bleaching earth

10 Counter-Current Bleaching q C q C2 q 1 q α c2 α C2 > α P > α q c2 - q 1 = q =driving force benefit Less bleaching earth α c α c2 α c 1 c 2 Co-current operating line Ideal counter-current operating line ( stages) ÖHMI bleach operating line (2 stages) 1 st physical+chemical effect 2 nd mechanical effect (filtration)

11 Bleaching with superfine bleaching earth super fine bleaching earth unbleached electric filtration bleached bleaching spent bleaching earth

12 Bleaching with superfine bleaching earth α E > α q E - q 1 = q =driving force benefit q E Less bleaching earth q 1 Equilibrium line for normal bleaching earth α E α Equilibrium line for normal Super fine bleaching earth c 1 c 2 Operating line for normal bleaching earth Super fine bleaching earth operating line physical+chemical effect

13 Comparison Co-current bleaching Filter press effect Tri-Clear ÖHMI bleach Super fine bleaching earth q E q C2 q P q T q 1 c 1 c 2

14 Conclusions Bleaching phase diagrams improve the understanding of the bleaching mechanism explains the potentials of the different bleaching processes c 1 c 2 q 1 Reduction of bleaching earth consumption and the byproduct spent bleaching earth by: 1. Process improvement 2. Combination of adsorbents 3. Higher adsorbent activity

15 Thank you for your Attention!