Oleochemicals and Catalysts Used

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Oleochemicals - What are they?
fatty acids
fatty alcohols
fatty methyl esters
fatty amines
glycerine
Oleochemical pathways
What are they used for?
Where do they come from?
Review of Organic Functional Groups
Fatty Acids
- Uses
- Process
- Splitting
- Hydrogenation
Ni Catalyst for FA hydrogenation
Catalyst deactivation in fatty acids by corrosion
Ni soap decomposition
Nickel dissolution in the presence of hydrogen
Comparison pore size & TG/FA molecules
Effect of pore dimensions in fatty acid hardening
Effect of premixing time on catalyst activity
Effects of catalyst dissolution summarized:
Reducing Ni soaps
Issues
Alternative catalyst for FA hydrogenation (i)
Precious metal catalyst cycle
Alternative catalyst for FA hydrogenation (ii)
Fatty Alcohols
- Uses
- Process
Fatty Ester Hydrogenolysis
Fixed Bed Hydrogenolysis
Slurry Phase Hydrogenolysis
Fatty OH polishing
Fatty Methyl Esters
- Uses
Advantages of ME vs FA as a feedstock
FME - Biodiesel
Fatty Amines
Glycerin
- Uses
- The Future
REFERENCE:
Some graphs and photographs, in particular the photo of "The nickel deposits in the tube section", were extracted from Johnson Matthey contributions to International conferences.

Oleochemicals and Catalysts Used

  1. 1. Gerard B. Hawkins Managing Director
  2. 2.  Chemical intermediates and products derived from natural triglycerides  5 basic oleochemicals: ◦ fatty acids ◦ fatty alcohols ◦ fatty methyl esters ◦ fatty amines ◦ glycerine
  3. 3. Glycerine Fatty Acids Fatty Acid Methyl Esters Fatty Alcohol Oils & Fats splitting esterification trans-esterification Partial glycerides Triacetine Fatty Acid esters F.A. ethoxylates Soaps Fatty Amines Alkyl chlorides F. OH ethoxylates F.OH sulfates Esters F.A. Alkanolamides Fatty Alcohols esterification esterification ethoxylation neutralization amination hydrogenation amidation direct hydrogenation Adapted from: Zoeblein, INFORM, Vol 3. no.6 a b c d
  4. 4.  Lubricants  Detergents  Plasticizer  Cosmetics
  5. 5. • Palm Oil (PO)- Primarily derived from the palm oil plantations in Malaysia and Indonesia is the major feedstock in Asia. • Coconut - Major source Philippines. Declining in use. • Fish oil (FH) - Predominantly used in Chile/Peru. Was popular in UK, Norway, Japan. • Canola/Rapeseed - Predominantly grown in Canada and northern Europe. Typically has higher poisons than soya. • Soyabean Oil (SO)- Primarily derived from the major soya states in the US, Brazil and Argentina. • Tallow - animal fat, usually a by-product of rendering. Lard from pigs also used. Where do they come from? • Whales - major source of oleochemicals for many years - oils, waxes, ester, spermaceti, squaleen. No longer available due to over- hunting
  6. 6.  Alcohols ◦ OH OH O CR OH H CR H H H NR O O CR H R1 • Amines – NH2 • Esters – COOR1 • Carboxylic Acids – COOH
  7. 7. Fatty Acids Soap CosmeticsLubricants Plasticizer Intermediates OH O CR
  8. 8.  Splitting  Hydrogenation  Distillation
  9. 9.  Different Process ◦ Twitchell  used catalyst ◦ Continuos  Colgate-Emery higher T & P than Twitchell ◦ Enzymatic  lipases  limited interest to date
  10. 10.  Usually to full saturatiuon ◦ i.e. break all double bonds  Catalysts used ◦ Ni on silica powder; slurry phase ◦ Pd on C powder; slurry phase ◦ Pd on C; fixed bed  Reactor systems ◦ Batch Dead End reactors ◦ Continuous Plug flow continuous reactors ◦ Loop reactors ◦ typical conditions 200°C & 20bar
  11. 11.  Typically a 22-25% Ni on silica or kieselguhr support  Used by the majority of the market  Particle diameter 6-14 microns  Narrow pores to prevent Ni dissolution  Used once and then must be discarded  Dissolved Ni soaps end up in distillate residues
  12. 12. Equilibrium is determined by hydrogen concentration ! Ni(fa)2 + H2 low pressure/ hydrogen shortage high pressure/ abundance of hydrogen Ni + 2 ffa
  13. 13. Fate of nickel crystallites: Nickel dissolution is chemically reversible, but catalytic surface vanishes drastically thereby (loss of Nickel dispersion): + ffa - ffa + Ni-soaps fresh catalyst 100 m²/g Ni used catalyst 10-20 m²/g Ni
  14. 14. 0 5 10 15 20 25 0 0.1 0.2 0.3 0.4 0.5 0.6 1/H2 pressure (bar-1) DissolvedNi(ppm) 2 bar10 bar30 bar Ni2+ = K.(H+)2/H2 Ni + 2H+ = Ni2+ + H2 Note Ni dissolution decreases by factor 100 for every pH unit rise! (data based on fatty acid hydrogenation 180 C)
  15. 15. Smaller pore sizes impede diffusion of larger molecules, i.e. triglycerides (Gly(fa)3) or nickel soaps (Ni(fa)2)
  16. 16. Soybean soap stock fatty acids, 15 bar, 200°C 1 10 100 1 10 pore size diameter (nm) final iodine value presumable course
  17. 17.  tallow olein fatty acids  vacuum  140°C  fast stirring  catalyst dosage  450 ppm Nickel 50 55 60 65 70 75 80 85 90 95 100 0 50 100 time (min) relativeactivity(%)
  18. 18.  Loss of Nickel dispersion  Nickel soap formation  Residual Nickel in final product
  19. 19.  Minimize contact time in absence of hydrogen ◦ Dose Ni to reactor just before addition of H2 or when it is already under H2 pressure ◦ Filter catalyst from FA as quickly as possible  If melting of catalyst pellets required, melt in triglyceride
  20. 20.  Ni residues  Environment
  21. 21.  Pd/C slurry phase  Typical 5% Pd on a carbon support  Can be re-used  Must have very efficient recovery  Current Pd price - $737/ounce  Financial management as important as operational management
  22. 22. 4 Fresh Catalyst 6 Spent catalyst 7 Incineration spent catalyst 8 Precious metal ash 2 Precious metal sponge 3 Precious metal salt solution 1 Precious metal 5 Customers process 9 Precious metal ash refining
  23. 23.  Pd/C fixed bed  Extrudates / Gauze  High working capital use  Efficient, continuous production  Ni fixed bed has proved difficult (basic supports, posion resistance) IV < 1 unsat FA
  24. 24. Fatty Alcohols Surfactants 80% Shampoo Powders Bath gels etc Cosmetics Lubricants in polymer processing Emulsifying agents OH O CR
  25. 25.  “Natural” fatty alcohols ◦ Hydrogenation (hydrogenolysis) of fatty methyl esters ◦ direct hydrogenation of fatty acids  Synthetic fatty alcohols ◦ Oxo-Alcohols ◦ Ziegler process
  26. 26.  Catalysts used: ◦ CuCr ◦ CuZn ◦ CuSi ◦ Raney Cu  Fixed bed and slurry phase units in operation  Move to eliminate Cr
  27. 27.  Feed: methyl esters  Gas phase FB ◦ 2900-3600psi; 230-250°C  Trickle-bed ◦ 2900-4350psi; 250 °C
  28. 28.  Higher cat consumption than FB  Greater flexibility  Vertical plug-flow reactor ◦ 3600psi; 250-300°C  Direct hydrogenolysis of fatty acids (Lurgi) ◦ Acid-resistant catalyst required ◦ Excess of fatty OH and loop employed ◦ 4350psi; 300°C
  29. 29.  Carbonyls in fatty OH can give unwanted color, odor, etc  Can be removed by hydrogenation with Ni ◦ e.g. fixed bed process with PRICAT HTC  Ni impregnated alumina trilobe extrudate ◦ 100-150°C; 20-50bar
  30. 30. Fatty M.E. Intermediates Biodiesel O O CR H R1
  31. 31.  Usually manufactured directly from oils via methanolysis with alkaline catalysts (e.g. sodium methylate) CH2OH CHOH CH2OH 3CHOH 3RCOOCH3 RCOOCH2 RCOOCH RCOOCH2 NaOCH3 + + methyl ester
  32. 32.  Lower energy consumption  Less corrosive -> less expensive equipment  More concentrated glycerine  Easier to distill  Superiority in some reactions  However the use of MeOH can have its downsides
  33. 33.  3-armed high viscosity molecule broken down to single chain low viscous fuel  Similar to cetane (C16) • Growth industry due to: – green movement and agricultural incentives in Europe – agricultural lobby and aim for domestic fuel production in USA cetane (C16) biodiesel
  34. 34. Most uses depend on the cationic nature of the amine Fatty Amines Corrosion Inhibitors Fabric Softeners Lubricant Additive Organoclays Sanitizing Agents H H NR
  35. 35. Primary amine Secondary amine Tertiary amine R-NH2 R2NH R3N
  36. 36. Which amines are produced depends on:  reaction conditions ◦ NH3 pressure ◦ temperature  Catalyst choice ◦ Raney Ni ◦ Supported Ni powders
  37. 37. Fatty nitriles Fatty acidsAl2O3 NH3 Unsaturated primary amine Saturated primary amine Saturated and unsaturated secondary amines Dialkyl monomethyl tertiary amine Ni(P) Raney Ni(D) Ni(D) Formaldehyde
  38. 38.  Batch slurry phase most common  Fixed bed or continuous slurry phase also used Product Temp (C) Pressure (bar) Catalysts Special Conditions Primary 80-150 10-550 nickel, raney nickel, cobalt Ammonia added to feed to suppress secondary and tertiary amine formation Secondary 150-200 50-200 nickel, cobalt Ammonia removed by purging with hydrogen Tertiary 160-230 7 - 14 nickel, cobalt Secondary Amine used as feed; hydrogen purge necessary to remove ammonia Unsaturated copper chromite, nickel powder similar to abovesimilar to above
  39. 39. R-COOH + NH3 R-COONH4 R-COONH4 R-CONH2 + H2O ammonium salt amide R-CONH2 R-CN + H2O nitrile R-CN + 2H2 FATTY AMINES
  40. 40. R-C≡N + H2 R-CH=NH imine First reaction step
  41. 41. R-CH=NH + H2 imine Primary amine formation R-CH2NH2
  42. 42. Secondary amine formation R-CH=NH + R-CH2NH2imine R-CH-NH-CH2-R NH2 1-aminodialkylamine
  43. 43. Secondary amine formation R-CH-NH-CH2-R NH2 1-aminodialkylamine R-CH=N-CH2-R - NH3 imine
  44. 44. Secondary amine formation R-CH2-NH-CH2-R secondary amine R-CH=N-CH2-R imine +H2
  45. 45. Secondary amine formation via hydrogenolysis R-CH-NH-CH2-R NH2 1-aminodialkylamine R-CH2-NH-CH2-R - NH3 secondary amine +H2
  46. 46. Tertiary amine formation proceeds via the same route as with the secondary amine formation. However, secondary amine condenses with imine to yield tertiary intermediates.
  47. 47.  By-product during manufacture of ◦ fatty acid ◦ methyl esters & bio-diesel ◦ fatty alcohols  Also synthetic manufacturing  Supply-Demand balance always difficult  What to do with it all?
  48. 48. Personal Care Glycerine Tobacco Pharmaceutical Food Explosives
  49. 49.  Supply will increase ◦ increasing production of biodiesel and use of oils and fats as industrial feedstock  New demands must be found/created ◦ some of these may involve catalytic processes ◦ e.g. glycerine to glyceric acid over gold catalyst

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