1. Transesterification Reaction by using Lewis acid based solid catalyst T.M.SankaraNarayanan National Centre for Catalysis Research 04.04.2009

2. What is BIODIESEL?

3. BIOFUELS or BIODIESEL Biodiesel is the name of a clean burning alternative fuel derived from plant or vegetable oils (vegetable derived esters or VDE) that can be used as a blend with or as a total substitute for petroleum diesel. It can be used in compression- ignition (diesel) engines even without any engine modifications.

4. Biodiesel is a variety of ester-based oxygenated fuels made from vegetable oils or animal fats. It is indigenous, renewable, biodegradable, and a nontoxic diesel fuel substitute. The first diesel engine was powered using peanut oil by Rudolf Diesel in 1895. He demonstrated the engine in 1900 at the World Exposition in Paris where he took the highest prize.

5. RAW MATERIALS Rapeseed Sunflower oil ( Italy and Southern France) Soybean oil (USA & Brazil) Palm oil (Malaysia) lard, used frying oil (Austria), Jatropha (India,Nicaragua & South Americas)

6. Advantages

7. Alternative fuel for diesel engines Made from vegetable oil or animal fat Meets health effect testing (CAA) Lower emissions, High flash point (>300F), Safer Biodegradable, Essentially non-toxic. Chemically, biodiesel molecules are mono-alkyl esters produced usually from triglyceride esters

8. Can be mixed in any ratio with petroleum diesel fuel or can be used 100%. Produces less particulates, soot, carbon monoxide, and hydrocarbon emissions than petroleum diesel fuel. Known to provide a substantial reduction in cancer risks. Produces pleasant exhaust odor unlike petroleum diesel. Has very good lubricity properties. Used as lubricity additive in severely hydro-treated diesel fuel. Oral toxicity effects are similar to those associated with laxatives.

9. Relative Greenhouse Gas Emissions 020406080100120140160 Gasoline CNG LPG Diesel Ethanol 85% B20 Diesel Hybrid Electric B100 Data from “A Fresh Look at CNG: A Comparison of Alternative Fuels”, Alternative Fuel Vehicle Program, 8/13/2001 B100 = 100% Biodiesel B20 = 20% BD + 80% PD

10. Catalyst for transesterification Reactions People are working on both homogeneous and Heterogeneous Catalysis. We are going to focus only heterogeneous catalyst

11. This talk mainly focused on Lewis acid based hydrophobic solid acid catalysts transesterification reactions P.Rathnasamy et al Applied Catalysis A: General 314 (2006) 148–159 P.Rathnasamy et al. Journal of Catalysis 241 (2006) 34–44

12. Double-metal cyanide (DMC) complexes possess zeolite-like cage structures Now a days have gained considerable attention for their interesting magnetic, electrochromic, magneto- optic, photomagnetic and nanomagnetic properties These Prussian blue-analogues are insoluble in most of the organic solvents and even in aqua regia. They are currently used as catalysts for the copolymerization of epoxides andCO 2

13. Catalyst preparation K4[Fe(CN)6]ZnCl 2 40 mL of double-distilled water 100 mL of distilled water and 20 mL of tert-butanol A 15-g sample of tri-block copolymer 2 mL of distilled water and 40 mL of tert-butanol solution 3Solution 2solution 1 Solution 2 was added to solution 1 slowly over 1 h at 323 K under vigorous stirring. A white solid was precipitated. Solution 3 was then added to the above reaction mixture over 5–10 min, and stirring was continued for another1 h. Fe–Zn-1 After activating at453 K for 4 h 0.01 mol 0.1 mol

14. Synthesis of Fe/Zn DMC catalysts

15. Tentative structure of double metal cyanide Fe–Zn complex

16. Catalyst characterization XRF analyses Elemental analyses X-ray Diffraction Diffuse reflectance Infrared Spectroscopy Diffuse reflectance UV–vis spectroscopy Temperature Programmed Desorption

17. Influence of the method of preparation

18. X-ray Diffraction

19. Scanning electron micrographs of Fe–Zn-1 catalyst

20. Diffuse reflectance Infrared Spectroscopy

21. Diffuse reflectance UV–vis spectroscopy

22. Methanolysis of sunflower oil over various double-metal cyanide catalysts effects of catalyst composition, method of preparation, polymer surfactant and catalyst reuse Reaction conditions: catalyst = 3 wt% of sunflower oil; oil = 5 g; oil:methanol = 1:15 mol/mol; temperature, =443 K; reaction time = 8 h. a Oil converion was estimated based on the isolated yield of glycerol.

23. Identification and Quantification of Lewis Acid sites By using FTIR and TPD. Identification and Quantification of Lewis Acid sites By using FTIR and TPD.

24. DRIFT spectroscopy of adsorbed pyridine on Fe–Zn double-metal cyanide complexes at (a) 323 K and (b) 448 K. (c) NH3-TPD of Fe–Zn complexes. Panel (d)shows the deconvolution plot of the NH3-TPD curve for Fe–Zn-1. Correlation Acid sites by using of FTIR and TPD

25. DRIFT spectra of adsorbed pyridine on Fe–Zn double metal cyanide catalysts. Diffuse reflectance Infrared Spectroscopy

26. The deconvolution plot of the NH3-TPD curve for Fe–Zn-1.

27. Influence of free fatty acids (FFA) (a) amount of the catalyst,(b) alcohol-to-oil molar ratio,

28. Influence of reaction parameters (c) reaction temperature (d) reaction time on ethanolysis of margarine oil over Fe–Zn-1 catalyst

29. Reaction conditions: catalyst (Fe–Zn-1), 3 wt% of oil; oil, 15 g; CH3OH, 8.2 g; oil:CH3OH(mol) = 1:15; temperature, =443 K; reaction time, 8 h; reactor type, closed autoclave (100 ml). a Except Safflower (Kardi) and margarine rest all are unrefined (raw) vegetable oils.

30. Reaction conditions: catalyst, 3 wt%of oil; oil, 5 g; oil:alcohol = 1:15 mol/mol; temperature, 443 K; reaction time, 8 h. Influence of the type of alcohol on the tranesterification of rubber seed and margarine oils over Fe–Zn-1 catalyst.

31. Reaction conditions: catalyst (Fe–Zn-1), 3 wt% of oil; unrefined sunflower oil, 5 g; CH3OH, 2.75 g; oil:CH3OH (mol) = 1:15; temperature, =443 K; reaction time, 8 h; reactor type, closed autoclave (100 ml).a Conversion of oil was estimated based on the glycerol recovered. Methanolysis of sunflower oil in the presence of added water over double-metal cyanide Fe–Zn catalyst (Fe–Zn-1)

32. Correlation of esterification (oleic acid) and transesterification (sunflower oil) activities over different double-metal cyanide catalysts Reaction conditions: catalyst, 3 wt% of acid or oil; oleic acid or oil, 5 g; temperature, 443 K. For esterification reaction—oleic acid:CH3OH = 1:2 mol/mol and reaction time, 45 min. For transesterification reactions—oil:CH3OH = 1:15 mol/ mol and reaction time = 8 h. Reaction conditions: catalyst, 3 wt% of acid or oil; oleic acid or oil, 5 g; temperature, 443 K. For esterification reaction—oleic acid:CH3OH = 1:2 mol/mol and reaction time, 45 min. For transesterification reactions—oil:CH3OH = 1:15 mol/ mol and reaction time = 8 h.

33. Active sites for transesterification of sunflower oil with methanol: structure–activity relationship NH3-desorption in the region 353–473 K due to Lewis acid sites (Fig. 5d). Relative intensity of the 1490 cm1 band characteristic of Lewis acid sites in the IR spectra of adsorbed pyridine per mol of Zn2+ ions (Fig. 5a) Reaction conditions: catalyst, 3 wt% of oil; sunflower oil (average molecular weight = 890), 5 g; oil:CH3OH (mol) = 1:15; temperature, =443 K; reaction time, 8 h; reactor type, closed autoclave (100 ml). Turnover frequency (TOF) = mmol of sunflower oil converted per mmol of Zn2+ ions per hour. Numbers in parentheses are normalized values.

34. Transesterification of propene carbonate with various alcohols over double metal cyanide Fe–Zn catalyst (Fe–Zn-1)

35. a) Reaction conditions: Fe–Zn-1 (pre activated at 453 K for 4 h), 0.25 g; PC, 10 mmol; ROH, 100 mmol; reaction temperature, 443 K; reaction time, 8 h. b) Product isolated by column chromatography. Isolated yield is reported. 1,2-propene glycol was formed in an equivalent amount. c)TON = moles of PC converted per mole of catalyst. a) Reaction conditions: Fe–Zn-1 (pre activated at 453 K for 4 h), 0.25 g; PC, 10 mmol; ROH, 100 mmol; reaction temperature, 443 K; reaction time, 8 h. b) Product isolated by column chromatography. Isolated yield is reported. 1,2-propene glycol was formed in an equivalent amount. c)TON = moles of PC converted per mole of catalyst.

36. Reaction of dimethyl carbonate with various alcohols over Fe–Zn-1 catalyst

37. Reaction conditions: Fe–Zn-1, 0.25 g; DMC, 10 mmol; ROH, 100 mmol; reaction temperature, 443 K; reaction time, 8 h.

38. Transesterification of propene carbonate (PC) with methanol Transesterification of propene carbonate (PC) with methanol. Influence of (a) reaction temperature, (b) CH3OH to PC ratio and (c) amount of catalyst on DMC yield. Reaction conditions for (a): catalyst Fe–Zn-1 (activated at 453 K for 4 h), 0.25 g; PC, 10 mmol; methanol, 100 mmol, reaction time, 8 h. Reaction conditions for (b): catalyst Fe–Zn-1 (activated at 453 K for 4 h), 0.25 g; reaction temperature, 443 K; PC, 10 mmol; reaction time, 8 h. Reaction conditions for (c): PC, 10 mmol; methanol, 100 mmol; reaction temperature, 443 K; reaction time, 4 h.

39. Run no.ROH Dialkyl carbonate yield (mol%) TON 1Methanol86.626 2Methanol (recycle-1)83.225 3Methanol (recycle-2)83.525 4Methanol (recycle-3)84.925 5Methanol (recycle-4)83.225 6Methanol (recycle-5)82.625 7Ethanol79.424 8Propanol77.523 9Butanol69.321 10Hexanol62.519 11Benzyl alcohol77.823

40. Tentative reaction mechanism for transesterification of propene carbonate with alcohols (ROH) over Lewis acid Zn 2+ cations in Fe–Zn double metal cyanide catalysts.

41. Conclusions A novel application of double-metal cyanide (DMC) complexes as highly active, heterogeneous catalysts for production of biofuels and lubricants from vegetable oil esterification/transesterification reactions is reported. These catalysts are Lewis acidic, hydrophobic (at reaction temperatures of about 443 K) and insoluble in most of the solvents including aqua regia. A catalyst containing of Fe 2+ –Zn 2+ and tert-butanol in its composition (K 4 Zn 4 [Fe(CN) 6 ]36H 2 O2(tert-BuOH); Fe–Zn-1) was superior to others. The role of surfactant molecules in the synthesis is probably to increase surface area and acid sites density thereby enhancing catalytic activity in both the esterification andtransesterification reactions. There is a correlation between catalytic activity and the concentration of acid sites as measuredby NH 3 or pyridine adsorptions.Coordinatively unsaturated Zn 2+ are the probable active (Lewis acid) sites for both the esterification and transesterification reactions.

42. References: An Overview of Biodiesel and Petroleum Diesel Life Cycles Presentation at the NH Science Teacher Association (NHSTA) Annual Conference, Session 15, March 22, 2005, Philips Exeter Academy. Exeter, NH

43. Thank you