A Novel Solid Catalyst Process for Biodiesel Production Dheeban Kannan Jack V. Matson June 25, th Annual Green Chemistry and Engineering Conference Washington, DC

2 Introduction Biodiesel – fatty acid methyl esters Biodiesel – fatty acid ( m ) ethyl esters Importance – energy Importance – energy environmental environmental economy economy Motivation Motivation Soluble liquid catalysts --> Solid catalysts Soluble liquid catalysts --> Solid catalysts  separation hassles

3 Background Current annual biodiesel potential of US: 280 million gallons Microalgae promises yields ~1000 times that of soybean Solid catalysts – Crucial for large scale commercial production Source: European Biodiesel Board National Biodiesel Board

4 Background Transesterification Reaction Transesterification Reaction R-COOCH 2 CH 2 OH R-COOCH 2 CH 2 OH l catalyst l l catalyst l R-COOCH + 3 CH 3 OH ̶ ̶̶ ̶> 3 R-COOCH 3 + CHOH l l l l R-COOCH 2 CH 2 OH R-COOCH 2 CH 2 OH triglyceride methanol methyl esters glycerol triglyceride methanol methyl esters glycerol (vegetable oil) (biodiesel) (vegetable oil) (biodiesel) where R denotes a hydrocarbon chain of carbon number 12~16. Conventional Process Information Conventional Process Information Reactants immiscible – reaction at interface Reactants immiscible – reaction at interface Liquid base catalysts used: 60˚C – 1.5 hr Liquid base catalysts used: 60˚C – 1.5 hr Separation of catalyst from product mixture poses problems – additional processing units Separation of catalyst from product mixture poses problems – additional processing units Feedstock with high free fatty acid content require additional acid-catalyzed preceding step Feedstock with high free fatty acid content require additional acid-catalyzed preceding step Wastewater Wastewater

5 Lead-up to Current Research Solid bases not effective for conventional reaction conditions Solid bases not effective for conventional reaction conditions Solid acids even behind in performance Solid acids even behind in performance Supercritical process 1 Supercritical process 1 No catalyst, 350˚C, 500 atm, 4 min No catalyst, 350˚C, 500 atm, 4 min 40:1 Alcohol:Oil Molar ratio [conventional 6:1] 40:1 Alcohol:Oil Molar ratio [conventional 6:1] Pressure too high, Thermal breakdown issues Pressure too high, Thermal breakdown issues Critical Point: Methanol 240˚C, 80 atm, Ethanol 247˚C, 65 atm Critical Point: Methanol 240˚C, 80 atm, Ethanol 247˚C, 65 atm With cosolvent 2, 280˚C, 130 atm, 10 min With cosolvent 2, 280˚C, 130 atm, 10 min [1]. Saka, S. and Kusdiana, D., Fuel (2001) 225 [2]. Cao et al., Fuel 84 (2005) 347

6 Lead-up to Current Research Critical regime desired for better miscibility Critical regime desired for better miscibility Alcohol both as a reactant and as a cosolvent Alcohol both as a reactant and as a cosolvent Could mild solid bases be effective near critical regime? Could mild solid bases be effective near critical regime? Packed-Bed Reactor - High T okay for continuous process Packed-Bed Reactor - High T okay for continuous process Suppes et al. 3 tried calcium carbonate Suppes et al. 3 tried calcium carbonate 260˚C, 70 atm, residence time 18 min 260˚C, 70 atm, residence time 18 min 50% biodiesel as cosolvent, otherwise poor yield 50% biodiesel as cosolvent, otherwise poor yield [3]. Suppes et.al., J. Am. Oil Chem. Soc., (2001) 139

7 Batch Tests Batch reactors used initially to test and screen catalysts Batch reactors used initially to test and screen catalysts Various weak solid base salts and mild metal oxide bases were tested Various weak solid base salts and mild metal oxide bases were tested Analytical Procedures: Gas Chromatography (GC) Analytical Procedures: Gas Chromatography (GC) Thin Layer Chromatography (TLC) Thin Layer Chromatography (TLC) Certain metal oxides showed good results (Patent Pending) Certain metal oxides showed good results (Patent Pending) ~95% conversion in 18 min ~95% conversion in 18 min Free fatty acid conversion of 93% observed. Probably due to the amphoteric nature of metal oxides. Eliminates the need of a separate acid-catalyzed preceding step. Free fatty acid conversion of 93% observed. Probably due to the amphoteric nature of metal oxides. Eliminates the need of a separate acid-catalyzed preceding step.

8 Performance of Catalysts – Batch Tests * Catalysts tested at 220, 200, 175, 150 ˚C – similar trend 40:1 Alcohol:Oil Molar ratio

9 Lab-Scale Packed-Bed Reactor Reactor Temperature 260˚C, Pressure ~70 atm

10 Lab-Scale Packed-Bed Reactor 40:1 Alcohol:Oil Molar ratio 260˚C, Pressure ~70 atm

11 Activity Sustenance Tests Performance of the catalysts checked for deterioration with time Performance of the catalysts checked for deterioration with time No deterioration for 200 hours No deterioration for 200 hours

12 Reaction Order Pseudo first order reaction  excess alcohol (40:1 ethanol:oil molar ratio) X = 1 – e -kt

13 Molar Ratio Tests WHSV Optimal Molar-Ratio Optimal Molar-Ratio Balance the better medium of interaction provided by the excess alcohol with reaction space Balance the better medium of interaction provided by the excess alcohol with reaction space

14 Pressure Effect

15 Near-Critical Regime 260° C 240° C 220° C 200° C 175° C 150° C 40:1 Molar ratio

16 Related Studies NiO, VO, FeO, ZnO and CoO tested in packed-bed reactor. Only FeO gives similar results NiO, VO, FeO, ZnO and CoO tested in packed-bed reactor. Only FeO gives similar results Free fatty acid tested in packed-bed reactor show 97 % conversion in 7.5 minutes – conversion rate even faster Free fatty acid tested in packed-bed reactor show 97 % conversion in 7.5 minutes – conversion rate even faster

17 Water Tests Ethanol:Oil 30:1 Molar ratio 1.58:1 Mass ratio Ethanol:Oil 30:1 Molar ratio 1.58:1 Mass ratio Water present in cheap feedstock 95% Ethanol with water considerably cheaper Water formed during reaction with high FFA content waste oil, animal tallow

18 Process Simplification Various Oil Feedstock Alcohol (Methanol) Methanol Recovery Transesterfication Reaction Mixing Tank Catalyst (NaOH) Free Fatty Acid Pretreatment Waste Water Product Separation Adsorption Polishing High Quality Biodiesel Water Wash Glycerol Distillation Product Drying High Quality Glycerol

19 Conventional Process Proposed Process Process TypeBatchContinuous Catalyst LifeVery Short (consumed)Long Conversion Time~90 minutes10~20 minutes Impurities (ASTM) Catalyst, soap, water, glycerol, glycerides Glycerol, glycerides Pretreatment of Free Fatty Acids YesNo Catalyst Mixing UnitYesNo Distillation of GlycerolYesNo Washing & WastewaterYesNo Product DryingYesNo

20 Acknowledgements Shaun Pardi Shaun Pardi Brian Dempsey Brian Dempsey Penn State Institutes of Energy and Environment Penn State Institutes of Energy and Environment Larry Duda and Ronald Danner Larry Duda and Ronald Danner Joe Perez and Wallis Lloyd Joe Perez and Wallis Lloyd CSPS Personnel – Adam Jones, Marc Russel, Ida Balashova, Lourdes Serna, Roman Galdamez CSPS Personnel – Adam Jones, Marc Russel, Ida Balashova, Lourdes Serna, Roman Galdamez Chris Torres and Brian Plunkett Chris Torres and Brian Plunkett Restek Restek

Thank You! Questions ? Our Team: Dheeban Kannan, Kevin Gombotz, Frank Higdon and Jack Matson