Biodiesel from Waste or Unrefined Oils Using Calcium Oxide-based Catalysts AICHe Meeting at Nov. 16 , 2008 Shuli Yan, Manhoe Kim, Steve O. Salley and K. Y. Simon Ng National Biofuels Energy Laboratory NextEnergy/Wayne State University Detroit, MI 48202 Hi, thank you very much for give me this chance to introduce our work on biodiesel production catalysts in our lab. 1

Content Introduction Experiment Results and Discussion Conclusion Biodiesel Traditional Processes for Biodiesel Production Literature Review Experiment Results and Discussion Catalyst Activity Catalyst Structure Effect of Water and FFA in Oil Feedstock Effect of H2O and CO2 in Air Effect of Reaction Conditions Transesterification Mechanism Conclusion

Introduction Biodiesel A mixture of fatty acid esters Derived from vegetable oils, animal fats, waste oils 3

Introduction Biodiesel - Advantages Biodegradable Low emission profile Low toxicity Efficiency High lubricity 99 00 01 02 03 04 05 06 4

Introduction Traditional Processes for Biodiesel Production Refined oils as feedstock (food-grade vegetable oils) Homogeneous strong base or acid catalysts (NaOH, H2SO4) FFA content is lower than 0.5 % (wt) Water content is lower than 0.06% (wt) High price Highly corrosive Long oil pretreatment process Long product purification process Large amount of waste water Long time for phase separation High process cost 5

Introduction Decrease of Feedstock Cost Decrease of Process Cost Using inexpensive oils as feedstock Crude vegetable oils, recycled cooking oils, trap grease etc. Simplifying the oil pretreatment process Simplifying the product purification process Replace homogeneous catalysts by heterogeneous catalysts 6

Solid Base Catalysts Catalyst T Time(h) Conv.(%) Ref. KNO3/Al2O3 65°C 7 87 1 ZnO 120°C 24 80 2 HT (Mg-Al) 180°C 92 3 SO42-/ZrO2 200°C 4 95.7 I2/Zn 96 5 Nafion acid resins 60°C 8 50 6 1. Catalytic activities of most of them are much lower than homogeneous catalysts such as NaOH. 2. Most of them were conducted at elevated temperature and pressure 3. there is little information regarding their catalytic durability. Goal

Solid Base Catalysts Catalyst T Time(h) Conv.(%) Ref. Nano-CaO Room temperature 6-24 95 10 CaO 65°C 24 93 11 3 60 12 CaO, Ca(OH)2, CaCO3 95.7 13 1. Catalytic activities much lower than NaOH. 2. Conducted at elevated temperature and pressure. 3. Low tolerant to water and FFA in feedstocks.

Research Goal Develop an effective biodiesel process catalyst with high activity Using solid catalysts to replace homogeneous NaOH An improved property in tolerance to water and FFA Using solid catalysts in food-grade, unrefined and waste oils.

Experiment Oil Feedstock

Ammonia-Carbon Dioxide Precipitate Method Experiment Catalyst Preparation Ca and La nitrate salts transparent solution Stirring for 3h at 60 oC Placing for 48h at RM Filter and Wash Drying for 24h at 100 oC Calcining for 8h at 750 oC Activation Ethanol 3 N Ammonia; CO2, 4 vol %, each hours Ammonia-Carbon Dioxide Precipitate Method

Experiment Catalyst Characterization Basic Property Hammett indicator method; Hammett indicator-benzene carboxylic acid titration method; Specific surface area Micromeritics model ASAP 2010 surface area analyzer (North Huntingdon, PA) TG/DTG Perkin Elmer Pyris-1 (Waltham, MA) XRD Rigaku RU2000 rotating anode powder diffractometer (Woodlands, TX) FTIR Perkin Elmer Spectrum 400 spectrometer (Waltham, MA)

Experiments Transesterification Product analysis 10.0 g of soybean oil and 7.6 g of methanol and 0.5 g activated catalyst GC-MS Karl Fischer (Water Content) titration (Fatty Acid Content) 13

Catalyst Activity Figure 1 Transesterification activities of Ca3La1, Ca1La0, Ca0La1, NaOH, and H2SO4 at 64.5 oC and 1 atm.

Catalyst Structure XRD Figure 2 XRD spectra of Ca3La1 (curve 1), fresh Ca3La1 (curve 2), Ca0La1 (curve 3) and the Ca3La1 exposed to air for 30 days (curve 4).

Catalyst Structure Table 3 Specific surface areas, XRD, basicity and catalytic activity of Ca1La0, Ca0La1, Ca3La1 and the Ca3La1 adsorbed water (Ca3La1-water) and Ca3La1 adsorbed FFA (Ca3La1-FFA).

Catalyst Structure FTIR Figure 3 FTIR analysis of Ca3La1 (1), Ca3La1 adsorbed water (2) and Ca3La1 adsorbed FFA (3)

Effect of Water and FFA in Oil Feedstock b Figure 4 Effect of water addition on transesterification..

Effect of Water and FFA in Oil Feedstock Figure 5 Yield of FAME in the presence of different FFA addition.

Single Step Conversion of Unrefined and Waste Oil b Figure 6 Yield of FAME using unrefined and waste oils (a) and diluted unrefined oils (b).

Effect of Water and FFA on Catalyst Structure Basic Property FTIR

Effect of H2O and CO2 in Air Table 4 Effects of storage and pretreatment conditions on the catalytic activity of Ca3La1.

Effect of H2O and CO2 on Catalyst Structure XRD FTIR Figure 7 FTIR spectra of Ca3La1 exposed to air about 3 min (1), 5 min (2), 8 min (3), 15 min (4) and 30 min (5).

Effect of H2O and CO2 on Catalyst Structure TG/DTG 8 % 16 % Figure 8 TG/DTG curves of Ca3La1 exposed to air for 12 hours.

Effect of Reaction Conditions Figure 9 FAME yields with different mass ratio of catalyst to oil (a), with different mole ratio of methanol to oil (b), and with different reaction temperatures (c).

Effect of Reaction Conditions Figure 9 FAME yields with different mass ratio of catalyst to oil (a), with different mole ratio of methanol to oil (b), and with different reaction temperatures (c).

Transesterification Mechanism Adsorption Sites Figure 10 FTIR spectra; (a) Ca3La1 adsorbed triglyceride (curve 1), free triglyceride (curve 2) and the fresh Ca3La1 (curve 3);

Transesterification Mechanism Adsorption Sites Figure 10 FTIR spectra; (b) free methanol (curve 1), the Ca3La1 adsorbed methanol (curve 2) and the fresh Ca3La1 (curve 3).

R1: alkyl group of fatty acid R2: alkyl esters of triglyceride Figure 11 Schematic representation of possible mechanism for transesterification of triglyceride with methanol.

Conclusion A single-step method using unrefined oils and calcium and lanthanum mixed oxides strong base strength, large amount of basicity and high surface area A strong interaction between Ca and La species Highly tolerant to water and FFA in oil feedstock 30

Acknowledgement Financial support of this research by the Department of Energy (DE12344458) and Michigan's 21st Century Job Fund program is gratefully acknowledged 31

Thanks!