Esterification of acidic oils: a way towards new products for the biorefinery CNR ISTM, via G. Venezian 21, I Milano Federica Zaccheria, Simona Brini, Rinaldo Psaro, Carine Chan-Thaw and Nicoletta Ravasio Why Esters? Deacidification and Esterification over Silica - Zirconia Conclusions Transesterification and Esterification of olive acidic oils Ve.Li.Ca Project OilStarting acidityFinal acidityConv % Jatropha Curcas (degummed) % oleic acid in rapeseed % oleic acid in rapeseed Tobaccoseed % oleic acid in rapeseed % oleic acid in rapeseed % oleic acid in rapeseed Olive Acidic Oils Palm Fatty Acid Distillates Tall Oil Chicken fat Animal fat 1 (cow, pig, chicken, sheep) Animal fat 2 (cow and pig) First run – 1 hSecond run – 1 h ESTERS Methylesters for fuels Triesters as lubricants Methylesters as products (soap, paint and varnish, resins, solvents…) Esters with sterols as food additives Esters with sorbitol as surfactants Because of the new European directive, only biofuels produced from non-food and secondary raw materials are permitted. In homogeneous alkaline conditions, transesterifcation of unrefined or crude oils containing more than 5 wt.% of free fatty acids (FFA) is not allowed because of soap formation (use of basic catalysts). Need of acid catalyzed pretreatments: Esterification with sulfuric acid and sulfonic resins to make methylesters. Corrosive and costly! Followed by transesterification of the triglycerides (TG) in homogeneous basic conditions. However, separation from the undesired products is difficult and costly Introduction Successful deacidification of different natural oil: from 20 to less than 1 wt% of FFA Able to esterify secondary raw materials Good results can be explained by the best trade-off among the Lewis acidity and surface –OH concentration features Lewis-acid catalysts have been shown to carry out both the transesterifcation of TG and the esterification of FFAs [1, 2], although their activity could be inhibited by H 2 O formed during the esterification process. Silica alumina (SiAl) and silica zirconia (SiZr) are active in acid-catalyzed reactions. SiZr, a Lewis-acid catalyst, is shown here to promote esterification of FFAs and concomitantly transesterifcation of TGs into methylesters. Esterification of acidic oils over a commercial silica zirconia catalyst eliminates the use of mineral acids in the pre-treatement. Moreover, after the treatment about 50% of the oil is already converted in methylesters, thus allowing one to reduce the amount of catalyst in the homogeneous, basic catalyzed, transesterification step, with the great advantage of minimizing the purification processes. SiO 2 - ZrO 2 active in both esterification and transesterifcation of low grade and waste oils No need to remove the in situ formed water [3] Fulfill EN14214 regulation for biodiesel with 97.2% of FAME (for ester and monoglycerides) Our project in biorefinery Biolubricants Polyols ω-3 IBC IBBA Genotype selection IBC Proteic hydrolisate Biomass ICRM Oligomers and carbohydrates Oil Pressing ISTM Glycerol ISMAC Biopolymers Packaging ISMAC Scutching Fibre Ve.Li.Ca. Project on Hemp and Flax Biorefinery Experimental Material: SiO 2 -ZrO 2 has a SSA of 304 m 2 g -1 and a PV of 1.62 mL g -1. Calcination at 270 °C for 30 min in air and under vacuo for 30 min Transesterification and deacidification: SiO 2 -ZrO 2 /oil= 1/10 wt.; MeOH/oil = 10/1 mol.; 180 °C, 1h, stainless steel autoclave Analysis: Agilent 7890N GC with a flame ionisation detector. Fatty mixtures were derivatized using N,O-bis (trimethylsylil)trifluoroacetamide (BSTFA) together with a standard mixture comprising C19:0 methylester, mono-, di- and triglycerides [1] R. Psaro, M.N. Ravasio, F. Zaccheria, European Patent Application EP (2007); PCT/EP2008/062255; WO A1 [2] F. Zaccheria, S. Brini, R. PSaro, N. Scotti, N. Ravasio ChemSusChem, 2 (2009) 535 – 5372 SiO 2 - ZrO 2 active in both esterification and transesterification of low grade and waste oils SiO2- ZrO2 is a promising catalyst for the production of biofuels from low and very low grade oils [3] K. Suwannakarm, E. Lotero, K. Ngaosuwan, J.G. Goodwin, Ind. Eng.Chem. Res. 48 (2009) Acknowledgements European Commission (ERIC), Regione Lombardia and ENI are acknowledged for the funding of this work.