Esterification of acidic oils: a way towards new products for the biorefinery

1. IBC Proteic hydrolisate Biolubricants Polyols Glycerol Biopolymers ISMAC ESTERS Packaging Scutching Fibre Biomass ISMAC Oligomers and carbohydrates ICRM Triesters as lubricants Esters with sterols as food additives Esters with sorbitol as surfactants Methylesters as products (soap, paint and varnish, resins, solvents…) First run – 1 h Second run – 1 h Esterification of acidic oils: a way towards new products for the biorefinery Federica Zaccheria, Simona Brini, Rinaldo Psaro, Carine Chan-Thaw and Nicoletta Ravasio Ve.Li.Ca Project CNR ISTM, via G. Venezian 21, I-20133 Milano e-mail:carine.chanthaw@istm.cnr.it Methylesters for fuels Introduction • 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 • 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 H2O 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. [1] R. Psaro, M.N. Ravasio, F. Zaccheria, European Patent Application EP 07425579.5 (2007); PCT/EP2008/062255; WO2009037226 A1 [2] F. Zaccheria, S. Brini, R. PSaro, N. Scotti, N. Ravasio ChemSusChem, 2 (2009) 535 – 5372 Deacidification and Esterification over Silica - Zirconia Our project in biorefinery Ve.Li.Ca. Project on Hemp and Flax Biorefinery ω-3 Oil IBC ISTM Pressing Genotype selection IBBA www.velica.org Why Esters? Experimental Material: SiO2-ZrO2 has a SSA of 304 m2g-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:SiO2-ZrO2/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 • 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 Transesterification and Esterification of olive acidic oils 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. • SiO2- ZrO2 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) [3] K. Suwannakarm, E. Lotero, K. Ngaosuwan, J.G. Goodwin, Ind. Eng.Chem. Res. 48 (2009) 2810 Acknowledgements Conclusions • SiO2- ZrO2 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 European Commission (ERIC) , Regione Lombardia and ENI are acknowledged for the funding of this work.