ORIGINAL PAPER A Bifunctional Copper Catalyst for the One Pot-One Step Esterification + Hydrogenation of Tall Oil Fatty Acids Federica Zaccheria • Nicoletta Ravasio • Carine E. Chan-Thaw • Nicola Scotti • Paolo Bondioli Published online: 22 June 2012 Ó Springer Science+Business Media, LLC 2012 Abstract An efficient copper catalyst for the one-pot one-step hydrogenation ? esterification of unsaturated free fatty acids is described. The high selectivity in hydroge- nation promoted by copper, combined with the high activity in esterification observed with solid mixed oxides allows one to directly obtain stabilized methyl esters. Keywords Esterification Á Solid acids Á Tall oil Á Selective hydrogenation Á Byproducts upgrade 1 Introduction Esters derived from free fatty acids (FFAs) represent a valuable class of products due to the wide range of their possible applications. Use of fatty acid methyl esters as a bio-based alternative for petro based diesel is the most prevalent application. However the demand for bio-based products such as lubricants, solvents or surfactants is continuously growing due to their beneficial environmental and commercial impact [1, 2]. Displacing the traditional homogeneous acid catalyst with alternative heterogeneous ones will provide a sustainable and profitable route for fatty acid esters. In the particular case of biodiesel, traditional transeste- rification processes based on the use of basic catalysts fail when FFAs are used as feedstock. Indeed, the use of basic catalysts is suitable only when the amount of FFAs in the material used does not exceed 0.5 % by weight. However, the use of non-acidic refined materials for the biodiesel production is a less and less viable practice, particularly in the European market. Economical and environmental issues prompt for the use of alternative sources not belonging to the alimentary chain and the double counting criterion introduced by the European Commission for the implementation of biofuel sustainability strongly encour- ages the use of waste materials [3]. The main part of waste and non conventional economical feedstock presents a high content in FFAs and it is necessary to add an esterification step before the transesterification one, or alternatively to completely hydrolyze the triglycerides and then to esterify the FFAs formed. In this scenario an interesting material to be used as a non conventional source for bio-based products is the Crude Tall Oil that is an important by-product of the Pulp and Paper Industry when using the Kraft process. The production of Tall Oil is around 30–50 kg/ton pulp, thus representing the third by-product besides lignin and hemicellulose [4]. Few processes are reported for the pro- duction of biodiesel from Tall Oil, relying on the use of acyl halide as catalyst [5] and via high temperature meth- anol reaction (280–340 °C) [6]. Unlike traditional vegetable oils, which are present in nature as triglycerides, Tall Oil Fatty Acids (TOFA) are constituted by a mixture of FFAs , with a minority fraction of resinic acids. In addition, the composition of TOFA is marked by the unusual presence of a fraction of conjugated C18:2, whereas in natural vegetable oils only unconjugated double bonds are present (Table 1). This particular feature imparts to the material a poor stability towards oxidation and properties similar to those F. Zaccheria Á N. Ravasio (&) Á C. E. Chan-Thaw Á N. Scotti CNR Istituto di Scienze e Tecnologie Molecolari, Via C. Golgi 19, 20133 Milan, Italy e-mail: n.ravasio@istm.cnr.it P. Bondioli INNOVHUB Stazioni Sperimentali per l’Industria, Divisione SSOG, Via Giuseppe Colombo,79, 20133 Milan, Italy 123 Top Catal (2012) 55:631–636 DOI 10.1007/s11244-012-9842-y