Vol.:(0123456789) 1 3 Waste Biomass Valor DOI 10.1007/s12649-017-0120-x ORIGINAL PAPER Infuence of Synthetic and Natural Antioxidants on the Oxidation Stability of Beef Tallow Before Biodiesel Production Maurício N. Kleinberg 1  · Maria A. S. Rios 3  · Hugo L. B. Buarque 4  · Marcelo M. V. Parente 1  · Célio L. Cavalcante Jr. 2  · F. Murilo T. Luna 2   Received: 21 June 2017 / Accepted: 23 October 2017 © Springer Science+Business Media B.V. 2017 containing BHT presented the best induction period values. The biodiesel samples produced from beef tallow containing technical CNSL (0.5 wt%) met the requirement of oxidation stability at 110 °C determined by the Brazilian specifcation. Keywords Beef tallow · Oxidative degradation · Antioxidants · Biodiesel Introduction Biodiesel production in Brazil has been increasing steadily over the last decade [1]. About 95% of the biodiesel produc- tion plants in Brazil use edible vegetable oils as raw material [2, 3]. Beef tallow is a promising alternative as a non-edible raw material for biodiesel production, due to its lower price compared to vegetable oils such as soybean oil, preventing the improper disposal of animal waste on the environment [4, 5]. Beef tallow is normally stored in industries at tempera- tures around 60 °C, since at lower temperatures, this feed- stock is in solid phase, which hinders its handling in the biodiesel production. The problem of using beef tallow as a raw material for biodiesel production is its high acidity level, found as a consequence of hydrolysis and oxidation reactions. These degradation processes are signifcant in the presence of high levels of humidity and temperature, which are usually found in the storage condition of beef tallow. High acidity levels afect the production yield of biodiesel, mainly due to high consumption of basic catalysts (more commonly used) and the saponifcation of the free fatty acids [6]. After an increase of acidity levels on beef tallow stored in a biodiesel industry, it is necessary to separate the excess acids contained in beef tallow by vacuum distillation or Abstract Beef tallow is a promising alternative as a non- edible raw material for biodiesel production, due to its lower price compared to vegetable oils such as soybean oil. The problem of using beef tallow as a raw material for biodiesel is its high acidity level, found as a consequence of hydrolysis and oxidation reactions. These degradation processes are signifcant in the presence of high levels of humidity and temperature, which are usually found in the storage condi- tions. In this study, the infuence of synthetic and natural antioxidants on the oxidation stability of beef tallow was evaluated using Rancimat tests and by monitoring their acid and peroxide values over 148 days of storage in an oven. The studied synthetic and natural (cashew nut shell liquid, CNSL) antioxidants were efective to prevent oxidation of beef tallow on storage conditions. Biodiesel samples were produced from samples of beef tallow with and without anti- oxidants. The biodiesel samples produced from beef tallow * F. Murilo T. Luna murilo@gpsa.ufc.br 1 Programa de Pós-Graduação em Energias Renováveis, Instituto Federal de Educação, Ciência e Tecnologia do Ceará, Campus Maracanaú, Av. Parque Central, S/N, Distrito Industrial I, Maracanaú, CE 61939-140, Brazil 2 Departamento de Engenharia Química, Grupo de Pesquisa em Separações por Adsorção, Núcleo de Pesquisas em Lubrifcantes, Universidade Federal do Ceará, Campus do Pici, Bl. 709, Fortaleza, CE 60455-900, Brazil 3 Departamento de Engenharia Mecânica, Grupo de Inovações Tecnológicas e Especialidades Químicas, Universidade Federal do Ceará, Campus do Pici, Bl. 714, Fortaleza, CE 60440-554, Brazil 4 Departamento de Química e Meio Ambiente, Instituto Federal de Educação, Ciência e Tecnologia do Ceará, Campus Fortaleza, Av. 13 de Maio, 2081, Benfca, Fortaleza, CE 60040-531, Brazil