Effects of accelerated oxidation on the selected fuel properties and composition of biodiesel

Improvement of oxidation stability of fatty acid methyl esters derived from soybean oil via partial hydrogenation using dielectric barrier discharge plasma

“…The average induction time period of an oxidation reaction in biodiesel is around 0.2 to 9.4 hours by Rancimat test 9 . The oxidation stability property influences the storage time, resulting in the change of fuel property, such as viscosity and acidity, or gums, and sediment formation because of oxidation products 10,11 . Due to the limitation of this property, pure biodiesel, or B100, is not recommended for high‐speed diesel engines, and biodiesel should be blended with petroleum‐based diesel before use.…”

“…The products from oxidation result in deterioration, clogging of engine parts, and operation problems. In addition, when biodiesel is contaminated with a base catalyst from the production process, fatty acid, being one of the oxidation products (fatty acid radical), causes soap formation 10,11 . Normally, oxidation of biodiesel can be delayed by adding an antioxidant (propyl gallate and lignin can be practiced, for example), using a suitable container and avoiding storage in pro‐oxidizing condition, removing impurity of metals, especially Cu, Fe, Ni, Sn, and brass, by the refined FAME method, or even using appropriate feedstocks with low percentages of polyunsaturated fatty acids 17,18 .…”

“…9 The oxidation stability property influences the storage time, resulting in the change of fuel property, such as viscosity and acidity, or gums, and sediment formation because of oxidation products. 10,11 Due to the limitation of this property, pure biodiesel, or B100, is not recommended for high-speed diesel engines, and biodiesel should be blended with petroleum-based diesel before use. Moreover, the low heating value, high lubricity, high density, and high viscosity of B100 decrease engine power and torque, resulting in higher fuel consumption.…”

“…In addition, when biodiesel is contaminated with a base catalyst from the production process, fatty acid, being one of the oxidation products (fatty acid radical), causes soap formation. 10,11 Normally, oxidation of biodiesel can be delayed by adding an antioxidant (propyl gallate and lignin can be practiced, for example), using a F I G U R E 1 Oxidation process of biodiesel, oxidation products, and soap formation (modified from the study of Rashed et al 15 and Bacha et al 16 ) suitable container and avoiding storage in pro-oxidizing condition, removing impurity of metals, especially Cu, Fe, Ni, Sn, and brass, by the refined FAME method, or even using appropriate feedstocks with low percentages of polyunsaturated fatty acids. 17,18 In case of a high proportion of polyunsaturated fatty acids in oils (soybean oil, canola oil, rapeseed oil, etc.)…”

Estudo da ação antioxidante e anticorrosiva de produtos naturais usados como aditivos ao biodiesel

“…Deste modo há o aumento de peróxidos, viscosidade, índice de iodo, índice de acidez elevado e depósitos de gomas que podem ocasionar a corrosão metálica. Em motores o uso do biodiesel nessas condições prejudica seu desempenho por resultar em obstrução do filtro por formação de incrustação, depósitos na câmera de combustão e outros componentes do sistema e caso haja resíduos de água ou ácidos graxos resultantes do processo de transesterificação a natureza corrosiva do biodiesel pode ser agravada (DUNN, 2005;HOSHINO;IWATA;KOSEKI, 2007;AMBROZIN;KURI;MONTEIRO, 2009;ZHOU et al, 2017;TOMIC et al, 2019).…”