Improvement of the oxidative stability of used-oil biodiesel by epoxidation reaction

Abstract

Improvement in the oxidative stability (OS) of biodiesel derived from used-oil (UO) was carried out by epoxidation of biodiesel. A 2 k factorial design was used to identify the effects of temperature, mole ratio of hydrogen peroxide (H 2 O 2 ):formic acid (HCOOH), stirring rate, and reaction time. The results indicated that the H 2 O 2 :HCOOH mole ratio, stirring rate, and their interaction had significant effect on the OS of biodiesel. At the derived optimum condition, greater than 99.4% of unsaturated carbon bonds in the used-oil biodiesel were converted to epoxy used-oil biodiesel with a selectivity of 69.0%. Only one species of by-product, hydroxyl-biodiesel, was observed in this system. Asides the cold flow properties and methyl ester content, all other key properties of biodiesel were within the specifications of the European Standard EN14214. The OS for the biodiesel was higher than the original. V C 2012 American Institute of Physics.

Bulky olefin epoxidation under mild conditions over Mo-based oxide catalysts

“…, solvents, plasticizers, lubricants, biofuels. 5,12,15–24 However, heterogeneous catalytic EPO of FAMEs presents challenges, such as the development of highly active, selective and stable catalysts, using catalyst synthesis methodologies which are timesaving and versatile ( e.g. , possibility of introducing different metals to meet superior performances).…”

“…14 EFAMEs have a growing global market with a broad applications profile, e.g., solvents, plasticizers, lubricants, biofuels. 5,12,[15][16][17][18][19][20][21][22][23][24] However, heterogeneous catalytic EPO of FAMEs presents challenges, such as the development of highly active, selective and stable catalysts, using catalyst synthesis methodologies which are timesaving and versatile (e.g., possibility of introducing different metals to meet superior performances). 14 In the choice of the types of catalytic materials, fully inorganic metal oxides may be preferable to materials possessing organic components, in what concerns thermal and chemical stabilities.…”