Two-Year Storage Study With Methyl and Ethyl Esters of Rapeseed

Abstract

B iodiesel is gaining recognition as a renewable alternative to diesel fuel. One step toward commercialization of biodiesel is establishing how well it stores and what affect storing for long periods has on the performance of the fuel. The problems of fuel deterioration with biodiesel during storage are expected to be more severe than for commercial diesel fuel. Although vegetable oils contain natural antioxidants, their high degree of unsaturation makes them susceptible to gum formation. Since fuel deterioration occurs mainly by oxidative polymerization leading to gum formations one purpose of this study was to determine the rate of oxidative polymerization for different fatty acid esters prepared from rapeseed, as effected by container types, and environments. Peroxide values measure the levels of the oxidation products in the samples. Another purpose of this study was to use short term engine coking and torque test procedures to determine whether the presence of the oxidation products affected the engine performance.

Oxidation, Thermal, and Storage Stability Studies of Jatropha Curcas Biodiesel

“…Thus the chain breaking antioxidants help to interrupt the oxidation chain reaction in order to enhance . The results were in agreement with the literature findings [16][17][18][19][20][21]. When antioxidants are mixed with JCB, the oxidation process is retarded resulting in the decrease in relative percentage of oleic acid as shown in Figure 6(a) and increase in relative percentage of linoleic and linolenic acid indicating the retardation of oxidation process after the addition of PY (Figures 6(a), 6(b), and 6(c)).…”

“…This is in agreement with the Das et al [16] who found that peroxide formation decreases with increase in antioxidant concentration, thereby leading to the lower rate of increase of viscosity that became lower. A number of reports confirm that the retardation of oxidation process became higher as the antioxidant concentration is increased [7,[16][17][18][19][20][21]. The reduced rate of peroxide formation led to the increase in long-term storage stability in terms of IP which indicates that it is possible to store biodiesel for longer period of time by adding the antioxidant.…”

Adsorption in Biodiesel Refining - A Review

“…In contact with oxygen, peroxides are formed that promote the formation of organic acids, and then of polymers (gums) that plug fuel lines and filters. Oxidative degradation during storage can also compromise fuel quality with respect to effects on kinematic viscosity, acid value, cetane number, total ester content, and formation of hydroperoxides, soluble polymers, and other secondary products (Du Plessis et al, 1985;Bondioli et al, 2002;Thompson et al, 1998). The increased acidity and peroxide values as a result of oxidation reactions can also cause the corrosion of fuel system components, the hardening of rubber components and the erosion of moving parts (Tang et al, 2008).…”

Characterization of Biodiesel Oxidation and Oxidation Products

“…Studies have shown that the development of ROOH over time exhibits one of two behaviors. First, ROOH levels can increase, achieve a plateau, and then hold that level in a steady state 4,50,87,95,100,101,106 . Alternatively, ROOH levels can increase, achieve a peak level, and then decrease 4,50,70,96,106,117 .…”

“…Aliphatic alcohols, formic acid, and formate esters have also been detected 32,55 . Increased acidity is always a result of oxidation of fatty oils and biodiesel 50,87,100,101,106 , due to the formation of shorter chain fatty acids 32,101 . As hydroperoxides decompose, oxidative linking of fatty acid chains can occur so as to form species with higher molecular weights, i.e.…”