Test methods for the determination of biodiesel stability

Optimization of Alkali, Switchgrass, and Extruder Parameters for Maximum Sugar Recovery

“…Similar equations were reported for extrusion pretreatment of miscanthus [7] and switchgrass [12]; alkali extrusion of corn stover, prairie cord grass, and big bluestem [35][36][37]; acid hydrolysis of sugarcane bagasse [17], oil palm empty fruit bunch [18], and eucalyptus [20], concentrated acid pretreatment of pine wood [11], acid catalyzed fractionation and enzymatic hydrolysis of flax shives [21] and hot-compressed water pretreatment of Japanese beech hydrolysis [22]. Those equations predict the responses well with high R 2 and low probability values.…”

“…RSM has been widely used in various fields ranging from food process operations including extrusion [15,16], new product development, biotechnology media composition, to bioprocessing, such as enzymatic hydrolysis and fermentation. Recently, RSM has been successfully applied to biomass pretreatment by many researchers [17][18][19][20][21][22]. Earlier extrusion pretreatment studies conducted by the authors yielded encouraging results; however, the alkali concentration and extrusion factors were not optimized.…”

Role of Antioxidants in Enhancing Oxidation Stability of Biodiesels

“…Along with the mechanism as discussed above, the radicals can react in many other ways. As the fatty oil peroxides and alkoxy radicals are formed, they decompose to lower molecular weight products or form insoluble and polymerized oxidation products , with high molecular weights. The alkoxyl radicals on scission and peroxy radicals on recombination followed by decomposition form a variety of products including alcohols, aldehydes, and ketones .…”

“…Biodiesel is an environmentally benign fuel with high biodegradability and lubricity when compared to the conventional diesel, but suffers with the disadvantage of having deterioration property due to its tendency to oxidize in the presence of oxygen at ambient temperature. The process results in the formation of innumerous undesirable oxidation products, − which may either cause high molecular compounds as polymers, gums, and sediments or decompose to lower aldehydes, ketones, alcohols, acids, epoxy compounds, olefins, etc . Acids formed during the process can corrode metals used in vehicle and distribution fuel handling systems severely.…”

“…Some of the products are soluble in the fuel, pass through the fuel filter, but stick to the surfaces of the fuel pump and fuel injectors. Hydroperoxides damage the elastomeric gasket materials in the engine combustion mechanical system . Short-chain carboxylic acids such as formic acid and acetic acid are miscible with water and dissociate to form reasonably strong acids (p K a 3.77 and 4.76, respectively), which lead to the increase in acid value of biodiesel.…”