Biodiesel fuels

Vegetable oils were eventually replaced by petroleum-based hydrocarbons. More recently, diesel fuel has been developed from vegetable oil sources that are derivatives of the fatty acids in the oils. Vegetable oils from soybeans and other biological sources are used to make biodiesel fuel as discussed in the following paragraph. 

Vegetable oils are fatty acid esters of glycerol, a 3-carbon alcohol with 3-OH groups attached. To produce biodiesel fuel, the glycerol esters are hydrolyzed by strong base (NaOH) in the presence of methanol alcohol (HOCH3) and the fatty acids are converted to their methyl esters, the molecules composing biodiesel fuel  

3H3CO-C-R -I- HjO Fatty acid methyl esters in biodiesel fael 

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C. Sharp, Exhaust emission and performance of diesel engines with biodiesel fuels, Southwest Research Institute, 1998. 

By 2006, the U.S. had 77 ethanol plants producing more than 3 billion gallons of ethanol per year. Canada produced an additional 60 million gallons. Corn was the feedstock in 62 of the 77 U.S. plants. Other feedstocks included seed corn, corn and barley, corn and beverage waste, brewery waste, cheese whey, corn and milo, corn and wheat starch, potato waste and various sugars. The U.S. had 11 additional plants under construction and 55 proposed. West Central Soy processes soybeans to a food grade oil. Alcohol and a catalyst are then used to produce biodiesel fuel and glycerin. 

The commercial biodiesel fuel significantly reduced PM exhaust emissions (75-83%) compared to the petrodiesel base fuel. However, NO exhaust emissions increased slightly with commercial biodiesel compared to the base fuel. The chain length of the compounds had little effect on NO, and PM exhaust emissions, while the influence was greater on HC and CO, the latter being reduced with decreasing chain length. Non-saturation in the fatly compounds causes an increase in NO exhaust emissions. 

Demirbas, A. 2003. Biodiesel fuels from vegetable oils via catalytie and non-eatalytie supereritieal aleohol transesterifieations and other methods a survey. Energy Convers Manage 44 2093-2109. 

Laforgia, D., Ardito, V. 1994. Biodiesel fueled IDl engines performanees, emissions and heat release investigation. Biores Teehnol 51 53-59. 

The TC biodiesel fuel processor instead consists of a two-reactor system, in which one reactor, the cracker, is used for production, while the other one is being regenerated by gasification of the deposited sohd C with steam yielding H, COj, CO and CH (Ledjefif-Hey et al., 2000). The product gas streams of the TC and the gasification unit are combined, cooled down to the shift inlet temperature and then fed to the shift reactor and the CO-purification step. First, the cracking of biodiesel takes place for the production of H ... 

Sgroi, M., Bollito, G., Saracco, G., Speeehia, S. 2005. BIOFEAT Biodiesel fuel processor for a vehiele fuel eell auxiliary power unit Study of the feed system. J Power Sources 149 8-14. 

Speeehia, S., Tillemans, F.W.A., van den Oosterkamp, PR, Saracco, G. 2005. BIOFEAT Conceptual design and selection of a biodiesel fuel processor for a vehicle fuel cell auxiliary power unit. J Power Sources 145 683-690. 

BIOFEAT - Development of a biodiesel processor for an on-board fuel cell APU. The expected result is a fully tested modular 10 kW biodiesel fuel processor for an SOFC or PEM APU for a vehicle. 

A byproduct of vegetable oil transesterification to make biodiesel fuel, glycerol (GO) has captured our attention for several reasons, in aqueous medium, GO itself can be converted to value-added commodity products such as propylene glycol (PG), lactic acid (LA) and ethylene glycol (EG) in the presence of a metal catalyst at mild conditions (2-7). An array of metals deposited on various supports have been examined as catalysts for the above reaction (6, 7). 

The process involves reacting the degummed oil with an excess of methyl alcohol in the presence of an alkaline catalyst such as sodium or potassium methoxide, reaction products between sodium or potassium hydroxide and methyl alcohol. The reaction is carried out at approximately 150°F under pressure of 20 psi and continues until trans-esterification is complete. Glycerol, free fatty acids and unreacted methyl alcohol are separated from the methyl ester product. The methyl ester is purified by removal of residual methyl alcohol and any other low-boiling-point compounds before its use as biodiesel fuel. From 7.3 lb of soybean oil, 1 gallon of biodiesel fuel can be produced. See FIGURE 12-5. 

Methyl ester based biodiesel fuel is commercially produced in Europe as rapeseed methyl ester (RME) and fatty acid methyl ester (FAME). Use in diesel fuel at 5% by volume is the most common application for RME. In the United States, soybean methyl ester (SME or SOME) is typically blended into diesel fuel at 20% by volume and is known as B20. Blends of 5%, B5, 10%, BIO and also neat 100%, B100, biodiesel are becoming available. 

TABLE 12-12. Physical, Chemica, and Performance Properties of Biodiesel Fuel and Biodiesel Fuel Blends... 

On the other hand, the storage stability of biodiesel is adversely affected by the presence of unsaturated alkyl components. The olefinic moieties in biodiesel fuel can undergo oxidative degradation via exposure to air with deleterious results, including formation of solids and gums. The degree of oxidative degradation has been shown to increase with fuel unsaturation. 

H. Noureddini, in System and process for producing biodiesel fuel with reduced viscosity and a cloud point below thirty-two (32) degrees fahrenheit , US, 2001. 

Lapuerta M, Armas O, Rodriguez-Femandez J (2008) Effect of biodiesel fuels on diesel engine emissions. Prog Energy Combust Sci 34 198-223... 

Stepwise degradation of sugars under catalytic conditions leads to shorter-chain sugars and such by-products as CO, C02, and H20 depending on the conditions (see also next section).348 Sucrose or other carbohydrates have been used for the preparation of new solid acidic catalysts by partial carbonization followed by sulfonation. This leads to sheets of amorphous carbon bearing hydroxyl, carboxyl, and sulfonic groups. These have been used for the production of biodiesel fuel.349... 

Carbonized sugar derivatives are used as solid acid catalysts for the production of biodiesel fuel,349 and carbonized sucrose treated with ethylene and then pyro-lyzed provides materials used as hard-carbon anodes for lithium-ion batteries.439... 

Bio G-3000 Biodiesel Fuel Nature Safe Versa Gen Bakery Feeds Cookie Meal... 

Fatty acid methyl esters (FAMEs) show large potential applications as diesel substitutes, also known as biodiesel fuel. Biodiesel fuel as renewable energy is an alternative that can reduce energy dependence on petroleum as well as air pollution. Several processes for the production of biodiesel fuel have been developed. Transesterification processes under alkali catalysis with short-chain alcohols give high yields of methyl esters in short reaction times. We investigated transesterification of rapeseed oil to produce the FAMEs. Experimental reaction conditions were molar ratio of oil to alcohol, concentration of catalyst, type of catalyst, reaction time, and temperature. The conversion ratio of rapeseed oil was enhanced by the alcohohoil mixing ratio and the reaction temperature. 

Index Entries Biodiesel fuel transesterification rapeseed oil molar ratio fatty acid methyl ester. 

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