Biodiesel consumption

Includes energy from wood and wood-derived fuels municipal solid waste from biogenic sources, landfill gas, sludge waste, agricultural byproducts and other biomass (through 2000, also includes non-renewable waste such as municipal solid waste from non-biogenic sources, and tire-derived fuels) and fuel ethanol and biodiesel consumption, plus losses and co-products from the production of fuel ethanol and biodiesel. 

TABLE 10.1 Ethanol and Biodiesel Consumption in Road Transport by Region in the New Policies Scenario... 

During the last decade many industrial processes shifted towards using solid acid catalysts (6). In contrast to liquid acids that possess well-defined acid properties, solid acids contain a variety of acid sites (7). Sohd acids are easily separated from the biodiesel product they need less equipment maintenance and form no polluting by-products. Therefore, to solve the problems associated with liquid catalysts, we propose their replacement with solid acids and develop a sustainable esterification process based on catalytic reactive distillation (8). The alternative of using solid acid catalysts in a reactive distillation process reduces the energy consumption and manufacturing pollution (i.e., less separation steps, no waste/salt streams). 

Today ethanol and biodiesel (FAME) are the most common biofuels. Alternative fuels from fossil energy sources are mainly LPG and CNG. Synthetic gasoline and diesel from coal (CTL) and natural gas (GTL) are produced mainly in South Africa. Electricity used in battery-electric vehicles plays a minor role today. The fuel consumption for road transport in the world today amounts to about 65 700 PJ per year (IEA, 2006a) in total, the share of alternative fuels for transport at the time of writing was about 2.7% (Table 7.24). 

Fontaras G, Kousoulidou M, Karavalakis G, Tzamkiozis Th, Pistikopoulos P, Ntziachristos L, Stoumas S, Samaras Z (2010) Effects of low concentration biodiesel blend application on modem passenger cars. Part 1 feedstock impact on regulated pollutants, fuel consumption and particle emissions. Environ Pollut 158 1451-1460... 

Biomass energy (including the use of energy from waste and the production of bioethanol and biodiesel) has been growing rapidly as well, both in the U.S. and elsewhere. Biomass power consumption in America grew from 1,562,307 billion BTUs in 1950 to 3,226,918 billion BTUs in 2006 and 3,584,000 billion BTUs in 2007. 

Demand for biodiesel, which is made by transforming vegetable oil with alcohol, is also growing. Biodiesel is the only fuel that does not require the purchase of a new or especially adapted vehicle. Europe is the largest market, helped by significant penetration of diesel-fueled cars. Germany alone uses about 450 million gallons of biodiesel a year — three percent of its total diesel consumption.34... 

In 2009, worldwide production of methanol was around 40 million metric tons. Although this amount represents only 0.01% of the worldwide gasoline production, it is nearly equivalent to the total biodiesel and bioethanol production [11], From this number, it is clear that a large-scale replacement of gasoline by methanol as fuel would require an enormous increase of worldwide methanol synthesis capacities. Today, chemical intermediates dominate methanol consumption. Formaldehyde a platform molecule for the synthesis of polymer resins - is responsible for nearly half of the total demand. Acetic acid, MTBE, and methyl methacrylate - a monomer -constitute another 25% [7, 12]. Direct fuel and additive usage accounts for 15% of demand but is expected to rise. 

Fuel density is important for blending characteristics, but also relates to emission levels, fuel consumption, and emission control systems. Similarly, the viscosity of the fuel is important. Kinematic Viscosity is included in the Biodiesel Standard because it relates directly to the injection system performance. In the Biodiesel Standards, viscosity is often set at a specific temperature point. With most fatty acid methyl esters this is never a problem, but viscosity changes at low temperature can be much more problematic. Biodiesel tends to thicken faster than fossil diesel. Specific additives might be required to deal with this. 

The reaction is catalyzed by a variety of both acids and bases but simple bases such as NaOH and KOH are generally used for the industrial production of biodiesel [200, 201]. The vegetable oil feedstock, usually soybean or rapeseed oil, needs to be free of water (<0.05%) and fatty acids (<0.5%) in order to avoid catalyst consumption. This presents a possible opportunity for the application of enzymatic transesterification. For example, lipases such as Candida antarctica B lipase have been shown to be effective catalysts for the methanolysis of triglycerides. When the immobilized form, Novozyme 435, was used it could be recycled 50 times without loss of activity [201, 202]. The presence of free fatty acids in the triglyceride did not affect the enzymes performance. The methanolysis of triglycerides catalyzed by Novozyme 435 has also been successfully performed in scC02 as solvent [203]. 

Biodiesel is presently making the transition in many countries of the world from a research curiosity to an accepted alternative to petroleum-based fuel. Europe is the leading region for the production and use of biodiesel, with an estimated 2001 output of 757-million L. Biodiesel production in the United States in 2001 was estimated at 79.5-million L. Production and consumption are rapidly increasing worldwide, with estimates of combined US and European output in 2003 at around 1,628 million liters (144). Present and anticipated use constitutes but a fraction of... 

On a liquid fuel basis, these feedstocks would equal about 3.7 billion gallons of diesel fuel, about 13% of the 28 billion gallons of diesel fuel consumed in the United States for transportation in 1996. If biodiesel was blended with petroleum diesel fuel, e.g., 20% biodiesel and 80% petroleum (B20), the total supply of this blended fuel would be about 18.7 billion gallons, or 67% of U.S. annual diesel consumption. This example uses the total average supply of all crop oils, animal fats, and yellow grease as the available feedstock supply (182). 

At current oil crop production levels and fuel consumption rates, biodiesel is unlikely to replace more than a very small portion of total diesel fuel consumed globally (1). However, biodiesel has many potential niche markets where its low toxicity and improved emissions can provide value that outweighs the added costs of using this fuel. Toxicity and biodegradability tests have determined that biodiesel is a... 

Figure 8.8 LCA analysis comparison of green diesel versus FAME biodiesel and a petroleum diesel energy consumption per unit of diesel energy.

The Calculated Cetane Index (CCI), though not an accurate predictor of Cetane Number for biodiesel, since it is based on a calculation using specific gravity and the distillation curve, was used to estimate the Cetane Number of the biodiesel and two diesel fuels. From the results it can be seen that biodiesel has a CCI value higher (55) than that of diesel No.2 (49). This accords the biodiesel with better cold-start properties, minimizes the formation of white smoke (emissions), and leads to less engine noise and hence improved engine durability and reduced fuel consumption. ... 

Soybean is the oilseed with the greatest production on a worldwide basis. Production of soybeans is increasing and is expected to continue to increase as demand for soybean oil for human consumption and biodiesel and demand for high-protein meal for animal feed grows in both developed and developing countries. Currently the United States is the largest producer of soybeans followed by Brazil, Argentina, and China (USDA—FAS, 2007). Table 2.1 shows the most recent data on world supply. 

One approach to reducing water consumption is to lower the pH of the biodiesel, either by direct acid addition or by adding acid to the wash water. Below pH 4.5, the soap dissolved in the biodiesel will be split into free fatty acids and salts. The free fatty acids stay with the biodiesel and as long as they do not exceed the Acid Value specification in ASTM D 6751 (0.5 mg KOH/g), they do not cause a problem. The salts are removed with a small amount of water (3 to 10%). 

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