Biofuels are liquid or gaseous fuels for the transport sector that are predominantly or exclusively produced from biomass. These include:* Conventional bioethanol: Commercially available biofuels derived from sugar and starch crops including: Brazilian sugarcane, corn, wheat and sugarbeets
* Conventional biodiesel: Commercially available biodiesel made from canola , palm, soybean, and sunflower oils
* Advanced bioethanol: Cellulosic ethanol derived from residues or energy crops including wood, switchgrass and wheat straw
* Advanced biofuels: Currently under development - fuels include algae-based fuels, liquid-phase catalytic processing of biomass and biomass-based Hydrogen
Biofuels can significantly contribute to the sustainable transportation and lessen our dependence on fossil fuels. Experts estimate biofuels can readily provide a long-term market share of 15% or more of the transportation market over the next few years. In the shorter term, these efforts help establish markets and an effective infrastructure biofuels. In the longer term, these efforts are expected to result in lower-cost fuels that are economically competitive in the marketplace.
The production of biofuels can provide numerous local, regional, and national economic benefits, if produced sustainably. The growth and conversion of biomass feedstocks creates jobs for local people in rural, agriculture-based areas. This is particularly the case in areas where local stakeholders are consulted, involved and actively participate in biofuel production. Increased demand for feedstock also helps reduce the amount of surplus crops and reduces the need for national farming subsidies. Conversion of the raw material into fuels also provides economic benefits through the construction and operation of processing facilities. These facilities provide local employment and development opportunities in the rural areas of both developed and developing countries and can help improve the financial infrastructure of these areas.
ETBE (ethyl tertiary-butyl ether) is formed by chemically reacting ethanol with fossil raw materials. The ETBE product is blended with gasoline at concentrations of 5 10% to increase the oxygen content of petrol. The added blended fuel burns cleaner than petroleum itself and reduces the emissions of carbon monoxide and unburned hydrocarbons from vehicles. ETBE is widely used in France at present, and other countries are also considering its use.
Purified biogas can be used in natural gas engines. The gas must be compressed and stored in cylinders in order to be used in vehicles. Buses operated with biogas or natural gas are used in municipal fleets. In Sweden a small network of filling stations offering biogas at normal filling stations has been established.
Most studies currently available indicate that biofuels can reduce the emission of carbon dioxide and other gases associated with global climate change. As plants or trees grow, they capture carbon dioxide from the atmosphere. When the biofuels derived from plants or trees are consumed, the carbon dioxide released during the combustion process is absorbed by new plants, effectively recycling the carbon. As a result, the use of biofuels can significantly reduce net emissions of greenhouse gases to the atmosphere. Many biofuels also have chemical compositions that help reduce the emission of other unwanted pollutants when they are burned. For example, the use of oxygenated biofuels such as ethanol and ETBE in gasoline blends reduces carbon monoxide emissions, and the use of ethanol in diesel engines reduces the emission of particles toward zero. The use of biodiesel reduces the emissions of carbon monoxide, unburned hydrocarbons and soot. The reduction of these unwanted products provides local and regional air quality and environmental benefits, particularly in industrial centers.For more info you can refer to:
Biodiesel is produced by chemically upgrading oils obtains from the pressing of oil plants like rape, sunflower, soybean and the fruits of oil palms. By means of transesterification, the tryglycerides of the oils can be transformed into biodiesel. One ton of oil and 110 kg of methanol produce one ton of biodiesel and 110 kg of glycerine. Plant oil can be also used in its untreated form or in mixtures with diesel fuel, but the market penetration of this fuel is still insignificant. Carbonization processes may shorten the service life of traditional diesel engines when this fuel is used, so it is necessary to use special engines for operation with pure plant oil. In Brazil, palm oil is used for the generation of electricity with stationary diesel engines, and special engines for the operation with plant oil have been developed in Germany. Biodiesel is now being produced in demonstration scale plants from plant oil and methanol and used for diesel engines for some years. In Austria, Sweden and Germany, pure biodiesel ("B100") is used in unaltered vehicles. In France, commercial diesel fuel typically contains up to 5% of biodiesel ("B5").