Biofuels from vegetable oils

Demirbas, A. 2008e. New liquid biofuels from vegetable oils via catalytic pyrolysis. Energy Edu Sei Teehnol 21 1-59. 

Rapeseed methyl ester (RME) is another alternative biofuel that can be used in diesel engines. RME has the advantages that it is renewable compared to diesel, non-toxic and less flammable compared with many other fuels, like ethanol. RME has the same cetane number, viscosity and density as diesel, contains no aromatic compounds and is biologically degradable with minor contamination in soil. RME can be produced from vegetable oils, but is mostly produced from rapeseed oil by pressing of the seeds or by extraction. Up to 3 tons of rapeseed can be produced from one hectare. The fatty acids in rapeseed oil are mostly oleic acid, linoleic acid and linolenic acid. The oil is pressed from the plant and after some purification allowed to react with methanol in the presence of potassium hydroxide as a catalyst, to produce a methyl ester, see Figure 6.6. 

Knothe, G., and Dunn, R. O. 2001. Biofuels Derived from Vegetable Oils and Fats. In Oleochemical Manufacture and Applications (pp. 106-163). Sheffield Sheffield Acadamic. 

Biodiesel is a type of biofuel that can be made from vegetable oil or animal fat. 

ENSEL [The name is probably derived from NCL, the National Chemical Laboratory in Pune, India, whose former director, Paul Ratnasamy, was the prime inventor of the catalyst for this process] A transesterification process for making biodiesel from vegetable oils, using a solid double metal cyanide catalyst. Developed in 2006 by the National Chemical Laboratory, India, and commercialized by Benefuel, a joint venture of Seymour Biofuels with SUd-Chemie. The first plant was built in Seymour, IN, from 2008. The novel catalyst was provided by Siid-Chemie India. 

The urge to find sustainable replacements for transport fuel has led to a drive to find renewable, nontoxic, and carbon-neutral biofuels. Biodiesel is a fuel composed of mono-alkyl ester derived from vegetables oil or fats oil, which is proven to contribute to reductions in the world s dependence on fossil oils (Mumgesan et al., 2009). The most significant advantages of biodiesel usage over fossil fuel are ... 

Cereals can yield around 1500-3000 litres of gasoline equivalent (lge)/ha sugarcane, 3000-6000 lge/ha sugarheet, 2000-4000 lge/ha vegetable oil crops, 700-1300 litres of diesel equivalent (lde)/ha and palm oil, 2500-3000 lde/ha (IEA, 2007). In addition, there are novel biofuel production processes under development, for example biodiesel from marine algae, which are claimed to have a 15 times higher yield per ha than rapeseed. 

The biorefinery scheme was developed initially for carbohydrate-containing feedstocks. Large biorefineries are currently operating in the USA (e.g., Cargill at Blair, Nebraska) and in Europe (e.g., Roquette Frs. at Lestrem, France). The concept can be extended to produce chemicals from other renewable feedstocks. An integrated production of oleochemicals and biofuels can be achieved in biorefineries using vegetables oils as main feedstock to produce versatile platform mole-... 

The role of biocomponents in traffic fuel is increasing. The European Union Directive [1] on the promotion of the use of biofuels for transport purposes states that by the end 2005 traffic fuels should have contained 2% of components produced from renewables. The figure rises to 5.75% by the end of 2010 and up to 20% by the end of 2020. This directive defines biofuel as a liquid or gaseous fuel for transport produced from biomass, biodiesel as a methyl ester produced from vegetable or animal oil, of diesel quality, to be used as biofuel and synthetic biofuel as synthetic hydrocarbons or mixtures of synthetic hydrocarbons, which have been produced from biomass. The European Commission also encourages member states to lower tax rates on pure and/or blended biofuels, to the offset cost premium over petroleum-based fuels [1, 2]. 

First generation bioethanol and biodiesel production, which mainly makes use of cereal grains and vegetable oils, represents a growing source of high quantities of protein as a valuable by-product. Sanders et al. (2007) estimated that a 10% substitution of fossil transportation fuels worldwide by first generation biofuels would result in an annual production of 100 million tonnes of protein - about four times the proteins requirement of the world s human population. A direct result of this would be the saturation of traditional protein markets. New opportunities would therefore emerge for chemical production from proteins. 

One approach that could enable the production of cheaper biodiesel is to utilize low-value vegetable oils that contain a high content of FFA. This is particularly attractive as such materials can be obtained from either waste or the cultivation of alternative crops, something that would increase the biodiversity from which biofuels... 

Chemical conversion of vegetable oils to general purpose liquid fuels ( biofuels, and biodiesel ) has also been successfully explored [34, 35]. However, the small size of this resource makes it unlikely that this could do more than supplement petroleum-based sources. Probably the more significant developments to extend petroleum-based liquid fuels lie in the recovery of oil from the tar sands, and the pilot plant projects involving oil shale pyrolysis experiments to liquid fuels. 

Several developed countries have introduced policies encouraging use of biofuels made from grain, vegetable oil, or biomass to replace part of their fossil fuel use in transport. These initiatives generally have at... 

Another example regards an aspect discussed before on the sustainability of land use for biofuels. We have already remarked the various problems in this analysis that can be summarized, in a simplified form, in reply to the question which use is the most sustainable for one ha of land. There are different possible options to produce (i) bioliquids (by fast pyrolysis), bioethanol or biodiesel, (ii) food, (iii) chemicals, (iv) electricity or (v) to feed animals. There are more options (e.g., biogas) but the present already allow a good comparison, although theoretical (land productivity depends on several factors and, for example, palms to produce the vegetable oil raw material for biodiesel is not locally in competition with the production of bioethanol from biomasses for which different climate and land characteristics are required). 

---