The New Generations of Biofuels

To date, these types of biomass have not been shown as the most profitable sources of energy, although in some cases controversy has arisen that has resulted in negative attitudes towards the use of various types of biomass for energy production these points will be discussed in the following sections. 

The first-generation biofuels can be identified as ethanol, which was produced via the alcoholic fermentation of cereals, and hio-oil or biodiesel, which was extracted from seeds such as sunflower, rapeseed, or palm. The use of cereals and sunflowers was rejected by public opinion and some scientific environments, because their use for energy production conflicted with their use as foodstuffs. In fact, the diversion of cereals to the production of ethanol for transport has led to a rise in the price of flour and derived goods, especially in Mexico. The same situation has arisen for some bio-oils, such that the source was shifted to palm-oil which, essentially, is produced in Asian countries such as Malaysia. 

Consequently, the first-generation ethanol, oils and bio-oils are no longer at the center of attention, and are not expected to contribute towards solving the problem of C02 emissions reduction in the transport sector. It is more likely that there will be a major surge of interest to identify substitutes for these materials. Some possible solutions to these problems are discussed later in the chapter. 

The new generations of biofuels must respond to the issues of reducing C02 accumulation in the atmosphere through a quasi-zero-emission energy production, but without competing with the food market. Hence, biomass that has no nutritional value for either humans or animals must be taken into consideration. 

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Catalytic dehydration of hexose polysaccharides to 5-hydroxymethylfurfural (HMF) is a highly valuable reaction. Indeed, from HMF, new generations of biofuel (e.g., dimethylfurane) and a wide range of intermediates and fine chemicals can be obtained [55-59]. Comprehensive reviews related to the utilization of HMF can be found in the literature [60-64] see also Chap, by M. Moser. 

There is a new McCauley on the scene in this new millennium. Brad McCauley finished his education at Kansas State University in 2001. He has acquired land and equipment in Doniphan County. While the previous generations of his family must be part of his desire to return to his roots, Brad knows that the wonder of agricultural technology for him is only beginning. A new twist for the McCauley s is their investment in value-added agriculture, including both biofuels and food. 

Recently, a novel microbial fuel cell harvesting energy from the marine sediment—seawater interface has been reported. Also, a novel photosynthetic biofuel cell that is a hybrid between a microbial and enzymatic biofuel cell has been reported for the very first time. More recently, reports of an unconventional biomass-fueled ceramic fuel cell can also be found in the literature. A new concept of Gastrobots —hybrid robots that utilize operational power derived from microbial fuel cells—has been introduced. Finally, the generation of electrical power by direct oxidation of glucose was demonstrated in mediatorless microbial fuel cells, which produced currents up to 3 fiA/cm at unknown cell voltage. ... 

The first biodiesel initiatives were reported in 1981 in South Africa and in 1982 in Austria, Germany and New Zealand. Since then, the production of this alternative fuel has seen enormous developments, particularly in Europe, where it reached 5.7 millions tons in 2007. It is expected to increase further to fulfill the recent decision of the European Parliament to substitute 10% of transport fuels with biofuels by 2020. According to assessments of the European Community, to reach this target, the production of bioethanol, biodiesel and second-generation biofuels should reach 36 Mtep (tep = tonnes equivalents petrol) in 2020. 

The development of second-generation biofuels may however require more patience. Some of the most popular biocrop feedstocks seem to belong to what are called "invasive species," better known as "weeds," with a high tendency to escape biofuel plantations and overrun adjacent farms and natural land [66]. One expert stated that investors have often started these new ventures in the expectation to produce biofuels in return and in the not-too-far future. It is understandable that they do not like negative assessments. But clearly this is another example where a proper assessment has to be made and patience needs to be applied. 

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. 

The full potential of amperometric biosensors has not yet been tapped, especially with respect to the versatile and broad range of applications for which biosensors can be used. Many contributions to the field of biosensors and biofuel cells still are at the proof-of-concept stage. Thus, the authors hope that this chapter will promote lively and valuable discussions in order to generate new ideas and approaches towards the development and optimization of biosensor architectures. 

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