is defined as “liquid, solid, or gaseous fuel produced by conversion of biomass such as bioethanol from sugar cane or corn, charcoal or woodchips, and biogas from anaerobic decomposition of wastes”
Biofuels supplied 3 % of the energy used worldwide for road transportation in 2011. In the United States which is the largest biofuel producer in the world, biofuels generated 4 % of the energy used for transportation in 2011. In 2009, in Brazil, which is the second largest biofuel producer in the world, a total of 23 % of the energy for road transportation came from biofuels. Large-scale biofuel production in the world can substantially reduce emissions from the transport sector. In this chapter, we discuss the present status of biofuel production in the world, as well as some of the challenges relating to the environment and to the use of land, that result from large-scale biofuel production.
Biofuel applications
Biofuels comprise fuels derived from organic materials such as plants and animals. These plant- and animal-based fuels include gaseous fuels such as hydrogen (H2) and methane (CH4), and liquid fuels such as methanol (CH3OH), ethanol (C2H5OH), biodiesel, and acetone (C3H6O), among others. An important discovery in 2009 by Zhang et al. introduced biofuels from hydrolysis of PHA into hydroxyalkanoates methyl esters that are combustible.78 In this work, the esterification of SCL-PHB and MCL-PHA with methanol resulted in hydroxybutyrate methyl ester (3HBME) and hydroxyalkanoate methyl ester (3HAME), respectively, as shown in Fig. These 3HBME and 3HAME biofuels had combustion heat values of 20 kJ g−1 and 30 kJ g−1, respectively, which is comparable to that of ethanol (27 kJ g−1).78 Furthermore, ethanol combustion values are enhanced by about 10% and 30% with the addition of only 10% 3HBME and 3HAME, respectively. In another work, a combined PHB synthesis pathway and metabolic route produced butanol, a liquid biofuel, from glucose. It is worth noting that PHA as a source of biofuel is obtainable from low-cost sources such as activated sludge or nutrient-rich wastewater, and PHA as a feedstock need not be purified to produce biofuels. In this regard, the use of low-cost sources eliminates the food-fuel controversy. Thus, PHA application in the production of biofuels is an exciting platform in the energy sector.
Webmaster Pakin Eurboonyanunt M.5/8 No.20
Biofuels are regarded as energy sources with the potential to solve a series of problems related to the climate and sustainability. Expectations are that pursuing policies supporting biofuels will be beneficial for welfare and sustainability in sociemental effects, energy security effects, and net economic effects. Reviewing the literature tties. It is convenient to divide the effects of such policies into four categories: Climate effects, other environo date reveals that the effects of converting from fossil fuels to biofuels do not necessarily have positive net welfare effects, and the argument to substitute biofuels for fossil fuels is not as obvious as it initially appears to be. Short-run stringent climate policy objectives are proposed to counteract global warming, and increasing the use of biofuels is promoted as an adequate strategy. One important conclusion drawn from recent studies is that biofuels are not entirely carbon neutral, as is commonly assumed. Therefore, the use of biofuels as an instrument in climate policy must be carefully scrutinized before set into play on a global scale.
