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Sustainability aspects of biofuels (0)

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Sustainability aspects of biofuels
  • Introduction
    The literature review will discuss the sustainability aspects of biofuels. Food production will be the main concern as it is the most debated issue , but other aspects, such as land use change and water consumption will be also considered as they are essential aspects in the biofuels sustainability criteria . The review will discuss the viability of biofuels based on the current technologies. Second-generation biofuels are not yet commercially viable and therefore will not be discussed; although they could significantly improve the sustainability of biofuels when they break through to the industrial scale .
  • The scale of biofuels production
    2.1. Drivers of biofuels production
    Lal (2010) stated that “three inter -connected challenges face humankind in the 21st century”: food security , climate change, and energy security. The world population is projected to reach 9 billion in 2050, posing more demands on energy, food, and other natural resources. It has been estimated that the world food production needs to double and meat production increase by 85% by 2050 to fulfill projected demand by population (Karp, 2011). In the recent decades, the food consumption in the most populous counties has shifted from grain-based diets to meat and dairy diets. Meat production requires times more biomass in the form of animal feed and that puts further pressures on natural resources. As food production is very energy intensive , it is closely linked to global energy consumption. Global fuel consumption has grown 50- fold since the end of the 20th century and it is projected to increase by another 55% by 2030 (Umbach, 2010). That is the reason why new resources for fuel are being sought and biofuels receive subsidies, and investment in development . In addition , transport sector is one of the largest primary energy consumers, and as the travel and car ownership is predicted to increase, more fuel needs to be dedicated to transport (Karp, 2011. There are many reasons why biofuels are necessary , but at the same time, they are controversial for a number of reasons.
  • Biofuels’ feedstock and future projections
    There are mainly two types of liquid biofuels, which have significantly grown in the last decade: that is bioethanol and biodiesel. Bioethanol is based on sugar , extracted from sugarcane and beet, or starch, which mainly comes from maize, wheat or cassava. Starch-based crops must be first converted into sugars in the saccarification process, which requires substantial volumes of enzymes to turn starch into sugars (Soetaert, W. 2008). The starchy products represent only a small percentage of the total plant mass. Other plants ’ building blocks like cellulose and lignin are currently not being used to make biofuels as there is not a commercial viable production method for making ethanol form cellulosic biomass (FAO, 2008).
    Biodiesel is based on the oil crops, such as rapeseed in Europe and soybean in the USA and Brazil . In tropical regions , biodiesel feedstock can also be sourced from palm , coconut and jatropha oils, but these are currently not major feedstock for biodiesel. Biodiesel is produced by combining vegetable oil with an alcohol and a catalyst through a chemical process known as transesterification (FAO, 2008).
    Figure 1. Proportion of global production of liquid biofuels (FO Licht , 2007). Biofuels production is concentrated in three countries: Brazil, the USA, and Europe
    On a global scale, there are three regions that produce biofuels: mainly France and Germany in Europe, the USA, and Brazil. Each region specialises on a specific crop, and the production technologies vary greatly. Biodiesel is concentrated in Europe and in 2005 France and Germany supplied 69% of the global biodiesel. Bioethanol production is concentrated in two countries: Brazil and the USA and in 2005, they together accounted for 80% of global ethanol production (Msangi et al. 2007; Zuurbier, 2008). While Brazil’s biofuels production has grown steadily since the 1980s, then in the USA, the production started to hike in 2003 with the Renewable Fuel Standard legislation . In Europe, biofuels production started to rise in 2005, as depicted on figure 2.
    Figure 2. World biofuels production ( F.o. Licht’s World Ethanol and Biofuels Report , 2006)
    Figure 3. Global biodiesel production projection (USDA, 2012). Biodiesel is mainly produced in Europe, but production in other countries is expected to increase.
    In Europe and the US, biofuels have been boosted with the government ’s goals to source certain percentage of transport fuel from biofuels and therefore biofuels production is heavily subsidised. For example, in the EU, by 2020, 10% of energy used in transport should come from biofuels. In the USA, there is a fixed quantity of renewable fuels that must be consumed each year. By 2015, it must be 15 billion gallons, and 36 by 2022 . In the USA, the legislation also requires to source fuels from advanced biofuels. Babcock (2008) has stated that, in the future, biofuels production will be determined by the level of crude oil prices and public policy incentives. So far, policy incentives have
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    The literature review will discuss the sustainability aspects of biofuels. Food production will be the main concern as it is the most debated issue, but other aspects, such as land use change and water consumption will be also considered as they are essential aspects in the biofuels sustainability criteria. The review will discuss the viability of biofuels based on the current technologies. Second-generation biofuels are not yet commercially viable and therefore will not be discussed; although they could significantly improve the sustainability of biofuels when they break through to the industrial scale.

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