The scale of biofuels production 2.1. Drivers of biofuels
(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
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 requirestimes more biomass in the form
of animalfeed and that puts further pressures on natural resources.
production is very energy intensive , it is closely linked to global energy consumption. Global fuel consumption has grown 50- foldsince 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.
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 totalplant 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 makingethanol form cellulosic biomass (FAO, 2008).
is based on the oil crops, such as rapeseed in Europe and soybean in
the USA and Brazil . In tropicalregions , 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
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)
3. Global biodiesel production projection (USDA, 2012). Biodiesel is
mainly produced in Europe, but production in other countries is
expected to increase.
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
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.