Introduction

There are unequivocal signs that global warming and the ensuing climate change are determined by the use of fossil fuels and represent a serious threat facing the planet. Dedicated crops are seen as one of the most interesting short-term option to replace fossil fuels and mitigate the global warming. Millions of hectares of energy crops are expected to be cultivated around the world in the next decades. Nonetheless, diverting agricultural lands to energy crops is a current subject of heated discussion, because of the possible threats to food security, and because of crop-related aspects, such as their environmental impacts, the economic sustainability and the site-specific adaptability. Nevertheless, global biofuel use is expected to increase twofold by 2015 and Brazil will remain the world’s top exporter, whereas the U.S. is expected to perform the largest increase in biofuel use per country. The most important liquid biofuels are bioethanol and biodiesel (FAME - Fatty Acid Methyl Ester) which are produced and as well as used world wide in reasonable amounts. Representatives of the following generation biofuels, such as hydrogenated vegetable oils (HVO), synthetic fuels (BtL - Biomass to Liquid), bioethanol and biodiesel from 2nd generation feedstocks (cellulose or hemi-cellulose) and Jatropha or algae are assumed to be superior to 1st generation biofuels. Beside biodiesel and bioethanol, there are several other biofuels under development, but only few of them passed the step of market launch and their availability is still limited. The most advanced technologies so far are the production of BtL-fuels by Fischer-Tropsch synthesis and HVO by hydrotreating of vegetable oils. BtL production claims to use the whole above-ground portion of ligno-cellulosic plants, but also residual material from biodiesel or bioethanol production. Hydrotreated vegetable oils (HVO) are vegetable oils which are transformed to hydrocarbons by a catalytic reaction.