Renewable Liquid Fuels

B ecoming independent of crude oil imports, mainly from the Middle East, is an urgent concern for many countries all over the world. In order to secure a sustainable energy supply, especially in the transportation sector, governments need to apply policies that promote the use of renewable energy technologies. The dependence on crude oil imports decreases as the production of total energy from renewable sources (renewabl e liquid fuels) increases. There are two major factors that will influence the amount offinal energy production from renewable sources.. First, sufficient quantities ofbiomass need to be acquired for conversion into liquid fuels. If a cou ntry cannot provide enough biomass, it has to compensate by importing it, which does not lead to energy independence. Biomass is a limited resource. Even though countries like the United States and Canada encompass large areas of rural land, agriculture and .forestry have distinct impacts for the economy as well as for the environment. The use of biomass for conversion to energy competes with other purposes such as food supply and forestry products. Land availability and crop yie1ds are key criteria in determining the quantities of biomass that can be obtained for energy use with in a country. What is more, the production of biomass for energy use must be sustainable, which requires a thorough understanding of the environmental impacts and the likely demand scenarios for renewable fuels. The amount of final energy obtained from domestic renewable energy also depends on the applied conversion technologies. The efficiency of processing biomass into liquid fuels affects the energy input-output ratio. The less enerb'Y needed to run the processes, the more that is available to enter