The term bioenergy refers to all types of energy derived from plant biomass such as the lignocellulose feedstocks under consideration here. The following bioenergy types can be obtained by application of different transformation technologies to the conversion of lignocellulose biomass:

1. Thermal energy is one of the most commonly used products of woody biomass transformation and provides heat required for cooking and heating through direct combustion. In addition, steam produced by combustion can be used for both domestic and industrial processes (e. g. drying, boiling, ceramic oven heating/baking, etc.). Heating needs differ and can be distinguished between urban and rural, domestic and industrial applications.

2. Electric energy can be obtained through several transformation technologies, the choice of which is mostly determined by the type and amount of biomass available. For instance, the steam generated in a combustion process can be used to produce electricity (cogeneration). Additionally, other conversion technologies such as gasification, pyrolysis and anaerobic digestion all produce gases (synthesis gas, bio-gas) suitable for electricity production.

3. Transportation fuel is the energy obtained in self-propulsion motors from biofu­els. These so-called ‘second generation biofuels’ originate from lignocellulosic biomass and can be obtained through several thermochemical and biochemical transformation technologies, as described in the sections below. Second gen­eration biofuels particularly refers to those that employ lignocellulose biomass resources as feedstock without competing with food production. Lignocellulose biomass can be collected as residues from various activities in different sectors, although it is also possible to specifically produce ethically suitable “energy crops” as feedstocks for bio-energy production (Sanchez and Cardona 2008).

Woody biomass is a renewable feedstock for the production of bioenergy that is available in relatively large amounts in many parts of the world. It can be collected as by-products from lumber, pulp and paper production or from dedicated energy crops such as short rotation woody crops (see Chap. 6). Lignocellulosic biomasses are characterized by their heterogeneous composition and structure, multiplying the possible approaches for conversion into bioenergy products. Among the dif­ferent feedstocks, this chapter will focus on the following genera: Pinus (pines), Eucalyptus (gums) and Acacia (wattles), given their wide and ready availability in the Southern hemisphere. Bioenergy transformation technologies are generally classified as being either thermochemical (combustion, pyrolysis, gasification, liquefaction) or biochemical (anaerobic digestion, microbial fermentation) in nature.