Lignocellulosic biomass is seen as an attractive feedstock for future supplies of renewable fuels and biochemicals. Their abundant supply makes them attractive candidates to replace oil-based liquid fuels and chemicals. Substantial investment is occurring in conversion technologies and in determining the most economic, practical and cleanest technology for the production of these lignocellulosic-based chemicals.

Two main routes can be distinguished for the conversion of lignocellulosic biomass: the biochemical route and the thermochemical route. The key bottleneck in the biochemical conversion of lignocellulosic biomass is the initial conversion of the biomass into sugars. Further improvement of the physicochemical pretreatment processes and new biotechno­logical solutions are needed to improve the efficiency of this conversion. This “biomass recalcitrance” remains one of the most significant hurdles to producing economically fea­sible chemicals from lignocellulosic biomass via the biochemical route [7]. Continued research and development is needed to develop and scale-up new biochemical routes.

Thermochemical processes can easily overcome this natural resistance of biomass due to the relative high temperatures that are used. Therefore, a broader range of feedstock can potentially be used. However, also for the thermochemical route technical and commercial barriers still exist [62]. Innovative R&D is needed to improve the energy efficiency and cost effectiveness of thermochemical conversion technologies. Gasification technology is considered to be ready for deployment between now and 2020. Other thermochemical routes like pyrolysis or liquefaction are not as well developed [63].

It is likely there will be no single preferred conversion technology for the production of cellulosic fuels or chemicals, but rather technologies appropriate for specific feedstock [52]. Feedstock restrictions for thermochemical conversion mostly pertain to particle size, moisture and ash content.

Overall it can be concluded that significant investment into research, pilot and demonstra­tion plants is ongoing and will be further needed to develop commercially viable processes utilizing biochemical and thermochemical conversion technologies for the production of biofuels and biochemicals from lignocellulosic biomass.

Acknowledgement

Sofie Dobbelaere works on the IWT project no. 080598, concerning the provision of Technological Services related to Industrial Biotechnology, set up by FlandersBio, Ghent Bio-Energy Valley and Essenscia Vlaanderen.