Alain Berthelot

Bioenergy II: Suitability of Wood Chips and Various Biomass Types for Use in Plant of BtL Production by Gasification

A characterization study has been performed of the French regional resources that may be used in Biomass-to-Liquid plants based on gasification in entrained-flow reactor. It is based on about 90 representative samples of wood chips from forestry, Short Rotation Coppice (SRC) and Short Rotation Forestry (SRF) and of agricultural biomass, including straws and energy crops. Results show that there is not much variability in properties inside the different families. The majority of properties do not seem to be problematical for the process. However, some properties may be questionable: (i) wood chips size distribution, with many small particles ( below 2 mm) and very large particles (above 70 mm), (ii) bulk density, which is very low in agricultural products (about 100 kg.m-3), (iii) sulphur, fluorine and chlorine contents, which are high, especially chlorine in agricultural straws (1000-8000 mg/kg) (iv) other impurities amounts, such as Ni and B, which are in relatively high amounts in some samples (v) ash content, which is high in SRC/SRF (3 wmf%) and very high in most agricultural raw materials (5 wmf%). Based on these statements, first conclusions on the suitability between feedstock and process may be drawn. Wood chips from forestry appear as the most suitable resource for the process and should be the first resource to be used in industrial plants. SRC/SRF also seem quite suitable for the process and may be seen as a short-term alternative. Agricultural raw materials seem to be more problematical and may be seen as a mid-term option.

Réflexions sur la rentabilité des taillis à courte et à très courte rotation d’Eucalyptus et de Peuplier

Based on the experience of the FCBA institute of technology in the area of short rotation coppice (SRC) of poplar and eucalyptus and French and foreign technical reference material in the area of very short rotation coppice (VSRC), we were able to identify and estimate four standard scenarios for these two species ranging from the lowest densities (SRC 1,000 stems/ ha) to the highest densities (VSRC for 10,000 stems/ha). Each planting density is associated with a given rotation time that varies from 2 to 10 years. The cost for these scenarios was reconstructed and compared to the cost of harvesting and the average sales price for the chips produced. With this data, a tentative assessment of the profitability of the SRC and VSRC scenarios was made. The results show that for these two species the profitability level for coppice increases the longer the harvesting cycles. The overall profitability for coppicing schemes appears to be moderate. Nonetheless, for players on the biomass market (industry, landowners and farmers) the return on investment in SRC / VSRC varies considerably. Profitability is achieved in practically every scenario depending on who implements it.

Potentialités de production de biomasse de quelques essences résineuses en conditions forestières : Douglas, Épicéa commun, Épicéa de Sitka, Cyprès de Leyland, Séquoia toujours vert

In anticipation of the increase in biomass demand, the authors investigate the possibility of increasing woody production on medium- to low-fertility forest soils by choosing appropriate species and silvicultural methods to produce biomass either exclusively (dedicated scenario), or partially (semi-dedicated scenario) for energy. The production of total aerial biomass is documented for six forest conifers on the basis of dendrometric results most of which were acquired through the FCBA test network (Douglas Fir, Common Spruce, Sitka Spruce, Leyland Cypress, Sequoia sempervirens, Japanese Cedar). The Maritime Pine was investigated through a review of the bibliography. For the most frequent species, the effect of some factors (forest capability class, plantation density, genetic level) was examined. The mean observed increases, which vary between 6 and 10 tonnes/ha/yr. towards 20 years for most species, are then compared to those arising from systems already developed for the purpose of producing biomass, e.g. the VSR Poplar or Eucalyptus coppices, but for which the data was mostly acquired under agricultural conditions. Finally, some of the consequences of intensification of woody production are discussed.

Qualité bioénergétique de la biomasse forestière en vue de la production de biocarburants de deuxième génération

Second-generation liquid fuels are now at the development stage that precedes their industrial implementation. They offer significant market opportunities for French lignocellulosic resources both from forests and crops. Those resources are limited and it is important to avoid competing against food crops or destabilising the sectors that already operate. It is therefore essential for the actors in research on these resources and processes to work in partnership and produce a common response to these issues. The REGIX project has provided an assessment of the suitability of various types of forests and cultivated biomass to the needs of processes for producing second-generation biofuels via biochemical and thermochemical processes. This article provides an overview of this approach for four classes of forest biomass: short and very short rotation coppice (SRC and VSRC), wood chips from hardwoods and from softwoods. The results show that these classes are very well-suited to most of the specifications for these processes, but a number of drawbacks were also noted, in particular for VSRC.