Tagasaste, leucaena and paulownia: three industrial crops for energy and hemicelluloses production

Background Burning fast-growing trees for energy production can be an effective alternative to coal combustion. Thus, lignocellulosic material, which can be used to obtain chemicals with a high added value, is highly abundant, easily renewed and usually inexpensive. In this work, hemicellulose extraction by acid hydrolysis of plant biomass from three different crops (Chamaecytisus proliferus, Leucaena diversifolia and Paulownia trihybrid) was modelled and the resulting solid residues were used for energy production. Results The influence of the nature of the lignocellulosic raw material and the operating conditions used to extract the hemicellulose fraction on the heat capacity and activation energy of the subsequent combustion process was examined. The heat power and the activation energy of the combustion process were found to depend markedly on the hemicellulose content of the raw material. Thus, a low content in hemicelluloses resulted in a lower increased energy yield after acid hydrolysis stage. The process was also influenced by the operating conditions of the acid hydrolysis treatment, which increased the gross calorific value (GCV) of the solid residue by 0.6–9.7% relative to the starting material. In addition, the activation energy of combustion of the acid hydrolysis residues from Chamaecytisus proliferus (Tagasaste) and Paulownia trihybrid (Paulownia) was considerably lower than that for the starting materials, the difference increasing with increasing degree of conversion as well as with increasing temperature and acid concentration in the acid hydrolysis. The activation energy of combustion of the solid residues from acid hydrolysis of tagasaste and paulownia decreased markedly with increasing degree of conversion, and also with increasing temperature and acid concentration in the acid hydrolysis treatment. No similar trend was observed in Leucaena diversifolia (Leucaena) owing to its low content in hemicelluloses. Conclusions Acid hydrolysis of tagasaste, leucaena and paulownia provided a valorizable liquor containing a large amount of hemicelluloses and a solid residue with an increased heat power amenable to efficient valorization by combustion. There are many potential applications of the hemicelluloses-rich and lignin-rich fraction, for example as multi-components of bio-based feedstocks for 3D printing, for energy and other value-added chemicals.

Méttodo Fuzzy para la identificación de áreas potenciales para la producción de leña. Aplicación de caso: comuna de Empedrado, región del Maule, Chile

Utilizando criterios ambientales y territoriales se identificaron12.828,6 hectáreas donde se pueden establecer plantaciones dendroenergéticasen la Comuna de Empedrado, Región del Maule, Chile. Lasespecies forestales propuestas fueron Acacia dealbata, Acacia melanoxylon,Chamaecytisus proliferus ssp. palmensis, Eucalyptus camaldulensisy Robinia pseudoacacia. Se elaboraron modelos de capacidad deacogida del territorio para cada especie con el fin de identificar áreas dealta, media y baja aptitud. La aptitud del terreno para recibir plantacionesdendroenergéticas se evaluó integrando la opinión de expertos enplantaciones forestales y dendroenergía, la información cartográfica ydigital disponible de Empedrado y los requerimientos ambientales de lasespecies. Nueve variables ambientales fueron jerarquizadas, representadasespacialmente y transformadas a una escala común utilizando sistemasde información geográfica (SIG). Al comparar estos modelosChamaecytisus proliferus posee mayor aptitud en un 70,3% de la superficiedisponible mientras que Robinia pseudoacacia no aparece comorecomendable.

Variations in Production and Oligomers Content Obtained Under Hydrothermal Treatment Among Five Fast-Growing Species

In order to identify fast growing species utilizable for olygomer and monomer production, five fast growing species (Paulownia fortunei, Chamaecytisus proliferus, Arundo donax, Leucaena.diversifolia and Sesbania grandiflora) were tested. Concurrently, the biomass productivity of these species was also tested on a field scale. The biomass productivity of the selected species studied ranges from 0.36 to 21.30 t ha-1 (o.d.b.) under Mediterranean conditions for the year 1 sprouts. In addition, the hydrothermal treatment results show that the selected species could be employed as alternative raw material for the production of oligomers, leading to a high concentration of oligomers (9.4-23.4 g/L-1 at 190ºC).