Production and quality analysis of pellets manufactured from five potential energy crops in the Northern Region of Costa Rica

Abstract

Modifications to a pellet manufacturing process must be made based on the characteristics of raw material used. The purpose of this work was to determine the alternations required to a wood pellet manufacturing process and the quality of the pellets produced using this process from five energy crops. Quality measurements include: the caloric value, the loss of moisture content in each production stage, the efficiency index of particle-pellet, ash content and quality as defined using the quantity of cracks and the transversal density and longitudinal density determined using X-ray radiography. The crops analyzed were rhizomatous plants, with caloric values ranging between 17.1 and 20.3 MJ kg À1. This work determined that it was possible to produce pellets with Gynerium sagittatum and Phyllostachys aurea using the same production process for wood; however, Arundo donax and Pennisetum purpureum needed pre-airdrying and the Sorghum bicolor required mechanical dewatering before drying. A. donax, P. purpureum and G. sagittatum provided the highest efficiency index. When evaluating the pellet quality P. aurea and G. sagittatum hard a large quantity of cracks, unlike A. donax, P. purpureum and S. bicolor. The transversal and longitudinal pellet density varied from 1129 to 1294 kg m À3. The highest values of bulk density were obtained in A. donax and P. purpureum, followed by G. sagittatum and P. aurea, and the lowest bulk density was obtained in S. bicolor. Althogh out, some species produced cracks and high ash content, this work demonstrated that it is possible to produce pellets with moderate quality.

Quality of Pellets Made from Agricultural and Forestry Crops in Costa Rican Tropical Climates

“…Aragón et al (2014) detailed the pellet manufacturing process from the moment the crops enter the plant to the pelletizing process.…”

Características y propiedades de pellets de biomasa torrefaccionada de Gmelina arborea y Dipterix panamensis a diferentes tiempos

“…The particle size varied between 1 and 3 mm length and 1 to 2 mm in diameter. A description of the process to obtain the particles used can be found in Aragón, Moya, Bond, Valaert, and Tomazello (2016).…”

Evaluación de la combustión de comprimidos cilíndricos fabricados con cultivos forestales y agrícolas en Costa Rica utilizando un quemador doméstico

“…Los pellets fueron fabricados por la empresa PELLETICS S.A. (http://pelletics.com/), ubicada en San Carlos en la provincia de Alajuela (Costa Rica). El detalle de las condiciones de fabricación es mostrado en Tenorio et al (2015aTenorio et al ( , 2015b y Aragón-Garita et al (2015).…”

“…En Costa Rica, así como en otros países de América Latina, los pellets han ganado popularidad ya que algunas industrias buscan trasladarse de fuentes fósiles a fuentes de carácter renovable en lo que a la producción de calor se refiere; para así alcanzar el carbono neutral (Aragón-Garita, Moya, Varlet, & Tomazello, 2015). En la actualidad, se conocen las adaptaciones tecnológicas al proceso de producción de pellets para muchos cultivos agrícolas tropicales (Aragón-Garita et al, 2015) (Tenorio, Moya, Tomazello, y Valaert, 2015a) y la información sobre la caracterización física, química o energética (Tenorio, Moya, Tomazello, & Valaert, 2015b).…”

“…En la actualidad, se conocen las adaptaciones tecnológicas al proceso de producción de pellets para muchos cultivos agrícolas tropicales (Aragón-Garita et al, 2015) (Tenorio, Moya, Tomazello, y Valaert, 2015a) y la información sobre la caracterización física, química o energética (Tenorio, Moya, Tomazello, & Valaert, 2015b). No obstante, el comportamiento de estos cultivos en algunos equipos como quemadores domésticos de pellet, su eficiencia energética y las emisiones producidas es poco conocida.…”