Characterization of Mexican waste biomass relative to energy generation

Abstract

In this work, physical and chemical analyses of 28 sawdust samples (tropical woods, pine woods, and oak woods) derived from the primary process of wood transformation and 4 samples of citrus residues were performed, as an option to make densified biofuels. The study included the determination of initial moisture, particle size distribution, proximate analysis, ultimate analysis, calculation of the calorific value, and ash microanalysis. The initial moisture content of the biomass samples ranged from 6.04 to 75.21%. The biomass granulometry results indicate that the highest proportion corresponds to the 1.0-mm (33.10%) (Fraction retained in mesh 0.5 mm). Other results obtained indicate the following ranges: ash content (0.27 to 6.27%), volatile matter (78.90 to 90.50%), fixed carbon (9.10 to 20.44%), carbon (49.13 to 50.78%), oxygen (42.62 to 44.49%), and hydrogen (5.24 to 6.55%). The calculated calorific value ranged from 17.65 MJ/kg to 20.72 MJ/kg. The chemical elements with the highest concentration in the biomass samples were K and Ca, followed in some cases by Al and P. The biomass with the greatest possibilities for making densified biofuels of better quality is the group of pine woods because they have low mineral content, low nitrogen content, and high calorific value.

On the basic chemical composition of selected biomass types from four regions of Mexico, for bioenergetic purposes

“…In the case of Manilkara zapota and Swietenia macrophylla, the values found here are lower than those previously reported (Rutiaga-Quiñones 2001). The total extractives content for the oak samples was 8.2%, which generally matched other reports (Rutiaga-Quiñones et al 2000;Rutiaga-Quiñones 2001;Herrera-Fernández et al 2017;Ruíz-Aquino et al 2020). The extractives content together with the ash content are two important parameters that affect the calorific value of wood, and therefore its use as fuel (Demirbaş and Demirbaş 2004).…”

“…This result indicates the presence of components of medium polarity; polyphenolic substances have been detected in these types of extracts in conifers and hardwoods (Kim et al 2008;Rocha-Guzmán et al 2009;Rosales-Castro et al 2009Argueta-Solís et al 2018). A high concentration of extractives in acetone and methanol has been observed in previous studies with tropical woods (Rutiaga-Quiñones 2001), oak woods (Rutiaga-Quiñones et al 2000;Rutiaga-Quiñones 2001;Herrera-Fernández et al 2017;Ruíz-Aquino et al 2020), and branches of some tree species (Räisänen and Athanassiadis 2013;Cárdenas-Gutiérrez et al 2018). Essential oils in lemon peel have appreciable antifungal and antibacterial activity (Qadir et al 2018).…”

“…The ash content in tropical woods is usually higher than in pine woods, and the results found here generally coincide with data for tropical woods (Fengel and Wegener 1983;Rodríguez-Jiménez et al 2019). The amount of inorganic substances in the oak samples are lower than the results reported for different oak species (Rutiaga-Quiñones et al 2000, 2001Herrera-Fernández et al 2017;Ruíz-Aquino et al 2020). In the case of branches, the results obtained here are within the range found in branches of different tree species (0.08% in Quercus rugosa, 1.3% in Q. candicans) (Cárdenas-Gutiérrez et al 2018).…”

“…Elemental analysis of these same biomass samples studied here was recently reported, and sulfur was not found in the samples. In this study it is concluded that the biomass samples have low nitrogen content, and low environmental impact is speculated when using this biomass to generate densified solid biofuels (Rutiaga-Quiñones et al 2020). In this study, Cl was not detected, which is scarce in wood (Obernberger et al 2006) and its concentration in biomass ranges from 0.01 to 2.3% (Khan et al 2009).…”

“…On the other hand, the chemical elements detected in these same biomass samples are also disclosed: Al (all samples), As (samples 1, 2, and 5), B, Ba, and Ca (all samples), Cr (samples 1 to 8, 10 to 13), Cu, Fe, K, Li, Mg, and Mn (all samples), Mo (samples 1 to 5, 12 and 13), Na, Ni (all samples), Pb (samples 4 to 9, 11 to 13), Si (all samples except sample 9), Sr (all samples), V (simple 3, 7, 8, 11, 12), and Zn (all samples, except sample 9). A high concentration of K is found (Rutiaga-Quiñones et al 2020), which would limit the use of this biomass to produce densified biofuels due to the problems of melting point, deposit formation, aerosols and emission of fine particles (Obernberger and Thek 2004); Van Lith et al 2006), however, high K content in ash can be advantageous for use as a fertilizer (Camps and Marcos 2008).…”