Assessment of Pellets from Three Forest Species: From Raw Material to End Use

Abstract

This study aimed to evaluate and compare the relationship between chemical properties, energy efficiency, and emissions of wood and pellets from madroño Arbutus xalapensis Kunth, tázcate Juniperus deppeana Steud, and encino colorado Quercus sideroxyla Humb. & Bonpl. in two gasifiers (top-lit-up-draft (T-LUD) and electricity generation wood camp stove (EGWCS)) in order to determine the reduction of footprint carbon. In accordance with conventional methodologies, we determined the extracts and chemical components (lignin, cellulose, holocellulose), and the immediate analyses were carried out (volatile materials, fixed carbon, ash content and microanalysis of said ash), as well as the evaluation of emission factors (total suspended particulate matter (PM2.5), CO, CO2, CH4, black carbon (BC), elemental carbon (EC), and organic carbon (OC)). The results were statistically analyzed to compare each variable among species and gasifiers. The raw material analyzed showed how the pH ranged from 5.01 to 5.57, and the ash content ranged between 0.39 and 0.53%. The content values of Cu, Zn, Fe, Mg, and Ca ranged from 0.08 to 0.22, 0.18 to 0.19, 0.38 to 0.84, 1.75 to 1.90, and 3.62 to 3.74 mg kg−1, respectively. The extractive ranges from cyclohexane were 2.48–4.79%, acetone 2.42–4.08%, methanol 3.17–7.99%, and hot water 2.12–4.83%. The range of lignin was 18.08–28.60%. The cellulose content ranged from 43.30 to 53.90%, and holocellulose from 53.50 to 64.02%. The volatile material range was 81.2–87.42%, while fixed carbon was 11.30–17.48%; the higher heating value (HHV) of raw material and pellets presented the ranges 17.68–20.21 and 19.72–21.81 MJ kg−1, respectively. Thermal efficiency showed statistically significant differences (p < 0.05) between pellets and gasifiers, with an average of 31% Tier 3 in ISO (International Organization for Standardization) for the T-LUD and 14% (ISO Tier 1) for EGWCS, with Arbutus xalapensis being the species with the highest energy yield. The use of improved combustion devices, as well as that of selected raw material species, can reduce the impact of global warming by up to 33% on a cooking task compared to the three-stone burner.

Pellets from Lignocellulosic Material Obtained from Pruning Guava Trees: Characterization, Energy Performance and Emissions

“…Finally, the results of the physical and energetic characterization of the pellets indicate, in general, a good potential for their use as solid densified biofuels. Quiñones-Reveles et al [77] and in this study. They include 14 species of pellets (with and without bark) and 2 types of firewood (pine and oak with and without bark).…”

“…OM = 1.9*OC. [38], Quiñones-Reveles et al [77] and in this study. They include 14 species of pellets (with and without bark) and 2 types of firewood (pine and oak with and without bark).…”

“…Johnson et al [38] report emission factors in field water boiling tests of 2800 ± 2667 mgCH 4 /kg of oak firewood for an open fire and 933 ± 933 mgCH 4 /kg of oak firewood for an improved stove (Patsari), while in our study there are emission factors of 426 ± 211 mgCH 4 /kg for guava pellets and 857 ± 324 mgCH 4 /kg of firewood for the open fire evaluated in the laboratory. Quiñones-Reveles et al [77], in evaluations of forest residue pellets, reported 114 ± 10 mgCH 4 /kg of Quercus Sideroxyla pellets with bark and 91 ± 10 mgCH 4 /kg of Juniperus deppeana pellets without bark. These values represent the range of 13 evaluated samples.…”

“…Figure 4 shows a correlation between PM 2.5 and OC in different types of biomass. With the results of this study and the literature, the correlation includes 14 species of pellets with bark and without bark combusted in a gasifier [77] and two types of firewood in improved stoves and open fires [38]. There is a correlation of R 2 = 0.97 (p < 0.05) for the 15 analyzed biomass species and a correlation of R 2 = 0.95 (p < 0.05) considering only the types of biomass evaluated in this study.…”

“…Correlation between 2.5 microns particulate matter (PM 2.5 ) and organic carbon (OC) in different types of biomass. Note: The 15 types of biomass are detailed in the studies by Johnson et al [38],Quiñones-Reveles et al[77] and in this study. They include 14 species of pellets (with and without bark) and 2 types of firewood (pine and oak with and without bark).…”