Potentials of Torrefied Pine Sawdust as a Renewable Source of Fuel for Pyro-Gasification: Nigerian and South African Perspective

Abstract

The impacts of fossil energy on the climate and environment emphasize the need for alternative energy resources. The use of waste wood is one such method to potentially reduce fossil-based energy dependence. However, raw biomass fuel properties are generally poor and unpredictable, thus requiring pretreatment to maximize their energy potentials for an efficient conversion to syngas via pyro-gasification. Two species of pine sawdust (PSD) wastes generated in abundance from large-scale timber industries in Nigeria and South Africa were investigated for improvements in their fuel properties after torrefaction. Samples were torrefied under optimum conditions of 300 °C and 45 min. Different analytical procedures show that the higher heating value (HHV), enhancement factor, energy density, and solid yield of the Nigerian PSD exceeded those of their South African counterpart by 2.38, 5.37, 3.49, and 11.15%, respectively. The HHV of the torrefied fuels increased by 57.29 and 37.9% for the Nigerian and South African PSDs, respectively, when compared to the raw fuels. Also investigated were improvements in their H/C and O/C ratios and thermal degradation at varied heating rates.

Calorific Characteristics of Larch (Larix decidua) and Oak (Quercus robur) Pellets Realized from Native and Torrefied Sawdust

“…Next, the crucibles were introduced into the calcination furnace for a period of about 30 min at a temperature of 650 • C. After that, in order to determine if the calcination process was finished, the crucibles were checked to see if they had a light greyish ash color and that there was no longer any spark and carbon. When the ash content was determined, the sawdust samples were completely dried out in an oven and the crucible mass was also kept into consideration, as seen in Equation ( 8) [19][20][21]. The black ash and the calcined ash masses were determined as proportions with the following relationships using Equations ( 4) and ( 5):…”

“…During the torrefaction process, instead of an inert nitrogen atmosphere, the resulting gases were used for the heat treatment process. The mass loss was 34% and the calorific value increased by 40% when the torrefaction temperature was 300 • C. Okoro et al [19] studied the role of wooden biomass obtained from two species of pine versus fossil resources, especially when they were thermally treated to obtain syngas via pyro-gasification. The optimum thermal treatment was at 300 • C for 45 min.…”

Formulating Eco-Friendly Foamed Mortar by Incorporating Sawdust Ash as a Partial Cement Replacement

“…The characteristics of the produced sawdust are primarily determined by the types of wood and the diameters of the saw teeth. The particles can be categorized into three groups according to their size: oversized particles (OS) for particles larger than 710 µm, coarse particle size (CPS) for particles between 24 and 60 mesh (350-710 µm), and fine particle size (FPS) for particles between 60 and 80 mesh (177-350 µm) [35][36][37]. The present investigation employed sawdust samples characterized by the following particle size and grain composition: 80.1% of the samples passed a diameter of 45 µm, the median particle size was 19.5 µm, and the maximum particle size was 75.5 µm.…”