Torrefaction of Agricultural and Wood Waste: Comparative Analysis of Selected Fuel Characteristics

Abstract

Abundant biomass is a potential energy source. However, it possesses several challenges when considered for energy applications. Torrefaction, a thermal pretreatment process can improve the properties of biomass as energy source. This study focused on comparing effect of torrefaction operating parameters on agricultural and wood wastes properties as fuel. The physiochemical properties, composition, moisture-biomass interaction and ash melting behavior were determined. The result show that higher torrefaction temperature and longer residence time increased lignin content, reduced hemicellulose and cellulose content. The moisture uptake of torrefied biomass was reduced in the range 2.47–9.94% compared with raw biomass depending on torrefaction temperature that indicate torrefied biomass was more hydrophobic than raw biomass. The moisture adsorption isotherm curve shows type II isotherm based on the Brunauer-Emmett-Teller’s (BET) classification and was best described by the Oswin model. In addition, torrefaction treatment showed significant influence on the melting behavior of the biomass ash. Especially for agricultural wastes, the fouling tendency shifted from serious range to low range with torrefaction treatment. Torrefaction showed promise for improving fuel characteristics of the studied biomass.

Influence of Torrefaction Temperature and Climatic Chamber Operation Time on Hydrophobic Properties of Agri-Food Biomass Investigated Using the EMC Method

“…The highest content of the ash was observed for butternut-squash peels and ranged from 8 to 20%. Similar changes of ash content in waste biomass after the torrefaction process were observed for other organic materials [37,38]. During the torrefaction process, a significant amount of volatile matter devolatilized from the waste biomass.…”

The Evaluation of Torrefaction Efficiency for Lignocellulosic Materials Combined with Mixed Solid Wastes

“…General definition says that biomass is an organic material obtained from plants growing through the process of photosynthesis [8]. Biomass is considered a carbon neutral source that is almost always available; in addition, it is available in large quantities [10]. It is believed that biomass energy has the potential for energy or power generation [11], despite the fact that its direct application is not always feasible due to several discovered issues [12].…”

“…For example, torrefaction of lignocellulosic biomass such as miscanthus [18], pine wood [19], or sawdust [20] has already been extensively taken into consideration, together with non-lignocellulosic biomass, such as sewage sludge [21] or algae [22]. Doddapaneni et al [10] studied the properties of torrefied sludge from the pulp industry. The torrefaction process was carried out at 250, 275, and 300 • C for 30 or 60 min, respectively.…”

Transformación de las hojas de caña de azúcar en biocarbón para su uso como combustible y agente reductor en procesos de reducción directa de minerales de hierro

“…Chen et al, (2015) sostienen que para biomasas torrefactadas el ratio O/C se encuentra en el rango de 0.1 -0.7 mientras que el ratio H/C está en el rango de 0.7 -1.6 por lo tanto los resultados obtenidos corresponden a valores esperados.Con relación al poder calorífico superior de las hojas tostadas, medido en base seca, este fue de 28.59 MJ/kg, evidenciando una significativa mejora respecto del valor que tenía el residuo antes de los pretratamientos aplicados. Este resultado es ligeramente superior a valores reportados en la literatura para otras biomasas torrefactadas los que se encuentran en el rango de 20 a 24 Mg/kg (Chen et al, 2015;Tumuluru et al, 2021;Cahyanti et al, 2021).…”