Analysis of chemical, morphological, energy efficiency, and fuel properties of bamboo torrefaction

Abstract

This study evaluates the outcome of torrefaction as a thermochemical pretreatment to biomass conversion on the properties of Bambusa vulgaris (Bamboo) under nitrogen-inert environment at atmospheric pressure. The dark solid torrefied products were produced by processing for 20, 30 and 40 min under the temperatures of 240, 260, 280 and 300 °C. The optimal torrefaction conditions are obtained at 300 °C for 40 min of residence time. The torrefaction at higher temperature results in severe loss of mass yield about 11.64% to 19.13% over its energy yield loss ranging from 6.88% to 14.81%, while the energy density increases upto 1.18 times. The bulk density decreases marginally to 0.24 g/cm³ under optimum torrefaction conditions. The consistent weight-loss structure enhances the higher heating value by about 18.62% from 19.80 MJ kg⁻¹ to 23.25 MJ/kg tended to that of sub-bituminous coal. Hydrophobicity of torrefied bamboo is observed approximately 56.75% low moisture absorption. Torrefied bamboo shows upgraded proximate and elemental composition in contrast to raw bamboo. Finally, torrefaction benefitted the result more efficiently in combustion reactivity, thermal performance, porosity, and grindability of the bamboo samples through thermogravimetric analysis, differential thermal analysis, and scanning electron microscope analysis respectively in a comparable manner with untreated bamboo.

Keywords:

• Torrefaction
• bamboo
• higher heating value
• morphological changes
• isothermal kinetics

Disclosure statement

No potential conflict of interest was reported by the authors.