Effect of Atmosphere on Torrefaction of Oil Palm Wastes

Abstract

Torrefaction is a low temperature treatment for lignocellulosic biomass at lower temperatures between 473 K and 573 K under an inert atmosphere, which has been found to be effective not only for improving the quality of lignocellulosic solid fuels, such as their energy density and shelf life, but also to make them useful as a feedstock for further decomposition such as gasification and liquefaction. Although more than ten papers on this subject have been published in the last several years, in all of these studies, the atmosphere has been inert (nitrogen). When we try to utilize waste thermal sources, such as flue gas from boilers for torrefaction, the gas contains some components other than nitrogen such as oxygen, carbon dioxide and water vapor. The most serious problem is thought to be the existence of oxygen in the gas. In this study, torrefaction of Malaysian oil palm wastes was carried out in a fixed bed tubular reactor under oxygen/nitrogen flow at a temperature range of 494 to 573 K, in order to clarify the effect of oxygen on torrefaction of lignocellulose. The effects of torrefaction conditions such as atmosphere, temperature and time, on the torrefaction behavior were investigated. The lignocellulosic biomass wastes utilized were mesocarp fiber and kernel shell of oil palm, which are typical agricultural wastes in Malaysia.

Torrefaction of Oil Palm Frond Petiole: Effect of Particle Sizes, Sections and Batches

“…The higher heating values (HHV) of the raw and torrefied OPF petiole were determined by bomb calorimetry (Model: IKA C2000, USA). The mass and energy yields [44], as well as higher heating value (HHV) yield [45] were determined from equations 1, 2 and 3, respectively: x 100% (3)…”

The Valorization of Rice Waste via Torrefaction Method

“…Although Eseltine et al [9], Medic et al [10], Uemura et al [11], Van der Stelt et al [12], Deng et al [13], and Bergman et al [14] proposed that the energy intensification and mass loss of biomass are proportional to the heating temperature of 200-300 °C but they are all tinged with uncertainty as the temperature range is too wide and does not specify a precise effect of different torrefaction temperature towards particular biomass. Hence, the objective of this study is to investigate effect of torrefaction on the physical characteristics of the rice waste at different temperature.…”