Torrefied pellets, a transportable renewable energy source,
have
a higher energy density than the regular wood pellets (control pellets).
The quality of torrefied pellets is determined mainly by the density,
hardness, and the hygroscopicity or moisture uptake. In this study,
the density and the hardness of torrefied pellets were systematically
examined by using torrefied samples prepared at different conditions
in a press machine. The hygroscopicity of prepared torrefied pellets
was evaluated in a humidity chamber by measuring the moisture uptake
rate of control and torrefied pellets. The results showed that the
density and the hardness of torrefied pellets mainly depended on the
densification die temperature and the weight loss of torrefied samples.
To make strong torrefied pellets of high density and low moisture
uptake from 30 wt % weight loss torrefied samples, a die temperature
of 230 °C or above was needed. Preconditioning torrefied samples
to a moisture content of ∼10% can improve the quality of torrefied
pellets. The moisture uptake of torrefied pellets was more sensitive
to the weight loss of torrefaction and the relative humidity of the
storage environment. The saturated moisture uptake of torrefied pellets
made from 30 wt % weight loss torrefied samples was at least 40% lower
than the control pellets.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.