WET torrefaction of miscanthus - characterization of hydrochars in view of handling, storage and combustion properties

Abstract

Properties of miscanthus hydrochars obtained through wet torrefaction were studied. The process was carried out in three different temperatures - 180, 200 and 220 °C and with four different ratios of water to biomass - 3:1, 6:1, 12:1 and 16:1. The obtained solid products were characterized with respect to their fuel properties. The best results were obtained for the temperature of 220 °C and showed a noticeable improvement in fuel properties - especially grindability and lowered ash content. The influence of water to biomass ratio was not so explicit and while high ratio showed an improvement in all mentioned properties, low ratio allowed to achieve the highest energy yield. The results obtained for miscanthus wet torrefaction and the literature data for dry torrefaction were compared.