Assessment of bio-combustibles production via slow pyrolysis of wine industry residues

With the aim of evaluating the potential production of high energy solid and liquid bio-fuels, a laboratory scale fixed bed reactor (FBR) derived from the standard Gray-King (GK) assay test on coal was used to carry out fixed bed pyrolysis experiments on wine industry by-products. The present study provides results on the pyrolysis of grape marc, residual from wine-making process, consisting of 50% by weight of grape seeds and 50% by weight of grape skins, at temperature between 150 and 500 °C, holding time of 30 minutes. Pyrolysis mass yields of solid (char) and liquid (tar) products and their corresponding energy properties, as a function of reaction temperature, are reported and discussed. Results indicate that char and tar mass yields varied linearly with temperature, Char yield on a dry basis (d.b.) decreased from 97% at 150 °C to approximately 38% at 500 °C. Tar yield increased with temperature from 1% at 150 °C to approximately 34% at 500 °C. The energy densification ratio (EDR) of solid residues increased with temperature up to a value of 1.43 at 500 °C. Both grape marc bio-char and tar showed energy properties compatible with their use as solid and liquid biofuel, respectively.