Depleting fossil resources require changes in the current energy mix towards renewable sources. Hence, upgrading processes such as torrefaction and hydrothermal carbonization (HTC) play an important role to in-crease biomass energy density and to convert biomass into a homogeneous coal product. This study focuses on the influence of temperature, residence time and feed concentration on the energy and ash yield of the process. Experiments have been carried out in a temperature and pressure controlled batch reactor using beech wood and rice shells to determine the influence of temperature, residence time and feedstock concentration on the solid bio coal. Experiments have shown that higher temperature increases carbon content and therefore the heating value of the coal. However, due to increasing mass loss with higher temperature the energy yield of the coal is affected negatively. In-creasing residence time leads to increasing heating value and increasing energy yield. Feedstock concentration has no effect on coal properties but increases mass yield and hence the energy yield of the process. Ash yield has been found to increase with increasing concentration due to a decreased mass loss.     «

Depleting fossil resources require changes in the current energy mix towards renewable sources. Hence, upgrading processes such as torrefaction and hydrothermal carbonization (HTC) play an important role to in-crease biomass energy density and to convert biomass into a homogeneous coal product. This study focuses on the influence of temperature, residence time and feed concentration on the energy and ash yield of the process. Experiments have been carried out in a temperature and pressure contr...     »