Production of biocoal from soft and hard wood pellets by torrefaction

In today's world, due to the worries about climate change stemming from increasing green house gas emissions, much attention has been given to the use of lignocellulosic biomasses as renewable raw materials in thermo chemical processes such as combustion, gasification and pyrolysis for energy production. Lignocellulosic masses are usually heterogeneous materials of complex chemical structure. Because of their physical and chemical compositions vary over a wide range depending on source, the applicability of thermo chemical process technologies is a complex issue. In majority of applications, they need taking up some pre-processes before the main process. In this study, it is aimed to convert the pellets prepared from hard and soft wood into a more valued solid fuel by torreaction process. For this reason, two different types of wood, such as oak and pine wood, were subjected to torreaction in a fixed bed system. The effects of parameters such as temperature, processing time and biomass type on product yield and solid product properties were examined. The torreaction was carried out at temperatures of 230, 260, 300 ° C and processing time of 10, 20, 40, 60 minutes. To determine the properties of the solid product obtained at the end of the process and to compare with raw biomass, proximate, elemental, TGA and DTG analyzes were performed. As a result of the study carried out with the aim of converting oak and pine wood into a usable solid fuel by torreaction process, it was determined that the yield of the product was affected mostly by the working temperature and the liquid product yield increased with increasing temperature while the solid product yield decreased. Process was found to be effective at low temperatures. It was determined that solid product yield obtained from oak wood was lower than pine wood. It was determined that the increased process temperature increased the solid carbon content of the solid product and caused a decrease in oxygen content. It was observed that torrefied pellets became more porous as severity of torrefaction increased. When the TGA and DTG curves of crude biomass and torrefied biomasses were examined, it was concluded that torreafaction temperature had an effect on the lignocellulosic structure and a solid product with high lignin content could be obtained with increasing torreaction temperature. It was observed that the lignin content in the solid product was significantly higher in oak wood.