Construction and Testing of Continuous Feed Biomass Thermosyphon Torrefaction Reactor

Abstract

Because of different heat mechanism, the temperature distribution inside a reactor has its own characteristic. This is the limitation to increase the capacity of the reactor. This idea led to modify fixed-bed reactor that has a limitation on non-uniform temperature distribution inside a reactor with increasing heat transfer area by setting thermosyphon tube since fixed-bed reactor has another limitation in capacity and heat loss. Therefore, modifying fixed-bed reactor to operate as semi-batch can fix the limitation and improve thermal efficiency of a reactor as well. In order to study the performance of the reactor for torrefaction process, analyzing the fuel properties of each torrefied biomass batch is necessary. The controlled variables of this research are the temperature of heating chamber, which are 350, 400 and 400°C with an allotted torrefaction time of 35 minutes per batch that is close to research condition of thermosyphon reactor fixed-bed type. Fuel properties analyzed in this research are high heating value (HHV), bulk density, and energy density. This research also recorded the temperature inside the reactor to determine the temperature distribution when operated as a semi-batch reactor. From the results gathered, it was discovered that when the operating reactor reached a steady behavior, the torrefaction process increased to a high level. As seen in energy density ratio, it reached a high level because of the increase of HHV ratio, that is 1.182 - 1.412 for 350 - 450°C. The bulk density ratio is also very low, and the value is close to a herbaceous biomass type that is usually seen in woody samples. These factors cause such energy density ratio in high levels and intensity of such process inside the reactor.