The effect of heat storage to properties and energy recovery of pyrolysis products from agricultural waste

Abstract

The pyrolysis process is the conversion of a biomass into biofuel but the process requires a high amount of external heat in order to increase the temperature of raw material which affects the production costs and energy efficiency. The effect of heat storage to control a temperature on the shell of pyrolysis reactor for the properties and energy recovery of pyrolysis products were considered in this study. Agricultural waste drop tube pyrolysis reactor that was designed into double layer shell wall to contain ceramic bead for heat storage. The parametric test of this study as temperature (350 oC – 550 oC), and biomass type (corncob, coffee grounds and coffee husk) were investigated. This result showed that, the heating rate of the reactor when starting to the setting temperature of the comparison testing (CT) was lower than that of the heat storage testing (HT). It indicated that the energy input for the reactor in case of HT was lower than that from CT. The yield of bio-oil and bio-char of the HT were lower than that of the CT in the same pyrolytic temperature. When increasing temperature for 350 oC to 550 oC effected to decreasing the yield of bio-char while the maximum yield of bio-oil found in the temperature of 450 oC. The heating value of pyrolysis products were increased in the higher temperature. The bio-fuel products from corncob had the higher heating value (HHV) and the energy recovery higher than that from another biomass.