Effects of Pyrolysis on Characterization of Rice Hull Charcoal as Growing Media for Plant

Abstract

Utilizing rice hulls as growing media is commonly practiced. However, it had low valued of Water Holding Capacity (WHC) and Cation Exchange Capacity (CEC) which caused rice hulls is considered as a low quality as growing media for plants. Based on previous study, pyrolysis could alter physical and chemical properties of rice hulls to form char. The aim of this study was to evaluate pyrolysis process by compare physical and chemical properties. This research was conducted at two peak temperatures (450 oC and 550 oC) with four different incubation periods (15, 30, 45, and 60 minutes). Particle size distribution, porosity, WHC, air pores, pH, and CEC values were then analyzed as the physical and chemical properties. Char resulted from pyrolysis at 450 oC with incubation period of 15 minutes produced the best physical and chemical properties among others pyrolysis treatment with dominant particle size with diameter 0.5-1 mm was 61.63 %; porosity 88.09 %; WHC 36.76 %; pH 8.57; and CEC 14.7 meq/ 100 g. It could be concluded from this experiment that pyrolysis was more effective than composting in increasing rice hulls quality as growing media for plants.