Production of empty palm bunch biochar using microwave-assisted pyrolysis at low temperature

Abstract

In this study, the production of palm empty fruit bunch biochar using microwave-assisted pyrolysis at low temperature was investigated. The empty palm bunch composition was analyzed by proximate analysis. The parameters relating to the production, i.e. type of microwave absorber, microwave power, heating time and ratio of palm empty fruit bunch to initial amount of microwave absorber, were studied to determine the optimum condition. The results found that the amount of fixed carbon in the empty palm bunch was approximately 10%. The optimum condition was microwave power 300-watt, heating 450 sec and ratio of empty palm bunch to concentrated sulfuric acid (the most suitable microwave absorber) 1:2.5. At this condition, the production yield was 50.78%. The iodine number of the biochar was 318.5 mg/g. The BET surface area of the biochar was 101.54 m2/g. The total pore volumes and pore diameter of the biochar were 0.144 cm3/g and 4.29 nm. respectively. The elemental analysis of biochar at the optimum condition was mainly composed of carbon and oxygen. The ratio of O/C is 0.73 indicating that the biochar is quite stable product against oxidation.