Characterization of pyrolysis products of oil palm empty fruit bunch

Abstract

Oil Palm Empty Fruit Bunch (EFB) is a waste product in the palm oil industry. Currently, EFB has not been optimally utilized because of its low calorific value. The purpose of this research is to analyze the potential of EFB conversion into solid (biochar), liquid (bio-oil), and synthesis gas (syngas). The experiment was carried out in the batch process at atmospheric pressure and temperature of 600°C (heating rate of 60°C/min). Biochar was cooled and analyzed its proximate, ultimate, and calorific value. The volatile matter of pyrolysis product was passed through a condenser so that bio-oil and water were condensed and separated based on density difference. Bio-oil was analyzed by fractionation based on its boiling point. The syngas composition was analyzed by using GC. The proximate analysis results of biochar, such as inherent moisture, ash, volatile matter, and fixed carbon, are 6.24%, 26.30%, 14.14%, and 53.32%. Meanwhile, the ultimate analysis of biochar showing the composition of C, H, O, S, and N is 55.76%, 2.92%, 12.5%, 0.34%, and 2.18%, respectively. The biochar calorific value is 4,966 kcal/kg adb, showing a similar characteristic to sub-bituminous coal, suggesting that biochar can be utilized as a coal substitution to reduce the CO2 emission on Electric Steam Power Plant. Bio-oil fractionation showed that the initial boiling point (IBP) temperature started at 67.8°C, and the final boiling point (FBP) temperature at 666.8°C. The largest fraction was kerosene (36.2%) and diesel, indicating that bio-oil can be processed further into fuel oil. Syngas analysis results showed that the main gas compositions are CH4 (13 – 17% vol), H2 (28 – 33% vol), CO (17 – 26% vol), and CO2 gases (16 – 31% vol) with a calorific value of 2,600 – 3,300 Kcal/Nm3. Some alternatives to syngas utilization are as a source of pyrolysis energy and for chemicals syntheses such as methanol and DME.