Pollution Research Paper

CO-PYROLYSIS OF TREE BRANCH AND PLASTIC TO INCREASECALORIFIC VALUE OF CHAR PRODUCT

WELLY HERUMURTI, EKA KRISTALIA KURYANI, IDAA WARMADEWANTHI, YULINAH TRIHADININGRUM ELLINA S. PANDEBESIE

Abstract

Organic waste such as tree branch is biomass that could be converted to char, oil, and gasesthrough pyrolysis process. In application, biomass product was needed to be upgraded due to its high oxygen, which led to low calorific value, corrosion problem, and instability. Co-pyrolysis technique involved two or more materials as feedstocks in burning offered effectiveness and simplicity to produce high-grade pyrolysis product. This research used slow pyrolysis by batch system at temperature 500°C for 60 minutes. Two variables used were pyrolysis feedstock; 3 kinds of branches were angsana (Pterocarpus indicus), trembesi (Samaneasaman), and waru (Hibiscus tiliaceus) obtained from Bratang Composting House, Surabaya; and mixed of branch and HDPE plastic bag. The variation waste mixture of branch and HDPE plastic was 0:100; 25:75; 50:50 and 0:100, and mass of feedstock was 100 gram. Measured parameters were char composition product, char proximate, and char calorific value. This research showed that co-pyrolysis could significantly improve the quantity and quality of pyrolysis char without the presence of any catalysts or solvents and free hydrogen pressure. The more addition of plastic in biomass pyrolysis resulted in higher calorific value of char product. Calorific value of char from branch feedstock pyrolysis was in range of 6,600 – 7,500 Kcal/Kg, while calorific value of char from co-pyrolysis branch and HDPE plastic was 8,300-11,000 Kcal/Kg. The optimum rise of calorific value was obtained from angsana – HDPE plastic co-pyrolysis by ratio 25:75 which was 62.92%, or rose from 6,606 Kcal/Kg into 10,762 Kcal/Kg.