Abstract:
It has been estimated that approximately four metric tons of refuse tea is produced daily from the tea
processing industries in Sri Lanka. At present refuse tea is considered as a waste product from tea
processing and, dumping and composting are the common practices of disposal. Manufacturing of biochar
from organic waste is an emerging technology where biochar can be used for soil applications,
environmental remediation and carbon sequestration. Hence, this research aimed to determine optimum
pyrolysis conditions for producing refuse tea biochar. The pyrolysis experiments were done in a small air-tied steel reactor which was kept in a muffle furnace. Initially, refuse tea was pyrolyzed at temperatures
between 300 °C and 500 °C for different residence time ranging from 15 to 60 minutes. The physical and
chemical characteristics of biochar such as moisture content, ash content, carbon content, volatile matter
content, bulk density, pH and electrical conductivity (EC) were analyzed following the biochar quality
standards proposed by International Biochar Initiatives (IBI). Results showed that the yield of biochar
varied with the residence time for a given temperature treatment. The proximate analysis of produced
biochar showed the fixed carbon content varied from 26%-58%, consequently, the volatile material
content was very high for optimum conditions. This research revealed that refuse tea can be effectively
converted to biochar between 450 to 500 °C temperatures subjected to residence time of 45 to 60
minutes.
