The Characteristic of Pelleted Broiler Litter Biochar Derived from Pilot Scale Pyrolysis Reactor and 200-Liter-Oil-Drum Kiln

Abstract

Biochar has been widely accepted as a soil fertilizer and soil conditioner. Pelleted broiler litter (PBL) can be converted to useful biochar which is produced by pyrolysis. In this study, PBL biochar was tested in two type of pyrolysis reactors including a pilot scale reactor (P kiln) and a 200-liter-oil- drum kiln (O kiln), respectively. PBL used in this study was selected from the Siriwan Co. Ltd.’ s network broiler chicken (Gallus gallus domesticus) farm in Saraburi province, Thailand and controlled its parameters such as domesticated age, material litter, and production cycle. Slow pyrolysis method was conducted with the highest temperature of 500 ºC for 5 hours. The results showed that biochar derived from O kiln (PBLBO) had higher Brunauer-Emmett-Teller (BET) surface area, total pore volume than that of biochar from P kiln (PBLBP) while average pore diameter was not different. Not only PBLBO was enriched with phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) but also contained more organic matter (OM) and cation exchange capacity (CEC). However, PBLBP had higher nitrogen and moisture content. Besides, heavy metals; cadmium (Cd), mercury (Hg), and lead (Pb) were not detected in both biochars. In sum, PBLBO can be used as effective soil fertilizer and soil conditioner and the biochar producing procedure has proved to be simpliest way and lowest cost for socio-economic, self-sustainable, and low carbon agriculture.

Keywords: Biochar, cation exchange capacity, pelleted broiler litter, slow pyrolysis, surface area.