PRODUCTION AND CHARACTERIZATION OF TOBACCO STALK BIOCHAR

Abstract

Pyrolysis temperature and time are known to have profound influence on biochar yield. The optimum parameters of pyrolysis for preparation of biochar from the tobacco stalk biomass are not known. An attempt has therefore been made to find out the optimum pyrolysis process parameters for preparation of biochar from tobacco stalks. The representative tobacco stalk biomass was subjected to thermo-chemical conversion at different temperatures (350 – 5000C) and holding time (60-90 min). Tobacco stalk biochar yield decreased with an increase in temperature and holding time. System operating conditions of 5000C temperature and 90 min holding time were optimum to ensure the complete charring of the biomass and maximum biochar yield. The biochar yield at optimized pyrolysis conditions was around 40% and had 74.9 % fixed carbon, 17.5% ash and remaining 7.6% as volatile matter. Total C and N content of the tobacco stalk biochar was 79 and 1.23%, respectively. While, the total C, N, P, K, Ca, Mg and micronutrient contents were higher in tobacco stalk biochar than in raw biomass. The amount of C conserved in the biochar was 70%. The recovery of total N was the lowest at 55%, while that of other major nutrients remained more or less same at about 80%. Our results indicate the optimum conditions for better biochar recovery from tobacco stalks along with nutrients.