Briquette Production from Teak and Neem Twigs Biochar with Selective Binding Materials

Abstract

Biochar is the solid residual material obtained after carbonisation or slow pyrolysis of biomass in a controlled condition, typically at a temperature range of 450(C to 510(C in the absence of oxygen to remove water and other volatile constituents from the parent biomass in a closed vessel. The Agricultural Engineering College and Research Institute (AEC & RI), Trichy campus premises has more than 1500 teak trees and neem trees. Pruned twigs of these trees are collected and converted into biochar briquettes through pyrolysis and briquetting technology. The fixed carbon content was found to be 11.5% for teak twigs and 12.5% for neem twigs biomass. Pyrolysis of raw materials is carried out at a temperature range from 450(C to 510(C in a 100 kg capacity pyrolysis reactor. An average biochar yield of 25.7 % and 31.6 % were obtained for teak and neem twigs respectively. The fixed carbon content of 65 % and 68.20% is obtained for the biochar produced from teak and neem twigs respectively. Cow dung and rice gruel starch were used as binders for making biochar briquettes. Cow dung and rice gruel starch were mixed with the biochar with different proportions at 30%, 40%, 50% and 60%. Biochar briquettes were analysed for their thermal and physical properties. The biochar to cow dung ratio of 1:0.3 for both teak and neem twigs gives stable briquettes of 13 cm in length. The fixed carbon content of teak twig biochar briquette and neem twig biochar briquette is 71.96% and 73.47% respectively by using cow dung as binder whereas it was 71.30% and 70.60% respectively with rice gruel starch as binding material.