Biochar Pelletisation and Physio-mechanical Properties of Pellets

Abstract

Application of powder biochar to soil is a major concern due to losses as high as 30 % at various stages as well as safety of applicator from dust pollution. A drum-type machine capable of using easily available binder materials as maize flour, rice starch, carboxymethyl cellulose sodium (CMC) and commercial starch with thermal treatment were evaluated. Results showed that on average commercial starch 66.4 % and rice starch binder yielded 62.77 % pellets in the desirable size range. The pellets were non-hygroscopic in nature, biochar field capacity was 93 % (d.b.), and pellets values varied from 57.8 % to 78 % (d.b.) depending on type of binder. Pellet using rice starch binder had highest bulk density of 390.2 kg.m-3. Pellet using rice starch binder also had 99.12 % and 97 % attrition resistance as compared to CMC (98.02 %) and inter-granular (91.78 %) in presence of similar size harder foreign material. Commercial and rice starch binder added pellets also showed promising value of crushing strength of 2.5 kg.cm-2 and 2.4 kg.cm-2, respectively.