Development and performance evaluation of batch type biomass pyrolyser for agricultural residue

Cotton stalks and other agricultural crop residues are available in plenty and are very potential as an energy source in Saurashtra region. These residues are sometimes, burnt in the field itself which creates an adverse condition to soil health. The objective of this research study was to develop a pyrolyser, methodology, to identify the physical-chemical-thermal properties and elemental analysis of bio-char. A small capacity (5 kg/batch) biomass pyrolyser was designed and developed for making bio-char from the shredded cotton stalk as feed stalk. Pyrolysis at various experimental temperatures 200, 300, 400 and 500 °C and residence time 60, 120, 180 and 240 min carried out for optimal parameter estimation. The quality of bio-char obtained at 500 °C temperature and 240 min is best out of the all experimental parameters. The calorific value of bio-char measured 33.89 MJ/kg and contents of nitrogen 1.56%, carbon 79.30% with C/N ratio 50.83. Conversion of agricultural residues into bio-char, bio-oil and pyro-gas will be a good option to be used as fuel and a safe sustainable soil amendment of bio-char to improve fertility.