Thermo-chemical behaviour of maize cob and bean straw briquettes

Abstract

Pre-treatment is essential to reduce logistic costs of agricultural residues. This work examined the interactions between pre-treatment conditions and thermo-chemical behaviour on product yields and properties. The effect of pyrolysis operating and briquetting conditions (i.e., temperature, pressure and bean straw-maize cob blend) on yields and properties of pyrolysis products from maize cob, bean straw and blended briquettes were investigated. It was found that briquetting conditions, heating rate and carrier gas flow rate had negligible effects on yields and properties of pyrolysis products. Temperature was the dominant factor that effected the yield and properties of the pyrolysis products. Increasing pyrolysis temperature increased the gas and reduced the char yield. Up to ∼ 45 % of the energy content of the raw material can be stored in smokeless char like material that can be easily transported and used for energy production e.g., household cooking. Pyrolysis of agricultural residues has the potential to reduce harmful particulate emissions whereas the high-water content bio-oil can be used as a binder in briquette production to reduce the pressure and temperature applied.

Keywords

• Briquette
• Pyrolysis
• Agricultural residues
• Biomass densification
• Energy generation