Torrefied banana tree fiber pellets having embedded urea for agricultural use

Abstract

Banana tree fibers (BF) torrefied in the absence of air and residence time of 60 min at temperatures between 180 and 600 ∘C were evaluated for its agglutination power when converted to pellets. The agglutination power was estimated as aqueous media residence time, being the most resistant pellets the ones obtained from 180 to 300 ∘C. The agglutination power was also evaluated for pellets samples containing from 10 to 90% (w/w) urea. BF torrefied with or without urea have been assessed by thermogravimetry (TG) and differential thermogravimetry (DTG), indicating increased stability on torrefaction temperature and the growth of urea. TG/DTG curves were also used to assess the kinetics of release of urea with time in aqueous by analyzing the residue of biochar BF. Kinetics of release was investigated using a semi-empirical model, known as the power law or the Korsmeyer–Peppas model, Ct/ Cinf= ktn. The value found for n lies between 0.5 and 1.0 indicating that urea release mechanism tends to non-Fickian diffusion or anomalous transport. FTIR spectra showed the weak interaction between urea and biochar.