Rheology of acid suspensions containing cassava bagasse: Effect of biomass loading, acid content and temperature

Evaluation of the acid pretreatment of agroindustrial waste assisted by high-intensity ultrasound for further bioethanol production

“…Physical properties of the medium are supposed to affect the cavitation degree. In this sense, acoustic intensity were correlated with experimental values of density ( ), specific heat (c p ), thermal diffusivity ( ), thermal conductivity ( ) reported by Polachini et al (2019b) and apparent viscosity observed by Polachini et al (2019a) at fixed shear rate of 10 s -1 ( 1 10 , s app ) at a temperature of 25 ºC. Thus, all of the physical properties showed to be highly correlated with the acoustic intensity (p value ) as showed the high figures of the (Table 5.4.3).…”

“…A significant linear and quadratic effect (p value <0.05) by the solids concentration on the heating rate was observed. The increase in the solids content resulted lower heating rates, probably due to the higher viscosity of concentrated suspensions in comparison to dilute ones (Polachini et al, 2019a). Consequently, higher acoustic intensity was observed for the more diluted suspensions at the higher amplitude of nominal input power in the closer position to the tip ( Figure 5.4.4).…”

“…As it is known that acoustic properties are dependent on the physical properties of the medium, it was evaluate the correlation between acoustic intensity and physical properties of the acid suspensions containing cassava bagasse. Among the physical properties, there are apparent viscosity (Polachini et al, 2019a), density, thermal conductivity and thermal diffusivity (Polachini et al, 2019b). The agreement between acoustic intensity and a given physical property was adressed by a Pearson correlation coefficient r and a probiliy value, p value , considered significant at 95% of confidence.…”

Ultrasound-assisted acid hydrolysis of cassava (Manihot esculenta) bagasse: Kinetics, acoustic field and structural effects

“…), determined in triplicate in a vacuum oven at 60 °C until constant weight (about 24 h). The chemical composition of the dried matter was characterized in a previous study [20] .…”

“…This biomass concentration was established because it was the maximum concentration that allowed an adequate mixing and coupling between the sample-sonotrode during the ultrasound-assisted process. Above this concentration, the suspensions assume non-Newtonian behavior and deviations from linearity should be also considered [20] . After that, the suspensions (150 g each one) were subjected to conventional agitation for 5 h at 50 °C in order to determine the amounts of total and reducing sugar in the cassava bagasse that were directly soluble (experiments B5AG0).…”