title: Mixing design for enzymatic hydrolysis of sugarcane bagasse: methodology for selection of impeller configuration.
abstract: One of the major process bottlenecks for viable industrial production of second generation ethanol is related with technical-economic difficulties in the hydrolysis step. The development of a methodology to choose the best configuration of impellers towards improving mass transfer and hydrolysis yield together with a low power consumption is important to make the process cost-effective. In this work, four dual impeller configurations (DICs) were evaluated during hydrolysis of sugarcane bagasse (SCB) experiments in a stirred tank reactor (3 L). The systems tested were dual Rushton turbine impellers (DIC1), Rushton and elephant ear (down-pumping) turbines (DIC2), Rushton and elephant ear (up-pumping) turbines (DIC3), and down-pumping and up-pumping elephant ear turbines (DIC4). The experiments were conducted during 96 h, using 10 % (m/v) SCB, pH 4.8, 50 °C, 10 FPU/g biomass, 470 rpm. The mixing time was successfully used as the characteristic parameter to select the best impeller configuration. Rheological parameters were determined using a rotational rheometer, and the power consumptions of the four DICs were on-line measured with a dynamometer. The values obtained for the energetic efficiency (the ratio between the cellulose to glucose conversion and the total energy) showed that the proposed methodology was successful in choosing a suitable configuration of impellers, wherein the DIC4 obtained approximately three times higher energetic efficiency than DIC1. Furthermore a scale-up protocol (factor scale-up 1000) for the enzymatic hydrolysis reactor was proposed.
authors.affiliation: PPGEQ/UFSCar, Chemical Engineering Graduate Program, Federal University of São Carlos, Rodovia Washington Luis Km 235, 13565-905, São Carlos, São Paulo, Brazil.
authors.forename: Luciano Jacob
authors.initials: LJ
authors.lastname: Corrêa
authors.affiliation: PPGEQ/UFSCar, Chemical Engineering Graduate Program, Federal University of São Carlos, Rodovia Washington Luis Km 235, 13565-905, São Carlos, São Paulo, Brazil.|Department of Chemical Engineering, Federal University of São Carlos, Rodovia Washington Luis Km 235, 13565-905, São Carlos, São Paulo, Brazil.
authors.forename: Alberto Colli
authors.initials: AC
authors.lastname: Badino
authors.affiliation: PPGEQ/UFSCar, Chemical Engineering Graduate Program, Federal University of São Carlos, Rodovia Washington Luis Km 235, 13565-905, São Carlos, São Paulo, Brazil. ajgcruz@ufscar.br.|Department of Chemical Engineering, Federal University of São Carlos, Rodovia Washington Luis Km 235, 13565-905, São Carlos, São Paulo, Brazil. ajgcruz@ufscar.br.
authors.forename: Antonio José Gonçalves
authors.initials: AJ
authors.lastname: Cruz
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D006867:Hydrolases / Q000737:chemistry*; D006868:Hydrolysis; D008956:Models, Chemical; D031786:Saccharum / Q000737:chemistry*
chemical_list: D002482:Cellulose; C027433:bagasse; D006867:Hydrolases
keywords: Bioethanol; Mixing time; Power consumption; Rheology; Scale-up