title: Effect of double-step steam explosion pretreatment in bioethanol production from softwood.
abstract: The study investigated the production of bioethanol from softwood, in particular pine wood chip. The steam explosion pretreatment was largely investigated, evaluating also the potential use of a double-step process to increase ethanol production through the use of both solid and liquid fraction after the pretreatment. The pretreatment tests were carried out at different conditions, determining the composition of solid and liquid fraction and steam explosion efficiency. The enzymatic hydrolysis was carried out with Ctec2 enzyme while the fermentation was carried out using Saccharomyces Cerevisiae yeast "red ethanol". It was found that the best experimental result was obtained for a single-step pretreated sample (10.6 g of ethanol/100 g of initial biomass dry basis) for a 4.53 severity. The best double-step overall performance was equal to 8.89 g ethanol/100 g of initial biomass dry basis for a 4.27 severity. The enzymatic hydrolysis strongly depended on the severity of the pretreatment while the fermentation efficiency was mainly influenced by the concentration of the inhibitors. The ethanol enhancing potential of a double-step steam explosion could slightly increase the ethanol production compared to single-step potential.
authors.affiliation: CIRIAF-Biomass Research Centre, University of Perugia, Via G. Duranti, 06125, Perugia, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Cotana
authors.forename: Gianluca
authors.initials: G
authors.lastname: Cavalaglio
authors.forename: Mattia
authors.initials: M
authors.lastname: Gelosia
authors.forename: Valentina
authors.initials: V
authors.lastname: Coccia
authors.forename: Alessandro
authors.initials: A
authors.lastname: Petrozzi
authors.forename: Andrea
authors.initials: A
authors.lastname: Nicolini
mesh_terms: D018533:Biomass; D002480:Cellulase / Q000737:chemistry*; D000431:Ethanol / Q000378:metabolism*; D006868:Hydrolysis; D012441:Saccharomyces cerevisiae / Q000254:growth & development*; D013227:Steam; D014934:Wood / Q000737:chemistry* / Q000378:metabolism
chemical_list: D013227:Steam; D000431:Ethanol; D002480:Cellulase