title: Life cycle assessment of advanced bioethanol production from pulp and paper sludge.
abstract: This work evaluates the environmental performance of using pulp and paper sludge as feedstock for the production of second generation ethanol. An ethanol plant for converting 5400 tons of dry sludge/year was modelled and evaluated using a cradle-to-gate life cycle assessment approach. The sludge is a burden for pulp and paper mills that is mainly disposed in landfilling. The studied system allows for the valorisation of the waste, which due to its high polysaccharide content is a valuable feedstock for bioethanol production. Eleven impact categories were analysed and the results showed that enzymatic hydrolysis and neutralisation of the CaCO3 are the environmental hotspots of the system contributing up to 85% to the overall impacts. Two optimisation scenarios were evaluated: (1) using a reduced HCl amount in the neutralisation stage and (2) co-fermentation of xylose and glucose, for maximal ethanol yield. Both scenarios displayed significant environmental impact improvements.
authors.affiliation: Unidade de Bioenergia, Laboratório Nacional de Energia e Geologia, I.P., Estrada do Paço do Lumiar, 1649-038 Lisboa, Portugal.
authors.forename: Diogo
authors.initials: D
authors.lastname: Sebastião
authors.affiliation: Unidade de Bioenergia, Laboratório Nacional de Energia e Geologia, I.P., Estrada do Paço do Lumiar, 1649-038 Lisboa, Portugal.
authors.forename: Margarida S
authors.initials: MS
authors.lastname: Gonçalves
authors.affiliation: Unidade de Bioenergia, Laboratório Nacional de Energia e Geologia, I.P., Estrada do Paço do Lumiar, 1649-038 Lisboa, Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Marques
authors.affiliation: Unidade de Bioenergia, Laboratório Nacional de Energia e Geologia, I.P., Estrada do Paço do Lumiar, 1649-038 Lisboa, Portugal.
authors.forename: César
authors.initials: C
authors.lastname: Fonseca
authors.affiliation: Unidade de Bioenergia, Laboratório Nacional de Energia e Geologia, I.P., Estrada do Paço do Lumiar, 1649-038 Lisboa, Portugal.
authors.forename: Francisco
authors.initials: F
authors.lastname: Gírio
authors.affiliation: Unidade de Bioenergia, Laboratório Nacional de Energia e Geologia, I.P., Estrada do Paço do Lumiar, 1649-038 Lisboa, Portugal.
authors.forename: Ana C
authors.initials: AC
authors.lastname: Oliveira
authors.affiliation: Unidade de Bioenergia, Laboratório Nacional de Energia e Geologia, I.P., Estrada do Paço do Lumiar, 1649-038 Lisboa, Portugal. Electronic address: cst.matos@gmail.com.
authors.forename: Cristina T
authors.initials: CT
authors.lastname: Matos
mesh_terms: D001709:Biotechnology / Q000379:methods*; D004777:Environment; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D006868:Hydrolysis; D007220:Industrial Waste; D010209:Paper; D012722:Sewage; D014994:Xylose / Q000378:metabolism
chemical_list: D007220:Industrial Waste; D012722:Sewage; D000431:Ethanol; D014994:Xylose; D005947:Glucose
keywords: Bioethanol; Life cycle assessment; Pulp and paper sludge; Waste valorisation