title: Integrated bioconversion of pulp and paper primary sludge to second generation bioethanol using Saccharomyces cerevisiae ATCC 26602.
abstract: Primary sludge, from different pulp and paper mills, was used as feedstock in simultaneous saccharification and fermentation (SSF) processes to produce ethanol. SSF was carried out with Saccharomyces cerevisiae ATCC 26602 yeast and NS 22192 enzymatic extract using 150gL(-1) of carbohydrates (CH) from primary sludge. The effect of sterilization, reduction of enzyme dosage and fed-batch vs. batch conditions were studied. The removal of sterilization can be considered since no contamination or atypical by-products were observed, although SSF efficiency slightly decreased. The reduction of the enzyme dosage from 35 to 15FPUgCH(-1) was successful. Despite of initial mixing difficulties, batch SSF enabled higher ethanol concentration (41.7gL(-1)), conversion yield (48.9%) and productivity (0.78gL(-1)h(-1)), compared to the fed-batch process at the same conditions of low enzyme dosage of 5FPUgCH(-1) and high solids content of 21.7%, rarely found in literature.
authors: CIEPQPF, Department of Chemical Engineering, Faculty of Sciences and Technology, University of Coimbra, Pólo II, Rua Sílvio Lima, 3030-790 Coimbra, Portugal. Electronic address: catvan@eq.uc.pt.
authors: Cátia V T
authors: CVT
authors: Mendes
authors: Department of Engineering and Food Technology, São Paulo State University, Rua Cristóvão Colombo, 2265, Jardim Nazareth, 15054-000 - São José do Rio Preto, São Paulo, Brazil. Electronic address: crispin@ibilce.unesp.br.
authors: Crispin H G
authors: CHG
authors: Cruz
authors: CIEPQPF, Department of Chemical Engineering, Faculty of Sciences and Technology, University of Coimbra, Pólo II, Rua Sílvio Lima, 3030-790 Coimbra, Portugal. Electronic address: di.jesse@gmail.com.
authors: Diana F N
authors: DFN
authors: Reis
authors: CIEPQPF, Department of Chemical Engineering, Faculty of Sciences and Technology, University of Coimbra, Pólo II, Rua Sílvio Lima, 3030-790 Coimbra, Portugal. Electronic address: mgc@eq.uc.pt.
authors: M Graça V S
authors: MGVS
authors: Carvalho
authors: CIEPQPF, Department of Chemical Engineering, Faculty of Sciences and Technology, University of Coimbra, Pólo II, Rua Sílvio Lima, 3030-790 Coimbra, Portugal. Electronic address: jrocha@eq.uc.pt.
authors: Jorge M S
authors: JMS
authors: Rocha
mesh_terms: D000431:Ethanol / Q000138:chemical synthesis*; D005285:Fermentation; D010209:Paper; D012441:Saccharomyces cerevisiae; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology*
chemical_list: D012722:Sewage; D000431:Ethanol
keywords: Bioethanol; Primary sludge; Simultaneous saccharification and fermentation; Unbleached pulp