title: Dilute sulfuric acid pretreatment of sunflower stalks for sugar production.
abstract: In this work the pretreatment of sunflower stalks by dilute sulfuric acid is studied. Pretreatment temperature and the concentration of acid solution were selected as operation variables and modified according to a central rotatable composite experimental design. Based on previous studies pretreatment time was kept constant (5 min) while the variation range for temperature and acid concentration was centered at 175°C and 1.25% (w/v) respectively. Following pretreatment the insoluble solids were separated by filtration and further submitted to enzymatic hydrolysis, while liquid fractions were analyzed for sugars and inhibitors. Response surface methodology was applied to analyze results based on the combined severity of pretreatment experiments. Optimized results show that up to 33 g of glucose and xylose per 100g raw material (65% of the glucose and xylose present in the raw material) may be available for fermentation after pretreatment at 167°C and 1.3% sulfuric acid concentration.
authors.affiliation: Department of Chemical, Environmental and Materials Engineering, Agrifood Campus of International Excellence ceiA3, University of Jaén, Campus Las Lagunillas, 23071 Jaén, Spain.
authors.forename: Encarnación
authors.initials: E
authors.lastname: Ruiz
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Romero
authors.forename: Manuel
authors.initials: M
authors.lastname: Moya
authors.forename: Cristóbal
authors.initials: C
authors.lastname: Cara
authors.forename: Juan D
authors.initials: JD
authors.lastname: Vidal
authors.forename: Eulogio
authors.initials: E
authors.lastname: Castro
mesh_terms: D001709:Biotechnology / Q000379:methods*; D002241:Carbohydrates / Q000096:biosynthesis*; D002480:Cellulase / Q000378:metabolism; D005285:Fermentation / Q000187:drug effects; D005947:Glucose / Q000032:analysis; D006368:Helianthus / Q000187:drug effects*; D006868:Hydrolysis / Q000187:drug effects; D013464:Sulfuric Acids / Q000494:pharmacology*; D014866:Waste Products; D014994:Xylose / Q000032:analysis
chemical_list: D002241:Carbohydrates; D013464:Sulfuric Acids; D014866:Waste Products; D014994:Xylose; D002480:Cellulase; D005947:Glucose; C033158:sulfuric acid