title: Solid acid-catalyzed depolymerization of barley straw driven by ball milling.
abstract: This study describes a time and energy saving, solvent-free procedure for the conversion of lignocellulosic barley straw into reducing sugars by mechanocatalytical pretreatment. The catalytic conversion efficiency of several solid acids was tested which revealed oxalic acid dihydrate as a potential catalyst with high conversion rate. Samples were mechanically treated by ball milling and subsequently hydrolyzed at different temperatures. The parameters of the mechanical treatment were optimized in order to obtain sufficient amount of total reducing sugar (TRS) which was determined following the DNS assay. Additionally, capillary electrophoresis (CE) and Fourier transform infrared spectrometry (FT-IR) were carried out. Under optimal conditions TRS 42% was released using oxalic acid dihydrate as a catalyst. This study revealed that the acid strength plays an important role in the depolymerization of barley straw and in addition, showed, that the oxalic acid-catalyzed reaction generates low level of the degradation product 5-hydroxymethylfurfural (HMF).
authors: University of Oulu, Research Unit of Sustainable Chemistry, P.O. Box 3000, FIN-90014 Oulu, Finland; University of Jyvaskyla, Kokkola University Consortium Chydenius, FI-67100 Kokkola, Finland.
authors: Laura
authors: L
authors: Schneider
authors: University of Oulu, Kajaani University Consortium, CEMIS-Oulu, FI-87400 Kajaani, Finland.
authors: Jasmiina
authors: J
authors: Haverinen
authors: University of Oulu, Kajaani University Consortium, CEMIS-Oulu, FI-87400 Kajaani, Finland.
authors: Mari
authors: M
authors: Jaakkola
authors: University of Oulu, Research Unit of Sustainable Chemistry, P.O. Box 3000, FIN-90014 Oulu, Finland; University of Jyvaskyla, Kokkola University Consortium Chydenius, FI-67100 Kokkola, Finland. Electronic address: ulla.lassi@oulu.fi.
authors: Ulla
authors: U
authors: Lassi
mesh_terms: D001709:Biotechnology / Q000379:methods*; D002241:Carbohydrates / Q000737:chemistry; D002384:Catalysis; D001467:Hordeum / Q000737:chemistry*; D006868:Hydrolysis; D007700:Kinetics; D019815:Oxalic Acid / Q000737:chemistry*; D058105:Polymerization; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014866:Waste Products
chemical_list: D002241:Carbohydrates; D014866:Waste Products; D019815:Oxalic Acid
keywords: Barley straw (Hordeum vulgare); Lignocellulose; Mechanocatalytical conversion; Oxalic acid dihydrate; Solid catalyst