Three selected alkali-based organosolv pulps (alkali-sulfite-anthraquinone-methanol (ASAM), alkali-anthraquinone-methanol (organocell) and ethanol-soda) from agrofibre crop giant reed (Arundo donax L.) were bleached by an ozone-based TCF (totally chlorine- free) bleaching sequence AZE(R)QP (where A is an acidic pulp pre-treatment, Z is an ozone stage, (E(R)) is an alkaline extraction in the presence of reducing agent, Q is a pulp chelating, P is a hydrogen peroxide stage) without oxygen pre-bleaching, and compared with a conventional kraft pulp used as a reference. The different response on bleaching conditions within each bleaching stage was noted for all tested pulps. The pulp bleachability, in terms of brightness improvement or lignin removal per unit of applied chemicals, was found higher for the organocell pulp. The ASAM and ethanol-soda pulps showed the highest bleaching selectivity, expressed by viscosity loss per unit of lignin removed or brightness improved. The overall bleaching results of organosolv pulps were superior to kraft.
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http://dx.doi.org/10.1016/j.biortech.2007.01.014 | DOI Listing |
Int J Mol Sci
August 2024
Department of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, 1001 Ljubljana, Slovenia.
The natural aromatic polymer lignin and its lignin-like oligomeric fragments have attracted attention for their antioxidant capacity and free radical scavenging activities. In this study, a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was employed to assess the antioxidant capacity of fractionated and partially depolymerized organosolv lignin by electron paramagnetic resonance (EPR) and UV-Vis spectroscopy. The results show significant antioxidant activity for both the lignin and oligomeric fragments, with the EPR measurements demonstrating their efficiency in quenching the free radicals.
View Article and Find Full Text PDFWorld J Microbiol Biotechnol
May 2024
Department of Forestry and Wood Technology, Linnaeus University, Georg Lückligs Plats 1, 35195, Växjö, Sweden.
Biological pretreatment of wood chips by fungi is a well-known approach prior to mechanical- or chemical pulp production. For this biological approach, a limited number of white-rot fungi with an ability to colonize and selectively degrade lignin are used to pretreat wood chips allowing the remaining cellulose to be processed for further applications. Biopulping is an environmentally friendly technology that can reduce the energy consumption of traditional pulping processes.
View Article and Find Full Text PDFPolymers (Basel)
January 2024
RISE PFI AS, Høgskoleringen 6B, 7491 Trondheim, Norway.
The aim of this study was to investigate new materials from organosolv fibers, organosolv lignin, kraft fibers, and their blends. The organosolv fibers showed reprecipitated lignin on the surface, a comparably low fiber length of 0.565 mm on average, and a high fines content of 82.
View Article and Find Full Text PDFInt J Biol Macromol
December 2023
Materials Technology Research Group (MaTReC), School of Chemical Sciences, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia. Electronic address:
Rust powder collected from an archeological iron was evaluated by complementary analyses such as FTIR, XRD, XRF, and SEM/EDX. The analyses revealed that lepidocrocite (L) was the major component in the archeological iron. Coconut husk (CH) can be classified as a type of lignocellulosic biomass of renewable resources that are widely available, especially in coastal areas.
View Article and Find Full Text PDFHeliyon
June 2023
School of Chemical Engineering, Department of Biosystems and Bioproducts, Aalto University, Vuorimiehentie 1, 02150, Espoo, Finland.
In this study, we propose a full gamma-valerolactone (GVL) organosolv biorefinery concept including the utilization of all pulping streams, solvent recovery, and preliminary material and energy balances. GVL is a renewable and non-toxic solvent that fractionates woody biomass. The silver birch chips were pulped (45-65 wt% GVL, 150 °C, 2 h) under a series of acid-catalyzed conditions (5-12 kg HSO/t), and the fully bleached pulp was spun into fibers by the IONCELL® process and knitted into the fabric.
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