Arundo donax L. reed: new perspectives for pulping and bleaching--organosolv delignification.Application: Comparative experiments on organosolv delignification of Arundo donax are necessary to select more promising pulping processes with possible use for additional optimization of pulping conditions. Comparative study on applicability to Arundo donax 1 reed of a few modern organic-solvent based technologies showed a great potential of organosolv pulping to produce high quality nonwood fibers. Pulps with high yield and low content of residual lignin lignin (lĭg`nĭn), a highly polymerized and complex chemical compound especially common in woody plants. The cellulose walls of the wood become impregnated with lignin, a process called lignification, which greatly increases the strength and , comparable with kraft pulps from hardwoods (Eucalyptus eucalyptus (y  'kəlĭp`təs): see myrtle. eucalyptus globulus L.) were produced by alkali-sulfite-anthraquinone-methanol (ASAM ASAM American Society of Addiction Medicine ASAM Advanced Surface-to-Air Missile ASAM Advanced Services Access Manager ASAM ATM Subscriber Access Multiplexer (Alcatel) ASAM Association for Solidarity with Asylum Seekers and Migrants ), alkali-methanol-anthraquinone (ORGANO-CELL), ethanol-soda, and peroxyacids organosolv processes. All organosolv methods were applied to Arundo donax without optimization using conditions reported for pulping of similar crops or hardwood such as ORGANOCELL. The results received should therefore be preliminary and might improve by by further adaptation of process-specific cooking conditions to Arundo donax. Results and discussion Table 1 shows the results of pulp properties of Arundo donax for the different organosolv processes and for the reference kraft pulping. The main benefit of ASAM pulping independent of the kind of raw material used is a high yield. The results of Arundo donax supported this tendency. The yield total and screened--and the viscosity of ASAM pulps are superior to kraft. This demonstrates resistance of the carbohydrate complex to degradation. Other workers showed that xylan xylan /xy·lan/ (zi´lan) any of a group of pentosans composed of xylose residues; major structural constituents of wood, straw, and bran. and cellulose are stable under these organosolv conditions and exhibit some tendency to degradation only in the final cooking phase. The low alkalinity al·ka·lin·i·ty n. The alkali concentration or alkaline quality of a substance that contains alkali. alkalinity 1. the quality of being alkaline. 2. and the presence of anthraquinone anthraquinone /an·thra·quin·one/ (an?thrah-kwin´on) 1. the 9,10 quinone derivative of anthracene, used in dye manufacture. 2. any of the derivatives of this compound, some of which are dyes. and methanol methanol, methyl alcohol, or wood alcohol, CH3OH, a colorless, flammable liquid that is miscible with water in all proportions. Methanol is a monohydric alcohol. It melts at −97. had a beneficial effect on carbohydrate dissolution through suppressing of a peeling reaction and alkaline hydrolysis hydrolysis (hīdrŏl`ĭsĭs), chemical reaction of a compound with water, usually resulting in the formation of one or more new compounds. . This provides high yield and high viscosity of pulps. The mechanical properties of ASAM pulp are comparable with kraft, and the bursting strength is higher. The remarkable feature of ASAM pulp from Arundo donax is a substantially higher brightness compared with the kraft pulp from Arundo donax or to industrial kraft pulps from E. globulus. Conclusions The organosolv delignification of Arundo donax L. reed showed the potential applicability of modern unconventional pulping technologies for this crop with production of high quality nonwood fibers. Bleachable grade pulps with high yield and low content of residual lignin comparable with kraft pulps from hardwoods (E. globulus L.) were produced by a few acid- and alkali-based organosolv processes (ASAM, ORGANOCELL, Ethanol-Soda and Peroxyacids). The papermaking pa·per·mak·ing n. The process or craft of making paper. pa  per·mak properties of
unbeaten organosolv pulps were higher than for kraft pulp from Arundo
donax. Some properties such as tear strength were superior to kraft pulp
from E. globulus. This offers promise to produce paper with competitive
properties.The main disadvantage of organosolv pulps and kraft pulp from Arundo donax is the fast response on beating combined with significant drainage problems compared with wood pulps wood pulp: see paper. .
1. Physical properties of unbeaten Arundo donax pulps produced by
conventional kraft and organosolv methods
DRAINAGE BURST TENSILE
RESISTANCE, INDEX, INDEX,
PULP [degrees]SR kPa*[m.sup.2]/g N*m/g
Kraft (reference) 10 0.5 17.4
ASAM 11 0.9 14.1
Ethanol-soda 11 1.7 27.9
ORGANOCELL 11 1.0 16.9
Peroxyacids 16 0.6 14.2
Kraft from E. globulus L. -- 2.0 46.9
TEAR
INDEX, BULK, BRIGHTNESS,
PULP mN*[m.sup.2]/g [cm.sup.3]/g % ISO
Kraft (reference) 10.5 2.1 22.8
ASAM 10.5 2.0 37.1
Ethanol-soda 11.4 1.8 36.5
ORGANOCELL 9.2 1.8 26.5
Peroxyacids 7.1 1.9 24.9
Kraft from E. globulus L. 6.0 1.6 --
Both authors are at Centro de Estudos Florestais, Universidade Tecnica de Lisboa, Instituto Superior de Agronomia Instituto Superior de Agronomia (ISA), School of Agronomy - Technical University of Lisbon, is a national and international renowned faculty of excellence for graduation and post-graduation studies in Agronomy, Forestry, Food Science, Landscape Architecture, Environment, Animal , Tapada da Ajuda, 1349-017 Lisboa Codex codex Manuscript book, especially of Scripture, early literature, or ancient mythological or historical annals. The earliest type of manuscript in the form of a modern book (i.e. , Portugal. Address correspondence to Shatalov by email at anatoly@isa.utl.pt. |
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