WOOD RESEARCH Volume 68, Number 1, 2023
Joni Prasetyo, Deliana Dahnum, Galuh Wirama Murti, Roni Maryana, Anto Tri Sugianto, and Bambang Sugeng

Delignification of palm oil empty fruit bunch by hydroxyl radical of microwave radiation under alkaline condition

This work assessed how to remove lignin of palm oil empty fruit bunch (EFB) in environmentally friendly method and less energy. Moreover, delignification was strengthened with additional H2O2 to perform hydroxyl radical by microwave radiation in low NaOH solution of concentration up to 0.8 M, 10%. Setting on microwave, solution was heating up and cause delignification work more effective. Observation at black liquor showed that temperature was influence by microwave radiation duration while NaOH concentration affected total suspended solid increasing. Optimally treated EFB at 0,2 M NaOH with effective lignin removal and holocellulose increasing reached 27% and 26%, respectively. Unfortunately, at higher NaOH concentration, the decomposition penetrated EFB interior, holocellulose and made lignin percentage high again. Therefore, EFB yield got less at higher NaOH concentration because more EFB was sludgy and lost during washing. XRD analysis showed the increasing crystallinity by 2.2%, closer to -cellulose. SEM showed successful impurities removal from EFB surface and Ca, Nb, Si, and Mg detected by EDS.

WOOD RESEARCH Volume 61, Number 5, 2016
Chu Jie, Ma Li, and Zhong Yang

Comparison of bamboo fibers in sulfuric acid, sodium hydroxide and glycerin pretreatments

The chemical compositions and structural characterizations of bamboo samples with three pretreatments using sand bath to heat were comparatively studied with Fourier infrared spectrum (FTIR). The results showed that the holocellulose and cellulose yields increased significantly and the dilute alkali (NaOH) pretreatment performed better lignin removal rate than that of dilute acid (H2SO4) and glycerin pretreatments.Furthermore, when the same solutions were used, the compositional changes were more remarkable at 135 than at 117°C, and the similar degradation of hemicelluloses was observed for the different pretreatments. With sodium hydroxide at 135°C, compared to un-treated bamboo, cellulose increased by 14.21 % and hemicellulose decreased to 13.98 %, counting the removal of lignin to 20.29 %. In which, the bamboo expressed the betterdelignification with sand bath and higher temperature and combinations with other methods of glycerin pretreatment should be evaluated in the future work.

WOOD RESEARCH Volume 62, Number 5, 2017
Balberčák Jozef, Boháček Štefan, Peter Medo, VLADIMÍR IHNÁT, and HENRICH LÜBKE

Chemical processing of waste wood based agglomerates Part I: Evaluation of properties of fluting liners made of semichemical pulp obtained by a mildly alkaline sulphur-free cooking process

The article describes the method of evaluation and preparation of fluting liners produced from semichemical pulp of waste wood particle boards (PB) and oriented strand boards (OSB) and after the combination with old corrugated cardboards (OCC) to improve strength properties. The semichemical pulp was obtained by a mildly alkaline boiling process from two fractions of waste PB and OSB. Properties as thickness, bulk density, gurley, tensile strength, tensile index, breaking length, burst index, CMT30 and SCT were monitored on lab sheets 127 g.m-2 and 170 g.m-2. Values of pH and residual NaOH and Na2CO3 were determined in batch leachate.

WOOD RESEARCH Volume 63, Number 1, 2018
Balberčák Jozef, Boháček Štefan, Pažitný Andrej, VLADIMÍR IHNÁT, and HENRICH LÜBKE

Chemical processing of waste wood based agglomerates Part II: Evaluation of properties of fluting liners made of semichemical pulp obtained by an alkaline cooking process

The article describes the method of evaluation and preparation of fluting liners produced from semichemical pulp obtained from waste wood particle boards (PB) and oriented strand boards (OSB). The semichemical pulp was obtained using an alkaline cooking process from a sorted fraction of the 4-8 mm chips. Properties as thickness, bulk density, air resistance of paper sheet, tensile strength, tensile index, breaking length, burst index, CMT30 and SCT were monitored on lab sheets 127 g. m-2 and 170 g. m-2. Values of pH and residual NaOH were determined in the batch leachate.

WOOD RESEARCH Volume 66, Number 4, 2021
Milica Galić, ‪Jasmina Ćilerdžić, Jelena Vukojević, and Mirjana Stajić

Agro-forestry residues valorization by ligninosome of Grifola frondosa

Grifola frondosa HAI 1232 was tested for ligninolytic enzyme activities and for lignin, cellulose and hemicellulose degradation during cultivation on eight common agro-forestry residues in Serbia. Wheat straw was favorable lignocellulosic for the production of Mn-dependent and Mn-independent peroxidases (2513.89 and 354.17 U L-1, respectively), while selected residues inhibited the synthesis of laccases. The highest lignin removal was observed during fermentation of blackberry sawdust (36.75%), while the highest selectivity index was recorded on oak sawdust (4.34). The dry matter loss varied between 8.17% in corn stalks and 14.16% in apple sawdust. According to the presented results, it can be concluded that G. frondosa HAI 1232 could be an important participant in various biotechnological processes due to its high capacity to selectively degrade different agro-forestry residues.

WOOD RESEARCH Volume 64, Number 3, 2019
Lifen Li, Liping Yu, Zhigang Wu, and Yingcheng Hu

Delignification of poplar wood with lactic acid-based deep eutectic solvents

A process for the delignification of poplar wood using lactic acid-based deep eutectic solvents (DESs) with different hydrogen bond acceptors (choline chloride, glycine) was studied. The effect of operational parameters on the yields of the pulps and the regenerated lignins, the chemical compositions of the pulps and the delignification extent was investigated with respect to several factors, such as the types of hydrogen bond acceptor, reaction temperature and time. The maximum delignification extent of approximately 90.4% was achieved with lactic acidcholine chloride DES at 120°C for 12 h, however only about 58.4% of lignin was removed with lactic acid-glycine DES under the same reaction condition. The structural characteristics of the pulps were subsequently investigated by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Thermogravimetric Analysis (TGA) and compared with original wood sample and microcrystalline cellulose.