DAMAGE BY DEFOLIATING INSECTS AND ITS EFFECT ON THE QUALITY OF WOOD FOR CHARCOAL PRODUCTION

The objective of the present work has been to evaluate the impact of damage caused by defoliating insects on wood quality and charcoal production, and to quantify the losses per hectare according to the charcoal produced. Seven-year-old Eucalyptus grandis × Eucalyptus urophylla (clone A) and Eucalyptus saligna (clone B) trees, both in healthy condition and damaged by defoliating insects, were selected, with five trees to be used per treatment. Wood disks were removed from the trees at 0, 25, 50, 75 and 100% of the commercial height for analyzing the properties of the wood and for preparing and characterizing the charcoal. Damage by defoliating insects decreased the basic density of the trees at all axial positions by up to 23 kg m-3. Also, the extractives and lignin contents increased, while the holocellulose content decreased in the attacked plants. Changes in the wood characteristics led to increased fixed carbon content and gravimetric yield, and a decrease in density. The charcoal productivity from the plants damaged by defoliating insects was lower, mainly because of the decrease in volumetric production.

Enzymatic Hydrolysis and Fermentation of Banana Pseudostem Hydrolysate to Produce Bioethanol

Banana pseudostem (BPS) is an agricultural waste with a high holocellulose content, which, upon hydrolysis, releases fermentable sugars that can be used for bioethanol production. Different pretreatment methods, namely, 3% (w/v) NaOH, 5% (v/v) H2SO4, and liquid hot water, applied on the BPS resulted in the availability of 52%, 48%, and 25% cellulose after treatment, respectively. Saccharification of the pretreated BPS with 10 FPU/g dry solids (29.3 mg protein/g d.s) crude enzyme from Trichoderma harzianum LMLBP07 13-5 at 50°C and a substrate loading of 10 to 15% released 3.8 to 21.8 g/L and from T. longibrachiatum LMLSAUL 14-1 released 5.4 to 43.5 g/L glucose to the biomass. Ethanol was produced through separate hydrolysis and fermentation (SHF) of alkaline pretreated BPS hydrolysate using Saccharomyces cerevisiae UL01 at 30°C and 100 rpm. Highest ethanol produced was 17.6 g/L. Banana pseudostem was shown as a potentially cheap substrate for bioethanol production.

Mechanical Performance and Dimensional Stability of Bamboo Fiber-Based Composite

The bamboo fiber-based composite (BFBC) has high-performce in terms of mechanical properties and dimensional stability. In this study, BFBCs were prepared with different hot-pressing temperatures (150 °C, 160 °C, 170 °C, 180 °C, 190 °C, and 200 °C) and designed with different densities (1.05 g/cm3, 1.10 g/cm3, 1.15 g/cm3 and 1.20 g/cm3), and their selected properties were evaluated. Temperature affected BFBC performance, which, with a general increase in temperature, showed a decrement in mechanical properties and an improvement in dimensional stability. Holocellulose content significantly decreased, and the color of BFBC became darker with the increasing of the press temperature. As the density of BFBC increased, the modulus of elasticity (MOE) significantly increased from 23.09 GPa to 27.01 GPa with the increase in temperature. The thickness swelling ratio (TSR), width swelling ratio (WSR) and water absorption ratio (WAR) declined by more than 30% with the increase in density. Overall, the results of this study provide a theoretical basis and a source of technical support to promote the design, application, and popularization of BFBC in different fields.

Chemical composition of Luffa aegyptiaca Mill., Agave durangensis Gentry and Pennisetum sp.

The particleboard industry faces problems of wood shortage, which has led to the use of non-wood lignocellulosic materials. Furthermore, there is also interest in looking for materials that improve their physical and mechanical properties. The species Luffa aegyptiaca Mill. (fruit), Agave durangensis Gentry (bagasse) and Pennisetum sp. (plant, leaves and stem) could be used in the elaboration of wood-based particleboards. The aim of this study is to determine the feasibility of using these materials to produce particleboards in accordance with their chemical composition. Five materials were studied, A. durangensis (bagasse), L. aegyptiaca (fruit) and Pennisetum sp. (whole plant, leaves and stem). Extractives, holocellulose, Runkel lignin and ash content was determined. The pH of the fibers was also measured and a microanalysis of the ash was performed. ANOVA and Kruskal-Wallis tests were carried out, in addition Tukey and Dunn tests for group comparison were performed. Pennisetum sp. leaves presented the highest total extractives and ash content, while L. aegyptiaca fruit and A. durangensis bagasse had the highest both content of holocellulose and Runkel lignin respectively. The lowest pH was presented by the L. aegyptiaca fruit, while the highest was from the Pennisetum sp. stem. The element with the greatest presence in the five materials was potassium, except in A. durangensis bagasse showing calcium. L. aegyptiaca fruit has better characteristics to be used in particleboards with greater mechanical resistance because of its higher holocellulose content. However, Pennisetum sp. (plant, leaves and stem) could be used to make particleboards with high resistance to water absorption.

Analisis Holoselulosa: Tinjauan Metode Analisis Kimia Konvensional

Holoselulosa merupakan fraksi karbohidrat yang merupakan gabungan antara selulosa dan hemiselulosa. Fraksi holoselulosa menjadi penting karena merupakan bahan baku yang digunakan menjadi berbagai produk yang memiliki bernilai tinggi. Kandungan holoselulosa bervariasi di antara berbagai spesies kayu. Analisis holoselulosa penting untuk memperoleh informasi mengenai karakteristik dan kualitas bahan baku, mengoptimalkan pemanfaatan sumber bahan baku, dan meningkatkan efisiensi proses sehingga memungkinan komersialisasi proses konversi biomassa menjadi bahan lain yang berekonomis tinggi. Prinsip analisis holoselulosa metode kimia konvensional adalah fraksinasi dan isolasi yaitu dengan menyisihkan lignin, ekstraktif, dan abu, namun menjaga selulosa dan hemiselulosa tetap utuh. Metode analisis holoselulosa biasanya menggunakan metode delignifikasi, menggunakan reagen pengoksidasi kuat pada pH rendah atau tinggi dan suhu tinggi. Metode tersebut meliputi klor dioksida, klor-piridin, klor-etanol amina, klor-1,4-dioksan, klorit asam, dan asam perasetat. Metode natrium klorit banyak digunakan untuk analisis holoselulosa dengan karena prosedur pemisahan sederhana dan delignifikasi cepat. Artikel ini memaparkan sejumlah metode analisis holoselulosa, prinsip penentuan, reaksi, keunggulan dan kelemahan masing-masing metode sehingga dapat memberikan gambaran untuk memilih metode yang sesuai dan akurasi masing-masing metode tersebut.Holocellulose Analysis: A Review of Conventional Chemical Analysis MethodsAbstractHolocellulose is a carbohydrate fraction that is a combination of cellulose and hemicellulose. Holocellulose fraction is important because it is the raw material used to be processed into various high-value products. Holocellulose content varies among various wood species. Holocellulose analysis is important to gain information on the characteristics and quality of raw materials, optimize the utilization of raw material sources, and improve process efficiency so that it is possible to commercialize the process of converting biomass into other high-economical materials. The principle of holocellulose analysis by conventional chemistry method is fractionation and isolation by removing lignin, extractives, and ash, but keeping cellulose and hemicellulose intact. Holocellulose analysis methods usually use the delignification method, using strong oxidizing reagents in low or high pH and high temperatures. Such methods include chlorine dioxide, chlorine-pyridine, chlorine-ethanol amine, chlor-1,4-dioxane, acid chlorite, and peracetic acid. The sodium chlorite method is widely used for the analysis holocellulose because of its simple separation procedure and rapid delignification. This article presents several holocellulose analysis methods, principles of determination, reactions, strengths, and weaknesses of each method to provide an overview for selecting the appropriate method and the accuracy of each method.Keywords: holocellulose analysis, conventional analytical chemistry method, delignification

Screening of cellulose-degrading fungi in forest litter and fungal effects on litter decomposition

Fungi were isolated using a rose bengal chloramphenicol agar as the culture medium. Congo red staining was used on sodium carboxymethyl cellulose medium to screen fungal strains that have potential to produce cellulolytic enzymes according to the cellulolytic index (CI). The ability of these isolates to break down holocellulose in three forest litter substrates (broad-leafed: Juglans mandshurica; coniferous: Larix gmelinii; broadleaf-conifer mixed: J. mandshurica and L. gmelinii) was tested over 80 days of incubation. The holocellulose content and the decomposition rule were studied. The strain with the most efficient degradation effect on natural cellulose in forest litter was selected. The growth of fungi was observed by scanning electron microscopy (SEM). The hydrolytic circles indicated the activity of cellulase produced by the fungi, and it implied that the fungi could degrade cellulose. The results showed that eight strains were able to degrade cellulose. The strain A2 (Peniophora incarnate) showed the highest CI, while A4 (Sarocladium strictum) was most capable of degrading holocellulose in various litter substrates. The SEM micrographs revealed that A4 had the ability to invade leaf tissue and degrade holocellulose in leaves. This study could be helpful for forest litter management, which provides a new way to cleanup forest litter using cellulose-degrading fungi.

Characterization of hemicelluloses from leaves and tops of the CC 8475, CC 8592, and V 7151 varieties of sugarcane (Saccharum officinarum L

In this research, the types of hemicellulose that predominate in the leaves and tops of the three most cultivated varieties (CC 8475, CC 8592, V 7151) of sugarcane (Saccharum officinarum L.) in Valle del Cauca, Colombia were determined. Hemicellulose analyses were performed after delignification with sodium chlorite and extraction with 18% NaOH and 24% KOH containing 0.26 M NaBH4. The main components of hemicellulose were identified via FTIR and NMR spectroscopy, and monomeric sugars were identified via HPLC. Hemicellulose A composed of arabinoxylans, glucomannans and arabinogalactactans and hemicellulose B primarily composed of arabinoxylans were extracted. The hemicelluloses of the Colombian varieties were more stable against heat than those of the Venezuelan variety. The results of this project allowed discovery of the potential use of agricultural sugarcane residues for bioethanol production because they have a holocellulose content of more than 60%.

PROPERTIES OF CHARCOAL PRODUCED FROM REACTION WOOD IN TREES INCLINED DUE TO WIND1

ABSTRACT Inclined trees produce reaction wood, whose properties are distinct from normal wood. This situation can affect the production of charcoal. This study was conducted to evaluate the quality of charcoal derived from reaction wood in trees of a commercial plantation inclined due to the action of wind. We used six year old wood from a Eucalyptus grandis xEucalyptus urophylla hybrid from plantations located in Minas Gerais. The physical and chemical properties of the wood were determined as well as the gravimetric yield and charcoal properties. According to the results, there were significant differences between the properties of the reaction and normal wood, with the reaction wood having lower levels of lignin and extractives, greater holocellulose content and low specific gravity. However, these characteristics of reaction wood did not significantly affect the properties of its charcoal.