Low Hemicellulose Research Articles

Exploring the constituents and thermal characteristics of miscanthus floridulus for biomass composites

Miscanthus floridulus (MF) possesses notable attributes including high photosynthetic efficiency, rapid growth, robust adaptability, and substantial biomass yield. It is widely researched in fields such as genetics, special materials, bioenergy, and ecological protection. However, the research on the addition of MF for biomass composites remains limited due to the absence of comprehensive analysis concerning the composition, internal molecular structure, and properties of MF. A thorough exploration of the fundamental properties of MF has the potential to broaden their advantages and facilitate the advancement of biomass. This investigation delves into the structural characterization and properties of MF, focusing on its stems, leaves, and tassels. Firstly, the primary constituents of MF comprise cellulose, hemicellulose, and lignin. Cellulose predominates in the stem, exhibiting the highest crystallinity, while lignin content peaks in the tassel with the lowest crystallinity. The leaf falls between these extremes in terms of crystallinity. Secondly, carbon and oxygen elements constitute over 95 % of MF's primary components, alongside trace elements like phosphorus and sulfur. Additionally, chemical structure of MF features abundant characteristic functional groups such as hydroxyl, carbonyl, and benzene rings. Studies indicate that samples with low hemicellulose and high lignin content demonstrate superior thermal stability. Consequently, the stem of MF exhibits optimal low-temperature thermal stability, while the tassel excels in high-temperature conditions. Finally, the data highlights a significant influence in the mechanical properties of polylactic acid materials upon the addition of MF. With a 5 % addition of MF, the tensile modulus and flexural strength of the PLA composite reached their optimal values of 933.91 MPa and 55.28±8.77 MPa, respectively. This research establishes a theoretical groundwork for integrating MF into biomass composite materials.

Production of high-quality dissolving pulp from eucalyptus wood chips using deep eutectic solvent and elemental chlorine-free bleaching

Deep eutectic solvent (DES) provides promising alternatives to conventional pulping and cellulose purification with significantly lower energy consumption and impacts on the environment. In this work, choline chloride – lactic acid (ChCl-LA DES) pulping of eucalyptus wood chips combined with several ECF bleaching sequences was investigated to produce high-grade dissolving pulps. Initially, the dependency of DES pulping yield and delignification efficiency on the moisture content (MC) of used wood chips was evaluated. The results exhibited the crucial influence of the MC of wood chips on the delignification efficiency of DES pulping. DES pulping under optimized conditions resulted in an unbleached pulp with kappa number of 42, relatively high screened yield 48.1% and viscosity 796 cm3/g, as well as very low hemicellulose content, typically less than 3.8%. Further purification of the obtained pulp using D-Ep-D and OO-D-Ep-D bleaching sequences produces several dissolving pulps characterized by a high viscosity 695 cm3/g and brightness 89.5% ISO, indicating low degradation of cellulose during DES pulping. DES pulping exhibited considerable potential to remove the hemicelluloses from wood chips and produce high-quality dissolving pulps. This could be attained through shorter pulping operations conducted at a lower temperature and a higher screened yield compared to current dissolving pulp production operations.

Evaluation of hardwood or softwood bark biomass as feed materials for aqueous-phase reforming gasification process

In the present study, pine (Pinus brutia) and poplar (Populus alba) tree barks, softwood and hardwood representative biomass were evaluated for production of gas biofuel, hydrogen by aqueous-phase reforming. The proximate composition, elemental composition, higher heating values (HHVs), proximate thermogravimetric and differential thermogravimetric analysis (TGA/DTG), fourier transform infrared (FT-IR), and volatile composition of these biomass materials were determined and their effect on gasification performance of the softwood and hardwood biomass were evaluated. Gasification was performed by aqueous-phase reforming of solubilized liquid fraction of the biomass materials in presence of carbon-supported Pd catalyst which was synthesized in the present study. Softwood contained significantly higher levels of ash and volatile matter, with lower hemicellulose but higher lignin content. Gasification results showed that softwood produced slightly higher amounts of hydrogen with significantly lower carbon monoxide compared to hardwood. Although solid hardwood bark composition was expected to produce more gaseous products, the results observed were opposite. The dissolution of biomass in pressured hot water prior to gasification resulted in a more dilute hydrolysate in softwood compared to hardwood, positively influencing the gasification performance. Despite of many advantages of the aqueous-phase reforming (APR) gasification process used in the present study, the process still needs to be improved further to make the process more economical. To increase the advantage of this process, new catalysts that are more robust and active and have high stability in organic-rich APR conditions should be developed.

Comparative computational fluid dynamics analysis of fast pyrolysis of agricultural feedstocks across different biomass categories

This article presents a comprehensive Computational Fluid Dynamics (CFD) assessment of fast pyrolysis of three different agricultural feedstocks representing three different categories: Red oak (hardwood), Switchgrass (herbaceous biomass), and Picea glauca (softwood). The study aimed to evaluate the performance of each feedstock based on particle density, temperature distribution, and volume fraction distribution. The comparison of the simulation results with experimental data showed an average error factor below 13%. The study discovered that Red oak had the highest bio-oil production yield, followed by Switchgrass, which had a yield 10% lower, and Picea glauca, which had the weakest performance having a yield 20% lower than Red oak. Interestingly, optimal operating conditions for the production of bio-oil across all three feedstocks comprised a temperature of 500 °C and particle size of approximately 400 μm. However, increasing the pyrolysis temperature resulted in an increase in gas yield, whereas increasing particle size led to a rise in char production yield. Furthermore, the findings suggest that herbaceous biomass tends to perform better in fast pyrolysis for bio-oil production compared to softwood. This is attributed to the higher hemicellulose content in herbaceous feedstock which has a significant impact on bio-oil yield compared to cellulose and lignin. Moreover, hardwood and herbaceous samples, which have similar levels of cellulose and hemicellulose, demonstrated superior performance compared to softwood, which has lower hemicellulose content. Nonetheless, herbaceous biomass had about 10% extractable content, which made it perform weaker than hardwood.

Biomass yield, quality, nutrient composition, and feeding value of oat (Avena sativa) silage subjected to different wilting durations and/or inoculant application.

In this study, we evaluated the biomass yield, physico-chemical characteristics, nutrient composition, and feeding value of oat (Avena sativa) grown without irrigation ensiled with or without supplemental inoculant following different wilting durations. Oat forage at early dough stage (79days after sowing) were harvested to assess the biomass yield, nutrient contents, and mineral composition. Oats were ensiled with or without the addition of inoculant and different wilting durations (0, 24, and 48h) in 3 × 2 factorial arrangement. After the ensiling (120days), the oat silages were opened, quality was measured in terms of pH, ammonia nitrogen (NH3-N), smell, structure, color, and Flieg point. Nutritional composition and feeding values were analyzed in oat silages. Oat grown without irrigation yielded 32 ton/ha fresh matter. Mean dry matter (DM), organic matter, crude protein (CP), crude fiber, crude ash, ether extract, nitrogen free extract, acid detergent fiber (ADF), neutral detergent fiber, acid detergent lignin, non-structural carbohydrates, hemicellulose, and in vitro dry matter digestibility of oat forage were 32.77%, 90.41%, 11.31%, 28.69%, 9.59%, 3.99%, 46.43%, 36.32%, 63.98%, 7.22%, 11.14%, 27.67%, and 74.81%, respectively. Addition of inoculant had no effect on the quality, nutritional composition, and feeding values of oat silages. Increasing wilting durations linearly increased the pH (P = 0.005) and decreased the smell score (P = 0.028) of ensiled oat. A linear increase was seen in the DM content of ensiled oat after increasing wilting durations (P = 0.001). Oat ensiled without wilting had greater CP content (P = 0.010 and linear P = 0.011) and lower ADF content than those ensiled after 24 or 48h of wilting (P = 0.013 and linear P = 0.007). Silages subjected to 24 or 48h of wilting had lower hemicellulose content (P = 0.019 and linear P = 0.012) and digestible DM (P = 0.013 and linear P = 0.007) than those without wilting. In conclusion, inoculant may not affect the quality, composition and feeding values of ensiled oat grown without irrigation whereas, wilting at different durations may negatively affect the pH, smell, CP, ADF, and feeding values of ensiled oats.

Semi-Simultaneous Saccharification and Fermentation Improved by Lignin and Extractives Removal from Sugarcane Bagasse

Lignocellulosic biomass and agro-industrial residues are a source of fermentable sugars; however, pretreatments are needed to overcome biomass recalcitrance. This study evaluated the effect of sugarcane bagasse hydrolysis and fermentation in response to dilute acid pretreatment. In natura bagasse, extractive-free bagasse, partially delignified bagasse, and bagasse with added butylated hydroxytoluene antioxidant were pretreated with diluted acid and investigated in semi-simultaneous saccharification and fermentation (S-SSF). The effect of butylated hydroxytoluene (BHT) resulted in lower yields of inhibitors in the liquid fraction of the acid pretreatment (0.01 g L−1 of furfural, 0.01 g L−1 of 5-hydroxymethylfurfural, and 0.68 g L−1 of acetic acid). Partially delignified material and material with BHT resulted in biomass with low hemicellulose and lignin contents, indicating that BHT influenced lignin removal. Extractives removal showed benefits for the acid pretreatment, decreasing the dioxane-soluble material, and a higher yield of glucose and ethanol via S-SSF for the partially delignified material. Enzymatic saccharification of partially delignified material showed 87% of cellulose conversion (24 h with 15 FPU/g), and after 48 h of S-SSF (25 FPU/g), residual 7.06 g L−1 of glucose and production of 15.17 g L−1 of ethanol were observed. The low content of extractives, lignin, and dioxane soluble material resulted in better cellulose accessibility and ethanol yield. Chemical compounds can help remove lignin from biomass favoring ethanol production by S-SSF.

The flame spread performance over discrete wooden chips varying wood species

Wood is believed to be a good material used for the thermal insulation of building. However, the wood species vary greatly from region to region in China. With an aim to have a deep understanding of the influence of wood species on upward flame spread performance, a series of tests were conducted to obtain the profile of mass loss rate (MLR), flame spread rate (FSR), total burning duration (TBD), and the maximum flame characteristic length (MFL) by using a traditional flame spreading measurement facility. During the tests, beech wood, fir wood, pine wood, camphor wood and elm wood were selected as typical samples. The results and discussion indicate that wood species imposed a strong effect on the flame spread performance. The total burning duration (TBD) of wood with high moisture content and high solidity is significantly higher than that of other types of wood. Softwoods with higher lignin content and lower hemicellulose can increase the FSR to a certain extent. Moreover, the moisture content of wood is found to have a big impact on the MLR. Based on the discussion of different parameters, it can be judged that the fire safety of the historic wooden buildings made of Fir wood is more excellent than others.

Physico-chemical characterization of Grewia Monticola Sond (GMS) fibers for prospective application in biocomposites

ABSTRACT New fibers extracted from plant barks are a recent subject of investigation as possible fillers for polymer composites. In this work, Grewia Monticola Sond (GMS) fibers have been characterized from a morphological, chemical, and thermal point of view. This involved using a number of techniques, including Fourier infrared spectroscopy (FTIR), X-ray diffraction (×RD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), atomic force microscopy (AFM), and 13C nuclear magnetic resonance (NMR). Results indicated that GMS fibers have relatively high cellulose (55%), with 33.5% crystallinity index and a crystallite size of 4.89 nm, and lower hemicellulose (14%) and lignin (15%) contents. The fibers showed cellulose degradation onset at around 324°C, while kinetic activation energy (74.18 kJ/mol) is quite low. The roughness of the fibers was in the range expected for similar natural fibers, and they may be considered silky according to their kurtosis values. As for possible application in composites, they would definitely withstand process temperatures with thermoplastics. However, their not very high crystallinity and low crystallite size might suggest a limited strength, to be verified in future after optimizing GMS fiber extraction from bark.

Multi-microscopy techniques combined with FT-IR spectroscopy reveals the histological and biochemical causes leading to fruit texture difference in oriental melon (Cucumis melo var. Makuwa Makino)

Multi-microscopy techniques and Fourier transform infrared (FT-IR) spectroscopy were used in this study to investigate the intrinsic causes leading to fruit texture difference between two cultivars of oriental melon ‘HDB’ (crisp) and ‘HPM’ (mealy). On the histological aspect, orderly arranged regular-shaped cells with tissue natural fracture pattern showed cell rupture in ‘HDB’ versus loosely arranged irregular-shaped cells with tissue natural fracture pattern showed cell-to-cell separation in ‘HPM’ of sarcocarp are histological causes for crisp and mealy fruit texture, respectively. On the biochemical aspect, FT-IR spectra (4000–850 cm−1) of sarcocarp tissue cell wall materials (CWM) happened a dramatic change at the mature stage in ‘HPM’, but not in ‘HDB’. Insightly, the lower de-methyl-esterified homogalacturonan (HG) abundance with higher water-soluble pectin (WSP) ratio and lower hemicellulose (HC) content contribute a poor intercellular adhesion in ‘HPM’ middle lamella (ML) at the mature stage compared to ‘HDB’.

Comparisons of Ramie and Corn Stover Silages: Effects on Chewing Activity, Rumen Fermentation, Microbiota and Methane Emissions in Goats

The study aimed to investigate the nutritional value of ramie (Boehmeria nivea) silage, and its consequences for chewing activity, rumen fermentation, and enteric methane (CH4) emissions in goats, by comparing it with corn stover (CS) silage. An in vitro ruminal experiment was firstly performed to investigate the substrate degradation and fermentation of CS and ramie silage. The ramie silage diet was formulated by replacing 60% of CS silage with ramie silage (dry matter (DM) basis). Eight female Xiangdong Black goats (a local breed in Southern China, 1 to 1.2 years of age) with BW of 21.0 ± 1.05 kg were used for this experiment and were randomly assigned to either one of the two dietary treatments in a cross-over design. The ramie silage had higher crude protein (CP) and ash content and lower hemicellulose content, together with decreased (p < 0.05) nutrient degradation and methane production and increased (p < 0.05) acetate molar percentage and acetate to propionate ratio through in vitro ruminal fermentation. Feeding the ramie silage diet did not alter feed intake (p > 0.05), decreased (p < 0.05) nutrient digestibility, and increased (p < 0.05) chewing activity and rumination activity, with reductions (p < 0.05) in eating activity and idle activity. Although feeding the ramie silage diet caused a greater (p < 0.05) molar percentage of acetate and lower molar percentage of propionate, it decreased the rumen-dissolved CH4 concentration and enteric CH4 emissions (p < 0.05). Feeding the ramie silage diet did not alter (p > 0.05) the population of bacteria, protozoa, and fungi; it increased the 16S rRNA gene copies of Ruminococcus flavefaciens (p < 0.05). Further 16SrRNA gene amplicon analysis indicated a distinct bacterial composition between the two treatments (p < 0.05). Feeding the ramie silage diet led to a lower abundance of genera Lawsonibacter, Sedimentibacter, Saccharofermentans, Sediminibacterium, and Bifidobacterium (p < 0.05). Ramie can be an alternative forage resource to stimulate chewing activity and reduce CH4 emissions in ruminants.

Oxidative delignification: The roles of lignin reactivity and accessibility

This study compared oxidative delignification of birch kraft pulp fibers to pulp fibers from acid hydrotropic fractionation (AHF) using p-toluenesulfonic acid (p-TsOH). Under oxygen delignification at 20% consistency, AHF pulps with lower hemicellulose content showed higher delignification than kraft pulps with similar lignin content despite its residual lignin (cellulosic enzymatic lignin, CEL) being less reactive with fewer β-O-4 ether aryl linkages based on 2D13C-1H nuclear magnetic resonance (NMR) spectroscopy. The water retention value (WRV) of AHF pulp fibers, a measure of fiber accessibility to water or oxidative chemicals, was substantially greater than that of kraft pulp fibers. Similar comparison of various AHF pulps further suggested that fibers with lower hemicellulose content were easier to delignify (bleach) despite having more lignin with lower reactivity (fewer β-O-4 linkages). Additionally, the present study also indicated that oxygen delignification was more effective at high fiber consistency, which can be attributed to thinner water films on the fiber surfaces at higher fiber loadings. These results indicated that mass transfer was the rate controlling process in oxidative delignification of wood fibers.

Enhanced enzymatic digestibility of water lettuce by liquid hot water pretreatment

Liquid hot water (LHW) pretreatment conditions were optimized from various severities using response surface methodology to convert water lettuce (WL; Pistia stratiotes) to fermentable sugars to enhance the enzymatic digestibility of pretreated WL. The LHW pretreatment was performed using a 2% (w/v) WL loading over a temperature range of 152–208 °C and pretreatment times of 9–51 min. The optimal conditions for the LHW pretreatment were determined to be 190.7 °C for 51 min [a severity factor (log R0) of 4.38], which gave the highest total reducing sugar yield (17.26 g/L) and a high removal level of hemicellulose (68.32%) in the subsequent cellulase digestion. The physical structure of WL after pretreatment revealed changes to the WL structure that increased its susceptibility to attack by enzymes; an increased crystallinity, surface area, and total pore volume together with a lower hemicellulose and lignin content compared to the untreated WL.

ON THE FRUIT AND VEGETABLES PLANT CELL WALL HEMICELLULOSE COMPOUND STRUCTURE

Plant raw material biochemical characteristics may vary depending on it`s species, organ and tissue type and even cultivation facilities, and this dependence may discover a great field of interest for researches. These researches may result not only in fundamental information on plant biochemical development regularity, but in determination of plant potential as a raw material for biological active additives obtaining. The neutral oligo- and polysachharides of cell wall belonging to hemicelluloses have different structure depending on plant tissue type and plant species. The polysachharides isolating from plant raw material can be used in food technology as thickeners and sorbents (pectin, gums), so the structure determinating for different plant species can be useful in technological potential determination of studying plant raw material for food additives obtaining. The article presents the review on hemicelluloses structures and hemicelluloses complex researches for different types of fruit and berries raw material in purchase to estimate the availability of the raw plant material as a food additives source. Analyzed resources allows us to conclude that there is no visible regularity in hemicellulose complex of studied fruit and berry species, and all of these species can be a used as a sourse of polysachharides, excepts black currant because of high level of oligosachharides and sugar beet because of low hemicellulose yields. Gelling ability appears only in polysachharides.

Extraction and Characterization of Agricultural Discarded Sesbania Aculeata Stem Waste as Potential Alternate for Synthetic Fibers in Polymer Composites

ABSTRACT Natural fibers have a wide range of potential applications in green composite manufacturing industrial sectors due to their renewable eco-friendly nature and remarkable properties. In the present work, the physico-chemical, thermal, tensile and morphological properties of Sesbania Aculeata Fibers (SAFs) are presented in first time. Chemical analysis results show that SAFs have relatively higher α-cellulose (70.1 wt.%) with lower hemicelluloses (10.2 wt.%), lignin (12.1 wt.%) and wax (0.6 wt.%) content. Structural analysis of SAFs was performed through fourier transform infrared (FTIR), energy dispersive X-ray microanalyzer (EDX) and NMR spectroscopy. X-ray diffraction (XRD) analysis evidenced that SAFs have a crystallinity index (CrI) of 65.5% with a crystalline size of 4.6 nm. The mechanical properties of the SAFs were investigated through a single fiber tensile test and fiber pull out test. The thermal stability of the SAFs was examined by thermogravimetric analysis (TGA). Based on the results, it is predicted that the SAFs can be used as a potential reinforcement in the polymer matrix composite structure.

Kalappia celebica, an endemic wood from Sulawesi Island: Chemical composition and its resistance against white rot fungi Ganoderma tsugae and G. lucidium

Kalapi wood (Kalappia celebica kosterm) is endemic to Sulawesi Island and is a monotype species in the Fabaceae family with limited distribution. This study investigates the chemical composition and natural durability of Kalapi (K. celebica Kosterm) wood against white rot fungi Ganoderma tsugae and G. lucidium. This study was conducted based on the TAPPI standard for moisture analysis content, ASTM-D for extractive content, holocelluloce, and lignin, and method Cross and Bevan for cellulose. Durability observation was conducted in 12 weeks by assessing the percentage damage of wood samples caused by the fungi according to SNI standards 01-7207-2014. Results show that K. celebica has holocelullose, cellulose, and extractives at a high level, lignin was moderate, and had low hemicellulose. The results of testing the durability of wood shown that K. celebica has resistance to G. tsugae attack (class II) but is not resistant to G. lucidium (class IV), with an average weight loss of 3.14 % and 18.82 %, respectively.

Hemicellulolytic bacteria in the anterior intestine of the earthworm Eisenia fetida (Sav.)

Tropical agriculture produces large amounts of lignocellulosic residues that can potentially be used as a natural source of value-added products. The complexity of lignocellulose makes industrial-scale processing difficult. New processing techniques must be developed to improve the yield and avoid this valuable resource going to waste. Hemicelluloses comprise a variety of polysaccharides with different backbone compositions and decorations (such as methylations and acetylations), and form part of an intricate framework that confers structural stability to the plant cell wall. Organisms that are able to degrade these biopolymers include earthworms (Eisenia fetida), which can rapidly decompose a wide variety of lignocellulosic substrates. This ability probably derives from enzymes and symbiotic microorganisms in the earthworm gut. In this work, two substrates with similar C/N ratios but different hemicellulose content were selected. Palm fibre and coffee husk have relatively high (28%) and low (5%) hemicellulose contents, respectively. A vermicomposting mixture was prepared for the earthworms to feed on by mixing a hemicellulose substrate with organic market waste. Xylanase activity was determined in earthworm gut and used as a selection criterion for the isolation of hemicellulose-degrading bacteria. Xylanase activity was similar for both substrates, even though their physicochemical properties principally pH and electrical conductivity, as shown by the MANOVA analysis) were different for the total duration of the experiment (120 days). Xylanolytic strains isolated from earthworm gut were identified by sequence analysis of the 16S rRNA gene. Our results indicate that the four Actinobacteria, two Proteobacteria, and one Firmicutes isolated are active participants of the xylanolytic degradation by microbiota in the intestine of E. fetida. Most bacteria were more active at pH 7 and 28 °C, and those with higher activities are reported as being facultatively anaerobic, coinciding with the microenvironment reported for the earthworm gut. Each strain had a different degradative capacity.

Hardened wood as a renewable alternative to steel and plastic

Hardened wood as a renewable alternative to steel and plastic

THE IMPROVEMENT OF RAMIE FIBER PROPERTIES AS COMPOSITE MATERIALS USING ALKALIZATION TREATMENT: NaOH CONCENTRATION

THE IMPROVEMENT OF RAMIE FIBER PROPERTIES AS COMPOSITE MATERIALS USING ALKALIZATION TREATMENT: NaOH CONCENTRATION. Ramie fiber is a plant fiber that has good quality and potential as a constituent of composite materials. In this study, ramie fiber surface modification was conducted through alkalization with various at 0%, 4%, 5%, 6%, 7%, 8%, and 9% concentrations of NaOH using a magnetic stirrer with a speed of 200 rpm at 70οC for 5 hours. Alkaline ramie fibers are characterized using the Cheson method to determine the chemical composition of ramie fiber, FT-IR test to determine the function group of ramie fiber, morphological test to know the surface structure and diameter of ramie fiber, as well as tensile test to know the tensile strength and tensile modulus of PLA/ramie composite. Overall, the increase of NaOH concentration up to 8% percentage was able to increase the level of cellulose and lignin ramie fibers by 88.180 % and 2.444 %, as well as lower hemicellulose levels of 1.446 %. The alkalization treatment of 8% NaOH, optimally reduces the hydrophilic properties of the fiber. The increased concentration of NaOH makes the fiber surface cleaner and the diameter smaller, but the fiber structure is damaged at a concentration of NaOH more than 8%. Tensile test results showed that alkalized ramie fibers with an 8% concentration of NaOH produced PLA/ramie composites with the highest tensile strength and tensile modulus of 57.37 MPa and 248.25 MPa. Thus, the optimum ramie fiber properties are increased using alkalization with an 8% concentration of NaOH.

Radial variability of fibrovascular bundle properties of salacca (Salacca zalacca) fronds cultivated on Turi Agrotourism in Yogyakarta, Indonesia

Abstract. Hakim L, Widyorini R, Nugroho WD, Prayitno TA. 2021. Radial variability of fibrovascular bundle properties of salacca (Salacca zalacca) fronds cultivated on Turi Agrotourism in Yogyakarta, Indonesia. Biodiversitas 22: 3594-3603. Fibrovascular bundles have properties variability not only based on species and varieties but also parts of species. This study, therefore, aims to characterize the FVB fundamental properties (anatomical, chemical, physical and mechanical) of Salacca zalacca (Gaertn.) Voss fronds, based on radial direction. The salacca fronds were divided into three parts, outer, middle as well as inner positions. Then the FVB's anatomical and physical properties were observed by light microscope and gravimetry analysis, respectively. Meanwhile, the variability of chemical and mechanical properties was investigated based on the ASTM standard. According to the results, the outer position has a higher variability of diameter, density, cellulose, lignin, and mechanical properties than the inner position, but has a lower hemicellulose value than the middle and inner position. Furthermore, the relationships between the anatomical, physical, chemical, and mechanical properties were discovered to form a pattern where increasing the mechanical properties is influenced by density and ratio vascular tissue area to total transverse area. Based on the results, the fibrovascular bundle of S. zalacca frond was concluded to possess anatomical, physical, chemical, and mechanical properties variability on the radial direction. There was a correlation between anatomical properties and mechanical properties.

Torrefaction and Thermochemical Properties of Agriculture Residues

In this study, the densification of three agriculture waste biomasses (corn cobs, cotton stalks, and sunflower) is investigated using the torrefaction technique. The samples were pyrolyzed under mild temperature conditions (200–320 °C) and at different residence times (10 min–60 min). The thermal properties of the obtained bio-char samples were analyzed via thermo-gravimetric analysis (TGA). Compositional analysis of the torrefied samples was also carried out to determine the presence of hemicellulose, cellulose, and lignin contents. According to the results of this study, optimum temperature conditions were found to be 260 °C–300 °C along with a residence time of 20 min–30 min. Based on the composition analysis, it was found that biochar contains more lignin and celluloses and lower hemicellulose contents than do the original samples. The removal of volatile hemicelluloses broke the interlocking of biomass building blocks, rendering biochar brittle, grindable, and less reactive. The results of this study would be helpful in bettering our understanding of the conversion of agricultural waste residues into valuable, solid biofuels for use in energy recovery schemes. The optimum temperature condition, residence time, and GCV for torrefied corn cobs were found to be 290 °C, 20 min, and 5444 kcal/kg, respectively. The optimum temperature condition, residence time, and GCV for torrefied cotton balls were found to be 270 °C, 30 min, and 4481 Kcal/kg, respectively. In the case of sunflower samples, the mass yield of the torrefied sample decreased from 85% to 71% by increasing the residence time from 10 min to 60 min, respectively.