High Hemicellulose Content Research Articles

Effect of Brittleness in Rice Straw on Rumen Fermentation by In vitro Gas Production Technique

The objective of this study was to examine the impact of rice straw brittleness on its efficacy as roughage for ruminants, in comparison to a wild-type variety, utilizing an in vitro study approach. The experimental design was a complete randomized design (CRD). The experimental treatments included various breeds of rice straw (RS), such as the wild-type (WT, T1), the green brittle bred line 8 and line 13 with brittleness level-3 (GBL8-B3, T2 and GBL13-B3, T3), and the purple brittle bred line 8 with brittleness level-5 (PBL8-B5, T4). The findings revealed that the brittleness RS group had higher levels of crude protein and hemicellulose, and lower levels of cellulose compared to the wild-type group. Brittleness RS varieties showed a significantly greater gas production accumulation (p = 0.001) and IVDMD (p = 0.003) compared to the WT group. At 8 h post-incubation, the brittleness RS group showed significantly higher (p = 0.004) total of volatile fatty acids concentration compared to the WT group. After 1 h of post-incubation, GBL8-B3 exhibited the highest (p = 0.032) proportion of propionate and the lowest (0.009) C2:C3 ratio. Additionally, the brittleness RS did not have any effect on the population of ruminal microorganisms. Based on the brittleness of RS, it can be deduced that it has a greater potential as a roughage source when compared to the wild-type variety, consequently enhancing the quality of RS for roughage intake by ruminants. HIGHLIGHTS Brittleness RS exhibited elevated levels of CP, high hemicellulose content, and lower cellulose levels compared to the WT group. The brittleness RS group displayed a rapid degradation rate impacting the total VFAs concentration and C2:C3 ratio, with the GBL8-B3 group demonstrating superior utilization efficiency. The brittleness of RS is indicative of a higher potential as a roughage source when compared to the wild-type variety, thereby improving the quality of rice straw for roughage consumption by ruminants. GRAPHICAL ABSTRACT

Determining the impact of different types of biofuels on the quality of iron ore pellets

The object of this study is the process of roasting iron ore pellets. The study solves the task of replacing fossil fuel with plant-based fuel in order to reduce environmental load and ensure the stable quality of pellets, which is necessary for use in blast furnaces. The influence of biofuel content at a given temperature and air speed on the strength of pellets after roasting was studied. As a result of the research, it was established that the fuel content has a decisive effect on the strength of pellets. Among all types of fuel that were investigated, pellets with the addition of sunflower husks and wood had the highest strength that meets the requirements for blast furnace melting of 200 kilograms. The use of wheat straw and charcoal does not make it possible to completely replace solid fuel in the layer of pellets. The results show that the use of up to 0.36 % of sunflower husk makes it possible to increase the strength of burned pellets compared to samples without biofuel content. Adding all other considered types of fuel reduced the strength of the pellets. These results are explained by the different content of lignin, cellulose, and hemicellulose, which determines the characteristics of the biomass. The high content of cellulose and hemicellulose allows for high hydrophilicity due to the high number of OH groups and positively affects the formation of raw pellets. Volatile substances released during the combustion of biofuel contribute to the formation of spherical pores, as well as their uniform distribution, which prevents the propagation of cracks under load. Research results make it possible to establish the optimal roasting mode, decrease harmful emissions, and bring down costs by reducing fossil fuel consumption

Evaluating the role of feedstock composition and component interactions on biomass gasification

Biomass gasification offers a solution to waste concerns while generating clean energy. This study examines the gasification of pine sawdust (PS), used ground coffee (UGC), and wheat straw (WS) under identical conditions. The compositions of the biomass samples are determined, and the gasification of individual components (hemicellulose, cellulose, and lignin) are conducted to understand the process’ dependency on the biomass characteristics. The results suggest cellulose and cellulose-rich biomass (PS) produces more tar and less hydrogen than lignin and lignin-rich biomass (UGC and WS). High lignin and hemicellulose content leave more char. Gasification of PS, UGC, and WS yields 12.7, 15.7, and 17.2 vol% hydrogen, respectively. Additionally, cellulose, hemicellulose, and lignin gasification yield 10.5, 22.1, and 30.4 vol% hydrogen, respectively. Comparing experimental and theoretical values for the three biomass samples reveals significant differences due to component interactions. Thermogravimetry analysis (TGA) indicates significant degradation interactions between hemicellulose-lignin, cellulose-hemicellulose, and cellulose-lignin. It is concluded that high cellulose content biomass shows more predictable results, while high lignin and hemicellulose biomass increases secondary reactions or interactions, exacerbating predictability. These findings assist in estimating gasification performance for better biomass selection.

Xylitol production from passion fruit peel hydrolysate: Optimization of hydrolysis and fermentation processes

The passion fruit peel (PFP) has a high cellulose and hemicellulose content, which can be used to produce fermentable sugars. In this context, this study aims to optimize the release of xylose and the production of xylitol from PFP. The optimized conditions were 0.71 M dilute sulfuric acid and a 21.84-minute treatment, yielding 19.03 g/L of xylose (PFP-1). Different PFP hydrolysates were evaluated to improve xylitol production by the yeast Kluyveromyces marxianus ATCC 36907: PFP-2 (PFP1 treated with Ca(OH)2), PFP-3 (PFP-1 treated with Ca(OH)2 and activated carbon), PFP-4 (PFP-3 with biological elimination of glucose with S. cerevisiae, and concentrated at different xylose concentrations). The applied methods resulted in higher xylitol production (14.97 g/L), when PFP hydrolysate was detoxified with Ca(OH)2, treated with activated charcoal for 1 h, biotreated for glucose removal, and concentrated to 40 g/L of xylose.

Oil palm frond leaves (OPFLs), a high recalcitrant biomass as an alternative cellulose source for glucose conversion

Among the oil palm biomass, oil palm frond leaves (OPFLs) are under-valued since they can be classified as a high recalcitrance feedstock due to the high lignin and hemicellulose content. This work proposes a new way of using OPFLs as alternative cellulose sources for glucose conversion by an application of various pre-treatments at varying parameters. From green pre-treatment, steam explosion (SE) is much more effective in disrupting the OPFLs structure in contrast to hydrothermal (HT) pre-treatment, by a vast dissolution of hemicellulose and depolymerization of lignin. The pre-impregnation with H2SO4 prior to steam explosion was beneficial to enhance the hemicellulose removal up to 89.94 %. The 2D-HSQC NMR analysis divulged the reduction of ß-O-4 linkage and S/G value after the SE and HT pre-treatment, verifying the degradation of lignin-carbohydrate linkage in OPFLs. Meanwhile, the dilute NaOH pre-treatment enhanced the delignification by 87.14 %. SEM analysis revealed a well-disrupted structure of pre-treated OPFLs exposing a higher cellulosic fraction, whereas SEC analysis divulged a decreasing pattern of degree of polymerization of cellulose. The enzymatic analysis revealed that pre-treated OPFLs yielded higher glucose ranging from 29.81 % to 49.98 % w/w, which was ∼3-fold higher than raw OPFLs (14.31 % w/w). A maximum cellulose digestibility (100 %) was achieved by steam-exploded OPFLs after 72 h of enzymatic hydrolysis. This suggests the potency of various pre-treatments to enhance enzymatic saccharification of OPFLs producing a higher glucose yield.

The Impact of Biomass Composition Variability on the Char Features and Yields Resulted through Thermochemical Processes.

This paper explores the intricate relations between biomass polymeric composition, thermochemical conversion routes, char yields and features in order to advance the knowledge on biomass conversion processes and customize them to meet specific requirements. An exhaustive characterization has been performed for three types of biomasses: (i) spruce bark, a woody primary and secondary residue from forestry and wood processing; (ii) wheat straws-agricultural waste harvest from arable and permanent cropland; and (iii) vine shoots, a woody biomass resulting from vineyard waste. Chemical (proximate and ultimate analysis), biochemical, trace elements, and thermal analyses were performed. Also, Fourier transform infrared spectroscopy, Scanning Electron Microscopy, and thermogravimetric analysis were conducted to establish the compositional and structural characteristics of feedstock. The main polymeric components influence the amount and quality of char. The high hemicellulose content recommends wheat straws as a good candidate especially for hydrothermal carbonization. Cellulose is a primary contributor to char formation during pyrolysis, suggesting that vine shoots may yield higher-quality char compared to that converted from wheat straws. It was shown that the char yield can be predicted and is strongly dependent on the polymeric composition. While in the case of spruce bark and wheat straws, lignin has a major contribution in the char formation, cellulose and secondary lignin are main contributors for vine shoots char.

Conversion of WastePaper into Dissolving Pulp: A Path for Circular Bioeconomy

AbstractFollowing the circular bioeconomy concept, this work studies the potential of an industrial wastepaper residue as an alternative raw material for dissolving pulp‐grade production. Prehydrolysis‐kraft cooking (PHK), elemental chlorine‐free (ECF) bleaching, and acid‐washing treatments were applied to achieve that aim. Considering the high lignin and hemicellulose content of the raw material, it was submitted to PHK pulping to enhance its cellulose content by removing those components. This processing resulted in a remarkable increase of 84 % in pulp Fock reactivity (from 45.6 % to 84.1 %). The dissolution extension and time in solvent systems LiCl/DMAc and NMMO/H2O were discussed regarding the pulp physicochemical properties. The dissolving pulp produced under this work showed great potential as raw material for textile applications, particularly highlighting the innovative process developed to improve its solubility.

Preliminary Study on the Chemical Properties of Non-Oak Wood Species: Suitability for Wooden Barrel Production

Oak wood (Quercus spp.) is the traditional and widely utilized raw material for wooden barrels deployed for the maturation of alcoholic beverages. The chemical compounds, extractives, lignin, hemicellulose, and others, in the wood are claimed to significantly influence the sensory attributes of the beverages during the aging process. The study aimed to assess the chemical properties of non-oak wood species. These species include Sandoricum koetjape (Burm. f.) Merr., Swietenia macrophylla King, Acacia mangium Willd., and Eucalyptus camaldulensis Dehnh., which are all locally available. The investigation was prompted by the limited availability and exorbitant fees associated with the importation of oak barrels into the country. The chemical properties of these non-oak wood species were compared to those of Quercus alba. The effects of tree species (TS) and tree portions (TP) on the chemical properties were evaluated using different TAPPI and ASTM methods. Results showed that S. macrophylla had the highest solubilities with 29.12, 14.64, and 9.09% in 1% sodium hydroxide solution, hot water, and ethanol-cyclohexane, respectively – higher than the solubilities of Q. alba in the three solvents. Meanwhile, E. camaldulensis had the highest lignin content (23.82%), whereas S. koetjape had the lowest lignin and S. macrophylla had the highest hemicellulose content. Q. alba had higher lignin content than all the species studied. The species’ alpha-cellulose contents were lower than that of Q. alba, whereas their holocellulose values were higher. Overall, the effect of TP (top, middle, and bottom) on the chemical composition of each of the wood samples was determined to have little to no effect on the chemical properties, hence indicating a relatively homogeneous distribution of chemical components from top to bottom. On the other hand, TS highly significant effect on the wood species on all the chemical properties analyzed. Overall, locally available non-oak wood species could be suitable as a raw material for wooden barrel fabrication. However, there is a need to conduct further studies on their anatomical, physico-mechanical, and other chemical properties.

Comprehensive assessment of turfgrass wear tolerance: A study on mechanical and chemical traits

A key criterion in the selection process for turfgrass breeding is effective wear tolerance, indicating the plant's capacity to endure forces that may impact leaves, stems, crowns, and roots. In this study, the correlation between mechanical and chemical traits and the wear tolerance of 37 cultivars belonging to seven turfgrass species was examined. Mechanical properties and fiber characteristics of wide range of turfgrass cultivars were determined and compared for the first time. The evaluation of turf wear tolerance (described as turf cover index, TCI) was conducted through a three-year field trial using a Brinkman traffic simulator. Tensile tests were conducted to determine biomechanical parameters. According to the TCI, the most wear-resistant cultivars were those of Lolium perenne, Most of these cultivars demonstrated a TCI below 0.1. The cultivar 'Nira' was the most resistant, with a TCI of − 0.285. The least resilient cultivars belonged to Festuca ovina and Festuca rubra, all exhibiting TCI values above 0.6. Agrostis stolonifera and Agrostis capillaris were characterised by lower cellulose and acid detergent fiber content but high hemicellulose content. The opposite result was determined for Festuca rubra and Festuca ovina. The highest hemicellulose ratio was obtained for Poa pratensis. Lolium perenne was characterised by relatively high content of cellulose, lignin and hemicellulose. Cultivars of Festuca arundinace distinctly differed from other cultivars, demonstrating higher mechanical resistance with an average force-to-break of 3.73 N. Cultivars of Agrostis stolonifera and Agrostis capillaris reached force-to-break values up to 1.0 N. The relationships between TCI and fiber composition of turfgrass leaves were significant for crude fiber, NDF and hemicellulose content. Thus higher NDF and hemicellulose content resulted in higher force-to-break and work-to-break parameters.

Environmental and economic analysis of the transformation of paper mill sludge treatment technologies in China.

Paper mill sludge (PMS) is featured with a high content of cellulose and hemicellulose, and using its characteristics to make paperboard can achieve a high-value utilization of PMS, which has attracted growing interest. In this study, currently prevalent landfill, incineration technologies (generating heat and electricity by incineration), and three paperboard technologies (medium density fiberboard, pulp board, and corrugated paper) were evaluated and compared via life cycle assessment (LCA) and life cycle costing (LCC) methods. LCA results show that the PMS-to-pulp board outperforms others with an energy conservation and emission reduction (ECER) value of - 2.86 × 10-8, while the landfill exhibits the highest overall environmental impact with an ECER value of 4.80 × 10-9. LCC results reveal that the PMS-to-pulp board delivers the highest economic profit with $257.357, while the landfill is the lowest with $ - 35.63. The PMS paperboard technologies are more economically friendly than the incineration technologies due to additional electricity/steam consumption during the PMS pre-drying process in incineration. In addition, different scenarios were set up to explore national GHG emission reduction potential by increasing paperboard technologies application rate and reducing the proportion of landfill and incineration. The scenario analysis suggests that replacing 90% of landfill and incineration ratio with PMS paperboard technologies could tremendously improve the overall emission reduction performance with - 9.08 × 1010 kg CO2 eq. This result indicates that the PMS treatment technology transformation has a significant favorable impact on the achievement of the "carbon neutrality" target.

Sugar content improvement by sonication in the pretreatment of empty fruit bunch hydrolysis

The empty palm fruit bunches (EFB) has great potential as an alternative feedstock for bioethanol production due to its high content of cellulose and hemicellulose. However, besides cellulose and hemicellulose, EFB also contains lignin, which can hinder the hydrolysis process and therefore requires delignification. This study aims to determine the effect of sonication in alkali delignification on the sugar content of hydrolysis. Ultrasonic in 37 KHz was performed at a temperature of 80 °C. Sonication process durations ranged from 30 minutes to 150 minutes using a 10 % (w/v) NaOH solvent. The hydrolysis of EFB fibers was carried out in a water bath at 80 °C using a 0.5 N sulfuric acid solvent in a ratio of 1:20 (w/v) for 2 hours. The sugar content was measured using the phenol-sulfuric acid method with UV-Visible spectrophotometry. In this study found that the ultrasonic irradiation time length gave good results at a time limit not exceeding 90 minutes due to hemicellulose characteristics . The highest sugar content was obtained at a sonication duration of 90 minutes, measuring 20.60 mg/L, which was 38.5 % higher than alkali delignification without sonication for 150 minutes. SEM analysis indicated that EFB had undergone changes in the surface morphology and structure. Qualitative FTIR analysis showed that the hydrolysis solution contained glucose and pentose, which are products of hydrolyzed cellulose and hemicellulose.

Production of activated carbon from agave residues and its synergistic application in a hybrid adsorption-AOPs system for effective removal of sulfamethazine from aqueous solutions

Tequila production in Mexico generates large quantities of agave bagasse (AB), a waste that could be used more efficiently. AB has a high cellulose, hemicellulose, and lignin content, which allows its use as a precursor for synthesizing carbonaceous materials. In the present work, the synthesis of activated carbon impregnated with Fe2+ (AG-Fe-II) and Fe3+ (AG-Fe-III) was carried out and evaluated in a hybrid adsorption-AOP (advanced oxidation process) methodology for sulfamethazine removal (SMT). The materials were characterized before and after the process to determine their morphological, textural, and physicochemical properties. Subsequently, the effect of the main operational variables (pH, initial SMT concentration, mass, and activator dosage) on the hybrid adsorption-degradation process was studied. The Fenton-like reaction was selected as the AOP for the degradation step, and potassium persulfate (K2S2O8) was used as an activating agent. The main iron crystallographic phases in AG-Fe-II were FeS, with a uniform distribution of iron particles over the material's surface. The main crystallographic phase for AG-Fe-III was Fe3O4. The hybrid process achieved 61% and 78% removal efficiency using AG-Fe-II and AG-Fe-III samples, respectively. The pH and initial SMT concentration were the most critical factors for removing SMT from an aqueous phase. Finally, the material was successfully tested in repeated adsorption-degradation cycles.

Catalytic Supercritical Water Gasification of Canola Straw with Promoted and Supported Nickel-Based Catalysts.

Lignocellulosic biomass such as canola straw is produced as low-value residue from the canola processing industry. Its high cellulose and hemicellulose content makes it a suitable candidate for the production of hydrogen via supercritical water gasification. However, supercritical water gasification of lignocellulosic biomass such as canola straw suffers from low hydrogen yield, hydrogen selectivity, and conversion efficiencies. Cost-effective and sustainable catalysts with high catalytic activity for supercritical water gasification are increasingly becoming a focal point of interest. In this research study, novel wet-impregnated nickel-based catalysts supported on carbon-negative hydrochar obtained from hydrothermal liquefaction (HTL-HC) and hydrothermal carbonization (HTC-HC) of canola straw, along with other nickel-supported catalysts such as Ni/Al2O3, Ni/ZrO2, Ni/CNT, and Ni/AC, were synthesized for gasification of canola straw on previously optimized reaction conditions of 500 °C, 60 min, 10 wt%, and 23-25 MPa. The order of hydrogen yield for the six supports was (10.5 mmol/g) Ni/ZrO2 > (9.9 mmol/g) Ni/Al2O3 > (9.1 mmol/g) Ni/HTL-HC > (8.8 mmol/g) Ni/HTC-HC > (7.7 mmol/g) Ni/AC > (6.8 mmol/g) Ni/CNT, compared to 8.1 mmol/g for the non-catalytic run. The most suitable Ni/ZrO2 catalyst was further modified using promotors such as K, Zn, and Ce, and the performance of the promoted Ni/ZrO2 catalysts was evaluated. Ni-Ce/ZrO2 showed the highest hydrogen yield of 12.9 mmol/g, followed by 12.0 mmol/g for Ni-Zn/ZrO2 and 11.6 mmol/g for Ni-K/ZrO2. The most suitable Ni-Ce/ZrO2 catalysts also demonstrated high stability over their repeated use. The superior performance of the Ni-Ce/ZrO2 was due to its high nickel dispersion, resilience to sintering, high thermal stability, and oxygen storage capabilities to minimize coke deposition.

Simulation and Optimization of Biohydrogen Production from Biomass Feed via Anaerobic Digestion

AbstractBiomass energy is a renewable energy source that is carbon‐neutral, versatile, and can never go extinct. In the current study, a simulation model of an anaerobic digester with parameters such as pretreatment temperature (PTT), hydraulic retention time (HRT), and feed‐to‐water (F/W) ratio was developed and a design of experiment was created. The results showed that the higher hemicellulose content in sugarcane bagasse (SB) gave a decent H2 yield (13–23 %). The significance sequence was PTT > F/W > HRT. The optimal values were HRT of 15–16 d; F/W of 1.5 (SB), 1.26 [rice straw (RS)], and 0.5 [sawdust (SD)]; and PTT of 63.3 (SB), 68.8 (RS), and 75 °C (SD). The optimal H2 yield was 19.80 (SB), 20.94 (RS), and 21.41 % (SD). Therefore, the present simulation and optimization showed concrete results to raise H2 yield.

Composts of diverse green wastes improve the soil biological quality, but do not alleviate drought impact on lettuce (Lactuca sativa L.) growth

AbstractIntense soil cultivation and climate change have detrimental effects on soils. Solutions are needed to improve the biological quality and water holding capacity of agricultural soils. A greenhouse experiment was conducted to investigate the interactive effect of compost application and drought stress on a soil/plant system in order to determine the improvement of soil quality and plant growth and the alleviation of drought stress. Lettuce (Lactuca sativa L.) was grown under greenhouse conditions in a sandy soil with sufficient mineral fertilizer application to test the effect of five compost types (three made from municipal garden and park wastes with differing nutrient contents, one from municipal household waste, and one from farm plant residues) applied at 30 Mg ha−1 dry weight, with which we compared soil quality and plant growth to soil without compost application. Treatment pots were irrigated or subjected to drought conditions during the last 14 days of lettuce growth. Assays of potential N mineralization during 28 days, dehydrogenase and β‐glucosidase activities, and a phospholipid fatty acid (PLFA) analysis were performed to assess effects on soil biological quality. Gas exchange, leaf relative water content, biomass, nitrogen accumulation, and root tip growth of lettuce were measured to investigate compost and drought stress effects on lettuce physiology. All composts improved indices of soil biological quality significantly, except for fungal abundance, relative to soil without compost. The greatest increase was obtained from farm compost, which significantly increased potential nitrogen (N) mineralization and soil enzyme activities of β‐glucosidase and dehydrogenase by factors of 4, 2, and 43, respectively. Furthermore, soil with farm compost generally showed a higher abundance of soil microbial organisms compared with soil without compost, which could be related to its high cellulose and hemicellulose contents. The lowest abundance of microbial organisms was generally found in soil with garden and park waste compost with a medium nutrient content, which could be related to its low organic matter content. The beneficial effect of compost on soil biological quality did not lead to improved lettuce growth, which suggests that soil biological quality (ameliorated by compost application) is not important for a fast‐growing crop, such as lettuce, that is sufficiently fertilized. Drought stress reduced aboveground lettuce biomass, root tip growth, and the abundance of most soil microbial groups significantly, but compost in soil did not alleviate these negative effects. In conclusion, the farm compost made from grass–clover, straw, and vegetable residues is superior to garden and park waste and household waste composts in terms of beneficial effects on soil biological quality. Compost clearly improved soil biological quality, but did not influence lettuce's response to drought stress. The knowledge gained in this study is useful for producing tailor‐made compost with desired effects of improved soil biological quality.

A comprehensive study on an integrated approach for water hyacinth management to conserve natural water resources in India

The rapid growth of the free-floating invasive weed Water Hyacinth (WH) has caused an environmental and social menace in most water bodies. Its large mat formation not only affects the underlying aquatic species by blocking sunlight and depleting oxygen, but it also interferes with commercial activities such as fishing and transportation. Public health is also affected as it provides shelter for disease-causing mosquitoes. Additionally, it is a bio-indicator of water bodies polluted with heavy metals. Removing and managing this weed is crucial for conserving natural water resources. Various manual, mechanical, chemical, and biological methods have been tried and tested to eradicate this plant. However, each method has its limitations, and the reoccurrence of this weed in a short time calls for an innovative approach to finding sustainable solutions. Recent studies focus on utilizing this weed for commercial purposes rather than eradicating it. The high cellulose and hemicellulose content in the plant make it an excellent source for renewable fuel production. It also finds application in industries that prepare animal food, compost, and bio-fertilizers due to the high nutrient content. Many states in India are utilizing the WH plant to produce eco-friendly and creative products, thus helping in local employment generation. This study's research contribution is evaluating the advantages and drawbacks of weed removal methods, the potential of WH plants in phytoremediation and biofuel production, case studies of successful alternate uses of WH plants, and possible action plans for economically and ecologically sustainable plant management to conserve water resources in India. The specific outcome of the study is that water hyacinth management is not the responsibility of a single body or entity, but rather the responsibility of different stakeholders and their combined efforts to combat this issue at a national level.

Effect of Chemically Pretreated Water Hyacinth Co-Digested with Poultry Litter in Anaerobic Digestion

This study focuses on the biogas production from water hyacinth (WH) while co-digested with poultry litter (PL) through bio methanation. The high content of hemicelluloses and cellulose present in the water hyacinth demands the need for pretreatment to enable the rapid anaerobic decomposition of the organic matter and resulting in improved process rate and biogas yield. Water Hyacinth is chemically pretreated using NaOH and lime to achieve partial disintegration of very long unbranched fibrils composed exclusively of glucose, with hydrogen bonding. The chemical disintegration of hemicellulose is achieved initially by hydrating the chopped WH in the ratio of 1:1. The hydrated WH is added with 1% by weight of NaOH and lime separately in batches. The digestion was performed in four fixed dome batch type digesters namely with raw WH, Lime pretreated WH+PL, and NaOH pretreated WH+PL and co-digestion of WH with PL. The digestion was carried out at mesophilic anaerobic condition and the pH is maintained at near neutral range for a hydraulic retention time of 21 days. As a result, it is observed that there is an increment of 51.57 % in biogas yield while codigesting with lime and more interestingly the digester with NaOH pretreatment results in 51.57% incremental biogas yield compared to the raw WH.

Rationally designed conductive wood with mechanoresponsive electrical resistance

Porous cellular foams, combining lightweight, high strength, and compressibility, hold great promise in a wide range of advanced applications. Here, the native structure of pine wood was modified by in-situ lignin sulfonation and unidirectional freezing, resulting in an alveolate structure inside the wood cell wall with arrays of sub-100 nm channels. The obtained wood foam exhibited highly enhanced permeability while retaining the native cellular arrangement and high lignin and hemicellulose content. Such engineered cellular foam contributed to superior mechanical performance with compressive strength of 9 MPa and Young’s modulus of 344 MPa in the longitudinal direction. The high porosity allowed homogeneous infiltration of conductive polymer PEDOT:PSS inside the wood cell wall. The resulting composite exhibited high conductivity, sponge-like compressibility and the ability to modulate electrical resistance in a reversible manner in the radial direction. This rationally designed conductive wood demonstrated potential in durable and ultrasensitive pressure-responsive devices and strain sensors.

Multi-step kinetic mechanism coupled with CFD modeling of slow pyrolysis of biomass at different heating rates

This study employed numerical modeling to investigate the reactivity and kinetics involved in the slow pyrolysis of lignocellulosic biomass. The model integrates a biomass multi-step kinetics scheme with heat, momentum, and mass transfer, and it was based on the transport of species and flow in a porous medium approach. To develop the multi-step kinetics model, two samples of biomass, avocado stone (AS) with a high hemicellulose content and α-cellulose (CEL), were subjected to TGA experiments in an inert atmosphere. Furthermore, several experimental data in the literature on the evolution of slow pyrolysis products and data obtained by TGA experiments were considered to refine and validate the proposed kinetic mechanism. The temperature range, from 25 to 700 °C, was explored using different heating rates (10, 20, and 40 °C/min). Experimental results showed that CO and CO2 are the predominant gases during primary devolatilization, whereas H2 and CH4 result from secondary reactions at temperatures above 400 °C. The proposed mechanism involves computational fluid dynamic (CFD) simulations of laboratory-scale biomass pyrolysis, comparing temperature and species concentrations with experimental data. The predicted results for individual non-condensable gas mass yields showed an average relative error of below 6.90 % and 11.59 % for CEL and AS, respectively. In the case of biochar, the error was 6.41 % and 9.74 % for AS and CEL, respectively. The developed kinetic model can be applied to simulate the slow pyrolytic degradation of biomass based on its chemical composition.

Preparation of natural antibacterial regenerated cellulose fiber from seed-type hemp

Seed-type hemp fiber is hard to spinning and weaving because of its high lignin and hemicellulose content. In this work, the impurities in seed-type hemp fiber were removed by alkali degumming method, ammonium oxalate-complex enzyme method, ethylenediamainetetraacetic acid disodium -complex enzyme method, ammonium oxalate-complex enzyme-chemical method and ethylenediamainetetraacetic acid disodium -complex enzyme-chemical method, and the results were compared. The fibers were characterized by scanning electron microscopy (SEM) and fourier-transform infrared spectroscopy (FTIR). The fiber after impurity removal is prepared into pulp, and the structure of pulp was characterized by fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The hemp pulp was dissolved into ZnCl2 aqueous solution at a specific temperature to prepare a spinning solution and spun to produce antimicrobial seed-type hemp regenerated cellulose fibers by using a self-made spinning machine. The surface morphology, strength, moisture regain, and antibacterial properties were evaluated, the regenerated fibers had a superior performance.